History And Overview

First described in humans in the 1920s, spongiform encephalopathy is now known to encompass a group of noninflammatory degenerative disorders characterized neuropathologically by a diffuse spongiosis and amyloid protein deposition in the brain. These disorders include kuru, Creutzfeldt-Jakob disease (CJD), Gerstmann-Straussler- Scheinker syndrome (GSS), and fatal familial insomnia (FFI). The report in 1966 that kuru, an epidemic ataxic illness limited to the eastern highlands of Papua New...

Arenavirus Lymphocytic Choriomeningitis Virus

The natural reservoir for the lymphocytic choriomeningitis virus (LCMV) is the common house mouse. Hamsters and laboratory animals can also be infected with this virus. Most human infections result from contact with house mice. y , y Four clinical syndromes due to infection with LCMV have been described (1) subclinical asymptomatic infection, (2) nonmeningeal influenza-like illness, (3) aseptic meningitis, and (4) meningoencephalomyelitis. y The LCMV was the first...

Directed Neurological Examination

Essential components of the directed physical examination include a neurological evaluation emphasizing the cranial nerves and orbital contents (to direct attention to lesions of the skull base) as well as a general evaluation of the ears, upper respiratory tract, and head and neck. Although much can be gained by evaluating the nose using anterior rhinoscopy, nasal endoscopy allows a more thorough assessment. With this procedure, the rhinologist can often directly visualize the olfactory...

Vestibular System

The peripheral vestibular system consists of a set of three-dimensional angular velocity transducers, the semicircular canals, and a set of three-dimensional linear acceleration transducers, the otoliths (utricle and saccule) (see Fig. 12-1 (Figure Not Available) ). y These transducers are suspended by an assembly of membranes and connective tissue, the membranous labyrinth, within channels in the temporal bone, the bony labyrinth. Three important spatial arrangements characterize the...

Evaluation Guidelines Table82

Most patients with suspected optic neuropathies should undergo neuroimaging to exclude a compressive RDERS OF CRANIAL NERVE II AND AFFERENT VISUAL PATHWAYS MRA carotid occlusion, stenosis, or dissection electroretinogram if photoreceptors are affected Elevated ESR in giant cell arteritis Vascular occlusion or leakage on fluorescein angiography Thromboembolic source on cardiac echography or carotid ultrasound MRI with gadolinium and fat saturation, coronal views optic nerve...

History And Definitions

In an attempt to distinguish the class of motor disturbances resulting from lesions of the basal ganglia, Kinnier Wilson coined the term extrapyramidal in his famous 1912 article'1 describing hepatolenticular degeneration, now known as Wilson's disease. This term was widely adopted thereafter and continues to be used today. The extrapyramidal system refers to the basal ganglia with their anatomical connections, and extrapyramidal disorders are hypokinetic and hyperkinetic states that ensue from...

Malignant Migraine

Various oxidative phosphorylation defects occur in the brain, although how they relate to the production of migraine is speculative. Migraine affects as much as 25 percent of the population and is frequently seen in maternal relatives of patients with diseases of oxidative phosphorylation. Malignant migraine refers to three situations migraine patients who turn out to have MELAS migraine patients who are maternal relatives of patients with oxidative phosphorylation diseases and who are...

Alcoholic Myopathy

There are two forms of alcoholic muscle disease (1) an acute, painful myopathy associated with weakness, cramps, swollen and tender muscles, high creatine kinase, and rhabdomyolysis with or without myoglobinuria and (2) a chronic myopathy that is painless and often unnoticed by the patient, causing proximal weakness and type II fiber atrophy on nerve biopsy. In addition to skeletal muscle involvement, patients may have an associated cardiomyopathy. 'sal Proposed mechanisms of alcoholic injury...

Purposes of Neuropsychological Examination

With the advent of modern structural imaging techniques such as computed axial tomographic imaging (CAT), and magnetic resonance imaging (MRI), and even newer functional imaging techniques such as positron emission tomography (PET) and functional magnetic resonance imaging (fMRI), the use of neuropsychological assessments to identify the location and type of CNS lesion has waned. y M y However, because they identify and quantify both cognitive strengths and deficits, neuropsychological...

Evaluation Guidelines j Table163

Many of the primary neurodegenerative movement disorders, whether hypokinetic or hyperkinetic, show no abnormalities on magnetic resonance imaging (MRI) or computed tomography (CT) scans other than mild to moderate cerebral atrophy. However, in N THE EVALUATION OF HYPOKINESIA AND HYPERKINESIA SYN In Parkinson's disease, MR and CT are normal. PET scans of F-dopa can show decreased uptake Usually not used. Can study tremor with tremorometer In multiple system atrophy putamen can...

Evaluation Guidelines Table95

Lesions of cranial nerves III, IV, and VI may occur anywhere along the course of the nerves, from the nuclei in the brain stem to the orbits. The possibility of focal neoplastic or inflammatory lesions requires evaluation with neuroimaging. Magnetic resonance imaging is more reliable than computed tomography for detecting brain stem, subarachnoid space, or cavernous sinus lesions. Magnetic resonance imaging is also the best procedure for imaging the orbits when fat suppression...

Evaluation Guidelines Table173

Immediate computerized tomography (CT) scanning or magnetic resonance imaging (MRI) has to be performed in the setting of acute and subacute cerebellar ataxia. Posterior fossa lesions (hemorrhage, ischemia, hydrocephalus, neoplasms, abscess, or parasitic infections) carry the risk of increased intracranial pressure and death because of the cerebellar tonsils moving downward and compressing the brain stem within the foramen magnum. Angiography of the vertebrobasilar vascular system...

Medulloblastoma

Almost two thirds of these tumors are located in the midline cerebellum, and over 90 percent are located in the vermis with encroachment on the cisterna magna. Laterally placed tumors are more common in adults. Ihe macroscopic appearance is that of a soft friable tumor with central necrosis. In children, these tumors are moderately demarcated, but in adults they are highly demarcated. Microscopically, neuropathological analysis has attempted to define these...

