Sensory neuropathy as part of the cerebellar ataxia neuropathy vestibular areflexia syndrome

Abstract

Objective: The syndrome of cerebellar ataxia with bilateral vestibulopathy was delineated in 2004. Sensory neuropathy was mentioned in 3 of the 4 patients described. We aimed to characterize and estimate the frequency of neuropathy in this condition, and determine its typical MRI features. Methods:Retrospective review of 18 subjects (including 4 from the original description) who met the criteria for bilateral vestibulopathy with cerebellar ataxia. Results:The reported age at onset range was 39-71 years, and symptom duration was 3-38 years. The syndrome was identified in one sibling pair, suggesting that this may be a late-onset recessive disorder, although the other 16 cases were apparently sporadic. All 18 had sensory neuropathy with absent sensory nerve action potentials, although this was not apparent clinically in 2, and the presence of neuropathy was not a selection criterion. In 5, the loss of pinprick sensation was virtually global, mimicking a neuronopathy. However, findings in the other 11 with clinically manifest neuropathy suggested a length-dependent neuropathy. MRI scans showed cerebellar atrophy in 16, involving anterior and dorsal vermis, and hemispheric crus I, while 2 were normal. The inferior vermis and brainstem were spared.

Dorsal root ganglionopathy is responsible for the sensory impairment in CANVAS

“…1 While the initial description of a syndrome of cerebellar ataxia and bilateral vestibulopathy noted the presence of a peripheral neuropathy in 3 of the 4 index cases, we later showed that in 18 patients a peripheral nerve disease was an integral component of the syndrome we renamed cerebellar ataxia with neuropathy and bilateral vestibular areflexia syndrome (CANVAS). 2 At this time, we noted that a neuronopathy (ganglionopathy) could not be definitively excluded. Subsequently, temporal bone histopathology 1 revealed a vestibular, facial, and trigeminal sensory neuronopathy.…”

Genetics of dizziness

“…Although most cases are apparently sporadic, cerebellar ataxia with neuropathy and bilateral vestibular areflexia syndrome (CANVAS) is probably a rare, late-onset, recessive disorder characterized by cerebellar ataxia, sensory neuropathy, bilateral vestibular loss and cerebellar atrophy involving anterior and dorsal vermis [31]. The loss of sensory and vestibular functions causes a severe disability in these patients.…”

Central Vertigo

“…In 89% of patients with CANVAS syndrome (cerebellar ataxia with neuropathy and bilateral vestibular areflexia syndrome) a circumscribed atrophy of the cerebellum of the anterior and dorsal vermis and crus I was seen in MRI. 22,29 …”