A Dictionary of Neurological Signs

There is debate as to whether jargon aphasia is simply a primary Wernicke/posterior/ sensory type of aphasia with failure to self-moni- tor speech output, or whether additional deficits (e.g., pure word deafness, intellectual impairment) are also required. Others suggest that jargon aphasia represents aphasia and anosognosia, leading to confabulation and reduplicative paramnesia.

References

Hillis AE, Boatman DB, Hart J, Gordon B. Making sense out of jargon. A neurolinguistic and computational account of jargon aphasia. Neurology 1999; 53: 1813-1824

Kinsbourne M, Warrington EK. Jargon aphasia. Neuropsychologia 1963; 1: 27-37

Cross References

Anosognosia; Aphasia; Confabulation; Echolalia; Logorrhea; Pure word deafness; Reduplicative paramnesia; Transcortical aphasias; Wernicke’s aphasia

Jaw Jerk

The jaw jerk, or masseter reflex, is contraction of the masseter and temporalis muscles in response to a tap on the jaw with the mouth held slightly open. Both the afferent and efferent limbs of the arc run in the mandibular division of the trigeminal (V) nerve, connecting centrally with the mesencephalic (motor) nucleus of the trigeminal nerve. The reflex is highly reproducible; there is a linear correlation between age and reflex latency, and a negative correlation between age and reflex amplitude.

Interruption of the reflex arc leads to a diminished or absent jaw jerk as in bulbar palsy (although an absent jaw jerk may be a normal finding, particularly in the elderly). Bilateral supranuclear lesions cause a brisk jaw jerk, as in pseudobulbar palsy (e.g., in motor neurone disease).

References

Fitzek S, Fitzek C, Hopf HC. Normative values of the masseter reflex (myotatic masseter reflex). Journal of Neurology 2000; 247 (suppl3): 176-177 (abstract 724)

Cross References

Age-related signs; Bulbar palsy; Pseudobulbar palsy; Reflexes

Jaw Winking

Jaw winking, also known as the Marcus Gunn phenomenon, is widening of a congenital ptosis when a patient is chewing, swallowing, or opening the jaw (i.e., a trigemino-oculomotor synkinesis). It is believed to result from aberrant innervation of the pterygoid muscles and levator palpebrae superioris.

Eyelid closure on jaw movement or opening of the mouth, inverse Marcus Gunn phenomenon, is also described, as the Marin-Amat syndrome, thought to be due to aberrant facial (VII) nerve regeneration.

References

Rana PVS, Wadia RS. The Marin-Amat syndrome: an unusual facial synkinesia. Journal of Neurology, Neurosurgery and Psychiatry 1985;

48: 939-941

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Recognized causes of the jugular foramen syndrome include: Skull base trauma/fracture

Glomus jugulare tumor

Inflammatory/infective collection at the skull base Ischemia.

The differential diagnosis includes retropharyngeal or retroparotid space occupying lesions, which may in addition involve the hypoglossal nerve (XII; Collet-Sicard syndrome) and the sympathetic chain with or without the facial nerve (VII; Villaret’s syndrome).

Cross References

Dysphagia; Dysphonia; Gag reflex

Junctional Scotoma, Junctional Scotoma of Traquair

Despite the similarity of these terms, they are used to refer to different types of scotoma:

●Junctional scotoma:

Unilateral central scotoma with contralateral superior temporal defect, seen with lesions at the anterior angle of the chiasm; this is said to damage the ipsilateral optic nerve plus the crossing loop of fibers (Wilbrand’s knee) originating from the inferonasal portion of the contralateral eye (it may be noted that some authors have questioned whether such a loop in fact exists).

●Junctional scotoma of Traquair:

A monocular temporal scotoma, sometimes even hemianopia, seen with optic nerve involvement sufficiently close to the chiasm to involve only ipsilateral crossing nasal axons, which subserve the temporal visual field, but sparing nasal axons crossing from the contralateral eye.

References

Larner AJ. A developing visual field defect. Postgraduate Medical Journal 2002; 78: 106, 112-113

Cross References

Scotoma; Visual field defects

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K

Kayser-Fleischer Rings

Kayser-Fleischer rings are deposits of copper, seen as a brownish discoloration, in Descemet’s membrane. Although often visible to the naked eye (difficult in people with a brown iris), they are best seen with slit-lamp examination. Since they are a highly reliable sign of intracerebral copper deposition in Wilson’s disease (hepatolenticular degeneration), any patient suspected of this diagnosis (i.e., with parkinsonism or dystonia presenting before age 50 years) should have a slit-lamp examination (as well as blood copper and ceruloplasmin, and urinary copper, measurements). Very occasionally cases of neurological Wilson’s disease without Kayser-Fleischer rings have been reported.