Neurological Examination

The neurological examination focuses on the general state of alertness. Patients may appear sleepy or even nod off during the examination if EDS is severe. Cognitive and psychological functioning is assessed for evidence of dementia or depression, both of which are associated with sleep pattern disruption. Excessive anxiety, fears, and concerns are frequent causes for insomnia, and clues to these problems may reveal themselves during cerebral assessments of memory, concentration, and...

Associated Neurological Findings

The cranial nerve examination is important for determining symmetry in general. Asymmetrical findings indicate a pathological process. The eye examination is the most important part of the cranial nerve examination. Gaze impersistence, an inability to maintain conjugate deviation of the eyes, may be seen in the side opposite a frontal lesion. Small pupils may suggest narcotic use. Anticholinergic overdose may cause large pupils. A left-sided field cut or cortical blindness may...

Psychotic Syndromes

Antipsychotics (neuroleptics) can be used in patients with acute psychoses while a specific etiology is being sought ( .Jable.3-4 ). Although some of these drugs are sedating, they have more specific effects on the thought and mood disorder. Many different agents are available including the phenothiazines, thioxanthenes, dibenzoxazepines, and butyrophenones. The acutely psychotic patient who is a danger to himself or others may be treated parenterally with intramuscular haloperidol (5 mg every...

Speech Related Disorders

Miscellaneous speech-related disturbances not classified as dysarthrias or dysphonias include phonic tics, vocalizations, coprolalia, and reiterative speech disorders. PHONIC TICS AND VOCALIZATIONS Phonic tics are either simple or complex vocal tics. Simple vocal tics are similar in character to motor tics and are expressed as inarticulate noises and sounds (throat clearing, grunts, coughs, shouts, snorts, word accentuation). Complex vocal tics include articulate words, phrases, or sentences...

Reviews And Selected Updates

Brodal A Neurological Anatomy in Relation to Clinical Medicine. New York, Oxford University Press, 1981. Dow RS, Moruzzi G The Physiology and Pathology of the Cerebellum. Minneapolis, University of Minnesota Press, 1958. Holmes G The cerebellum of man. Brain 1939 62 1-30. Nitschke MF, Kleinschmidt A, Wessel K, Frahm J Somatotropic motor representation in the human anterior cerebellum. A high-resolution functional MRI study. Brain 1996 119 1023-1029. Tatu L, Moulin T, Bogousslavsky J, Duvernoy H...

Druginduced And Iatrogenic Neurological Disorders

ADCA, autosomal dominant cerebellar ataxia CNS, central ataxia. Alcoholic cerebellar degeneration (thiamine deficiency) 40 Chronic panencephalitis of congenital rubella 41 Varicella, measles, rubella, echo, coxsackie A B, polio, Epstein-Barr, herpes simplex Postinfectious disseminated encephalomyelitis Mumps, cytomegalic Mycoplasma pneumoniae Toxoplasmosis Lyme disease Plasmodium falciparum Cysticercosis Tuberculosis Cerebellopontine angle tumors (acoustic neurinoma, meningioma) Metastases lung...

Postgastroplasty Polyneuropathy

Some patients undergoing bariatric, or weight reduction, surgery develop a syndrome of acute or subacute sensory loss, weakness, and areflexia in the limbs, usually following a period of dramatic weight loss and repeated bouts of protracted vomiting. y A few patients have also developed a type of encephalopathy that is clinically and pathologically identical to WKS, with or without an associated polyneuropathy. y Indeed, Wernicke and Korsakoff each described young women with intractable...

Stroke Incidence and Prevalence

Stroke is a major public health problem, ranking among the top three causes of death in most countries. It affects the brains of almost a half million people every year, causing 150,000 deaths, and there are now approximately 3 million stroke survivors in the United States. Overall, ageadjusted incidence rates range between 100 and 300 per 100,000 population per year. Stroke is the major cause of serious disability in adults and is responsible for 20 billion in annual costs per year in lost...

Thiamine

The discovery and isolation of vitamins began with the study of beriberi in the 19th century. Although beriberi has been recognized for centuries, it was not until the Industrial Revolution that the disease reached epidemic proportions. Grain mills began producing polished rice, which was mechanically stripped of the nutrient-rich husk. Epidemics of painful polyneuropathy and heart failure rapidly developed in regions where rice was the major source of carbohydrate, particularly in Asia. In...

Rocky Mountain Spotted Fever

Rocky Mountain spotted fever is a rickettsial disease caused by Rickettsia rickettsi, a small intracellular parasite. Infection is acquired by a tick bite. The majority of infections are acquired in the south Atlantic coastal and the western and southern central states with the highest incidence in Virginia, North Carolina, South Carolina, Oklahoma, and Tennessee. The disease typically occurs during spring and summer. Fever, rash, and a history of exposure to ticks is the classic triad of Rocky...

References

Carpenter MB Core Text of Neuroanatomy, 4th ed. Philadelphia, Williams & Wilkins, 1991, pp 176-182. 2. Burr HS, Robinson GB An anatomical study of the gasserian ganglion, with particular reference to the nature and extent of Meckel's cave. AnatRec 1925 29 269-282 3. Gudmundsson K, Rhoton AL, Rushton JG Detailed anatomy of the intracranial portion of the trigeminal nerve. jNeurosurg 1971 35 592-600 4. Feindel W, Penfield W, McNaughton F The tentorial nerves and localization of intracranial...

Combined Upper and Lower Motor Neuron Syndromes

Motor neuron disease refers to a group of disorders in which selective degeneration of both upper and lower motor neurons occurs. y Amyotrophic lateral sclerosis (ALS, Lou Gehrig's disease) is the prototypical motor neuron disease. Several varieties or subtypes are recognized based on the sites at which the motor neurons are first and most prominently involved. The spinal form most commonly TABLE 15-12 -- EXAMPLES OF COMMON NEUROPATHIES CAUSING WEAKNESS Patterns of Muscle Weakness and Reflex...

