Which medication do I need to manage dizzy patients?

Vertigo and dizziness are not independent disease entities, but instead symptoms of various diseases. Accordingly, a variety of treatment approaches are required. Here we review the most relevant drugs for managing dizziness, vertigo, and nystagmus syndromes. It is important to differentiate symptomatic treatment of nausea and vomiting with, for example, dimenhydrinate and benzodiazepines, and prophylactic treatment of motion sickness with scopolamine from a causal therapy of the underlying disorders. Examples of such causal therapy include aminopyridines for downbeat nystagmus and episodic ataxia type 2; carbamazepine for vestibular paroxysmia, paroxsymal dysarthria and ataxia in multiple sclerosis, and superior oblique myokymia; betahistine, dexamethasone, and gentamicin for Menière's disease; gabapentin and memantine for different forms of acquired and congenital nystagmus; corticosteroids for acute vestibular neuritis and Cogan's syndrome; metoprolol and topiramate for vestibular migraine; and selective serotonin reuptake inhibitors such as paroxetine for phobic postural vertigo. The clinical entities are briefly described, the various medications are discussed in alphabetical order, and dosage, major side effects, contraindications, and alternative medications of each drug are displayed in boxes for easy reference.

Latency of herpes simplex virus type-1 in human geniculate and vestibular ganglia is associated with infiltration of CD8+ T cells

Herpes simplex virus type-1 latency and CD8+ T-cell occurrence were investigated in the trigeminal, geniculate, and vestibular ganglia from seven deceased humans. The HSV-1 "latency-associated transcript" was assessed by in situ hybridization and quantitative RT-PCR. Infiltration of CD8+ T cell was detected by immunohistochemistry and quantitative RT-PCR. The data show that HSV-1 latency and CD8+ T-cell infiltration are not solely confined to the trigeminal ganglia but can also occur in other cranial ganglia along the neuroaxis. However, the HSV-1 latency transcripts in the geniculate and vestibular ganglia were expressed at a very low level. The difference in CD8 transcript levels among HSV-1 latently infected trigeminal ganglia, geniculate, and vestibular ganglia was less conspicuous. Colocalization of latent HSV-1 and CD8+ T cells in geniculate and vestibular ganglia supports further the hypothesis that HSV-1 reactivation is possible in these ganglia and is the cause of Bell's palsy and vestibular neuritis.

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).

The disturbance of gaze in progressive supranuclear palsy: implications for pathogenesis

Progressive supranuclear palsy (PSP) is a disease of later life that is currently regarded as a form of neurodegenerative tauopathy. Disturbance of gaze is a cardinal clinical feature of PSP that often helps clinicians to establish the diagnosis. Since the neurobiology of gaze control is now well understood, it is possible to use eye movements as investigational tools to understand aspects of the pathogenesis of PSP. In this review, we summarize each disorder of gaze control that occurs in PSP, drawing on our studies of 50 patients, and on reports from other laboratories that have measured the disturbances of eye movements. When these gaze disorders are approached by considering each functional class of eye movements and its neurobiological basis, a distinct pattern of eye movement deficits emerges that provides insight into the pathogenesis of PSP. Although some aspects of all forms of eye movements are affected in PSP, the predominant defects concern vertical saccades (slow and hypometric, both up and down), impaired vergence, and inability to modulate the linear vestibulo-ocular reflex appropriately for viewing distance. These vertical and vergence eye movements habitually work in concert to enable visuomotor skills that are important during locomotion with the hands free. Taken with the prominent early feature of falls, these findings suggest that PSP tauopathy impairs a recently evolved neural system concerned with bipedal locomotion in an erect posture and frequent gaze shifts between the distant environment and proximate hands. This approach provides a conceptual framework that can be used to address the nosological challenge posed by overlapping clinical and neuropathological features of neurodegenerative tauopathies.

Structural and functional plasticity of the hippocampal formation in professional dancers and slackliners

The acquisition of special skills can induce plastic changes in the human hippocampus, a finding demonstrated in expert navigators (Maguire et al. (2000) Proc Natl Acad Sci USA 97:4,398-403). Conversely, patients with acquired chronic bilateral vestibular loss develop atrophy of the hippocampus, which is associated with impaired spatial memory (Brandt et al. (2005) Brain 128:2,732-741). This suggests that spatial memory relies on vestibular input. In this study 21 professional dancers and slackliners were examined to assess whether balance training with extensive vestibulo-visual stimulation is associated with altered hippocampal formation volumes or spatial memory. Gray matter voxel-based morphometry showed smaller volumes in the anterior hippocampal formation and in parts of the parieto-insular vestibular cortex of the trained subjects but larger volumes in the posterior hippocampal formation and the lingual and fusiform gyri bilaterally. The local volumes in the right anterior hippocampal formation correlated negatively and those in the right posterior hippocampal formation positively with the amount of time spent training ballet/ice dancing or slacklining at the time of the study. There were no differences in general memory or in spatial memory as assessed by the virtual Morris water task. Trained subjects performed significantly better on a hippocampal formation-dependent task of nonspatial memory (transverse patterning). The smaller anterior hippocampal formation volumes of the trained subjects may be the result of a long-term suppression of destabilizing vestibular input. This is supported by the associated volume loss in the parieto-insular vestibular cortex. The larger volumes in the posterior hippocampal formation of the trained subjects might result from their increased utilization of visual cues for balance. This is supported by the concomitant larger volumes in visual areas like the lingual and fusiform gyri. Our findings indicate that there is a spatial separation of vestibular and visual processes in the human hippocampus.

Long-term course of Menière's disease revisited

CONCLUSIONS

The investigated studies disclose a large variability of the many symptoms appearing in the course of Menière's disease.

OBJECTIVES

To analyze the data of 46 mostly retrospective studies (with a total of 7852 patients).

METHODS

We present a short overview of the literature on the long-term course of Menière's disease. Special emphasis is placed on the most relevant and distressing symptoms of these patients, such as vertigo attacks, vestibular and hearing function, drop attacks, and the probability of transition from unilateral to bilateral involvement.

RESULTS

The frequency of vertigo attacks diminishes within 5-10 years. Hearing loss (of about 50-60 dB) and vestibular function decrement (of about 35-50%) take place mainly in the first 5-10 years of disease. Drop attacks may occur early or late in the course of the disease, and remission is spontaneous in cmost cases. Bilaterality of the condition increases with increasing duration of the disease (up to 35% within 10 years, up to 47% within 20 years).

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.