Australian X disease See Murray Valley encephalitis
A. Fulfils criteria for migraine with aura
2. In electromyography, compound muscle action potentials evoked from orbicularis oculi muscles as a result of brief
2.5 SEM. 2643
by other voluntary activity, despite which they may be so intractable as to produce functional blindness.1649,2811 See also Meige syndrome.
Rating scales for blepharospasm have been con-structed.1729
In a variant form, patients with Parkinson disease or progressive supranuclear palsy are unable to initi-ate or sustain eye opening in the absence of overt spasm of the orbicularis muscles.1648
blepharospasm-oromandibular dystonia See Brue-ghel syndrome.
Blessed-Roth dementia instruments (Newcastle De-mentia Scale, Information-Memory-Concentration Test) A two-part measure designed to quantify the cognitive and behavioral symptoms of dementia, comparing these manifestations with measures of underlying brain neu-ropathology. Some of the elements have been included in the CAMDEX4814and the CERAD Instrument.3997
The Blessed Dementia Scale is a behavioral rating scale evaluating functional and emotional impairment and consisting of 22 items measuring changes in perform-ance of everyday activities, self-care habits, and per-sonality interests and drives. The Blessed Information-Memory-Concentration Test603 is a well-validated measure of cognitive impairment. Dr G. Blessed is a neuropsychologist in Newcastle, UK. See Information-Memory-Concentration Test.
blind headache A once-popular term for migraine.
blind spot A physiological defect in the visual fields due to the absence of rod and cone receptors on the head of the optic nerve. Its presence was first remarked in 1688 by E. Mariotte (1620–1684), a French physicist, who also described the red reflex.
blindisms (digito-ocular maneuver) The repetitive rubbing of the eyes, an action performed frequently by some people with congenital pigmentary retinal de-generations.
blindsight The capacity to detect (or at least make saccadic movements in the direction of) visual stimuli presented within the area of a field defect in the absence of acknowledged awareness. This may occur when the blindness results from damage to the striate cortex.5901 blink rate The frequency of involuntary repetitive blinking. In the normal subject this is 24 15 per minute.
The rate is decreased in depressive illnesses, Parkinson disease, and progressive supranuclear palsy.4851 blink reflex
1. Clinically, closure of the eyes with sudden visual stimu-lation or with tactile stimustimu-lation of the upper part of the face. The reflex was known to Descartes and to Jean Fer-nel (1506–1588). See also palpebral reflex, orbicularis oculi reflex.
2. In electromyography, compound muscle action potentials
which the subject is required to manipulate multiple-patterned blocks in order to match a composite pattern presented on a card, a measure of (right hemisphere) spatial functioning.5889
block vertebral anomaly A rare spinal column and cord anomaly with scoliosis, abnormal rib cage, and lo-cal myelopathy resulting from a failure of segmentation at the affected level.4972
blocking 1. The apparent temporary obliteration of EEG rhythms in response to physiological or other stimuli such as electrical stimulation of the brain. See attenuation. 2. A condition of temporary unrespon-siveness of the EEG amplifier caused by major overload and manifested initially by extreme flat-topped pen ex-cursion(s) lasting up to a few seconds. See also clip-ping. (Adapted from the report of the Committee on Terminology, IFCN,989© 1974, with permission from Elsevier Science.) 3. A brief interruption of a train of thought with a temporary difficulty in logical verbal ex-pression. Although this is a common occurrence in the normal, fatigued person and increases with age, repet-itive brief periods of complete inhibition of thought is a symptom of schizophrenia of the first rank, and can occur in depressive illness. 4. A term used in single fiber electromyography to describe dropout of one or more components of the potential during sequential firings. If more than one component drops out simul-taneously it is described as concomitant blocking. This is usually seen when jitter values exceed 80 to 100 sec.
A sign of abnormal neuromuscular transmission, which may be due to primary neuromuscular transmission disorders, such as myasthenia gravis and other myas-thenic syndromes. Also seen as a result of degeneration and reinnervation in neuropathies or myopathies. Con-comitant blocking may be generated by a split muscle fiber or failure of conduction at an axon branch serv-ing several muscle fibers. (From the 2001 Report of the Nomenclature Committee of the American Association of Electromyography and Electrodiagnosis.10Used by permission, copyright © 2001, AAEM.)
blocking reaction The abrupt inhibition or cessation of a voluntary movement.
