Several diseases associated with hyperuricemia implicate defective purine and pyrimidine metabolism and fit into this category; the enzymatic defect of Lesch-Nyhan disease is not present, however. Occlusion of the common carotid artery accounts for less than 1 percent of cases of carotid artery syn drome, the remainder being because of disease of the internal carotid artery itself. The deficiency results in the accumulation of galactocerebroside; a toxic metabo lite, psychosine, leads to the early destruction of oligo dendrocytes and depletion of lipids in the cerebral white matter. If clinical recovery does not begin in 1 or 2 weeks, the outlook is poor for both motor and language functions. But in some cases, a skin lesion is not observed or may have been forgotten, or there may have been only a few or no secondary lesions and the patient is first seen in the neurologic phase of the illness. Once coma and pupillary changes supervene, few patients survive, even with surgery; however, rapid 34-24) and are generally presumed Ant. It is possible that certain p atients who are showing an explosive myelitic illness are suffering from a necrotizing lesion of similar type, but pathologic evidence in support of this view has been difficult to obtain. Usually the respiratory tract is the portal of entry, less often the skin and mucous membranes. The presence of a bruit in the neck is an indication of cerebrovascular disease but its detection is not highly correlated with the presence of severely stenotic lesions as assessed by ultrasonography or angiography. Generalized seizures, con fusional psychosis, and a state of agitation may follow. Attempts to reproduce these findings by Kuhle and colleagues did not meet with success and there is no serum test for multiple sclerosis that has proven consistent, nor is there a predictive test for relapse. Furthermore, swallowing fails in ways similar to breathing as a consequence of neurologic diseases. By the third month of life, Birch and Belmont recognized individual differences in activity-passivity, regularity-irregularity, intensity of action, approach withdrawal, adaptivity-unadaptivity, high-low thresh old of response to stimulation, positive-negative mood, high-low selectivity, and high-low distractibility. The unsatisfactory nature of all the currently offered theories of causation of pseudotu mor cerebri are reviewed by Walker, but at the moment our reading of the literature suggests that venous ste nosis from granulations or from some as yet undefined functional change, does account for a proportion of what had previously been considered to be idiopathic cases. Skeletal deformities, enlargement of liver and spleen, seizures, or other neurologic abnormalities are notably lacking. The syndrome was originally described by Westphal in 1872 following small pox and typhoid fever in adults, but Batten is credited with drawing attention to the more common ataxic ill ness that occurs after common childhood infections such as measles, pertussis, and scarlet fever. First, many types of tumor, both primary and secondary, occur in the cranial cavity and spinal canal but certain ones are much more frequent than others and are prone to occur in particular age groups. Stupor, chorea, and aseptic meningitis were the main neurologic findings in the case reported by Friedland and Yahr, and acute cerebellar ataxia and deafness were observed in the case of Erzurum and associates (see also Chaps. It is interesting that neurons moving up the scaffold must pass through neu rons that are already in position in the cortex, leading to an "inside-out" lamination in which the most recently born and arrived neurons reside on the outermost surface of the forming cortex. Lesser degrees of microencephaly have been associ ated with progressive motor neuron disease and degen eration of the substantia nigra (Halperin et al). Congenital syphilis represents a special problem, which is discussed with developmental diseases in Chap. In some instances, the process culminates in a catastrophic rupture into the ventricles. In a large population-based study carried out in British Columbia by Sadovnick and colleagues (1988), it was found that almost 20 percent of index cases had an affected relative, again with the highest risk in siblings. Curiously, almost one-fifth of post operative strokes in some series have been of lacunar type. Nonetheless, the overall mortality rate remains high, with large hemorrhagic venous infarctions found in 10 to 20 percent of cases. Pathogenesis these epidemiologic data point to both a genetic suscep tibility and some environmental factor that is encoun tered in childhood that, after years of latency, evokes the disease. Wolff and colleagues have described a syndrome of periodic hyperthermia, associated with vomiting, hypertension, and weight loss and accom panied by an excessive excretion of glucocorticoids; the symptoms had no apparent explanation, although there was a symptomatic response to chlorpromazine. The setting in which embolism from nonbacterial endocarditis occurs is distinctive.
