Evaluation of Nerve Conduction Parameters in Patients with Primary Hypothyroidism: A Cross-Sectional Study in a Tertiary Care Hospital

Background: As neuromuscular dysfunction is associated with hypothyroidism, the nerve conduction parameters are expected to be altered in these patients. Early electrophysiological diagnosis of neuropathy can help clinicians to determine the extent of disease and the course of the treatment. A very few similar studies have been done in eastern India. Materials & Methods: History regarding the duration of the disease, clinical and neurological complaints, and the use of medicines and the level of control of hypothyroidism were recorded on the history record sheet. After history taking, a general clinical examination was done. Then, a neurological examination was conducted with special attention. Neuro-MEP-Micro (version 2009) Machine and its accessories (Manufactured by Neurosoft Medical Diagnostics Limited, Ivanova, Russia). Electrophysiological parameters like nerve conduction study parameters (latency, amplitude, conduction velocity of bilateral median and ulnar motor nerves and median and ulnar sensory nerves) were recorded. Biochemical parameters like T3, T4, and TSH values were recorded from patients’ test reports and from Endocrinology OPD prescriptions. Results: The study showed that the mean (±SD) of distal motor latency (DML) of bilateral median motor nerves was significantly increased in cases than that of the control. Mean (±SD) of compound Muscle Action Potential of bilateral median motor nerves was significantly decreased in cases than that of the control. It shows the mean (±SD) of Distal Motor Latency (DML) of bilateral ulnar motor nerves was significantly increased in cases than that of the control. Mean (±SD) of compound muscle action potential of both ulnar motor nerves was significantly decreased in cases than that of the control. MNCV of both-sided median nerves and the ulnar nerves showed a significant decrease in their means as compared to the control. Similarly Distal sensory latency (DSL) of the bilateral median and the Ulnar sensory nerves was significantly increased in cases than in controls. There was a significant decrease in bilateral median and ulnar sensory nerve action potential amplitude (SNAP) in the cases compared to the controls. SNCV of bilateral median and ulnar sensory nerves were significantly reduced in cases as compared to controls. Similarly, the left median SNCV of the cases were significantly (p value < 0.05) less than that of the controls. Conclusion: The motor and sensory amplitudes of both-sided median and ulnar nerves were significantly decreased in cases compared to the control. The motor conduction velocity of both-sided median and ulnar nerves and the sensory conduction velocity of the median and ulnar nerves were significantly decreased in cases as compared to controls. There is no significant correlation between nerve conduction study parameters and the duration of the disease in hypothyroid patients.