Blocq, Paul-Oscar (1860–1896) French neuropsychi-atrist, born and trained in Paris, where he worked at the Salpétrière before his premature death. He published his own textbook in 1894, contributed chapters on chorea and syphilis to Charcot’s Traité de Médicine, and de-scribed the syndrome of astasia-abasia in 1888.606 Blocq syndrome (astasia-abasia) Hysterical inability to walk or even stand, although all movements are normal in the lying position. Jacoud, Charcot, and Weir Mitchell had touched upon the subject, but Blocq’s 1888 monograph was the definitive text.606As he put it, the patient “can even jump in some cases or walk on all fours, but has lost the memory of the specialized
movements necessary to hold himself upright (astasia) and to walk (abasia).”
All but one of Blocq’s patients were under 28 years old. By his description there appears to be some resem-blance to Bamberger’s saltatory spasms, but Blocq de-nied this. In fact, both were manifestations of hysteria.
However, with vermis lesions (e.g., due to medulloblas-toma in children), leg movements may be unimpaired in recumbency even though the gait is very ataxic. [JF]
blood–brain barrier A physicochemical mechanism whereby solutes and materials in suspension in the blood are held back from entering the internal envi-ronment of the brain.
The search for the nature of this barrier was initiated by Ehrlich in 1886 as a result of his work on aniline dyes as staining reagents, during which he noticed that the vital acid dyes such as trypan blue stained every-thing in the body except the brain, which was, however, stained by the basic dyes. In 1913, Goldman injected acid dyes into the ventricles and showed that they did then stain the brain tissue, indicating the presence of a selectively permeable barrier between blood and brain, considered to be at the level of the endothelial cell.5610 Within the brain, only the area postrema, median eminence, pineal gland, neurohypophysis, pineal crest, and a few other areas are not shielded by this barrier.
Clinically, it is highly effective in preventing entry into the CNS of various medications, including some an-tibiotics. The barrier may, however, be lowered by in-flammation, as in meningitis, and by certain other tox-ins. The barrier is crossed more easily by nonionized, low-molecular-weight, lipid-soluble molecules.
Bloom syndrome A congenital dysmorphic syn-drome characterized also by microcephaly, short stature, hirsutism, facial telangiectasias, vitiligo, café-au-lait spots, and photosensitivity of the skin.5085 blowout fracture A fracture of the floor of the orbit as a result of blunt trauma to the globe or to the inferior orbital rim. Multiple ocular motor palsies may result, and entrapment of the inferior rectus muscle within the fracture may lead to restriction of upward gaze.3330 blue diaper syndrome (Drummond syndrome) A recessively inherited diffuse encephalopathy character-ized by hypercalcemia, nephrocalcinosis, and indica-nuria. Craniostenosis, mental retardation, and dwarfism are less constant features.
The condition is due to the slow absorption of tryp-tophan from the bowel, followed by its conversion to indoles, which are absorbed and excreted in the urine to produce the bluish staining.1519
blue edema See Charcot edema.
blue jeans syndrome Compression of the sciatic nerve by shrinking wet jeans.3696
blue rubber bleb nevus syndrome An uncommon congenital neurocutaneous disorder manifesting blue BLUE RUBBER BLEB NEVUS SYNDROME 117
hemangiomas of the skin and vascular malformations of internal organs, sometimes including the brain and its venous sinuses but more commonly the gastroin-testinal tract. Seizures may be a complication. It was first described by William Bean in 1958.4929
B-mode ultrasonography A technique whereby high-frequency sound waves are transmitted through tissues, the returning echoes providing an image of the area evaluated.
It allows identification of the arterial wall and lumen of vessels to the extent that even minor disease of the internal carotid can be detected, but it does not read-ily distinguish flowing blood from clot.
bobbing See ocular bobbing.
bobble-headed doll syndrome A congenital syn-drome characterized by intermittent, arrhythmic, to-and-fro (flexion-extension) bobbing or nodding movements of the head at 2–3 Hz associated with rhyth-mic flexion and extension of the arms and legs in the presence of severe, slowly progressive hydrocephalus. It is usually caused by a tumor of the third ventricle, but tumors of the corpus callosum, frontal lobe, or basal ganglia may also be responsible.477,5961
Generalized obesity, optic atrophy, behavioral prob-lems, emotional lability, sensory deficits, choroid plexus tumors, and arachnoid cysts are other reported features.