Clinical Features and Associated Findings

The onset of measles is characterized by fever, cough, coryza, and conjunctivitis associated with Koplik's spots, which are small, white punctate lesions on the buccal mucosa. A maculopapular rash appears 2 to 3 days later, first on the face and behind the ears and then spreading in a centrifugal fashion to the trunk and extremities.' The cephalocaudal spread of the maculopapular rash is quite characteristic of measles. Postinfectious Encephalomyelitis. Postmeasles encephalomyelitis...

Chronic Progressive External Ophthalmoplegia and Kearns Sayre Syndrome

Ihese conditions are discussed together because of a common overlap. y Most cases are spontaneous and have mtDNA deletions. Over 100 different deletions have been identified 90 percent occur between the large arc between the two points of replication. Deleted mtDNAs localize to distinct regions along muscle fiber, whereas normal mtDNAs are evenly distributed, resulting in a periodic respiratory deficiency along the muscle fiber. Ihe loss of tRNAs is rate limiting in these areas, causing...

Basic Principles and Techniques

The beginning of myelography has its roots in the early 1900s when subarachnoid injections of air were performed to localize spinal cord tumors. This technique of pneumomyelography was eventually supplanted by the subarachnoid injection of an iodized poppy seed oil, Lipiodol, the myelographic medium of choice during the 1930s. Lipiodol had its disadvantages, including a very high viscosity, its immiscibility with CSF (thereby making it difficult to perform satisfactory diagnostic studies as...

Other Stereotypies

Stereotyped motor behavior can occur in normal children and in children with a variety of other primary neurodegenerative conditions. Repetitive head banging, an example of stereotypic activity, is seen in 15 percent of normal children. y In addition, thumb sucking, rocking, and other ritualistic behaviors are common during childhood. Most stereotypies, however, represent evidence of underlying brain dysfunction and hence require recognition. Stereotypic movements occur in at least a third of...

Other Segmentation And Cleavage Disorders

Septo-optic dysplasia is pathologically defined as absence of the septum pellucidum and hypoplastic optic nerves. This clinical constellation of symptoms and signs has also been referred to as de Morsier's syndrome. Other abnormalities are variably reported, suggesting considerable heterogeneity underlying this phenotype. Clinically, there are optic nerve hypoplasia resulting in visual impairment, endocrine abnormalities resulting from hypothalamic-pituitary insufficiency, and frequently...

Adrenal Disorders

The adrenal gland is the effector organ of the hypothalamic-pituitary-adrenal (HPA) axis and secretes cortisol in response to stimulation by pituitary-derived corticotropin (adrenocorticotropic hormone ACTH ). Pituitary function, in turn, is under the control of corticotropin-releasing hormone from the hypothalamus. Dysfunction anywhere in the HPA axis may result in adrenal insufficiency. Primary adrenal insufficiency (PAI), is due to bilateral adrenal gland...

Wilsons Disease

Wilson's disease (WD), or hepatolenticular degeneration, is an autosomal recessive disorder of copper metabolism. The specific genetic biochemical defect appears to be an abnormality of a copper-binding, membrane-associated adenosine-triphosphatase-associated protein, and the allele for this protein has been localized to the long arm of chromosome 13. '751 It is postulated that most of the symptoms result from excess deposition of copper in tissues,...

Definitions And History

In 1981, the Centers for Disease Control and Prevention (CDC) reported the occurrence of Pneumocystis carinii pneumonia (PCP) in five Los Angeles homosexual men. Within months of this report, clusters of similar cases of young, previously healthy homosexual men, who had developed unusual neoplasms and unexplained opportunistic infections (OIs), were reported in New York and California. The disorder, which had the clinical and immunological hallmarks of a cell-mediated immunodeficiency...

Atherothrombotic Disease

Atherothrombosis implies a reduction or occlusion of blood flow caused by a localized thrombotic process in one or more atherosclerotic cervicocranial arteries. Branching points of arteries are the predilection sites of development of atherosclerosis (Fig. 45-3 (Figure Not Available) ). In atherosclerosis, fibrous and muscular tissues of the vessel wall overgrow in the subintima, and fatty materials form plaques that can encroach on the lumen. Platelets adhere...

Gilles de la Tourette Syndrome and Other Tic Disorders

Tics are repetitive movements that usually involve the eyes, face, shoulders, neck, and vocal apparatus more than the rest of the body. When childhood-onset tics are multifocal, motor, and vocal, last longer than 1 year, and naturally wax and wane, the term Gilles de la Tourette syndrome (GTS) is applied. y Once considered a rare psychiatric condition, GTS is now recognized as a relatively common neurological disorder with both motor and behavioral...

Clinical Uses of the EEG

The EEG is useful in the evaluation of patients with several types of neurological disorders, including seizures, encephalopathy, and focal cerebral abnormalities. It also provides an ancillary aid to the diagnosis of brain death and may suggest certain specific neurological diagnoses when characteristic EEG findings are recorded in patients with clinical disorders of uncertain nature. The EEG is important in the evaluation of patients with known or suspected epilepsy. The interictal occurrence...

Sodium Disorders

Although dietary intake varies, body fluid composition and volume remain fairly constant, a reflection of multiple compensatory mechanisms. Although it is frequently cited that total body water (TBW) constitutes approximately 60 percent of body weight, the percentage varies with age, gender, and body habitus from 42 percent (obese, elderly female) to 75 percent (infant). y The cell membrane serves as an interface between the intracellular fluid and extracellular fluid (ECF) compartments their...

Vertebrobasilar System

Depressed consciousness, global aphasia Emotional lability, aphasia (left), apraxia (right) Lower altitudinal defect saccade pursuit defects Ipsilateral amaurosis fugax, contralateral HH Transient CN findings-diplopia, dysarthria Retinal emboli, contralateral HH, conjugate eye deviation Transient uni- or bilateral quadriparesis Transient contralateral weakness or clumsiness Transient bilateral weakness or clumsiness Ipsilateral weak palate, Horner's syndrome, decreased p t ipsilateral face...

