Characteristics and correlates of sensory function in chronic inflammatory demyelinating polyneuropathy

Sensory assessments are included in clinical and research practice in chronic inflammatory demyelinating polyneuropathy (CIDP). However, their characteristics and relevance in relation to motor involvement and function have rarely been studied.

To investigate the characteristics and correlates of sensory function in CIDP.

We evaluated the sensory clinical and electrophysiological features in 31 clinically-stabilized, prospectively recruited, CIDP patients and analyzed their relation with motor strength and function as well as with electrophysiology.

Sensory function primarily affected large fibres and was predominant in the lower limbs. Sensory Sum Scores (SSS) correlated with Medical Research Council (MRC) motor scores, Overall Neuropathy Limitation Scores (ONLS) and presence of positive sensory symptoms, in upper and lower limbs. Rydel-Seiffer vibration scores correlated with MRC and ONLS scores, in the lower limbs only. Correlations of SSS with sensory nerve action potential (SNAP) amplitudes and summated compound muscle action potential (CMAP) amplitudes, were present in the lower limbs but not in the upper limbs, whereas such correlations were ascertained in all extremities for Rydel-Seiffer scores. SNAPs correlated with ONLS scores exclusively in the legs.

These results show that sensory involvement relates to motor function in CIDP, suggesting that the disease activity affects concurrently motor and sensory fibres in the disorder. The findings of this cross-sectional analysis may otherwise suggest the practical reliability and usefulness of clinical sensory scores, particularly the SSS, in monitoring disease progression and effects of treatment in the disorder. Further longitudinal study is required to confirm this.