References

Finelli PF. Kayser-Fleischer ring: Hepatolenticular degeneration (Wilson’s disease). Neurology 1995; 45: 1261-1262

Cross References

Dystonia; Parkinsonism

Kernig’s Sign

Kernig’s sign is pain in the lower back (and also sometimes the neck) and resistance to movement with passive extension of the knee on the flexed thigh in a recumbent patient. It is indicative of meningeal mechanosensitivity due to inflammation, either infective (meningitis) or chemical (subarachnoid hemorrhage), in which case it may coexist with nuchal rigidity and Brudzinski’s (neck) sign. If unilateral it may indicate irritation of the lumbosacral nerve roots from a ruptured intervertebral disc (in which case Lasègue’s sign may also be present).

References

Pearce JMS. Kernig and Brudzinski. In: Pearce JMS. Fragments of neurological history. London: Imperial College Press, 2003: 365-366

Cross References

Brudzinski’s (neck) sign; Lasègue’s sign; Nuchal rigidity

Kernohan’s Notch Syndrome

Raised intracranial pressure as a result of an expanding supratentorial lesion (e.g., tumor, subdural hematoma) may cause herniation of brain tissue through the tentorium into the subtentorial space, putting pressure on the midbrain. If the midbrain is shifted against the contralateral margin (free edge) of the tentorium, the cerebral peduncle on that side may be compressed, resulting in a hemiparesis which is ipsilateral to the supratentorial lesion (and hence may be considered “false-localizing”).

There may also be an oculomotor nerve palsy ipsilateral to the lesion, which may be partial (unilateral pupil dilatation).

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References

Cohen AR, Wilson J. Magnetic resonance imaging of Kernohan’s notch. Neurosurgery 1990; 27: 205-207

Kernohan JW, Woltman HW. Incisura of the crus due to contralateral brain tumor. Arch Neurol Psychiatry 1929; 21: 274-287

Kole MK, Hysell SE. MRI correlate of Kernohan’s notch. Neurology 2000; 55: 1751

Cross References

“False-localizing signs”; Hemiparesis; Hutchinson’s pupil

Kinesis Paradoxica

Kinesis paradoxica is the brief but remarkably rapid and effective movement sometimes observed in patients with Parkinson’s disease or post-encephalitic parkinsonism, despite the poverty and slowness of spontaneous movement (akinesia, hypokinesia; bradykinesia) seen in these conditions. It often occurs in response to alarm, excitement or emotion (e.g., in response to a genuinely funny joke).

Cross References

Akinesia; Bradykinesia; Hypokinesia; Parkinsonism

Klazomania

Klazomania was the term applied to the motor and vocal tics seen as a sequel to encephalitis lethargica (von Economo’s disease), along with parkinsonism and oculogyric crises. This observation helped to promote the idea that tics were due to neurological disease rather than being psychogenic, for example in Gilles de la Tourette syndrome.

References

Wohlfart G, Ingvar DH, Hellberg AM. Compulsory shouting (Benedek’s “klazomania”) associated with oculogyric spasm in chronic epidemic encephalitis. Acta Psychiatrica Scandinavica 1961; 36: 369-377

Cross References

Coprolalia; Echolalia; Parakinesia, Parakinesis; Tic

Kleptomania

Kleptomania, a morbid impulse to steal, has been related to the obses- sive-compulsive spectrum of behaviors in patients with frontal lobe dysfunction.

References

Kozian R, Otto FG. Treatment of a patient with kleptomania and frontal lobe dysfunction. Journal of Neurology, Neurosurgery and Psychiatry 2001; 70: 279 (abstract)

Cross References

Frontal lobe syndromes

Klüver-Bucy Syndrome

The Klüver-Bucy syndrome consists of a variety of neurobehavioral changes, originally observed following bilateral temporal lobectomy (especially anterior tip) in monkeys, but subsequently described

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in man. The characteristic features, some or all of which may be present, are:

Visual agnosia (e.g., misrecognition of others) Hyperorality

Hyperphagia, binge eating Hypermetamorphosis Hypersexuality

Emotional changes: apathy; loss of fear, rage reactions

Clinical causes of the Klüver-Bucy syndrome include:

Sequel of bilateral temporal lobectomy

Post-ictal phenomenon in a patient with a previous unilateral temporal lobectomy

Sequel to minor head trauma; subdural hematoma Tumor

Meningoencephalitis Pick’s disease

Alzheimer’s disease: especially hyperorality and hyperphagia, but it is rare to have all features

References

Anson JA, Kuhlman DT. Post-ictal Klüver-Bucy syndrome after temporal lobectomy. Journal of Neurology, Neurosurgery and Psychiatry

1993; 56: 311-313

Klüver H, Bucy P. Preliminary analysis of functions of the temporal lobes in monkeys. Archives of Neurology and Psychiatry 1939; 42: 979-1000.