Alcoholism and Movement Disorders

In addition to the classic postural tremor associated with alcohol withdrawal, other movement disorders can occur in the setting of alcohol abuse and withdrawal. y 1 A rare, slow tremor of the lower extremities can also occur in alcoholics and is produced by the synchronous flexion- extension of the muscles of the hip girdle. y.1 This 3-Hz tremor is associated with alcoholic cerebellar degeneration affecting the anterior superior vermis and cerebellar hemispheres. y.61 When they are supine,...

Cranial Nerve Xi Nucleus

The spinal accessory nerve (CN XI) is classified as a special visceral efferent (SVE) nerve because it innervates striated muscles that arise embryologically from the branchial arches. CN XI consists of two distinct portions, the cranial (or accessory) portion and the spinal portion ( Fig 14-1 ) z These are sometimes referred to as the ramus internus and ramus externus, respectively, y each with distinctive embryological developmental The cranial and spinal portions of CN XI arise from separate...

Cushings Syndrome Cushings Disease

Hypertension, diabetes, hyperphagia, central obesity moon facies, dorsocervical fat deposition (buffalo hump may cause Mental status changes, idiopathic myelopathy), hirsutism, acne, menstrual disorders evidence of protein cataboism (eg, easy bruising myophathy intracaranial hypertension, visual field osteopenia), cutaneous lesions (hyperpigmentation wide, purple striae), psychiatric manifistations defects, optic neumpathy Data from Lazer RB Neuromuscular manifestations of endocrine disease. In...

Oligodendroglioma and Oligoastrocytoma

Because these tumors arise from oligodendrocytes, they usually occur in the white matter of the cerebrum, and because there are relatively more oligodendrocytes in the frontotemporal area, oligodendrogliomas have a predilection for these areas. Usually surgical specimens contain areas that are identifiable as astrocytoma. Increasing difficulty in the diagnosis of these tumors centers on the percentage of oligodendro-glioma cells needed to categorize these...

Forearm Exercise Testing

Muscle fibers develop tension and shorten, thereby producing movement. These processes, including contraction and relaxation, are coordinated by the nervous system and are energy-requiring. Skeletal muscle meets its energy demands by converting chemical energy into mechanical energy. One feature unique to skeletal muscle, compared with other tissues, is the energy requirement difference between its resting and fully active states, a value that can approach two to three orders of magnitude.' 1...

Arteriovenous Malformations

Vascular malformations are congenital in origin. They are classified into several subtypes according to the predominant vasculature. The most common type is venous angiomas, which are composed of anomalous veins without any direct feeding artery. The next most common is telangiectasia, usually found deep within the brain, particularly in the brain stem. It is composed of vessels morphologically resembling capillaries but slightly larger and often found at...

Acute Bacterial Meningitis

There are approximately 25,000 cases of bacterial meningitis in the United States each year, but this disease is much more prevalent in developing countries. Group B streptococci and gram- negative enteric bacilli are the etiological organisms of the majority of cases of bacterial meningitis during the neonatal period in developed countries. In underdeveloped countries, gram-negative bacilli, predominantly Escherichia coli, are the most common pathogens. Risk...

Nerve Selection and Techniques

Biopsy of peripheral nerve is usually completed either as a full-thickness nerve biopsy (i.e., a complete transection of the nerve to remove a segment), or as a fascicular biopsy (i.e., a longitudinal dissection of the nerve to remove segments of only one or several fascicles), sparing at least a portion of the nerve. Full-thickness nerve biopsy is considered technically easier to perform and is preferable when the pathological evaluation should include both nerve fibers and surrounding...

Table 305 Glycogenoses

Type 1 Von Gierke's disease (Cori) (glucose-6-phosphatase) Type 2 Pompe's disease (Cori) (acid maltase) Type 3 Smith's disease (late infantile) (acid maltase) y , y Type 4 Engel's disease (adult) (acid maltase) '39 Type 5 Forbes' disease (Cori) (debrancher- or amylo-1,6-glucosidase) Type 6 Anderson's disease (Cori) (debrancher- or amylo-transglucosidase) Type 7 MeArdle's disease (Cori) (myophosphorylase) Type 8 Hers' disease (Cori) (hepatophosphorylase) Type 9 Tarui's disease (Cori)...

Poliovirus

Poliomyelitis was the most frightening infectious disease during the first half of the twentieth century. Large epidemics led to extensive research in the epidemiology and pathogenesis of the disease. The poliovirus was first isolated in 1908 by inoculation of monkeys with a cell-free extract made from the spinal cord of a patient with fatal poliomyelitis. y , y It was not, however, until 1937 that the virus was isolated from intestinal washings, and by 1941 it...

Choroid Plexus Papilloma

Choroid plexus papillomas are extremely rare vascular tumors that are often located in the ventricular areas of infants and children of both sexes. Although the lateral ventricles are the most common location, these tumors can present in the third or fourth ventricles, especially in adults. Although some believe the childhood predilection suggests that these tumors are congenitally derived, no risk factors are known. Patients commonly present with symptoms of increased intracranial pressure. In...

Upper Motor Neuron Syndromes

The upper motor neuron syndrome is marked by weakness, spasticity, hyperactivity of the tendon reflexes, and the presence of the flexor reflex (Babinski sign). This pattern of motor disturbance occurs when there is an interruption of the descending projections from the motor neurons in the cerebral cortex and brain stem that modulate excitation of the internuncial pool of inhibitory interneurons and the alpha and gamma motor neurons. The net effect is a reduction of inhibitory influences and an...

Brain Abscess

Brain abscess is a rare disease in immunocompetent individuals. In adults, otitis media and paranasal sinusitis (frontal, ethmoidal, or sphenoidal sinuses) are the most common predisposing conditions for brain abscess formation. In children, otitis media and cyanotic congenital heart disease are the most common predisposing conditions for brain abscess formation. Individuals with the acquired immunodeficiency syndrome (AIDS) are at increased risk for focal...

