Are white matter abnormalities associated with “unexplained dizziness”?

INTRODUCTION Although cerebral small vessel disease is a significant contributor to the development of imbalance and falls in the elderly, whether it causes dizziness is not known. METHODS A retrospective case analysis was conducted for 122 dizzy patients referred to two neuro-otology tertiary centres in London and Pisa. Patients were divided into 'explained' causes of dizziness (e.g. benign positional vertigo, vestibular neuritis, orthostatic hypotension, cerebellar ataxias) and 'unexplained' dizziness. White matter hyperintensities (WMH) in MRI (T2 weighted and FLAIR sequences) were blindly rated according to the Fazekas scale. RESULTS 122 patients; 58 (mean age=72, SD=7.95 years) in the 'unexplained' group and 64 (mean age=72.01, SD=8.28 years) in the 'explained' group were recruited. The overall frequency of lesions (Fazekas 1-3) significantly differed between groups (p=0.011). The frequency of severe lesions (Fazekas 3) was significantly higher in the 'unexplained' group (22%) than in the 'explained' group (5%; p=0.003). CONCLUSION Increased severity of WMH in cases of unexplained dizziness suggests that such abnormalities are likely contributory to the development of dizziness. WM lesions may induce dizziness either because patients perceive a degree of objective unsteadiness or by a disconnection syndrome involving vestibular or locomotor areas of the brain.