Boder-Sedgwick syndrome See ataxia-telangiectasia.
Bodian, David (b. 1910) American anatomist.
Bodian stain A method for staining nerve fibers and nerve endings, using colloidal silver, invented by Bo-dian in 1936.617
body clock That mechanism within the brain which regulates cycles of human activity as a pacemaker. It is considered to exist within the suprachiasmatic nucleus.
body image agnosia See topographical agnosia, finger agnosia.
body righting reflex See righting reflexes.
body schema See body scheme.
body scheme (body schema) The term of Head, Holmes, and Brain for an individual’s conception of his body’s size, shape and position, the body parts, right and left sides, etc.
The mechanism is directly involved when a person cannot recognize parts of his own body, a phenome-non termed asomatagnosia.
Boe, Franciscus de la (1614–1672) Dutch physiolo-gist and professor of the practice of medicine at Ley-den; also known as Sylvius. He described the lateral (sylvian) fissure in 1637, and named the aqueduct, al-though he was not the first to describe it. He also made the first differentiation between static, postural, and ac-tion tremors.
Bogorad, F.A. (fl. 1928) Russian neurologist.
Bogorad syndrome See crocodile tears, the syn-drome aptly named by Bogorad in 1928,625but previ-ously described by Oppenheim in 1913.
bombesin A peptide found in the brain and in the gastrointestinal tract that causes a feeling of satiety.
bonbon sign Movement of the tongue inside the mouth, producing a bulge in the cheek, as though the subject has a candy in her mouth. It is seen in dystonic or choreic states.
Bondin-Barbizet syndrome See epileptic en-docrine syndrome.
Bonhoeffer, Karl Ludwig (1868–1948) German psy-chiatrist who studied in Tübingen and Munich. After psychiatric training in France and Germany, he was as-sistant to Wernicke and later succeeded Kraepelin at Heidelberg University before moving on, eventually to Berlin University, as professor of psychiatry. He au-thored nearly 100 publications on various topics in neu-rology, psychiatry, pathology, and alcoholism. He died 3 years after his son, a Lutheran pastor, was hanged for outspoken criticism of the Nazi régime.
Bonhoeffer symptom Chorea, which he considered to be caused by a lesion in a region posterior to the op-tic thalamus, presumably the caudate, in which case he was right.652
Bonhoeffer syndrome (exogenous psychosis) See delirium.
Bonnet, Amedée (1809–1858) French surgeon who trained in Lyon and Paris and after internship there re-turned to Lyon University, where he became professor of clinical surgery in due course.
118 B-MODE ULTRASONOGRAPHY
Bonnet, Charles (1720–1793) Swiss lawyer, natural-ist and philosopher. A wealthy man, he never practiced
Charles Bonnet
law (which he disliked) but rather studied natural his-tory. He wrote on sensation and discernment in plants, and anticipated Darwin’s theory of evolution, by im-plication. His studies of respiratory pores in Lepi-doptera led to his election as a fellow of the Royal So-ciety, although he never left Switzerland.5047After his sight failed, he turned from biology to philosophy. He described the Bonnet syndrome in his grandfather.
Bonnet, Paul French ophthalmologist in Lyon.
Bonnet sign Pain in the back occurring with adduc-tion of the thigh, but not when the flexion is passively performed without the adduction; it is positive in lum-bosacral root irritation. The sign was described inci-dentally, in Bonnet’s two-volume book on joint disease (1845).
Bonnet syndrome (syndrome of Charles Bonnet) 1. The occurrence in elderly people with normal men-tal faculties of recurrent, vivid, dynamic, neutral, or pleasant visual pseudohallucinations. The original de-scription was of this problem and autoscopy occurring in Charles Bonnet’s grandfather who had had an oper-ation for cataract 11 years before: “his double, the smoker, appeared regularly each evening the moment he lit his pipe. Immediately after he would describe an-other decoration or some an-other vision; and having jested over these fictions of the brain, he would calmly resume his discourse.”654Strangely, when Charles Bon-net also went blind at the end of his life, he also expe-rienced visual hallucinations.1258
The condition is not all that rare if elderly people are asked directly about such experiences, but they seldom volunteer the information. Although originally de-scribed in people with eye disease, it may also occur as a cortical dissociation syndrome described by Paul Bon-net.
