Balance deficit with opened or closed eyes reveals involvement of different structures of the central nervous system in multiple sclerosis.

OBJECTIVE: To evaluate whether balance deficit in patients with multiple sclerosis (MS), as assessed with eyes opened (EO) and closed (EC), is associated with damage of different structures of the central nervous system (CNS).
METHODS: Fifty patients with MS and 20 healthy controls (HCs) underwent static posturography to calculate the body's center of pressure displacement (COP path) with EO and EC. They were scanned using a 3.0T magnet to obtain PD/T2 and 3D-T1-weighted images of the brain and spinal cord. We determined the mid-sagittal cerebellum area (MSCA) and upper cervical cord cross-sectional area (UCCA). We also measured the patients' lesion volumes (T2-LVs) on the whole brain and at different infratentorial levels.
RESULTS: MS patients had wider COP paths with both EO and EC (p < 0.001), and lower values in both MSCA (p = 0.01) and UCCA (p = 0.008) than HCs. The COP path with EO was associated with MSCA (Beta = -0.58; p = 0.004) and T2-LV on middle cerebellar peduncles (Beta = 0.59; p = 0.002). The COP path with EC was associated with UCCA (Beta= -22.74; p = 0.003) and brainstem T2-LV (Beta = 0.52; p = 0.01).
CONCLUSIONS: Balance deficit in MS was related to atrophy of both the cerebellum and spinal cord, but the extent of COP path under the two different conditions (EO or EC) implied different patterns of damage in the CNS.