Cross References

Apathy; Hypermetamorphosis; Hyperorality; Hyperphagia; Hypersexuality; Visual agnosia

Knee Tremor

A characteristic tremor of the patellae, sometimes known as knee bobbing, juddering, or quivering, may be seen in primary orthostatic tremor (POT; “shaky legs syndrome”). It is due to rapid rhythmic contractions of the leg muscles on standing, which dampen or subside on walking, leaning against a wall, or being lifted off the ground, with disappearance of the knee tremor; hence this is a task-specific tremor. Auscultation with the diaphragm of a stethoscope over the lower limb muscles reveals a regular thumping sound, likened to the sound of a distant helicopter. EMG studies show pathognomonic synchronous activity in the leg muscles with a frequency of 14-18Hz, thought to be generated by a central oscillator (peripheral loading does not alter tremor frequency).

A number of drugs may be helpful in POT, including phenobarbitone, primidone, clonazepam, and levodopa, but not propranolol (cf. essential tremor).

References

Heilman KM. Orthostatic tremor. Archives of Neurology 1984; 41: 880-881

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Brown P. New clinical sign for orthostatic tremor. Lancet 1995; 346: 306-307

Cross References

Tremor

Körber-Salus-Elschnig Syndrome

- see NYSTAGMUS

Kyphoscoliosis

Kyphoscoliosis is twisting of the spinal column in both the anteroposterior (kyphosis) and lateral (scoliosis) planes. Although such deformity is often primary or idiopathic, thus falling within the orthopedic field of expertise, it may also be a consequence of neurological disease which causes weakness of paraspinal muscles.

Recognized neurological associations of kyphoscoliosis and scoliosis include:

Chiari I malformation, syringomyelia

Myelopathy (cause or effect? Skeletal disease, such as achondroplasia, is more likely to be associated with myelopathy than idiopathic scoliosis)

Cerebral palsy Friedreich’s ataxia Neurofibromatosis

Hereditary motor and sensory neuropathies Spinal muscular atrophies

Myopathies, e.g., Duchenne muscular dystrophy

Stiff person syndrome may produce a characteristic hyperlordotic spine. Some degree of scoliosis occurs in virtually all patients suffering from paralytic poliomyelitis before the pubertal growth spurt.

Cross References

Camptocormia; Stiffness

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L

Lagophthalmos

Lagophthalmos is an inability to close the eyelid in a peripheral facial (VII) nerve palsy, with partial opening of the palpebral fissure. A similar phenomenon may be observed with aberrant regeneration of the oculomotor nerve, thought to be due to co-contraction of the levator palpebrae superioris and superior rectus muscles during Bell’s phenomenon.

Cross References

Bell’s palsy; Bell’s phenomenon; Facial paresis

Lambert’s Sign

Lambert’s sign is gradual increase in force over a few seconds when a patient with Lambert-Eaton myasthenic syndrome is asked to squeeze the examiner’s hand as hard as possible, reflecting increased power with sustained exercise.

Cross References

Facilitation

Lasègue’s Sign

Lasègue’s sign is pain along the course of the sciatic nerve induced by stretching of the nerve, achieved by flexing the thigh at the hip while the leg is extended at the knee (“straight leg raising”). This is similar to the maneuver used in Kernig’s sign (gradual extension of knee with thigh flexed at hip). Both indicate irritation of the lower lumbosacral nerve roots and/or meninges. The test may be positive with disc protrusion, intraspinal tumor, or inflammatory radiculopathy. Pain may be aggravated or elicited sooner using Bragard’s test, dorsiflexing the foot while raising the leg thus increasing sciatic nerve stretch, or Neri’s test, flexing the neck to bring the head on to the chest, indicating dural irritation.

A positive straight leg raising test is reported to be a sensitive indicator of nerve root irritation, proving positive in 95% of those with surgically proven disc herniation. The specificity may be somewhat lower.

Various modifications of Lasègue’s sign have been described. crossed straight leg raising, when the complaint of pain on the affected side occurs with raising of the contralateral leg, is said to be less sensitive but highly specific. Femoral stretch test (q.v.) or “reverse straight leg raising” may detect L3 root or femoral nerve irritation.