There may also be scattered hemorrhages in the white matter along lines of force from the point of impact to the contralateral side. With regard to differential diagnosis, bitemporal hemi anopia with a normal-size sella indicates that the causative lesion is probably a saccular aneurysm of the circle of Willis or a meningioma of the tuberculum sellae; mul tiple sclerosis may simulate this pattern and eventration of a greatly hydrocephalic third ventricle is an uncertain cause (see Chap. In humans, infarction of brain tissue because of arterial occlusion (thrombosis or embolism) or venous occlusion (thrombophlebitis) appears to be a common and perhaps necessary antecedent by way of causing of a necrotic nidus. A manifest hand preference at an early age should always raise the suspicion of a uni lateral motor defect. Reduction in size of cortical neurons and their dendritic arborizations is said to be demonstrable in some cases. These are thought to reflect autoregulatory failure of the cerebral vasculature in the face of abrupt restoration of normal blood pres sure and perfusion. Additional structures of importance are the stria terminalis, which runs from the amygdala to the ventromedial hypothalamic nucleus, and the fornix, which connects the hippocampus to the mam main efferent fiber systems-the mammillothalamic tract millary body; septal nuclei, and periventricular parts of the hypothalamus. Seizures may occur but are less common, in our experience, than they are as the introductory feature of gliomas. The sudden nature of the embolic deficits helps to distinguish this process from the usual forms of cerebral metastases. The problem that continues to plague all attempts to use long-term anticoagulants, as already noted in the discussion regarding heparin in the acute sit uation, is the risk of hemorrhage estimated by Whisnant and colleagues to be 5 percent overall and considerably higher in elderly patients who have been treated for more than 1 year. Although the milder forms of developmental delay tend to be familial, this does not by itself separate them from the severe forms of developmental delay. Because the blood may appear as a subtle shadow along the tentorium or in the sylvian or adjacent fissures, it is more easily appreciated in the noncontrast study. The visualization of a fracture line across the groove of the middle meningeal artery and knowledge of which side of the head was struck (the clot is on that side) are of aid in diagnosis and lateralization of the lesion. Most of these patients have had an episode of sepsis or have mul tiple organ failure (see Chap. Among such patients we have also found instances of isolated unilateral or bilateral phrenic nerve paresis that followed abdominal or cardiac surgery or an infectious illness. Acute Cerebel l itis (Acute Ataxia of Childhood) A comment is made here concerning a dramatic syn drome of acute ataxia that occurs in the context of an infectious illness, mainly in children. Perceptive mothers may be aware of a paucity of fetal movements in utero; in most cases the motor defect becomes evident soon after birth or the infant is born with arthrogrypotic deformities. All the aforementioned biologic events are equally applicable to congenital and childhood neurosyphilis. However, the dysmyelinating leukodystrophies discussed in this chapter may manifest late in life and enter into the differ ential diagnosis of this imaging appearance. Secondary deposits usually occur without metastases to the brain itself and reach the skull either via the systemic circulation (as in carcinoma of the breast) or via the Batson vertebral venous plexus-a valveless system of veins that runs the length of the vertebral column from the pelvic veins to the large venous sinuses of the skull, bypassing the systemic circula tion (the route presumably taken by carcinoma of the pros tate). Many years later there is a diffuse vascular involve ment that leads to hypertension, renal damage, cardio megaly, and myocardial ischemia. The cirrhosis is not always evident in a liver biopsy (some regenerative nodules are large, and the biopsy may be taken from one of them). Such an individual, with both normal cells and cells containing the mutant gene, is referred to as a mosaic. Such disorders, while uncommon, neverthe less are important because they must be considered in the differential diagnosis of degenerative diseases. The myelopathy is characterized by a rapidly ascending sensorimotor deficit that terminates fatally in a matter of weeks. In this study, it was found that the use of intravenous meth ylprednisolone followed by oral prednisone did, indeed, speed the recovery from visual loss, although at 6 months there was little difference between patients treated in this way and those treated with placebo. Lesions of the lower group of nerves (Collet-Sicard) and Bernard-Horner syndrome with ptosis and lniosis. As with septic lateral sinus phlebitis, anticoagulants have been used, but their value has not been proved. The rise of pressure as 500 mL of fluid is allowed to flow gradually into the bladder, the emptying contractions of the detrusor, and the volume at which the patient reports a sensation of bladder fullness can be recorded by a manometer. Rarely, it presents elsewhere in the cerebellum or other parts of the brain in adults (Peterson and Walker). Careful inquiry will usu ally disclose that neurologic symptoms compatible with intracranial tumor growth had preceded the onset of hemorrhage or the primary neoplasm had been revealed previously. Four types of pineal tumors are now recognized: germinoma, nonger minatous germ cell tumors, pinealoma (pineocytoma, would include teratomas in this group.
Similar cases occur with both cerebellar ataxia and an irregular tremor, which we have interpreted as myoclonic in character. It excited great interest, for it gave promise of a break through into a hitherto obscure group of "degenerative" disorders. They also show fragile hair follicles that break at thickened nodes (trichorrhexis nodosa). Hypothalamic lesions, principally involving the paraventricular nuclei, may also cause adrenal insufficiency, but less frequently than do pituitary lesions. Both in animals and in humans, electrical stimulation in this region can arouse each emotion, but the circuitry subserving fear appears to be located lateral to that of anger and rage. In embryonic life the most rapidly growing parts of the neural tube induce unique changes in, and at the same time are influenced by, the overlying mesoderm (a process termed induction); hence abnormalities in the formation of skull, orbits, nose, and spine are regularly associated with anomalies of the brain and spinal cord. Extreme degrees of descent of the pelvic floor are believed to injure the pudendal nerves, as reflected in prolonged terminal latencies in nerve conduction studies. The benign nature of the illness has precluded adequate pathologic examination; hence some of these statements are speculative. With large tumors that compress normal pituitary tissue, thyroid and adrenal function will also be impaired. The point being made here is that these structures may also be involved in a number of noninfective processes, some of obscure origin. Because of the similarities between pellagra and Hartnup disease, the usual practice is to give nicotinamide in doses of 50 to 300 mg daily. If the patient is still sensitive to o-pen icillamine or if severe reactions (lupus-like or nephrotic syndromes or myasthenia gravis) occur, the drug should be discontinued and another chelating agent, triethylene tetramine (trientine) or ammonium tetrathiomolybdate may be substituted. In those patients who had hemorrhages while receiving warfarin, they were, however, more likely to be fatal. Beginning in late childhood and adolescence (11 to 18 years) in a previously normal individual, the disease announces itself by a seizure, a burst of myoclonic jerks, or both. This is surrounded by a narrow red areola, which in turn, is surrounded by an erythematous flare that extends 1 to 3 em beyond the border of the wheal. No such change occurs in cases of parasympathetic (vagal) denervation of the heart, the most common such conditions being diabetes and the Guillain-Barre syn drome and the most dramatic being the brain death state, in which there is no longer any tonic vagal activity to be ablated by atropine. In almost all other circumstances, there is overall benefit to obliterating the unruptured aneurysm. The Gram stain of the spinal fluid sediment permits identification of the causative agent in most cases of bac terial meningitis; pneumococci and H. This general idea of psychologic deprivation has been the basis of many interesting educational programs for poor and neglected children. Mawet and colleagues reported on 20 cases they extracted from their experience but could not determine which process occurred first and could only speculate as to the relationship. With slowly evolving processes involving the upper cord, such as multiple sclerosis, the bladder spasticity and urgency worsen with time and incontinence becomes more frequent. The cause of recurrent bleeding is not understood but is related to naturally occurring mechanisms of clot lysis at the site of initial rupture, usually at the dome of the aneurysm. What was further noteworthy in most of these cases, and in those reported by ellinger and Seitelberger, was the presence of additional lesions in the region of the reticular activating system and small hemorrhagic soften ings in the corpus callosum, superior cerebellar pedun cles, and dorsolateral tegmentum of the midbrain. Dizziness, another prominent symptom, is usually not a true vertigo but a giddiness or light-headedness. In childhood, progressive blindness is a particularly dire complication from a tumor mass composed mainly of astrocytes (optic glioma). Differentiation from cerebral gliomatosis, brain lym phoma, toxic forms of leukodystrophy, and progressive multifocal leukoencephalopathy, all affecting deep cere bral or white matter structures, offers less difficulty. With a hemiple gia of pontine origin, however, the eyes may deviate to the side of the paralysis, i. The reduction in conduction veloc ity and decrease in amplitude of motor nerve potentials and, to a greater extent, of sensory nerves in the aged may be taken as other indices of loss of motor and sensory axons.