Channeldisease

Skeletal muscle sodium alpha subunit Hyperkalemic penodic paralysis With myotonia Without myotonia With paramyotonia congenita Paramyotonia congenita Sodium channel myotonia Myotonia fluctuans Myotonia permanens Acetazolamide-responsive myotonia Skeletal muscle calcium channel alpha-1 subunit Hypokalemic periodic paralysis Skeletal muscle chloride channel AD myotonia congenita (Thomsen's) AR myotonia congenita (Beeker's) AD, Autosomal dominant AR, autosomal recessive odic paralysis. Recent...

Autonomic Innervation of Specific Organs

The heart receives parasympathetic and sympathetic innervation. The cell bodies of the parasympathetic preganglionic neurons innervating the heart are located in the medulla (nucleus ambiguous and dorsal motor nucleus of the vagus). The axons of these neurons, which are part of the vagus nerve, join the cardiac neural plexus after entering the thorax to synapse with neurons in the intracardiac ganglia. y From these ganglia, short postganglionic parasympathetic neurons emerge to innervate the...

Magnesium Disorders

Although magnesium (Mg) is the fourth most common cation in the body, less than 0.5 percent is present in the serum, y of which about 30 percent is protein bound, 15 percent is chelated to serum anions, and 55 percent exists in the ionized (physiologically active) form. y The amount of protein-bound Mg is directly proportional to the serum albumin concentration and the pH, and is inversely proportional to the serum anion concentration. In addition, transcellular shifting between the...

Cytomegalovirus

Cytomegalovirus (CMV) is the most common life- and sight-threatening opportunistic viral infection in patients with AIDS. 127 Central nervous system infection by CMV in patients with AIDS may take the form of one or more of five distinct neurological syndromes retinitis, polyradiculomyelitis, encephalitis with dementia, ventriculoencephalitis, and mononeuritis multiplex. 128 Organ transplant recipients are also at risk for encephalitis due to CMV. Newborns with...

Withdrawal Syndromes

The manifestations of alcohol withdrawal occur when a person decreases or stops a high level of alcohol intake, either after a binge lasting a matter of days or after the regular ingestion of alcohol sustained over many months. Although the exact mechanisms are not known, most symptoms appear related to overactivity of various portions of the nervous system resembling a rebound phenomenon after profound suppression, and its basis may relate to alterations in the function of GABA or NMDA...

Nonhereditary Idiopathic Cerebellar Ataxia

Idiopathic cerebellar ataxia (IDCA) refers to a heterogeneous group of nonhereditary degenerative ataxias that begin after the age of 25 years.y The etiology of IDCA is unknown. Clinically and pathologically, there are two major types. The cerebellar type, IDCA-C, is characterized by a purely cerebellar syndrome and an almost exclusive degeneration of the cerebellar cortex. The plus type, IDCA-P, often has additional clinical features that suggest involvement...

Abnormal Findings and Clinical Uses of Polysomnography

Polysomnography is important in the investigation of patients with excessive daytime somnolence, disorders of initiating and maintaining sleep, disorders of the sleep-wake cycle, and disorders associated with certain sleep stages (parasomnias). It is important in confirming the existence of insomnia and characterizing its nature by determining, for example, whether it is associated with nocturnal myoclonus or periodic leg movements. Some patients complain of insomnia but, in fact, have a normal...

Anatomy of Declarative Memory

A broad convergence of human and animal research indicates that declarative memory depends on an interaction between domain-specific neocortical regions and domain-independent medial-temporal, diencephalic, and basal forebrain regions. Long-term memories are thought to be stored in the neocortex, the neocortical location reflecting the content of the memory. Thus, knowledge about the visual appearance of a tool may be stored separately, TABLE 5-1 -- CLINICO-ANATOMICAL CORRELATIONS OF MEMORY...

Table 383 Major Causes Of Hypocalcemia

Normal or increased parathyroid function (renal failure, vitamin D deficiency) Protein-binding and anion-chelation of ionized ealeium Medications (anticalcemic and antineoplastic agents) Multifactorial (gram negative sepsis) Modified from Spiegel AM The parathyroid glands, hypercalcemia, and hvpocalcemia. In Bennett JC, Plum F (eds) Cecil Textbook ,of Medicine, 20th ed. Philadelphia, WB. Saunders, 1995, pp 1364-1373 . may be caused by PTH or 1,25-DHCC deficiency, as well as by end-organ...

Evaluation Guidelines Table52

Neuroimaging techniques provide valuable information in the assessment of extent of structural and functional brain abnormalities in a patient. These data can be used to target further assessment of a patient's memory complaint. Gross structural abnormalities are often adequately revealed by computed tomography (CT), but more refined volumetric assessment of the deep cortical structures such as the hippocampal formation and amygdala are better visualized by magnetic resonance...

Altered Sexuality Syndromes

Altered sexuality may take many forms. The loss of libido is the most common form and can present as inhibited excitement or orgasm. Hypoactive sexual desire may be due to a number of psychiatric, medical, and neurological disorders. Typically, the cause is functional and the condition occurs in the presence of anxiety or depression. Hyposexuality associated with hypergraphia, hyper-religiosity, irritability, and elation comprise the main features of the Gastaut-Geschwind syndrome. This...

Intraparenchymal Metastases

To establish a metastatic colony, tumor cells must grow within the primary site of malignancy, escape from the primary tumor, penetrate the circulatory system either as single cells or small tumor emboli, survive while circulating, arrest in the microvasculature of other organs, extravasate into the organ parenchyma, and efficiently grow and compress or invade tissue at the secondary site. Solid tumors or metastases larger than 1 or 2 mm in diameter must be...

Pharmacological Neuroanatomy

A number of neurotransmitters, specifically the catecholamines (norepinephrine and dopamine) and serotonin, are closely related to mood, emotion, and thought disorders. Catecholamines are formed in brain, chromaffin cells, sympathetic nerves, and sympathetic ganglia from tyrosine, their amino acid precursor (Fig. 3-1 (Figure Not Available) ). Tyrosine is taken up from the bloodstream and concentrated within the brain and other sympathetically innervated tissue via active transport. In the...

