Central Vestibular Syndrome Research Articles

Audio-vestibular disturbances in Behcet’s patients: report of 62 cases

This study was carried out to determine the characteristics and incidence of hearing loss and vestibular disturbance in Behcet’s syndrome with a large number of patients. Sixty-two patients with Behcet’s syndrome were included in this study, 34 men and 28 women whose mean age was 33.7 (15–60). Sixty-two healthy normal control subjects (38 male and 24 female) were included. Patient and control groups were questioned about any history of audio-vestibular disturbance and underwent physical and ENT examination and the following audiologic tests: pure tone audiometric test (0.25, 0.5, 1, 2, 4, and 6 kHz), tympanogram, speech discrimination, short increment sensitivity index, tone-decay test, auditory brainstem response. Vestibular system was evaluated by videonistagmogram and caloric test. Cranial and brainstem magnetic resonance imagine (MRI) of patients who have vestibular disturbances were practiced to examine the central nervous system. Both the patient and the control groups were tested with the HLA-B51 antigen. Pure tone audiogram showed sensory-neural hearing loss (⩾25 dB hearing level in at least two frequencies) in 20 of the 62 (32%) Behcet’s patients while the control group were normal. There was a hearing loss involving high frequencies in the audiograms of Behcet’s patients with hearing disturbances. The recruitment investigation tests and auditory brain stem response confirmed cochlear involvement in all 20 patients. Caloric stimulation tests revealed a normal vestibular function in all patient and control group. In electronystagmography, 21 (34%) patients had hypometric or hypermetric saccades and smooth pursuit tests showing that 4 (6%) patients had pathological changes while the control group was normal. HLA-B51 antigen was found positive in 15 of 20 Behcet’s patient with hearing loss. Conclusion: (1) The hearing and vestibular disturbances in Behcet’s syndrome is more prevalent than previously recognized; (2) Hearing loss in high frequencies in Behcet’s patients is an indicator of cochlear involvement in this disease; (3) There is a higher prevalence of central vestibular syndrome in Behcet’s patients than it was thought before; (4) HLA-B51 antigen may be able to be a prognostic factor for sensorineural hearing loss in Behcet’s patients.

Vertical vestibular responses to head impulses are symmetric in downbeat nystagmus.

Downbeat nystagmus (DBN), a frequent ocular motor sign often caused by cerebellar lesions, is a fixational nystagmus with fast phases directed downward. Its precise etiology is not known. One hypothesis is that it is caused by a central imbalance of pathways of the vertical vestibulo-ocular reflex (VOR). Such an imbalance would cause not only ocular drift but also deficient and asymmetric vertical VOR responses. To test this hypothesis, the authors analyzed the functionally relevant VOR responses to head impulses in the roll, pitch, and yaw planes. Head and eye movements were measured with the search-coil method in 10 patients with DBN and 10 age-matched control subjects. Analysis revealed no gain difference in patients with DBN compared with control subjects. Specifically, upward and downward VOR responses in patients with DBN in the pitch plane were symmetric. These findings do not support the hypothesis of a vertical VOR imbalance and put into question the view that DBN is a central vestibular syndrome in the sense of vestibular dysfunction. Although DBN possibly involves vestibulocerebellar pathways, in the patients that we studied, DBN did not affect the immediate VOR responses in the high-frequency range that corresponds to natural head movements.

Evaluating patients with vertigo: bedside examination.

Dizziness and vertigo are common complaints in patients referred for neurological evaluation. With a basic understanding of vestibular physiology and proper examination techniques, a correct diagnosis can generally be made at the bedside. This article reviews the most common peripheral and central vestibular syndromes as well as the key elements of the bedside vestibular system examination.