First, the clinician must determine whether the event is a stroke rather than some other process that may have a similar sudden onset, such as migraine, seizure, or syncope. Once recurrent seizures and focal neurologic deficits appear, they may persist indefinitely. Mucormycosis and coccidioidomycosis are less frequent, and blastomycosis and actinomycosis (Nocardia) occur in isolated instances. Harriette and coworkers emphasize the frequency of hypoplastic or dysplastic tongue, palatal involvement, and general motor clumsiness. Lifelong replace ment therapy is usually required, with a glucocorticoid (cortisone, 25 to 50 mg, or prednisone, 7. Also, the presence of ragged red fibers differ entiates the mitochondrial myopathies from the glyco genoses but it bears emphasizing that ragged red fibers are rare in infants and young children, even in those with confirmed mitochondrial disease. There is no treatment other than finding the source of the meningeal blood and pre venting further hemorrhage and treating hydrocephalus if it is present. Just as no two persons are physi cally identical, not even monozygotic twins, so, too, do they differ in any other refined quality one chooses to measure, particularly those that determine behavior and modes of thinking. They then are surgically elevated, preferably within the first Mechanism of Concussion the core features of loss of consciousness or confusion are notable for being immediate after trauma (not delayed even by seconds) and for being entirely reversible. These subsyndromes may consist of vertigo and ptosis, toppling and vertical diplopia, hoarseness and disequilibrium, or other combinations short of the entire syndrome. Among these, endo vascular obliteration of the lumen of the aneurysm holds the most promise. Respiratory failure as a result of paralysis of the intercostal and diaphragmatic muscles or of depression of the respiratory centers in the brainstem calls for the use of a positive-pressure respirator and in most patients, for a tracheostomy as well. Scoliosis is frequent and may secondarily give rise to root compression and impaired respiratory function. These biologic mechanisms have bearing on the treat ment and prevention of stroke. If the onset is in the first postnatal months, before the infant has had time to develop the normal complex repertoire of behavior, the first signs of disease may take the form of subtle delays in maturation rather than of psychomotor regres sion. The combination of a heteroplasmic state and the capricious dispersion of mitochondria to daughter cells (replicative segregation) explains the variable expres sion of mitochondrial mutations in different tissues and in different regions of the nervous system. The adventitia of the subarachnoid vessels, both of arterioles and venules, is actually formed by an investment of the arachnoid membrane, which is invariably involved by the infectious process. The complete detachment of the child with psychosis, the amorality of the constitutional sociopath, the major dis turbances in thinking of the schizophrenic, and the mood swings of the bipolar also express themselves in many, if not most, instances by adolescence and sometimes by late childhood. Later in life the causes vary, but the most common are pituitary surgery, infarct of the gland from a rapidly growing adenoma (pituitary apoplexy, see "Pituitary Apoplexy" in Chap. Our usual practice with asymptom atic cases has been to reevaluate the lumen of the internal carotid artery (using ultrasonography) at 6- to 12-month intervals. Greenberg and colleagues found that apolipoprotein E4, the same marker that is overrepresented in Alzheimer disease, is associated with severe amyloid angiopathy and a risk of intracerebral hemorrhage, but others have found an association with the E2 allele. The expansion of knowledge of neuroendocrinol ogy during the past few decades stands as one of the significant achievements in neurobiology. Arguments notwithstanding that better mechani cal devices will lead to improved outcomes, the results of systematic studies so far make it difficult to endorse intraarterial methods to revascularize cerebral vessels after acute stroke outside the confines of a clinical trial. Almost imperceptible at first, these disturbances of language become increasingly apparent as the disease progresses. Occasionally the arteries of the oculomotor nerves are also involved, causing various ophthalmoplegias. Seizures occur in approximately one-third of the cases, and it is not uncommon to observe a delay in all developmental sequences, especially those that depend on the motor system. In the cell, mitochondria with mutant genes may exist next to normal mitochondria (heteroplasmy), a state that permits an otherwise lethal mutation to persist Gohns). Acute lesions tend to demonstrate tissue expansion due to edema that is evident as T1 hypointensity and T2 hyperintensity. The main problem in diagnosis is to differentiate this disease from a pontine form of multiple sclerosis, a vascular malformation of the pons (usually a cavern ous hemangioma), or brainstem encephalitis, and to distinguish the focal from the diffuse type of glioma (see below). In infants with meningitis, one should be prepared to find a unilateral or bilateral sympathetic subdural effu sion regardless of bacterial type. Approximately 15 percent of patients have early symp toms and signs of increased intracranial pressure; an even smaller number have focal cerebral signs (hemiparesis).
