Vestibular Impairment in Frontotemporal Dementia Syndrome

BACKGROUND: No studies to date have attempted to evaluate frontotemporal lobar degeneration from the perspective of the vestibular system. OBJECTIVE: The present study examined vestibular function in patients with frontotemporal dementia (FTD) clinical syndrome and evaluated whether vestibular disorders are involved in the clinical symptoms due to FTD. METHODS: Fourteen patients with FTD syndrome, as well as healthy elderly controls without dementia, were included in the present study. All subjects underwent vestibular function tests using electronystagmography, such as caloric tests and visual suppression (VS) tests, in which the induced caloric nystagmus was suppressed by visual stimuli. The association between clinical symptoms and vestibular function in the FTD syndrome group was further examined. RESULTS: In the FTD syndrome group, caloric nystagmus was not necessarily suppressed during VS tests. Furthermore, VS was observed to be significantly impaired in FTD syndrome patients with gait disturbance as compared to those without such disturbance. CONCLUSION: The present study revealed that impairment of VS in patients with FTD results in an inability to regulate vestibular function by means of visual perception, regardless of multiple presumed neuropathological backgrounds. This could also be associated with gait disturbance in patients with FTD syndrome.