Head position during resting modifies spontaneous daytime decrease of downbeat nystagmus.

BACKGROUND: The intensity of downbeat nystagmus (DBN) decreases during the daytime when the head is in upright position. OBJECTIVE: This prospective study investigated whether resting in different head positions (upright, supine, prone) modulates the intensity of DBN after resting. METHODS: Eye movements of 9 patients with DBN due to cerebellar (n = 2) or unknown etiology (n = 7) were recorded with video-oculography. Mean slow-phase velocities (SPV) of DBN were determined in the upright position before resting at 9 am and then after 2 hours (11 am) and after 4 hours (1 pm) of resting. Whole-body positions during resting were upright, supine, or prone. The effects of all 3 resting positions were assessed on 3 separate days in each patient. RESULTS: Before resting (9 am), the average SPV ranged from 3.05 °/s to 3.6 °/s on the separate days of measurement. After resting in an upright position, the average SPV at 11 am and 1 pm was 0.65 °/sec, which was less (p < 0.05) than after resting in supine (2.1 °/sec) or prone (2.22 °/sec) positions. CONCLUSION: DBN measured during the daytime in an upright position becomes minimal after the patient has rested upright. The spontaneous decrease of DBN is less pronounced when patients lie down to rest. This indicates a modulation by otolithic input. We recommend that patients with DBN rest in an upright position during the daytime. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that for patients with DBN 2 hours of rest in the upright position decreases nystagmus more than 2 hours of rest in the supine or prone positions (relative improvement 79% upright, 33% supine, and 38% prone: p < 0.05).

A bucket of static vestibular function.

OBJECTIVE: Validation of a bedside test to measure the monocular and binocular subjective visual vertical (SVV). METHODS: Monocular and binocular measurements of the SVV were made in 30 healthy subjects (mean age 46.1 +/- 16.4 years) and 30 patients with acute peripheral or central vestibular lesions (mean age 51.3 +/- 17.1 years). The established method uses a hemispheric dome (adjustment of a bar to the vertical without spatial orientation clues in a motor-driven, hemispheric dome randomly covered with colored dots). It was compared to a simple, self-made bucket method, in which the subject estimates true verticality by attempting to properly align a straight line visible on the bottom of a bucket that is rotated at random by the examiner. RESULTS: Comparative measurements of the whole group (n = 60) showed no difference in the distribution of monocular or binocular SVV values while using the hemispheric dome or the bucket method. Intertest reliability was 89% for monocular and 90% for binocular SVV measurements. Intratest reliability of the bucket method in 10 repetitions was 92% for binocular and monocular SVV determinations. With the bucket method, the range of absolute deviations of SVV values from true verticality in healthy subjects was 1.1 +/- 0.7 degrees for monocular and 0.9 +/- 0.7 degrees for binocular measurements (mean +/- SD). There was no significant effect of age or gender. CONCLUSIONS: The bucket method is an easily performed and reliable bedside test for determining monocular and binocular subjective visual vertical. The bucket can be modified within 1 hour and costs less than $5.

[Pharmacotherapy of central oculomotor disorders]. / Pharmakotherapie zentraler Nystagmusformen.

Nystagmus causes blurred vision due to oscillopsia, as well as impaired balance. Depending on etiology, additional cerebellar and brain stem signs may occur. We present the current pharmacotherapy of the most common forms of central nystagmus: downbeat nystagmus (DBN), upbeat nystagmus (UBN), acquired pendular nystagmus (APN), and congenital nystagmus (CGN). Recommended medical therapies are aminopyridines (4-AP) for DBN and UBN, gabapentin and memantine for CGN and APN, and baclofen for periodic alternating nystagmus (PAN).

Follow-up of vestibular function in bilateral vestibulopathy.

OBJECTIVE: Bilateral vestibulopathy (BV) leads to a bilateral deficit of the vestibulo-ocular reflex and has various aetiologies. The main goal of this study was to determine the frequency and degree of recovery or worsening of vestibular function over time. METHODS: 82 patients (59 males, 23 females; mean age at the time of diagnosis 56.3 (SD 17.6) years) were re-examined 51 (36) months after the first examination. All patients underwent a standardised neuro-ophthalmological and neuro-otological examination. Electronystagmography with bithermal caloric irrigation was analysed by measurement of the mean peak slow phase velocity (SPV) of the induced nystagmus. Patients evaluated the course of their disease in terms of balance, gait unsteadiness and health related quality of life. RESULTS: Statistical analysis of the mean peak SPV of caloric induced nystagmus revealed a non-significant worsening over time (initial mean peak SPV 3.0 (3.5) degrees/s vs 2.1 (2.8) degrees/s). With respect to subgroups of aetiology, only patients with BV due to meningitis exhibited an increasing, but non-significant SPV (1.0 (1.4) degrees/s vs 1.9 (1.6) degrees/s). Vestibular outcome was independent of age, gender, time course of manifestation and severity of BV. Single analysis of all patients showed that a substantial improvement > or = 5 degrees/s occurred in two patients on both sides (idiopathic n = 1, Sjögren's syndrome n = 1) and in eight patients on one side (idiopathic n = 6, meningitis n = 1, Menière's disease n = 1). In 84% of patients there was impairment of their health related quality of life (42% slight, 24% moderate, 18% severe). Forty-three per cent of patients rated the course of their disease as stable, 28% as worsened and 29% as improved. CONCLUSIONS: Our data support the view that more than 80% of patients with BV do not improve. Thus the prognosis of BV is less favourable than assumed.

Phobic postural vertigo--a long-term follow-up (5 to 15 years) of 106 patients.

One hundred and six patients diagnosed between 1987 and 1998 to have somatoform phobic postural vertigo were examined in a follow-up study with a self-evaluating questionnaire. The improvement rate after a mean follow-up time of 8.5 years (5 to 15.9 years) was 75% (27% of the patients reported a complete remission). While the majority of these patients experienced improvement or remission during the first year after assessment of diagnosis and a short-term psychotherapeutic approach, some patients also had considerable improvement even after two or more years. There was a negative correlation between the duration of the condition before assessment of the diagnosis and the improvement/regression rate. The improvement/regression rate was independent of gender, age, preceding vestibular or non-vestibular organic disorders, and the various medical, physical, or psychotherapeutic interventions. Transient relapses occurred in 47% of the improved patients once or repeatedly. The probability of developing a relapse remained constant throughout the entire follow-up. None of the patients required a revision of the initial diagnosis on the basis of the questionnaire.

[The most common form of dizziness in middle age: phobic postural vertigo]. / Häufigste Schwindelform im mittleren Alter: phobischer Schwankschwindel.

Up to now, there have been only a few valid epidemiological investigations of dizziness or vertigo as key symptoms. According to an analysis of 4,214 patients examined between 1989 and 2002 in an outpatient dizziness unit, benign peripheral paroxysmal positional vertigo (BPPV) and phobic postural vertigo (PPV) constitute the two most frequent syndromes. In this study, the relative age and sex distribution of both disorders was analysed. In the age group from 20 to 50 years, PPV was comparatively the most frequent form of dizziness, with a share of 22% to 26%. When left untreated, PPV becomes chronic in most cases and leads to considerable impairments, also at work. However, when diagnosed correctly, it can be treated successfully in more than 70% of cases. Thus, it takes on considerable medical and socioeconomic significance and should be part of the diagnostic repertoire of every doctor.