Although momentary "stunning " without loss of con sciousness represents the mildest degree of concussion, Pathologic Changes Associated With Severe Head Injury In contrast to concussion, in cases of traumatic brain injury that are fatal or very serious, the brain is usually bruised (contused), swollen, or lacerated, and there are hemorrhages, both meningeal and intracerebral, as well as hypoxic-ischemic lesions. With progression of the neurologic disease, the Kayser-Fleischer rings become more evident. On average, at 18 months the child can combine an average of much later in human evolution were alphabets devised. Cerebellar ataxia may be combined with sensory ataxia, owing to involvement of the posterior columns of the spinal cord or medial lemnisci of the brainstem. Prusiner is credited with doggedly pursuing this problem, for which he was awarded the Nobel Prize. Bilateral mesiotemporal-occipital lesions also cause a lack of recognition of faces (prosopagnosia). In one group there is no clear evidence of cognitive delay or impairment of neurologic or auditory function. Free radical scavengers such as vitamin E have been rec ommended without proof of their effectiveness. Cushing considered the typical signs of cerebellar herniation to be episodic tonic exten sion and arching of the neck and back and extension and internal rotation of the limbs, with respiratory distur bances, cardiac irregularity (bradycardia or tachycardia), and loss of consciousness. Although neurologic medicine has done little more than describe and classify some of the clinical states dominated by emotional derangements, knowledge of this type is nonetheless of both theoretical and practical importance. The mini-epidemic began in 1986, with putative trans mission of the disease to some 24 humans. Starting at age 6 to 7 years, there is a steady improvement in intelligence scores that parallels chronologie age up to about age 13 years; thereafter the rate of advance diminishes. DeMyer found that 4 of 11 monozygotic twins were concordant for autism and that siblings have a 50 times greater risk of developing the disorder than normal chil dren. Corticosteroids are usually administered, but with the exception of cases with demonstrable edema, their effect is uncertain. The small brainstem hemorrhages secondary to temporal lobe herniation and brainstem compression (Duret hemor rhages), hypertensive encephalopathy, and brain purpura might be included in a stroke. Tall, slender habitus; great length of limbs, sometimes scoliosis and arachnodactyly (long, spidery fingers and toes); thin and rather weak muscles; knock-knees; highly arched feet; and kyphosis are the typical skeletal features. There are, in addition, several syndromes that are typical of multiple sclerosis and may be the initial mani festations. Later in life, the more common causes are medications, illicit drug use, focal cerebral lesions, hyperosmolar nonketotic state, antiphospholipid antibody syndrome, among many oth ers discussed in Chap. These anatomic abnormalities had been demonstrated many years before by pneumoencephalog raphy and were found to be related to the number of bouts (Ross et al; Casson et al). The core of the the diagnosis, or the preceding systemic illness is absent or obscure, a differentiation between the two may not be possible on clinical grounds alone. As the hours pass, and occasionally with unanticipated suddenness, the patient becomes stu porous and then comatose or suddenly apneic as a result of brainstem compression, at which point reversal of the syndrome, even by surgical therapy, is seldom success ful. The wall of the cyst and the solid parts of the tumor consist of cords and whorls of epithelial cells (often with intercellular bridges and keratohyalin) separated by a loose network of stellate cells. Exceptionally, there is infiltration of the endoneurium and degeneration of myelinated fibers, leading to the appearance of fatty macrophages and proliferation of Schwann cells and fibroblasts. However, many patients are left with some degree of clumsiness or slowness of move ment of the affected side. Some of the characteristics of vestibular neurosyphilis are identical to those of Meniere disease, including episodic loss of function (Baloh and Honrubia). Treatment Quinine and artesunate, and related drugs are curative if the cerebral symptoms are not pro nounced, but once coma and convulsions supervene, 20 to 30 percent of patients do not survive. Rapid correc tion of hyperglycemia and acidosis and treatment with liposomal amphotericin or posaconazole have resulted in recovery in some patients. The fontanels may bulge, the liver and spleen enlarge, the skin becomes yellow (in excess of the common neonatal jaundice), and anemia develops. As already mentioned, Crowe and coworkers expressed the view that 80 percent of patients with von Recklinghausen disease can be diagnosed by the pres ence of more than 6 cafe-au-lait spots. As Solomon and Fink point out, this can be accomplished without fear of aneurysmal rupture if blood pressure is allowed to rise only minimally. The final expulsion of gastric contents is effected through a combination of lowering of intrathoracic pres sure by inspiration against a closed glottis and an increase in abdominal pressure during abdominal muscle contrac tion. However, involuntary choreic movements usually do not appear in the upper limbs before matures and by In congenital hypo 5 to 6 months of age and often are plasia of the optic nerves, the nerve heads are extremely small.
