Somatosensory impairment and its association with balance limitation in people with multiple sclerosis

Background: Somatosensory impairments are common in multiple sclerosis. However, little data are available to characterize the nature and frequency of these problems in people with multiple sclerosis. Objective: To investigate the frequency of somatosensory impairments and identify any association with balance limitations in people with multiple sclerosis. Methods: The design was a prospective cross-sectional study, involving 82 people with multiple sclerosis and 30 healthy controls. Tactile and proprioceptive sensory acuity were measured using the Rivermead Assessment of Somatosensory Performance. Vibration duration was assessed using a tuning fork. Duration for the Timed Up and Go Test and reaching distance of the Functional Reach Test were measured to assess balance limitations. The normative range of sensory modalities was defined using cut-off points in the healthy participants. The multivariate linear regression was used to identify the significant predictors of balance in people with multiple sclerosis. Results: Proprioceptive impairments (66.7%) were more common than tactile (60.8%) and vibration impairments (44.9%). Somatosensory impairments were more frequent in the lower limb (78.2%) than the upper limb (64.1%). All sensory modalities were significantly associated with the Timed Up and Go and Functional Reach tests (p < 0.05). The Timed Up and Go test was independently predicted by the severity of the neurological lesion, Body Mass Index, ataxia, and tactile sensation (R2 = 0.58), whereas the Functional Reach test was predicted by the severity of the neurological lesion, lower limb strength, and vibration sense (R2 = 0.49). Conclusions: Somatosensory impairments are very common in people with multiple sclerosis. These impairments are independent predictors of balance limitation.