2. (trigeminosympathetic neuralgia) Trigeminal neuralgia with Horner syndrome and with vasomo-tor disturbance in the area supplied by the trigeminal nerve.655,5047The condition may be a form of Raeder syndrome.
3. (Bonnet-Déchaume-Blanc syndrome, neuroretino-angiomatosis) Unilateral tortuosity of the retinal ves-sels (cirsoid aneurysms) with vascular malformations of the orbit or midbrain and of the face, described by Paul Bonnet and his colleagues in 1937.656,657
Miscellaneous other lesions of the orbits, central or peripheral nervous systems, or skin are also described.
See also Wyburn-Mason syndrome, which may be the same thing.
Bonnet-Collet syndrome See Collet-Sicard syn-drome.
Bonnet-Dechaume-Blanc syndrome See Bonnet syndrome (2).
Bonnevie, Kristine (1872–1950) Norwegian zoolo-gist.
Bonnevie-Ullrich syndrome A sporadic congenital syndrome characterized by ptosis, ophthalmopareses, cataracts, hyperelastic skin, hypertrichosis, muscular hy-potrophy, and lymphangiectatic edema of the extremities.
The condition may be a variant of Turner syndrome.2987 Bonnier, Paul (1861–1918) French physician.
Bonnier syndrome (Deiter’s nucleus syndrome) Vertigo, pallor, tachycardia, somnolence, trigeminal pain, weakness, and marked apprehension; contralat-eral hemiplegia may be a feature. The syndrome is due to a vascular or neoplastic lesion of Deiter’s nucleus.660 Bontius, Jacobus (1592–1631) Dutch physician who gave the first account of beriberi and of nutritional amblyopia in his book De Medicina Indorum after working for the Dutch East India Company.
Boorgard angle (foraminobasilar angle) The angle defined by the intersection of the plane of the clivus and the plane of the foramen magnum, normally 126°–136°. The value changes with age and increase is not always associated with genuine basilar invagination, so this measurement is now little employed.5282 borderland of epilepsy The term of Sir William Gowers for a group of disorders including fainting, va-gal and vasovava-gal attacks, vertigo, migraine, and sleep disorders which by their abrupt onset, repetitive nature, and brief duration resemble seizure disorders.
The clinical characteristics of these conditions, with speculations on their underlying pathophysiology, were published by Gowers in a book of the same name in 1907.2237
borderzone infarction Infarctions along the bound-aries of recognized vascular territories, most commonly following an episode of profound reduction in global cerebral perfusion.
Bordier-Fränkel sign Upward and outward devia-tion of the eye on the side of a peripheral facial nerve lesion.4723
Börjeson-Forssman-Lehmann syndrome A rare, X-linked recessive dysmorphic syndrome (or at least ex-pressed fully only in males), consisting of severe obe-sity, genital infantilism, hypogonadism, seizures, mental retardation, hypothyroidism, narrow palpebral fissures, and cromegaloid facial appearance. Short stature, nystagmus, strabismus, ptosis, blepharophimo-sis, microcephaly, seizures, and hypogonadotrophic hy-pogonadism are also described.666,5047
Borna virus A recently detected virus capable of caus-ing damage to the central nervous system (especially to the hippocampus) without evidence of inflammation.4840 Bornholm disease See epidemic pleurodynia.
borreliosis (relapsing fever) Infection with Borrelia re-currentis, a spirochete transmitted to humans by lice or ticks. The disease is characterized by malaise, high fever, BORRELIOSIS 119
headache, vomiting, and myalgias followed by he-patosplenomegaly with jaundice, bronchitis, a petechial skin rash, and meningoencephalopathy causing confu-sion, drowsiness up to coma, seizures, and focal neuro-logical signs. The CSF often shows a lymphocytic pleocy-tosis. Further but milder relapses of the initial illness occur over the next few weeks.826Acrodermatitis chronica at-rophicans is a late manifestation and is associated with a distal sensory polyneuropathy.3047See also Lyme disease.
