Cognitive functions in acute unilateral vestibular loss.

Cognitive deficits mainly involving visuospatial functions have been defined in patients with bilateral and even unilateral vestibular loss (UVL). We compared the cognitive test results of 21 patients with acute UVL with age- and education-matched healthy controls. The diagnosis of UVL was based on the clinical findings, a normal magnetic resonance imaging with diffusion-weighted sequence and canal paresis on the affected side on caloric testing. Cognitive tests assessing visuospatial functions (Benton's Judgment of Line Orientation test, Verbal and non-verbal Cancellation tests, Rey-Osterrieth Complex Figure test) and global mental status, verbal memory, learning, retention of information, and recalling (Mini Mental State Examination, Oktem Verbal Memory Process Test, Forward and Backward Digit span) were used in addition to Beck depression and Anxiety inventories. Abnormalities in verbal and non-verbal cancellation tests (p < 0.005), Benton's Judgment of Line Orientation test (p = 0.042) and backward digit span (p = 0.029) was found. A very prominent difference regarding Beck depression (p = 0.012) and anxiety inventories (p < 0.001) was present. On multiple regression analysis, the abovementioned cognitive tests' results lost their statistical significance (p > 0.05) when depression and anxiety scores were taken into consideration. The severity of canal paresis was found to be correlated with Benton's Judgment of Line Orientation test (p = 0.008, r = - 0.5639) and Rey-Osterrieth Complex Figure test copying scores (p = 0.029, r = - 0.477). Comparison of all the results in right- and left-sided lesions did not reveal a significant difference (p > 0.05). Vestibular patients are prone to develop anxiety, and depression. Deficits in visuospatial functions, mental manipulation, psychomotor speed and short-term memory detected in our patients with acute UVL seem to be enhanced by accompanying anxiety and depression. The extent of vestibular dysfunction was correlated with the severity of deficits in visuospatial skills. Lesion side did not cause alterations in cognitive or emotional status.