References

Pearce JMS. JJ Forst and Lasègue’s sign. In: Pearce JMS. Fragments of neurological history. London: Imperial College Press, 2003: 362-364

Cross References

Femoral stretch test; Kernig’s sign

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Lateral Medullary Syndrome

The lateral medullary syndrome (or Wallenberg’s syndrome, after the neurologist who described it in 1895) results from damage (usually infarction) of the posterolateral medulla with or without involvement of the inferior cerebellum, producing the following clinical features:

●Nausea, vomiting, vertigo, oscillopsia (involvement of vestibular nuclei)

●Contralateral hypoalgesia, thermoanesthesia (spinothalamic tract)

●Ipsilateral facial hypoalgesia, thermoanesthesia, + facial pain (trigeminal spinal nucleus and tract)

●Horner’s syndrome (descending sympathetic tract), +/− ipsilateral hypohidrosis of the body

●Ipsilateral ataxia of limbs (olivocerebellar/spinocerebellar fibers, inferior cerebellum)

●Dysphagia, dysphonia, impaired gag reflex

●+/− eye movement disorders, including nystagmus, abnormalities of ocular alignment (skew deviation, ocular tilt reaction, environmental tilt), smooth pursuit and gaze holding, and saccades (lateropulsion)

●+/− hiccups (singultus); loss of sneezing.

Infarction due to vertebral artery occlusion (occasionally posterior inferior cerebellar artery) or dissection is the most common cause of lateral medullary syndrome, although tumor, demyelination, and trauma are also recognized causes.

References

Fisher CM, Karnes W, Kubik C. Lateral medullary infarction: the pattern of vascular occlusion. Journal of Neuropathology and Experimental Neurology 1961; 20: 103-113

Pearce JMS. Wallenberg’s syndrome. In: Pearce JMS. Fragments of neurological history. London: Imperial College Press, 2003: 233-236 Sacco RL, Freddo L, Bello JA, Odel JG, Onesti ST, Mohr JP. Wallenberg’s lateral medullary syndrome. Clinical-magnetic resonance imaging correlations. Archives of Neurology 1993; 50: 609-614

Cross References

Anesthesia; Dysphagia; Dysphonia; Environmental tilt; Gag reflex; Hemiataxia; Hiccup; Horner’s syndrome; Hypoalgesia; Hypohidrosis; Medial medullary syndrome; Nystagmus; Ocular tilt reaction; Oscillopsia; Saccades; Skew deviation; Sneezing; Vertigo

Lateral Rectus Palsy

- see ABDUCENS (VI) NERVE PALSY

Laterocollis

Laterocollis is a lateral head tilt; this may be seen in 10-15% of patients with torticollis.

Cross References

Torticollis

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Lateropulsion

Lateropulsion or ipsipulsion is literally pulling to one side. The term may be used to describe ipsilateral axial lateropulsion after cerebellar infarcts preventing patients from standing upright causing them to lean to toward the opposite side. Lateral medullary syndrome may be associated with lateropulsion of the eye toward the involved medulla, and there may also be lateropulsion of saccadic eye movements.

Laughter

- see AUTOMATISM; PATHOLOGICAL CRYING, PATHOLOGICAL LAUGHTER

Lazarus Sign

Various spontaneous and reflex movements are described in brain death, the most dramatic of which has been labeled the Lazarus sign, after Lazarus, raised from the dead by Christ (John 11:1-44). This spinal reflex manifests as flexion of the arms at the elbow, adduction of the shoulders, lifting of the arms, dystonic posturing of the hands and crossing of the hands.

References

Saposnik G, Bueri JA, Mauriño J, Saizar R, Garretto NS. Spontaneous and reflex movements in brain death. Neurology 2000; 54: 221-223

Bueri JA, Saposnik G, Mauriño J, Saizar R, Garretto NS. Lazarus’ sign in brain death. Movement Disorders 2000; 15: 583-586

Leadpipe Rigidity

- see RIGIDITY

Levator Inhibition

- see EYELID APRAXIA

Levitation

Spontaneous levitation may be displayed by an alien limb, more usually an arm than a leg, indicative of parietal lobe pathology. It is most often seen in corticobasal (ganglionic) degeneration, but a few cases with pathologically confirmed progressive supranuclear palsy have been reported.

References

Brunt ER, van Weerden TW, Pruim J, Lakke JW. Unique myoclonic pattern in corticobasal degeneration. Movement Disorders 1995; 10: 132-142

Cross References

Alien hand, Alien limb

Lhermitte’s Sign

Lhermitte’s sign, or the “barber’s chair syndrome,” is a painless but unpleasant tingling or electric shock-like sensation in the back and spreading instantaneously down the arms and legs following neck flex-

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