Ocular Misalignment Syndromes

Lesions of the oculomotor nerve can involve the nucleus in the midbrain, or nerve fascicles within the ventral midbrain, subarachnoid space, cavernous sinus, superior orbital fissure, or orbit. As an example, in the setting of an isolated right nuclear third nerve lesion (see Fig. 9-7 (Figure Not Available) ), there is complete disruption of the outflow of that nerve. Additionally, fibers from the left subnuclei for the superior rectus (contralateral outflow) and levator palpebrae (bilateral...

Epidemiology and Risk Factors HIV1 is transmitted

By either sexual contact, parenteral exposure to blood, blood products or body fluids, or from mother to infant. In the United States, western Europe, Australia, and in some Latin American countries, the majority of AIDS cases were initially among men infected through sex with other men. In the United States, the proportion that this group now represents has declined from approximately 72 percent in 1936 to 53 percent. y It is estimated that 75 percent of HIV-1 infection worldwide is the result...

Orthostatic Hypotension

Management of orthostatic hypotension requires patient education to avoid factors that precipitate a fall In blood pressure. Patients should be made aware of the hypotensive effects of certain drugs, large meals, environmental temperature Increases, and physical activities. Other Instructions Include Institution of a high-fiber diet to lessen straining resulting from constipation and the use of physical maneuvers that help to Increase postural tolerance. These maneuvers Include crossing the...

Lower Motor Neuron Syndromes

Diseases of the lower motor neuron may affect the cell body itself in the anterior spinal gray or its axon as it leaves the spinal cord in the spinal root and becomes a peripheral nerve. Signs of disease of the lower motor neuron include muscular weakness, atrophy, fasciculations, and loss of tendon reflexes. PROGRESSIVE SPINAL MUSCULAR ATROPHY SYNDROMES There may be selective degeneration of the anterior horn cells of the spinal cord or brain stem or both. This results in a progressive...

Segmentation Cleavage And Midline Defects

These disorders are believed to arise from a defect in midline development. The result is a failure of midline structures, like the corpus callosum, to form. Included are also abnormalities in the separation of the neural tube into two hemispheres. This later defect is believed to result in holoprosencephaly and related disorders. Pathogenesis and Pathophysiology. Completion of neural tube closure is followed by segmentation in the anteroposterior axis. Although these segments were originally...

Occlusive Disease of Small Penetrating Arteries

The small penetrating arteries deep within the brain parenchyma are the sites of various occlusive processes that are different from those of the larger arteries. Pathogenesis and Pathophysiology. Lipohyalinosis, a destructive vasculopathy linked to severe hypertension, affects arteries 40 to 200 pm in diameter. The arterial lumen is compromised not by an intimal process but by thickening of the vessel wall itself. Subintimal lipid-laden foam cells and pink-staining fibrinoid material thicken...

Spinal Metastases

The vertebral column is the most common site of skeletal metastases, which may be due to the rich concentration of growth factors in its bone marrow stroma that may stimulate proliferation of malignant cells in vitro. y Spread from the primary site to the bone marrow occurs through the arterial system, retrograde spread of malignant cells through Batson's plexus particularly during Valsalva maneuvers, and direct invasion of the tumor through the intervertebral...

Cranial Nerve Dysfunction

Miller-Fisher variant of GBS Opic neuritis Wilson's disease Neurosyphilis (paretic) H'lLV-l Poliomyelitis Spinal cord tumor Chronic inflammatory demyelinating polyradiculopathy (CIDP) Inherited neuropathies Neurosyphilis (tabes dorsalis) pr, cell cts, IgG, OCB pr, cell cts pr, cell cts pr, cell cts pr, gl, cell cts See above See above VDRL, pr, gl, cell cts pr (45 to 60 mg dl), 50 percent with mild + + VDRL, pr 50 to 100 mg dl, cell cts 25 to 75 leukocytes mm2 pr (50 to 200 mg dl), nl gl, mild...

Cocaine

Blockade of the uptake of monoamines into the presynaptic terminals is probably responsible for the acute effects produced by cocaine. Depending on the synapse affected, this blockade leads to increased levels of dopamine (DA), norepinephrine, or serotonin. The increase in neurotransmitters can TABLE 39-7 -- SUMMARY OF NEUROLOGIC SIGNS AND SYMPTOMS OF DRUG ABUSE TABLE 39-7 -- SUMMARY OF NEUROLOGIC SIGNS AND SYMPTOMS OF DRUG ABUSE Opiates. stimulants,...

Supranuclear Syndromes

Facial sensory loss may occur in the setting of lesions involving the trigeminothalamic pathways, corona radiata or internal capsule white matter projections from the VPM nucleus of the thalamus to primary sensory cortex, or within sensory cortex itself. Specific pathological processes affecting these pathways include ischemia, hemorrhage, neoplasm, and demyelinating diseases. All result in contralateral hemifacial and hemibody numbness. In seizures, facial tingling often occurs in association...

Pulmonary Causes

Secondary muscle dysfunction electrolyte disturbances, malnutrition, reduced respiratory drive metabolic alkalosis, sedation Other (e.g., pulmonary parenchymal or airway disorders, cardiac failure) Modified from Jozefowicz RF Neurologic manifestations of pulmonary disease. Neurol Clin 1989 7 605-616 and Bennett DA, Bleek TP Diagnosis and treatment of neuromuscular causes of acute respiratory failure. Clin Neuropharmacol 1988 11 303-347 two categories is important and is usually afforded by a...

Primary Sensory Neuropathy Pure Sensory Distal Nerve Lesions

Primary sensory neuropathies reflect a focal mononeuropathy of a nerve that carries only sensory fibers. Examples (see Fig 19-3 and Fig 19-4 ) include the Meralgia paresthetica with involvement of the lateral femoral cutaneous nerve Gonalgia paresthetica due to entrapment of the infrapatellar saphenous nerve Cheiralgia paresthetica due to entrapment of the superficial branch of the radial nerve Medial antebrachial cutaneous neuropathy Dorsal ulnar neuropathy Sural neuropathy Diffuse Sensory...