Borries syndrome Headache, fever, increased cells and protein in the CSF, and focal signs suggesting brain abscess but in fact due to localized nonsuppurative en-cephalitis.669
The condition was described in 1921 by G.V.T. Bor-ries, a Danish physician in Copenhagen.
Bors-Comarr classification A system for grading the degree of bladder involvement, introduced for the man-agement of patients following spinal shock.670 See Chart B–4.
Chart B–4. Bors-Comarr Classification of Bladder Disorders
Complete Lesions Above Conus (S2–4); Somatic Upper Motor Neuron Lesion
Balanced (automatic Small capacity, increased residual or neurogenic reflex urine; reflex, spontaneous bladder) or conditioned initiation;
no inhibition; no desire to void Imbalanced Initially flaccid-atonic with large
capacity, 400 ml or more; later autonomous with capacity 150–
250 ml; finally spastic, with ca-pacity150 ml
Incomplete Lesions above Conus (S2–4); Somatic Upper Motor Neuron Lesion
Balanced (uninhibited Residual 10–20%, capacity neurogenic 200–300 ml; desire to mic-bladder) turate present; initiation
precip-itate; inhibition inadequate Imbalanced Residual 10% or more; capacity
200–1000 ml or more
Complete Lesions At or Below Conus (S2–4); Somatic Lower Motor Neuron Lesion
Balanced (autonomous/ Residual 0–10%, capacity 400 ml automatic bladder) or more; desire to micturate
absent; initiation with straining;
inhibition passive
Imbalanced Residual 10% or more; capacity 400 ml or more
Incomplete Lesions At or Below Conus (S2–4); Somatic Lower Motor Neuron Lesion
Balanced Residual 0–10%, capacity 300–400 ml; desire to micturate present;
initiation with straining or nor-mal; inhibition active but inad-equate;
Imbalanced (tabetic Residual 10% or more; capacity bladder) 600 ml or more; sensation absent The term balanced here refers to coordinated coordination of the forces of expulsion and relaxation. The amount of residual urine is considered to be in proportion to the imbalance between these functions. (From Bors E.
Urological aspects of rehabilitation in spinal cord injuries. Copyright 1951.
American Medical Association. JAMA 1951;146:225–229.670)
Boston craniosynostosis A dominantly inherited form of craniosynostrosis mapped to chromosome 5q Boston Diagnostic Aphasia Examination A com-prehensive instrument for assessing language, in par-ticular spontaneous speech, naming, repetition, com-prehension of oral language, reading, and writing, used for classifying as well as detecting aphasias.2192
The examination may be prolonged and requires ex-pertise on the part of the interviewer.
Boston Naming Test A sensitive test of visual con-frontation naming ability, in which the subject is re-quired to name a series of 60 objects presented as line drawings, with standardized verbal or phonemic clues being provided when initial recognition fails.2921
A shorter version is also available, for use with de-mented patients.3550
Boston sign Intermittent descent of the globe on downward gaze, seen in dysthyroid orbitopathy.4723 Boston Society of Psychiatry and Neurology One of the oldest medical societies in the United States, it was founded in 1880, largely with the inspiration of Walter Channing, for the informal and social discussion of medical subjects. Its proceeding were reported in the Boston Medical and Surgical Reporter (the forerunner of the New England Journal of Medicine). Members have continued to present and discuss topics in both psy-chiatry and neurology at monthly meetings held con-tinuously since its founding.1686
bottoms-up dissection Dissection of the extracranial carotid artery, considered to have been produced by repetitive neck extension during the act of throwing back the head in order to drain the contents of drink-ing glasses.5644
botulinus toxin A group of seven serologically dis-tinct neuroparalytic toxins produced by Clostridium botulinum, all of which block the release of acetyl-choline by the nerve terminal and cause slowly re-versible effects indistinguishable from typical denerva-tion. The type A toxin is used therapeutically to produce local suppression of muscle contraction in certain dys-tonias and in hemifacial spasm. Guidelines for its use were suggested by the American Academy of Neurol-ogy in 1990.13
The use of the agent in the management of headaches and of the facial evidences of aging is less well sub-stantiated.
botulism (from Lat, a sausage) Poisoning with the exotoxin of Clostridium botulinus (commonly of types 120 BORRIES SYNDROME
A, B, and E), initially described after poisoning by in-fected sausages.
