Nerve Conduction study in Unilateral Limb Weakness Patients- A Retrospective Descriptive Analysis

Background: Limb weakness is most common complaint in neurology patients. Nerve conduction studies (NCS) help in differentiating between various classes of neuropathies, with the help of various NCS parameters. Hence, this research was planned to evaluate nerve conduction parameters in unilateral limb weakness patients. Material and Methods: This was a retrospective, descriptive research carried out in 78 unilateral limb weakness patients. We studied distal motor latency (DML), compound muscle action potential amplitude (CMAP), motor nerve conduction velocity (MNCV), F minimal latency, sensory nerve action potential amplitude (SNAP) and sensory nerve conduction velocity (SNCV) in unilateral median, ulnar, radial, suprascapular, axillary, musculocutaneous, tibial, peroneal and sural nerves using RMS-Aleron. Results: Neurophysiology data of total 78 cases was obtained. Out of those cases, 41 were upper limb and 30 were lower limb weakness cases. Among upper limb cases, motor axonal neuropathy was found in median nerve (22%), ulnar nerve (31.7%) and radial nerve (41.46%). Sensory axonal neuropathy was found in median (29.26%), ulnar and radial nerves (39% each). Motor demyelinating neuropathy was found in median nerve (9.75%), in ulnar nerve (12.19%) and radial nerve (24.39%). Sensory demyelinating neuropathy was found in median and ulnar (26.82% each), and radial nerves (39%).Among lower limb cases, motor axonal neuropathy was found in tibial in 20%, and peroneal in 60% cases. Sensory sural axonal neuropathy was found in 36.67%. Motor demyelinating neuropathy was found in tibial nerve in 10%, and peroneal involvement in 36.67% cases. Sensory sural demyelinating neuropathy was found in 20% cases. Conclusion: Axonal neuropathy was observed more frequently than demyelinating pattern in both motor and sensory nerve conduction parameters among patients with unilateral upper or lower limb weakness. Combined unilateral upper and lower limb weakness were assumed to be upper motor neuron lesion.

Keywords: Electroneurography, F waves recording, Peripheral Neuropathies, Mononeuropathy, Radial Palsy.