Vascular vertigo syndromes

Ischemia,hemorrhages, and other vascular disorders can result in various central or peripheral vestibular syndromes with vertigo, oculomotor/balance disturbances, and nausea. The vascular vertigo syndromes listed in Table 1 can however be brought about by other causes such as demyelitizing focuses in multiple sclerosis or space-occupying lesions, so that not only localization of the damaged structure but also the various etiologies are decisive for the choice of therapy. Occasionally, combined functional disturbances of the peripheral and central vestibular system appear, such as an infarction of the inferior anterior cerebellar artery, which supplies the labyrinth and parts of the brainstem and cerebellum. In rare cases, a central lesion can have the same signs as a peripheral-vertibular disturbance: a lacunar infarct at the root entry zone of the eighth nerve can mimic a unilateral partial loss of labyrinth function as it occurs in vestibular neuritis, thus named "pseudoneuritis". Differential diagnosis between vestibular migraine, vestibular paroxysmia, transient ischemic brainstem attacks, and Meniere's disease is sometimes so difficult that only trial therapies such as prophylaxis with beta blockers, carbamazepine, thrombocyte aggregation inhibitors, antiplatelet drugs, or betahistin can clarify the issue.

The topographic diagnosis of acquired nystagmus in brainstem disorders

Evidence is presented for a clinical classification of central vestibular syndromes according to the three major planes of action of the vestibulo-ocular reflex (VOR): yaw, pitch, and roll. The plane-specific vestibular syndromes are determined by ocular motor, postural, and perceptual signs. Yaw plane signs are horizontal nystagmus, horizontal past pointing, rotational and lateral body falls to the right or to the left, and horizontal deviation of perceived straight-ahead. Pitch plane signs are upbeat/downbeat nystagmus, forward/ backward tilts and falls, and upward or downward deviations of the perceived horizontal. Roll plane signs are torsional nystagmus, skew deviation, ocular torsion, tilts of head, body, and perceived subjective visual vertical. The VOR syndromes defined in this way allow a precise topographic analysis of brainstem lesions according to their level and side. The lesional sites of yaw syndromes are restricted to the pontomedullary level (vestibular nucleus). A tone imbalance in pitch indicates bilateral (paramedian) lesions of the medullary or pontomesencephalic brainstem or bilateral dysfunction of the flocculus. A tone imbalance in roll indicates unilateral lesions, ipsiversive at the pontomedullary level (vestibular nuclei) and contraversive at the pontomesencephalic level (MLF and INC).A unilateral lesion (or stimulation) of the graviceptive pathways, which transduce input from vertical semicircular canals and otolith, affects function in roll, whereas bilateral lesions affect function in pitch.

Maladie de Lyme chez l'enfant en Haute-Normandie: à propos d'une enquête hospitalière

This study presents the results of a hospital survey on Lyme disease in children living in upper Normandy, a region that is quite densely wooded (with 18% forest areas and woods). The aim of this survey was to assess the prevalence of this disease in children from the Seine-Maritime and L'Eure, hospitalized in pediatric wards in the Seine-Maritime department, which includes Rouen, Dieppe, Fécamp, Elbeuf, and Le Havre. Fifteen cases of Lyme disease were diagnosed between September 1988 and June 1997. The children (6 girls and 9 boys) were aged between 5 and 14 years old. Only 7 subjects showed primary symptoms, while secondary symptoms were observed in 12 children. In the study population, a high prevalence (11 out of the 15 children) of neurological disorders was found. The following secondary symptoms were noted: 5 cases of erythema migrans, 2 cases of non-malignant cutaneous lymphocytoma, and 4 cases which in fact had previously displayed primary clinical signs (3 subjects with erythema migrans and 1 subject with non-malignant cutaneous lymphocytoma); 7 cases of uni- or bilateral facial paralysis, the most frequent neurological manifestation with or without lymphocytic meningitis; 1 case of central vestibular syndrome with a hyperalgesic meningoradicular reaction in the vicinity of the tick bite; 1 case of peripheral radicular involvement and intense pain in the left lower limb; 4 cases of ocular disorders (3 diplopias, 1 bilateral conjunctivitis complicated by kerato-uveitis, 1 bilateral complete cecitis). Only 10 child had rheumatological symptoms, i.e., Lyme arthritis of the right knee. Treatment consisted of amoxicillin (10 children) administered at a dosage of 50 to 100 mg/kg/d over a period ranging from 10 days to 1 month, or ceftriaxone (7 children) at a dosage of 50 to 100 mg/kg/d administered intravenously over a period ranging from 8 days to 3 weeks. Two of the children received combined antibiotic therapy, and 5 subjects had adjunct corticotherapy.