The toxin binds to cholinergic nerve terminals, in-hibiting acetylcholine release and clinically leading to weakness, especially of the ocular and bulbar muscles, acute autonomic dysfunction (pupillary dilatation oc-curs in half the cases), and gastrointestinal symptoms.
The electrical signs resemble those of the Lambert-Eaton myasthenic syndrome but nerve conduction ve-locities are normal.
Infantile botulism results from botulinal neurotoxin produced in vivo following colonization of the gas-trointestinal tract in children aged 1 to 9 months. The disease spectrum varies from “failure to thrive” to “the floppy baby syndrome” (the most common form) and sudden infant death syndrome or “crib death.” Typical symptoms in the floppy baby syndrome include lethargy, diminished sucking, constipation, weakness, feeble cry, and diminished spontaneous activity with loss of head control, followed by extensive flaccid paral-ysis.998,999
Adult botulism is usually caused by ingestion of pre-formed toxin, less often from wound infection. Pro-gressive descending paralysis develops, involving ex-traocular, bilbar, respiratory, and proximal more than distal limb muscle weakness with autonomic dysfunc-tion.
Bouchard, Charles (1837–1909?) French neurologist who trained in Lyon and Paris; he studied under Char-cot at the Salpétrière for some of this time and co-authored a number of papers with him, particularly on the relationship of miliary aneurysms to cerebral hem-orrhage, the subject of his doctoral thesis. Bouchard rose quickly in the hierarchy and was appointed pro-fessor of general pathology at the University of Paris in 1879. After this, however, he distanced himself from Charcot and strove for the advancement of his own stu-dents against Charcot’s; thus he prevented the ap-pointment of Babinski to the position of professeur agrégé.2750
bouche de Tapir (Fr, mouth of a tapir) Involuntary protrusion of the upper lip, a sign of bilateral facial weakness as in some cases of facial myopathy, described by Karl Westphal in 1886.
Bouillard, Jean-Baptiste (1796–1881) French physi-cian, professor of medicine at the Charité in Paris. He differentiated between expressive and receptive dys-phasias and localized the lesion to the frontal lobes.
boundary infarct See watershed infarct.
Bourdon test A test of attention in which the subject is required to strike out all the examples of a given let-ter in a line of printed random letlet-ters.
Bourneville, Desiré-Magloire (1840–1909) French physician who trained under Charcot and became pe-diatric neurologist and psychiatrist at the Bicêtre
hos-pital in Paris where he was in charge of care of the men-tally retarded patients. Apart from his description of tuberous sclerosis, he also demonstrated the virtual identity of cretinism and myxedema (1880), wrote on multiple sclerosis, hysteria, medical photography, and thermometry, and was a founder both of the French Archives de Neurologie in 1880 and of La Presse Med-icale. Bourneville was an important figure in arranging the publication of Charcot’s lectures.
He described tuberous sclerosis in 1880,682,683 the same year as Hartdegen in Germany reported the con-dition independently (but von Recklinghausen1181had already noted the same features in 1863). Outside med-icine, he was elected to the Chambre des Deputés in Paris in 1873, and introduced legislation to improve hospital conditions and medical practice in obstetrics.7 BOWDITCH LAW 121
Desiré-Magloire Bourneville Bourneville disease See tuberous sclerosis.
Bourneville-Brissaud disease See tuberous sclero-sis.
Bourneville-Pellizzi disease See tuberous sclerosis.
Bourneville-Pringle disease See tuberous sclerosis.
bovine spongiform encephalopathy (‘“mad cow disease”) A neurological disease transmitted by an un-conventional, resistant agent (an aberrant isoform of prion protein), with a latency of some 18 months. This is a “slow virus” disease, equivalent to the disease scrapie in cattle.5914
The possibility that this condition might be respon-sible for a future outbreak of Jakob-Creutzfeldt disease has recently caused concern in the United Kingdom.
Bowditch law Peripheral nerve fibers do not fatigue with repetitive stimulation; a truth enunciated by Henry Pickering Bowditch (1840–1911), an American