What Is Behind Cerebellar Vertigo and Dizziness?

The differential diagnosis of vertigo or dizziness as a result of cerebellar disorders can be difficult as many patients with a cerebellar pathology do not present with the full spectrum of cerebellar signs. The main goal of this study was to describe the typical clinical features of these patients with vertigo or dizziness of a cerebellar origin. We reviewed the medical records of 5400 patients with vertigo and dizziness from our tertiary outpatient clinic for vertigo and balance disorders. In 459 the diagnosis of "cerebellar vertigo or dizziness" was made; 90 patients were excluded from further analysis due to evident structural changes in MRI. Of the remaining 369 patients (67.0 +/- 15.1, 54% female, symptom duration until diagnosis 5.5 +/- 6.9 years), 81% suffered from persistent vertigo or dizziness, 31% from attacks of vertigo and dizziness and 21% from both. Neuro-ophthalmologically, 95% had saccadic smooth pursuit, 80% gaze-holding deficits, 64% a pathological fixation suppression of the VOR, 24% central fixation nystagmus (in 64% of these cases downbeat nystagmus (DBN)), 23% rebound nystagmus, and an ocular misalignment in 84% in near view and 50% in distance view. Eleven percent had isolated mild to moderate cerebellar ocular motor disturbances without any other typical cerebellar signs. The most common diagnoses were sporadic adult-onset degenerative ataxia in 26%; idiopathic DBN syndrome in 20%; cerebellar ataxia, neuropathy, and vestibular areflexia syndrome in 10%; episodic ataxia type 2 in 7%; and multiple system atrophy cerebellar type in 6%. In posturography, a typical cerebellar 3-Hz sway was found in 16%. The diagnostic key to patients with cerebellar vertigo or dizziness is a careful examination of eye movements since practically all of them have cerebellar ocular disturbances.