Some exhibit a peculiar anhedonia that renders them indifferent to both punish ment and reward. The leukodystrophies are a group of inherited metabolic diseases of the nervous system characterized by progressive, symmetrical, and usually massive destruction of the white matter of the brain and sometimes of the spinal cord; each type of leukodystro phy is distinguished by a specific genetic defect in myelin metabolism. Normally, the heart rate varies by as many as 15 beats per minute or even more between expiration and inspiration; differences of less than 7 beats per minute for ages 60 to 69 and 9 for ages 50 to 59 may be abnormal. These germ line alterations are to be distinguished from acquired partial duplications and deletions of parts of genes that occur as acquired somatic mutations in many tremors and from variations in copy number of segments of genes that are emerging as possible explanations for a number of diseases such as autism. The incidence of unruptured aneurysms in routine autopsies is almost 2 percent-excluding minor vessel outpouchings of 3 mm or less. Often in these disorders, the various stages of language development described earlier are not attained at the usual age and may not be achieved even by adult hood. The clinical picture in its fully developed form includes progressive dementia, dysarthria, myoclonic jerks, action tremor, seizures, hyperreflexia, Babinski signs, and Argyll Robertson pupils. Ounsted C, Lindsay J, Richards P (eds): Temporal Lobe Epilepsy, 1 948-1 986: A Biological Study. In the case of very large infarcts in the middle cerebral artery territory, swelling of the infarcted tissue may occur, followed by displace ment of central structures, transtentorial herniation, and death of the patient after several days. Clinical deterioration occurs usually on the third to fifth days, sometimes later, but may rarely evolve as quickly as several hours after the onset. Hypotonia (floppy infant), areflexia, small stature, dysmorphic facies, and hypoplastic genita lia are evident, and arthrogryposis may be present at birth. Other X-linked forms of developmental delay that have few or no dysmorphic features include the Partington, Lowe, Lesch-Nyhan, and Menkes syndromes and adre noleukodystrophy, each with special characteristics in addition to developmental delay, as discussed in Chap. Postmortem, some of these tumors, if small, are found pro truding into the fourth ventricle, never having produced local symptoms. Associated with other neuromuscular abnormalities (muscular dystrophy; cerebellar ataxia, etc. There is also a well-described myopathy associated with sarcoidosis; it is discussed below, and also consid ered in Chap. Even distal to the posterior communicating artery, an occlusion may cause relatively little damage if the collateral flow Posterior Cerebra l Artery Stroke Syndro m es In approximately 70 percent of individuals, both poste rior cerebral arteries are formed by the bifurcation of the basilar artery and thin posterior communicating arteries join this system to the internal carotid arteries. The sarcoid, noncaseating granuloma may be found in all organs and tissues, including the nerve roots, peripheral, and central nervous systems, but the most frequently involved are the mediastinal and peripheral lymph nodes, lungs, liver, skin, phalangeal bones, eyes, and parotid glands. It is a purplish red, highly vascular tumor composed of large epithelioid cells, arranged in an alveolar pattern and possessing an abundant capillary network. The finding of an abnormal mitochondrial genome in the endothe lium and smooth muscle of cerebral vessels has been sug gested as a basis for the strokes and migraine headaches. In addition, such infants may have been exposed to certain prenatal risk factors (toxemia of pregnancy, ante partum uterine hemorrhage, maternal hypotension, and certain epidemiologic associations such as hypothyroid ism or fertility treatment), or their growth may have been abnormal (small-for-date babies). Differences are noted in the neurologic picture depending on the level of the lesion. Dipyridamole in high doses has not been as well tolerated by many of our patients because of dizzi ness induced by peripheral vasodilatation. The draining vein itself is often visualized most easily and fills with contrast concur rently with normal cerebral. From these and other trials it can be inferred that endarterectomy does not reduce the incidence of strokes in patients who have asymptomatic carotid stenosis with luminal narrowing that is less than 60 to 70 percent of nor mal diameter. It appears that all structures and functions share in the Table aging far better than others, and Biologists have measured many of these changes. Dale and colleagues comment that von Economo and his contem poraries in fact doubted that there was a connection to influenza. In the case of purely intracranial dissection of the middle cerebral or basilar arteries, there is usu ally no preceding trauma, but a few patients have had minor head injuries, extreme coughing, or other recently Valsalva-producing events. The clinical effects have not been clearly determined, but Cuneo and colleagues have attributed decerebrate posturing and pupillary changes-initially both pupils are miotic but still reactive, progressing to anisocoria and enlargement-to this type of brain displacement. With increasing muscular tone, opisthotonic recurvation of the neck and trunk develops. Only in late childhood do mental retardation and dementia become clearly distinguishable and measurable by standardized tests. For example, defects caused by chromosomal abnormalities occur in approximately 0. Early in the disease there may be a more-or-less-equal number of polymorpho nuclear leukocytes and lymphocytes, but after several days lymphocytes predominate in the majority of cases.
Indium-111-octreotide (Indium). Praziquantel.