Glucose Metabolism Disorders Hypoglycemia

Unlike other body tissues, the CNS relies almost exclusively on glucose as an energy substrate. CNS features that promote its vulnerability to hypoglycemia include its low glucose level (about 25 percent of the serum glucose value), its inability to store significant glucose as glycogen, and the high cerebral metabolic rate (5 mg 100 g brain tissue min) for glucose. yj Thus, for a 1400 g brain, the glucose requirement is 70 mg min. The brain's dependence on...

Action or Non Rest Tremors TabieMB

Essential tremor (EI) is the most frequent hyperkinetic movement disorder. Its age-adjusted prevalence is 2 to 5 percent y and, as a lifelong illness, EI may affect any age group. It has a bimodal distribution of age at onset, with two peaks, adolescence and the fourth to fifth decade of life. In many families, EI is inherited in an autosomally dominant pattern, and in these patients, the term familial tremor can be used interchangeably with EI. Although central mechanisms are thought to be...

Comments

Indistinguishable clinically from AIDP and CIDP in Most common HIV-l-related form of neuropathy Prominent lower extremity syndrome resembling spinal cord compression Laryngeal nerve involvement can ocour and lead to hoarseness with vocal cord paralysis Modified from So YT Holtzman DM Abrams Dl Olney RK Penpheral neuropathy assoeiated with acquired immunodeflciency syndrome prevalence and clinical features from a population-based survey Arch Neurol 1988 45 945 948. AIDP Acute inflammatory...

Subjective Objective

Anorexia, Jaundice, scleral icterus, Kayser-Fleischer rings (Wilson's disease, primary biliary cirrhosis'p, fetor hepaticus (musty, sweet breath odor), spider nevi, fatigue gynecomastla. caput medusa (dilation of the umbilical vessels), splenomegaly, aseites, xanthomas, palmar crythema, Dupuytren s contractures of the The onset of FHF is much more rapid and is typically associated with severe liver disease. Mental status changes, such as agitation, inappropriate behavior, and impaired judgment,...

Lesions in the Retroparotid or Retropharyngeal Spaces and Distal Peripheral Nerve Lesions

CN XI and XII may be affected by a number of distal peripheral nerve lesions resulting from surgical trauma, y y local infections, stretch,y , y neck irradiation, 41 or local tumors.y y A dissecting carotid aneurysm may result in hypoglossal nerve palsy. y A self-limited idiopathic hypoglossal nerve palsy also has been reported. y , 49 The resultant findings (i.e., weakness and atrophy) in peripheral nerve lesions have been described earlier. Occasionally, a lesion may affect CN IX through XII,...

Nuclear Brain Stem Syndromes

Trauma, ischemic injury, and tumors may affect the trigeminal system within the brain stem. These syndromes are characterized by sensory paresthesias, numbness, or pain in the distribution of the V1 to V3, along with combinations of cranial nerve palsies and distinct sensory and cerebellar system signs. Reflecting the lateral circumferential TABLE 10-3 -- SELECTED ETIOLOGIES ASSOCIATED WITH TRIGEMINAL NERVE DISORDERS TABLE 10-3 -- SELECTED ETIOLOGIES ASSOCIATED WITH TRIGEMINAL NERVE DISORDERS...

Myotonic Dystrophy

Myotonic dystrophy (DM), or Steinert's disease, is an autosomal dominant multisystem degenerative disease characterized by myotonia, progressive muscular weakness, gonadal atrophy, cataracts, and cardiac dysrhythmias. Pathogenesis and Pathophysiology. The molecular basis of DM is an unstable trinucleotide repeat sequence, cytosine, thymine, and guanidine (CTG) in the protein kinase-encoding gene (DMK), located at 19q13.3. The repeat is present 50 to several thousands of times in patients with...

Cranial and Spinal Epidural Abscess

Cranial epidural abscesses develop in the space between the dura and inner table of the skull and are usually caused by the spread of infection from the frontal sinuses, middle ear, mastoid, or orbit. y Epidural abscesses may also develop as a complication of a craniotomy or compound skull fracture. At present, the most common cause of a cranial epidural abscess is craniotomy that has been complicated by an infection of the wound, bone flap, or epidural space.y...

Dysarthria

Dysarthria is the inability to form or produce understandable speech due to lack of motor control over peripheral -- USEFUL STUDIES IN THE EVALUA ION OF SPEECH AND LANGUAGE DISORDERS Mass lesion compressing the tenth cranial nerve, or on the vocal cords Abnormal decrement of CMAP with repetitive stimulation in myasthenia gravis. Single-fiber EMG showing jitter in NMJ defects Carcinoma of the vocal cords, carcinomatous meningitis Normal language and cognitive function Vocal cord pathology...

Hereditodegenerative Disorders

Corticobasal ganglionic degeneration Metastatic neoplasms and paraneoplastic syndromes of movements involved in gestures, including emblems and pantomimes. Two forms of ideomotor apraxia can be identified. A posterior form can be induced by left parietal cortex (angular or supramarginal gyrus) lesions, while an anterior form can occur following lesions anterior to the supramarginal gyrus that disconnect the visual kinesthetic motor engrams from the premotor and motor areas. Patients with...

Syndromes of Intracerebral Hemorrhage

There are general features of the clinical syndrome of intracerebral hemorrhage that may help to characterize it. Historical features include a presentation that is maximum at the onset in one third of patients and gradual with smooth progression over 30 minutes in two thirds of patients. Interestingly, most hemorrhages occur during activity rather than during sleep. y , y A headache is present in approximately one half of patients. Nausea and vomiting are present in over 50 percent of...

Thyroid Disorders

Ihe thyroid gland synthesizes and secretes tetraiodothyronine (14 ) and, in much smaller quantities, triiodothyronine (I3 ), which is at least two to four times more potent than I4 . Both of these hormones regulate tissue metabolism. Iodine is bound to tyrosine residues of thyroglobulin in the thyroid gland (organification), and these iodinated residues are then coupled to form I4 and I3 . Both protein-bound (inactive) and unbound (active) thyroid hormone fractions exist in serum. In the...

