Long-term course and relapses of vestibular and balance disorders.

The long-term course and the frequency of relapses for various peripheral vestibular disorders and somatoform phobic postural vertigo are discussed with respect to the clinically most important questions for thus afflicted patients. This review is mainly based on our own long-term follow-up studies and takes into consideration the most relevant literature. The following syndromes are discussed in detail. Vestibular neuritis: the recovery rate of peripheral vestibular function lies between 40-63% depending on early-onset treatment with corticosteroids; the recurrence rate within 10 years is 2%. Menière's disease} loss of auditory and vestibular function occurs mainly in the first 5 to 10 years; frequency of vertigo attacks may decline after 5 to 10 years; bilateral involvement increases with increasing duration of the condition in up to 30-50%; vestibular drop attacks may occur early or late within the course, mostly with spontaneous remission; high-dose and long-term treatment with betahistine significantly reduces attack frequency in Menière's disease, Benign paroxysmal positioning vertigo: the recurrence rate is 50% within 10 years (in females 58%, in males 39%), most recurrences (80%) being observed within the first year after initial relief; recurrence rate in the seventh decade is half of that in the sixth decade. Vestibular paroxysmia: medical treatment with carbamazepine or oxcarbazepine leads to a continuous significant reduction in attack frequency, intensity, and duration of 10-15% of baseline. Bilateral vestibulopathy: recovery of vestibular function is limited to single cases depending on their etiology. Phobic postural vertigo: within 5 to 16 years 27% of the patients are symptom-free, 48% improve, 22% remain unchanged, and 3% worsen; a detailed explanation of the mechanisms that cause and the factors that provoke attacks is imperative, as well as instructions for self-controlled desensitization within the context of behavioral therapy.

Bilateral vestibular failure as an early sign in Creutzfeldt-Jakob disease.

Bilateral vestibular failure causes dysfunction of the vestibulo-ocular reflex with consecutive symptoms like apparent movements of the visual environment during head movements (oscillopsia) and unsteady gait in darkness or on uneven ground. A definite case of Creutzfeldt-Jakob disease in which bilateral vestibular loss was one of the first clinical signs is reported. Further, in a series of 9 consecutive patients with Creutzfeldt-Jakob disease (6 probable, 3 definite), 3 had bilateral vestibular loss at initial presentation. The vestibular nuclei are known to be severely affected in animal spongiform encephalopathies. They might also be a vulnerable target in human prion diseases.

Saccular function less affected than canal function in bilateral vestibulopathy.

Bilateral vestibulopathy (BV) is characterized by impaired or lost function of both labyrinths or eighth nerves. The diagnosis is routinely established by the head-thrust test, caloric irrigation and rotational testing with electronystagmography to determine the high- and low-frequency deficit of the vestibulo-ocular reflex. All three methods evaluate semicircular canal function only. Vestibular-evoked myogenic potentials (VEMPs) provide a measure of saccular otolith function. The aim of this study was to evaluate the frequency and extent of saccular dysfunction in patients with BV and to correlate saccular with horizontal semicircular canal dysfunction. A total of 84 BV-patients (23 females, mean age 62 +/- 15 (SD) years at the time of diagnosis assessment) were examined with VEMPs, electronystagmography with caloric irrigation and a standardized neuro-ophthalmological and -otological examination; 47 healthy subjects (18 females, mean 56 +/- 19 years) served as controls. Amplitudes P1-N1 were significantly lower in patients with BV compared to controls (mean P1-N1 of all ears 82.1 +/- 50.7 microV in the patients vs. 130.8 +/- 85.9 microV in healthy volunteers). VEMPs were absent unilaterally in four patients with BV and in none bilaterally. In contrast, caloric responses were absent bilaterally in 40 patients. There was no correlation between amplitude P1-N1 and caloric-induced nystagmus. The latencies P1 and N1 were not significantly different between patients and controls. Thus, in our study population saccular function appeared to be less affected than horizontal semicircular canal function.

Nicotine-induced nystagmus correlates with midpontine activation.

The pathomechanism of nicotine-induced nystagmus (NIN) is unknown. The aim of this study was to delineate brain structures that are involved in NIN generation. Eight healthy volunteers inhaled nicotine in darkness during a functional magnetic resonance imaging (fMRI) experiment; eye movements were registered using video-oculography. NIN correlated with blood oxygen level-dependent (BOLD) activity levels in a midpontine site in the posterior basis pontis. NIN-induced midpontine activation may correspond to activation of the dorsomedial pontine nuclei and the nucleus reticularis tegmenti pontis, structures known to participate in the generation of multidirectional saccades and smooth pursuit eye movements.

Superficial cerebral and spinal haemosiderosis caused by secondary tethered cord syndrome after resection of a spinal lymphoma.

Superficial haemosiderosis results from chronic subarachnoid haemorrhage during which haemosiderin is deposited in the leptomeninges around the brain, spinal cord and cranial nerves. We describe an exceptional case of superficial haemosiderosis characterised by two special aspects. (1) The cause was a secondary tethered cord syndrome due to dural adhesions which had developed 8 years after resection of a thoracic lymphoma and (2) an explorative neurosurgical procedure with complete untethering caused normalisation of the cerebrospinal fluid and stopped disease progression.

Causative factors and epidemiology of bilateral vestibulopathy in 255 patients.

OBJECTIVE: To determine the causative factors and epidemiology of bilateral vestibulopathy (BV). METHODS: This is a retrospective review of 255 patients (mean age, 62 +/- 16 years) with BV diagnosed in our dizziness unit between 1988 and 2005. All patients had undergone a standardized neurophthalmological and neurootological examination, electronystagmography with caloric irrigation, cranial magnetic resonance imaging or computed tomography (n = 214), and laboratory tests. RESULTS: Sixty-two percent of the study population were male subjects. Previous vertigo attacks had occurred in 36%, indicating a sequential manifestation. The definite cause of BV was determined in 24% and the probable cause in 25%: The most common causes were ototoxic aminoglycosides (13%), Menière's disease (7%), and meningitis (5%). Strikingly, 25% exhibited cerebellar signs. Cerebellar dysfunction was associated with peripheral polyneuropathy in 32% compared with 18% in BV patients without cerebellar signs. Hypoacusis occurred bilaterally in 25% and unilaterally in 6% of all patients. It appeared most often in patients with BV caused by Cogan's syndrome, meningitis, or Menière's disease. INTERPRETATION: The cause of BV remains unclear in about half of all patients despite intensive examinations. A large subgroup of these patients have associated cerebellar dysfunction and peripheral polyneuropathy. This suggests a new syndrome that may be caused by neurodegenerative or autoimmune processes.

A clinical test of otolith function: static ocular counterroll with passive head tilt.

When roll-tilted around the naso-occipital axis, humans exhibit compensatory torsional rotation of the eyes in the opposite direction owing to the torsional vestibulo-ocular reflex. In the static condition (sustained head roll), the utricles act as responsible sensors for 'static ocular counterroll'. Contributions of cervico-ocular reflexes remain unknown. To find an easy, clinically useful test of utricular function, we induced ocular counterroll in 10 healthy study participants (two men, mean age 27+/-2 years) under three stimulation conditions (active/passive head tilt and passive whole body tilt in roll plane), used three-dimensional video-oculography to measure it, and compared values. Active head-tilt-induced ocular counterroll varied most and was thus less reliable than passive head and body tilt-induced ocular counterroll. Utricular function can thus be tested simply by measuring passive head tilt with video-oculography.