Involvement of cervical roots and compression of the spinal cord gave rise to variable degrees of parapa resis in association with root pain, paresthesia, sensory loss, and amyotrophy of the upper limbs. Thus a certain proportion of stutterers will become more fluent under certain conditions, such as reading aloud; others will stutter more severely at this time. Some cases can be cured at this stage by the adequate administration of high-dose antibiotics. In determining the most likely invading organism, the age of the patient, the clinical setting of the infection (community-acquired, postsurgical, or nosocomial), the immune status of the patient, and evidence of systemic and local cranial dis ease all must be taken into account. Persistent hypo tension at 1 min indicates sympathetic adrenergic failure and the later measurement affirms this if blood pressure fails to recover or continues to decline. When they present later in adolescence and adult life they evolve more slowly than childhood forms. The new larvae penetrate all tissues but survive only in striated muscle, where they become encysted and eventually calcify. Denny-Brown, Adams, and Fitzgerald found the geniculate ganglion to be only slightly affected in a man 96 h). Ocrelizumab in relapsing remitting multiple sclerosis: A phase 2, randomised, placebo controlled multicentre trial. When the syndrome is protracted, neurologists are vexed by the condition-a problem intensified by worried patients and family. These views on the site and mechanism of concus sion are not fully accepted but have been supported by a number of additional physiologic observations. Hacke W, Schwab S, Hom M, et al: "Mali gn a nt" middle cerebral artery territory infarction: Clinical course and prognostic signs. The Dandy-Walker syndrome represents a more restricted form of migration and neural tube defect. Diseases in this age period have a diversity of mani festations, yet each disease tends to have a certain char acteristic pattern of neurologic expression, as though the pathogenetic mechanism were acting more selectively on particular systems of neurons. By contrast, when septic material embolizes from infected lungs, pulmonary arteriovenous fistulas, or congenital heart lesions, or extends directly from ears or sinuses, more than one type of bacterial flora common to these sources may be transmitted. The entire gland is invested by a rich vascula ture to receive the released peptide (in some mammals the blood flow per gram of pineal tissue is surpassed only by that of the kidney). There is atherosclerosis in some and small degrees of arterial dissection in others. The results were much the same as those of the first study except that in patients with mild closed head injuries, there was only a slight excess risk of developing seizures-a risk that remained elevated only until the fifth year after injury. Once the memory disorder has become pronounced in the prototypic disorder, other failures in cerebral function become increasingly apparent. Small cell cancer of the lung, adenocarcinoma of the breast and ovary, and Hodgkin disease are the tumors most often associated with these disorders, but the paraneoplastic neurologic syndromes occur in only a very small propor tion of patients with these tumors. To describe each in detail would be impractical in a book on the principles of neurology; consequently, the non-Friedreich ataxias are only tabulated here. The enlargement of the brain in this disease must be distinguished clinically from G M2 gangliosidosis, Alexander disease, Krabbe disease, and nonprogressive megalocephaly and pathologically from a variety of dis orders characterized by vacuolation of nervous tissue. It is likely that genetic analyses of tumor material from individual patients will become an increasingly important part of therapeutic decisions. As indicated earlier, the distal territory of the middle cerebral artery may also be ren dered ischemic by failure of the systemic circulation, especially if the carotid artery is stenotic; this situation may simulate embolic branch occlusions. Some 70-year-olds perform better on psychologic testing than some "normal" 20-year olds. Injury to the ophthalmic and maxillary divisions of the trigeminal nerve may be the result of either a basal fracture across the middle cranial fossa or a direct extracranial injury to the branches of the nerves. Any increase in headache, vomiting, or difficulty arous ing the patient should prompt a return to the emergency department. Other mutations are quite small, involving only a single 38), birth injuries, epilepsy; disharmonies of development, and learning disabilities (see Chap. In some of these instances, it has been found to be caused by a defective ryanodine receptor. Their innervation, via the pudendal nerves, is derived from a densely packed group of somatomotor neurons (nucleus of Onuf) in the anterolateral horns of sacral segments 2, 3, and 4. Both are inherited in an autosomal dominant pattern with a high degree of penetrance, but half the cases are a result of spontaneous mutations.
The basilar artery is singularly susceptible to this syndrome because the vertebral arter ies are smaller in caliber than the basilar, allowing a clot to slowly traverse the larger vessel; furthermore, a clot in the basilar artery is prone to occlude the small orifices of arteries that supply blood to the brainstem. The spinal cord lesions in cases of neuromyelitis optica are often necrotizing, centrally located in the cord, and occupying several contiguous vertebral segments, leading eventually to cavitation. The reader is referred to an extremely thorough clinical and genetic review of the syndrome by Pober. These soon give way to a severe and progressive intellec tual deterioration in association with focal or generalized seizures, widespread myoclonus, ataxia, and sometimes visual disturbances caused by progressive chorioretinitis. The following are less frequent causes: Staphylococcus aureus and group A (Streptococcus pt;ogenes) and group D streptococci, usually in association with brain abscess, epidural abscess, head trauma, neuro surgical procedures, or cranial thrombophlebitis; E. The causes of anencephaly are multiple and include chromosomal abnormalities, maternal hyperthermia, and, apparently, deficiencies of folate, zinc, and copper (see Medical Task Force on Anencephaly). In the older person, it is the impairment of intellectual functions that assumes greater prominence. Kampfl A, Franz G, Aichner F, et at: the persistent vegetative state after closed head injury: Clinical and magnetic resonance imaging findings in 42 patients. Because the levels were considerably lower than in cases of hypervitaminosis A with symptomatic forms pseudotumor (see below), the meaning of these findings is uncertain. The age of onset is in mid adult life, and it is more common in females than in males, in a ratio of 3:1. Cases have been reported during pregnancy; both those who have symptoms for the first time during pregnancy and a larger group with ongoing pseudotumor who become pregnant. Together, these actions serve to maintain normal blood pressure and allow reflex maintenance of blood pressure with changes in body position. It will become clear in the following discussion that the current theme in the study of degenerative diseases is that of aggregation within specific neurons of normal cellular proteins such as amyloid, tau, synuclein, ubiq uitin, and huntingtin. The carotid vessels are subject to atherosclerotic narrowing, atherothrombotic occlusion, arterial dissection and rarely, other processes such as various forms of vasculitis. Improvement could continue over a period of 31 percent; 3 percent were left in a persis tent vegetative state, and 16 percent remained severely disabled neurologically (Murray et al). Intratumoral calcification can be seen in more than half the cases and is a helpful diagnostic sign, but in the context of seizures, this finding also raises the possibility of an arteriovenous malformation or a low-grade astrocytoma. Orbital tissue, especially