Dysosmia

Dysosmia (disordered smell perception) presents as either a distortion in the perceived quality of an odor ( parosmia, cacosmia) or as the presence of a strange odor in the absence of actual odor stimulation (phantosmia or olfactory hallucinations). Most dysosmias reflect dynamic elements associated with degeneration (or, more rarely, regeneration) of the olfactory epithelium and remit over time. However, it is common for patients with anosmia to report that prior to the onset of anosmia they...

Cortical Versus Subcortical Dementing Syndromes

A distinction has been noted between the cortical dementia typically seen in Alzheimer's or Pick's disease and the subcortical dementia typified by Huntington's and Parkinson's disease but noted also in progressive supranuclear palsy, multiple sclerosis, Wilson's disease, and human immunodeficiency virus (HIV) infection. y Dementia seen in diseases with primarily subcortical neuropathology feature slowed movement (bradykinesia) and thought (bradyphrenia), disproportionate problems in the...

Progressive Diseases of Infancy and Childhood

A large number of amino and organic acid disorders appear primarily with neurological symptoms. Only four disorders, phenylketonuria (classic form and biopterin-dependent variant) homocystinuria, type 1 glutaricaciduria, and biotinidase deficiency are presented here. DEFICIENCY OF PHENYLALANINE HYDROXYLASE Pathogenesis and Pathophysiology. Although phenylalanine hydroxylase (PAH) is a liver enzyme, the clinical manifestations of classic phenylketonuria (PKU) relate to the CNS. There are no...

Language Related Disorders

Aphemia was the term originally used by Broca to describe all language disturbances, but he later accepted the term aphasia promoted by Trousseau (1864). Bastian (1887) used aphemia to denote a specific syndrome described here others have termed the same language abnormality pure motor aphasia, cortical anarthria, or apraxia of speech. The patient presents acutely with mutism but is able to communicate using written language. When verbalization returns, the output is hypophonic, slow, and...

Contributors

Associate Professor of Neurology, Department of Neurology, University of Michigan Medical Center Director, Sleep Disorders Center, University of Michigan Medical Center, Ann Arbor, Michigan Sleep Disorders Professor of Neurology, School of Medicine, University of California Attending Physician and Director of the Clinical Neurophysiology Laboratories, University of California Medical Center, San Francisco, California Electrophysiology Instructor of Neurological Sciences, Rush University...

Disease and Enzymes

Maple symp urine disease branched-chain alpha-keto acid dehydrogenase (E1, E2, and E3 subunits) E1alpha l9ql3 1-ql3 2 E* 6p21-p22 E2 Propionicacidemia propionyl-CoA carboxylase Methylmalonicacidemia methylmalonyl-CoA mutase, hydroxycobalamin reductases, adenosyl transferase and Urea cycle disorders carbamoylphosphate synthetase (CPS), ornithine transcarbamylase (OTC), argininosuccinic acid Classic PKU phenyllalanine hydroxylase Biopterin-dependent PKU GTP cyclohydrolase, 6-pyruvoyl...

Peroxisomal Leukodystrophies Adrenoleukodystrophy

The peroxisomal leukodystrophies (see Tab e 3.0. 6 ) represent a relatively new concept for neurologists. Peroxisome refers to the subcellular organellae in the cell body that are deranged by being absent, malformed, or dysfunctional. These conditions include neonatal disorders such as Zellweger's disease and adrenoleukodystrophy as well as later-onset adult conditions such as Refsum's disease. The pioneering work of Moser and associates on the peroxisomal entities has established the fact that...

Internuncial Pool

More complex reflexes use even more of these inhibitory interneurons, sometimes referred to as the internuncial pool. One of these inhibitory interneurons with a special action was described by Birdsie Renshaw and is known by his name. U The Renshaw cell receives a recurrent collateral, i.e., a branch of the axon of the alpha motor neuron before it leaves the ventral horn ( Fig, 15-11 ). The axons of the Renshaw cells contact the alpha motor neuron. An action potential down the axon of the...

Anatomical and Physiological Hypotheses for Hypokinesia and Hyperkinesia

Based on these data, models of hypokinetic and hyperkinetic disorders have been proposed and examined in animals as well as in humans. In monkeys treated with the toxin profound hypokinesia develops, and pathologically, there is highly focused damage of the pars compacta substantia nigra (. Fig, 1.6-4 ). Physiologically, as predicted by a resultant enhancement of the indirect pathway and a diminished influence of the direct pathway, the degenerated pars compacta and the associated loss of...

Neuronal Migration Defects

Anomalous cerebral cortical development is generally characterized as a cortical migrational abnormality, although an actual defect in migration has yet to be conclusively demonstrated. Rorke y has hypothesized a variety of factors that must be considered in the pathogenesis of cortical migrational abnormalities. Among the various components of development, cellular proliferation, cell death, postmigrational intracortical growth and development, and...

Autonomic Dysfunction Secondary to Focal Central Nervous System Disease

The autonomic nervous system syndrome may also be classified anatomically into telencephalic, diencephalic, brain stem, and spinal cord disorders ( Ia.b. p 2.1 5. ). Telencephalon Syndromes. Temporolimbic seizures may induce changes in heart rate, heart rhythm, and blood pressure. Cardiovascular manifestations of seizures include sinus tachycardia or bradyarrhythmias (including sinus arrest) with syncope. Seizure-induced ventricular tachycardia and fibrillation have been implicated in sudden...

Tendon Reflex Amplitude

Present but decreased in amplitude and velocity from the normal range and elicited with reinforcement Normal amplitude and velocity without reinforcement Increased in amplitude and or velocity with spread to adjacent site Increased in amplitude and or velocity with spread to adjacent site and duplication of the jerk or clonus cutaneous reflexes are noted as present or absent. Tendon reflexes are elicited with a percussion hammer, of which many types are available. The two most commonly used are...