Perceived vertical and lateropulsion: clinical syndromes, localization, and prognosis.

We present a clinical classification of central vestibular syndromes according to the three major planes of action of the vestibulo-ocular reflex: yaw, roll, and pitch. The plane-specific syndromes are determined by ocular motor, postural, and perceptual signs. Yaw plane signs are horizontal nystagmus, past pointing, rotational and lateral body falls, deviation of perceived straight-ahead to the left or right. Roll plane signs are torsional nystagmus, skew deviation, ocular torsion, tilts of head, body, and perceived vertical in a clockwise or counterclockwise direction. Pitch plane signs are upbeat/downbeat nystagmus, forward/backward tilts and falls, deviations of the perceived horizon. The thus defined vestibular syndromes allow a precise topographic analysis of brainstem lesions according to their level and side. Special emphasis is placed on the vestibular roll plane syndromes of ocular tilt reaction, lateropulsion in Wallenberg's syndrome, thalamic and cortical astasia and their association with roll plane tilt of perceived vertical. Recovery is based on a functionally significant central compensation of a vestibular tone imbalance, the mechanism of which is largely unknown. Physical therapy may facilitate this central compensation, but this has not yet been proven in prospective studies.

Direction-specific impairment of motion perception and spatial orientation in downbeat and upbeat nystagmus in humans

Downbeat and upbeat nystagmus can be classified as central vestibular syndromes in the vertical (pitch) plane of the vestibulo-ocular reflex (VOR) which are defined by ocular motor, perceptual, and postural manifestations. While the ocular motor syndrome was often studied investigations on the perceptual consequences for spatial orientation and motion perception are rare. Subjective visual straight ahead (SVA) and perception of object motion were measured in 11 patients with downbeat ( n=6) and upbeat ( n=5) nystagmus. Upward deviations of SVA (median +5.2°) were found in downbeat nystagmus, and downward deviations (median −7.8°) in upbeat nystagmus. SVA was deviated toward the slow phase of the vertical nystagmus in the pitch plane and associated with increased fore-aft body sway. Perception of object motion was more severely impaired for vertical (particularly for motion in the direction of slow nystagmus phases) than for horizontal directions in both downbeat and upbeat nystagmus. Impairment of motion perception in the vertical pitch plane of the VOR is beneficial to the extent that it alleviates disturbing oscillopsia due to the involuntary retinal slip. Thus, our findings confirm the hypothesis that downbeat and upbeat nystagmus reflect a central tone imbalance of the VOR in the vertical pitch plane with ocular motor, postural, and perceptual manifestations.

Central vestibular syndromes in roll, pitch, and yaw planes: Topographic diagnosis of brainstem disorders

Evidence is presented for a clinical classification of central vestibular syndromes according to the three major planes of action of the vestibulo-ocular reflex (VOR): yaw, pitch, and roll. The plane-specific vestibular syndromes are determined by ocular motor, postural, and perceptual signs. Roll plane signs are: torsional nystagmus, skew deviation, ocular torsion, tilts of head, body, and perceived vertical; pitch plane signs are: upbeat/downbeat nystagmus, forward/backward tilts and falls, deviations of perceived horizontal; yaw plane signs are: horizontal nystagmus, past pointing, rotational and lateral body falls, deviation of perceived straight-ahead. The thus defined VOR syndromes allow for a precise topographic diagnosis of brainstem lesions as to their level and side. A tone imbalance in roll indicates unilateral lesions (ipsiversive at pontomedullary level, contraversive at pontomesencephalic level). A tone imbalance in pitch indicates bilateral (paramedian) lesions or bilateral dysfunction of t...