the upper eyelid, is almost invariably involved; congenital buphthalmos may enlarge the eye before birth and glaucoma may develop later in that eye, causing blindness. The Tl hyperintensity tha t is shown in the left upper and lower images is due to thrombus within the false lumen of the vessel. Churg J, Strauss L: Allergic granulomatosis, allergic angiitis and periarteritis nodosa. Second, some primary intracranial and spinal tumors, such as craniopharyngioma, meningioma, and schwannoma, have a disposition to grow in particular parts of the cranial cavity, thereby producing characteristic neu rologic syndromes. These lesions appeared more than 10 years after the initial treatment, and many cases of even longer latency are on record. The relative sizes of the vertebral arteries vary considerably, and in approximately 10 percent of cases, one vessel is so small that the other is essentially the only artery of supply to the brainstem. The margins of the infarct are hyperemic, being supplied by meningeal collaterals, and here there is only minimal or no parenchymal damage. This represents a twofold improvement in efficacy compared to what has been reported with interferon and glatiramer acetate. Signs of carotid occlusion include transient mon ocular blindness or visual loss or dimness of vision with exercise, after exposure to bright light, or on assuming an upright position; retinal atrophy and pigmentation; atrophy of the iris; peripapillary arteriovenous anasto moses in the retinae; and claudication of jaw muscles. Lanska was able to collect from the literature 70 patients with meningeal infection, most of whom were encephalopathic. Pathologically, there is dysgenesis of the cerebral cortex and degeneration of white matter as well as a number of visceral abnormalities-cortical renal cysts, hepatic fibrosis, intrahepatic biliary dysgenesis, agenesis of the thymus, and iron storage in the reticuloendothelial system. The interstitial nucleus of the hypothalamus is reportedly smaller in the homosexual male, evidence perhaps that homosexual ity has a recognizable morphologic basis (Levay). Th e re is transependymal move ment of water tha t appears as a T2 signal rimming the lateral ventricles. If the subclavian artery is blocked proximal to the origin of the left vertebral artery, exercise of the arm on that side may draw blood from the right vertebral and basilar arteries, retrograde down the left vertebral and into the distal left subclavian artery sometimes resulting in the symptoms of basilar insuf ficiency.
The spirometric flow-volume loop in cases of neuromus cular respiratory failure shows low airflow rates with diminished lung volumes that together simulate restric tive lung disease. Here, Alzheimer disease, normal pressure hydrocephalus, and frontal-corpus callosum tumors are the most common pathologic states underlying apathy and placidity, but these disturbances may compli cate a variety of other frontal and temporal lesions, such as those occurring with demyelinating disease or as an aftermath of ruptured anterior communicating aneurysm. A vascular nevus is observed at birth to cover a large part of the face and cranium on one side (in the territory of the ophthalmic division of the trigeminal nerve). Balo and Sch ilder Diseases the concentric sclerosis of Balo has as its distinguishing feature the occurrence of alternating bands of destruc tion and preservation of myelin in a series of concentric rings that represent alternating areas of myelin loss, and preservation. Therefore, headache, acute hyperten sion, and vomiting with hemiplegia in the case of bleeding into the cerebral hemisphere are the cardinal features and serve most dependably to distinguish hemorrhage from ischemic stroke. In the majority of patients the rash and sensorimotor signs are limited to the territory of a single dermatome, but in some, particu larly those with cranial or limb involvement, two or more contiguous dermatomes are involved. Also of interest is the observation by van Exel and colleagues that women in this age group perform better than men on cognitive tests. The biology of cerebrovascular amyloid is summarized by Viswanathan and Greenberg. It was concluded that endarterectomy may be justified for asymptomatic carotid stenosis of this degree in men (not so in women) but that an audited surgical risk below 3 percent was required to obtain favorable results Qust as for symptomatic carotid stenosis). Heredity is self-evident in only a minority of cases50 percent in some series and as little as 14 percent in the series of Bundag and Evans (cited by Brett). The review by Polkey and colleagues provides a more extensive list of diseases that cause these problems. With treatment, these radiologic changes become less marked (Williams and Walshe). Naloxone mitigates some of the aspects of spinal shock; this may be, at least in part, the result of release of preformed endogenous opioids from the distal axons that are separated from their cells of origin in the periaq ueductal gray region. Rarely have they caused demonstrable postmortem cerebral lesions, and surviving patients have no residual neurologic signs. In a survey of pigmented spots in the skin, Crowe and associates found that 10 percent of the normal population had one or more spots of this type; however, anyone with more than 6 such spots, some exceeding 1. Sensory loss, when it occurs, is mainly of the discriminative modalities but it may be mild or absent. A similar multinodular appearance occurs with intravascular lymphoma discussed in a later section. For more severe cases, we perform careful vascular imaging and correction of venous sinus occlu sions as noted above. A second broad group of children with speech delay or slow speech development (no words by 18 months, no phrases by 30 months) comprises those in whom an overt pathologic basis is evident. Chordomas are locally invasive, espe cially of surrounding bone, but they do not metastasize. The affected arter ies no longer pulsate, hence the descriptive term pulseless disease. In most instances of bacteremia or septicemia, the nervous sys tem seems not to be infected; yet sometimes a bacteremia caused by pneumonia or endocarditis is the only apparent predecessor to meningitis. Alterations of skin-photosensitivity (Cockayne syn drome and one form of porphyria); papular nevi and angiokeratoma (Fabry disease, fucosidosis); telangi ectasia of ears, conjunctiva, chest (ataxia-telangiec tasia); ichthyosis (Sjogren-Larsen disease, caused by fatty alcohol dehydrogenase deficiency); plaque-like lesions in Hunter syndrome 8. The distinction may be particularly difficult in rare instances of the vasculitic process in which the neurologic manifestations take the form of a relapsing or steroid-responsive myelitis. It has also been proposed that an "intracerebral steal" can result in hypoperfusion of the surrounding brain (Homan et al). A brief period of corticosteroid administration gener ally produces few adverse effects but some patients com plain of insomnia and a few will develop depressive or manic symptoms. The causes of the first category are numerous and 778 include chronic hypertension, coagulopathies that arise endogenously or as a result of anticoagulant medications, vascular malformations of the brain, cranial trauma, and hemorrhage that occurs within the area of an ischemic stroke. Less than 30 percent of such patients survive beyond 1 year and the long-term results of treating these patients have not been encouraging. Unilateral severe headache is the most com mon symptom and may be the only manifestation. Mixed essential cryoglobulinemia, a vasculitic disorder that more often affects the peripheral than the central nervous system, may nonetheless produce an encephalopathy. Treatmen t and Outcome of Carcinomatous Meningitis this consists of radiation therapy to the symptomatic areas (cranium, posterior fossa, or spine) followed in selected cases by the intraventricular admin istration of methotrexate, but these measures rarely stabi lize neurologic symptoms for more than a few weeks.
