Vertigo: Streamlining the Evaluation through Symptom Localization

Vertigo is defined as the illusion of internal or external motion. The evaluation of a patient with vertigo in the primary care setting should not necessarily focus on providing a specific diagnosis. Rather, the physician should aim to localize the lesion. This practice streamlines the workup of patients. This article provides detailed information regarding appropriate organ system-based clinical history and the clinical workup of vertigo. Additional signs and symptoms that can facilitate appropriate referral and treatment are highlighted. Although disorder-specific treatments exist the mainstay of therapy for vertigo-induced pathology is physical therapy.

Clinical significance of spontaneous nystagmus in pediatric patients

OBJECTIVE

To analyze spontaneous nystagmus recorded in pediatric patients and determine its diagnostic value.

MATERIALS AND METHODS

Retrospective review of 86 patients (mean age = 13.9 ± 4.7 years) with definitive spontaneous nystagmus recorded by videonystagmography (VNG). Spontaneous nystagmus was categorized and analyzed based on its characteristics. Correlations between spontaneous nystagmus and established clinical diagnoses were explored.

RESULTS

Among the patients seen in a period of three years at our pediatric vestibular clinic, 15.4% (86 out of 560) were found to have spontaneous nystagmus and half of them had horizontal nystagmus with a fixed-direction. The majority of cases with spontaneous nystagmus (77%, 66/86) were present without fixation only, while the presence of spontaneous nystagmus with and without fixation was found in 16 patients (19%). Most patients with spontaneous nystagmus without fixation only (68%) were diagnosed with a peripheral vestibular disorder (e.g., vestibular neuritis) or vestibular migraine. In contrast, vertical nystagmus was found in 15 patients, most of whom had central vestibular disorders. Other rare forms of nystagmus or abnormal eye movements, such as pendular nystagmus, ocular oscillation or flutter were recorded in only four patients.

CONCLUSIONS

Spontaneous nystagmus in children and young adults with possible vestibular impairments may vary in clinical presentation. Identification of its characteristics may help to make an accurate clinical diagnosis. While spontaneous nystagmus associated with peripheral vestibular disorders can be readily recognized, spontaneous nystagmus in pediatric patients with vestibular migraine appears to be more complex and variable in form.

Update on the pharmacotherapy of cerebellar and central vestibular disorders

An overview of the current pharmacotherapy of central vestibular syndromes and the most common forms of central nystagmus as well as cerebellar disorders is given. 4-aminopyridine (4-AP) is recommended for the treatment of downbeat nystagmus, a frequent form of acquired persisting fixation nystagmus, and upbeat nystagmus. Animal studies showed that this non-selective blocker of voltage-gated potassium channels increases Purkinje cell excitability and normalizes the irregular firing rate, so that the inhibitory influence of the cerebellar cortex on vestibular and deep cerebellar nuclei is restored. The efficacy of 4-AP in episodic ataxia type 2, which is most often caused by mutations of the PQ-calcium channel, was demonstrated in a randomized controlled trial. It was also shown in an animal model (the tottering mouse) of episodic ataxia type 2. In a case series, chlorzoxazone, a non-selective activator of small-conductance calcium-activated potassium channels, was shown to reduce the DBN. The efficacy of acetyl-DL-leucine as a potential new symptomatic treatment for cerebellar diseases has been demonstrated in three case series. The ongoing randomized controlled trials on episodic ataxia type 2 (sustained-release form of 4-aminopyridine vs. acetazolamide vs. placebo; EAT2TREAT), vestibular migraine with metoprolol (PROVEMIG-trial), cerebellar gait disorders (sustained-release form of 4-aminopyridine vs. placebo; FACEG) and cerebellar ataxia (acetyl-DL-leucine vs. placebo; ALCAT) will provide new insights into the pharmacotherapy of cerebellar and central vestibular disorders.