Vestibular pathology and spatial working memory

Thanks to wide central connections the vestibular system is not merely involved in reflexes, but it is also connected to cognitive processes. A growing body of literature suggests that it has a substantial impact on cognitive function. These cognitive interactions include memory, attention, mental imagery, body awareness and social cognition. Spatial working memory (SWM) is a kind of short-term memory that allows to temporarily store and manipulate spatial information. It has a limited capacity and is quite vulnerable to interference. The single most important nonverbal task for assessment of visuo-spatial working memory (VSWM) is the Corsi block tapping task (CBTT), also known as the Corsi Span Test. We evaluated 263 patients suffering from chronic unilateral or bilateral vestibular loss (VL) by eCorsi Block-Tapping test before and after 5 days of instrumental vestibular training (IVT). The data were compared with those of 834 subjects submitted to the same test: 430 healthy people (HP) and 404 patients suffering from chronic VL but not treated by IVT. At all ages, the Corsi block test score was extremely statistically significantly higher (p < 0.0001) in HP than in both groups of VL. The score showed a statistically significant difference with age and sex in healthy subjects as younger males obtained the best results. Our study confirms the significant interference of the vestibular input on VSWM and impairment of this cognitive function in patients suffering from chronic UL or BIL. It also shows that IVT is able to improve VSWM even in cases where the deficit is greater.