Similar to demyelinating and lymphomatous lesions, these abnormalities may recede temporarily in response to treatment with corticosteroids and there is corre sponding clinical improvement. The pre senting symptoms were visual failure-a slowly advanc ing bitemporal hemianopia with a sella of normal size. Amyloid angiopathy and an uncharacterized cerebral small vessel disease also have caused this picture of a multiplicity of small hemor nic purpura this entity. There may be a seizure, a transitory worsening of the tumor symptoms, or signs of increased intracranial pressure. These findings are of interest and may well be a means of determining exact age, but many more observations are needed with follow-up data on later development before they can be fully accepted. At the end of 6 months, 8 of every 100 patients had died of the original hemorrhage and 59 had a recurrence (with 40 deaths), making a total of 48 deaths and 52 survivors. Similar to the drugs described above, they each have particular idiosyncratic side effects, but it is patient preference in avoiding injections and infusions that is driving the development of this class. The Glasgow Coma Scale is used as a rapid refer ence to accomplish this purpose (Table 35-1) but does not substitute for a fuller neurologic examination. The infection may take the form of a brainstem encephalitis, or "rhombencephalitis," specifically with several days of headache, fever, nausea, and vomiting fol lowed by asymmetrical cranial-nerve palsies, signs of cere bellar dysfunction, hemiparesis, quadriparesis, or sensory loss. In these cases, either the hemorrhage has extended into the ventricular system or intracranial pressure becomes elevated to levels that preclude nor mal perfusion of the brain. Later it was determined that obesity and hypogonadism could occur together or separately and were often combined with a loss of vision and unprovoked rage, aggression, or antisocial behavior. Fatigue, sometimes severe, is a prominent complaint in most patients, and abdominal pain and vomiting in oth ers. Fibrin components have been identified by immunofluorescent techniques; some investigators have demonstrated dis seminated intravascular platelet aggregation rather than fibrin thrombi. There it was pointed out that although intel ligence is modifiable by training, practice, and schooling, it is much more a matter of native endowment and not simply a question of environment and providing the stimulus to learn, although these are clearly factors. Further notable is the later occurrence of meningeal hemosideriosis as a result of these lesions, particularly with amyloid angiopathy (see Linn and colleagues). Cases of familial adult-onset Leigh disease have been described by Kalimo and colleagues. In a few such instances, postmortem examination has disclosed a decreased number of neu rons in the supraoptic and paraventricular nuclei. Hypertension is also the most readily recognized factor in the genesis of primary intracerebral hemorrhage. Rosette forma tion, highly characteristic of the below-described neu roblastoma is seen in half of medulloblastomas. Pitu itary Insufficiency Loss of function of the anterior pituitary gland may result from disease of the pituitary itself or from hypothalamic disease. Many cases seem to be of an entirely different type, displaying long segments of vascular attenuation in the angiogram and no evidence of an inflammatory process in biopsy or autopsy mate rial. In some cases the onset of pulmonary symptoms is associated with a petechial rash over the thorax, especially in the axillae and also in the conjunctivea and 1 in 3 cases is said to show fat globules in the urine. Treatment of the Hyperammonemic Syndromes the treatment of acute hyperammonemic syndromes is directed at lowering ammonia levels by hemodialysis, exchange transfusions, and administration of arginine and certain organic acids. With bilateral lesions that involve the inferomedial portions of the temporal lobes, including the hippocampi and their associated structures, the impairment of mem ory may be severe, causing the Korsakoff amnesic state. In a summary of published cases and series of patients with pseudotumor cerebri treated by endovascular stent ing of venous sinus stenosis, Aroc and colleagues con cluded that approximately 80 percent were relieved of their main symptoms, and a similar proportion showed resolution, or improvement in papilledema. Conversely, a stroke-like onset of cerebral symptoms in a young adult should always raise a suspicion of demy elinative disease. Disturbances of swallowing, respiration, and vasomotor control are related to neuronal lesions in the medullary reticular formation, centered in the region of the nucleus ambiguus, as mentioned earlier. The group of moderately delayed, like the severely affected ones, is divisible into groups with somatic sys temic and neurologic abnormalities, although the propor tions are not the same.