Spinal cord dysfunction contributes to balance impairment in multiple sclerosis patients

Balance impairment is very common in multiple sclerosis (MS) but its causes are still unclear. Some studies suggest that balance deficit originates mainly from damage in specific locations of the central nervous system such as cerebellum and spinal cord, that are involved in transmission and integration of sensory inputs and motor outputs. The aim of this study is to investigate the contribution of spinal cord to MS-related imbalance, by combining neurophysiologic and neuroimaging techniques.

Balance performance was correlated with clinical, neurophysiological and MRI findings. The functionality of spinal cord was tested by somatosensory (SEP) and motor (MEP) evoked potentials. MRI was used to identify spinal and cerebellar lesions. Balance performance was assessed by Tinetti Scale (TS). Clinical disability was measured by EDSS.

38 patients were included. Linear regression model revealed significant negative correlations between TS and EDSS scores, between TS and cervical lesions, and between TS and SEP findings.

Our study, by combining neurophysiologic and neuroimaging techniques, confirms that spinal cord plays an important role for balance control and that its dysfunction, especially in lower limbs somatosensory ascending pathways conveying proprioceptive information, contributes to balance impairment in MS patients.