Eye Movements in a Familial Vestibulocerebellar Disorder

Abstract

Eye movement abnormalities consisting of poor or absent smooth pursuit and vestibulo-ocular reflex suppression, gaze-paretic and rebound nystagmus, slow build-up of optokinetic nystagmus, mildly hyperactive vestibulo-ocular reflex, and a high incidence of strabismus were inherited in an autosomal dominant fashion in 10 members of a non-consanguineous English caucasian family. The onset was in early childhood, but was not congenital. In 7 cases there was no tremor, dizziness, consistent ataxia, or other cerebellar signs that are often associated with these ocular motor deficits, and apart from strabismus, patients were asymptomatic. Magnetic resonance imaging of the propositus was normal. After childhood there appears to be no progression, with the oldest affected member being 40 years. Two members had been prone to falling in childhood, and one admitted to dizziness when tired. This condition, which is probably benign, has not been previously described and may represent a very mild variant of episodic ataxia or a new vestibulocerebellar syndrome.

Familial vestibulocerebellar disorder maps to chromosome 13q31-q33: a new nystagmus locus

“…The clinical features of this family have been previously described 6 and are further summarised in table 1. In brief, the affected subjects nearly all acquired an eye movement disorder within the first two years of life.…”

“…As described previously, the type of nystagmus most resembles that seen in acquired vestibulocerebellar disorders, rather than congenital or latent types. 6 We previously proposed either a novel condition or an unusually benign variant of one of the dominant ataxias. 6 Our results now confirm the existence of a locus on chromosome 13q31-q33 that does not correspond to any known existing gene or locus responsible for either congenital nystagmus or the cerebellar ataxias.…”

“…The family was initially published several years ago, but the pedigree has enlarged since that time (OMIM 193003). 6 Although similar eye movement disorders have been described in dominantly inherited conditions such as the group of spinocerebellar atrophies (SCA), the early onset and lack of progression or other neurological features make these other diagnoses unlikely. The features bear some resemblance to the condition autosomal dominant episodic ataxia, which represents several clinical entities.…”

Expression of a novel splice variant of FRMD7 in developing human fetal brains that is upregulated upon the differentiation of NT2 cells

“…The vestibulocerebellum primarily regulates balance and spatial orientation. Any damage in this area causes disturbances in balance and gait (26), as well as nystagmus (27,28). These results indicate that the expression of the FRMD7 _ SV2 gene exhibits spatially and temporally restricted distribution in the human fetal brain, indicating that the majority of FRMD7 _ SV2 functions are associated with cerebellum development.…”

Movimentos oculares no bebê: o que eles nos indicam sobre o status oftalmológico e neurológico

“…Displasias corticais e lesões cerebelares podem contribuir para levar a alterações nos movimentos optocinéticos (Harris, Walker, & Shawkat, 1993). Assimetria do nistagmo optocinético tem sido descrita em crianças de 4-5 meses de idade com lesões parietais .…”