Vestibular syndromes in the roll plane: Topographic diagnosis from brainstem to cortex

Central vestibular syndromes may be classified according to the three major planes of action of the vestibuloocular reflex, secondary to a lesional tone imbalance in either the horizontal yaw plane or the vertical pitch or roll plane. The clinical signs, both perceptual and motor, of a vestibular tone imbalance in the roll plane are ocular tilt reaction (OTR), ocular torsion, skew deviation and tilts of the perceived visual vertical (SVV). Either complete OTR or skew torsion without head tilt indicates a unilateral peripheral deficit of otolith input or a unilateral lesion of graviceptive brainstem pathways from the vestibular nuclei (crossing midline at the pontine level) to the interstitial nucleus of Cajal (INC) in the rostral midbrain. SVV tilts are the most sensitive sign of a vestibular tone imbalance in roll and occur with peripheral or central vestibular lesions from the labyrinth to the vestibular cortex. All tilt effects, perceptual, ocular motor and postural, are ipsiversive (ipsilateral eye undermost) with unilateral peripheral or pontomedullary lesions below the crossing of the graviceptive pathways. All tilt effects are contraversive (contralateral eye undermost) with unilateral pontomesencephalic brainstem lesions and indicate involvement of the medial longitudinal fasciculus or the rostral midbrain (INC). Unilateral lesions of vestibular structures rostral to the INC typically manifest with deviations of perceived vertical without concurrent eye-head tilt. OTR in unilateral paramedian thalamic infarctions indicates simultaneous ischemia of the paramedian rostral midbrain including the INC. Unilateral lesions of the posterolateral thalamus can cause thalamic astasia and moderate ipsiversive or contraversive SVV tilts, thereby indicating involvement of the vestibular thalamic subnuclei. Unilateral lesions of the parietoinsular vestibular cortex cause moderate, mostly contraversive SVV tilts. An SVV tilt found with monocular but not with binocular viewing is typical for a trochlear or oculomotor palsy rather than a supranuclear graviceptive brainstem lesion.

MAN IN MOTION

This is a review of selected aspects of the history of the vestibular system (J. E. Purkyne, E. Mach, A. Crum-Brown) and of our current understanding of vestibular malfunction in clinical vertigo syndromes. Evidence is presented for a preliminary classification of central vestibular brainstem syndromes according to the three major planes of action of the vestibulo-ocular reflex (VOR): (1) disorders of the VOR in the horizontal (yaw) plane (horizontal nystagmus, pseudo 'vestibular neuritis'); (2) disorders of the VOR in the sagittal (pitch) plane (downbeat nystagmus; upbeat nystagmus); (3) disorders of the VOR in the frontal (roll) plane (ocular tilt reaction; lateropulsion). The pathophysiology of peripheral vestibular disorders is discussed: a specific gravity differential between the cupula fluid and the endolymph (buoyancy mechanism) causes vertigo in benign paroxysmal positioning vertigo and positional alcohol nystagmus. Vestibular neuritis is probably a partial unilateral vestibular paralysis due to viral infection of the superior division of the nerve trunk. The common post-traumatic vertigo is explained by otolith dysfunction secondary to dislodged otoconia resulting in unequal loads on the macula beds and a tonus imbalance between the two otoliths.

Meningioma in a woodchuck exhibiting central vestibular deficits.

An 11-yr-old captive-raised male woodchuck (Marmota monax) presented with ataxia, poor balance, left-sided weakness, circling to the left and nystagmus with the fast-phase directed towards the left. The clinical signs were compatible with a central vestibular deficit syndrome. Necropsy and histologic findings revealed a meningotheliomatous meningioma centered over the ventrolateral left pons and medulla along with acute bronchopneumonia, chronic glomerulopathy, interstitial nephritis, and phthisis bulbi.