Electrodiagnostic Study of Cranial Nerves in Patients with Chronic Inflammatory Demyelinating Polyneuropathy

الملخص

Background: Chronic inflammatory demyelinating polyneuropathy (CIDP) is frequently misdiagnosed in nearly 50% of patients. The diagnosis is made using clinical characteristics followed by electrophysiological criteria due to a lack of consensus.

Objectives: to test for cranial nerve involvement in typical CIDP, and correlate the findings with clinical characteristics of CIDP patients. Also, to assess subclinical involvement of the cranial nerves in spite of normal neurological examination.

Methods: A case-control study of 26 patients with CIDP with duration of illness of 2-300 months and 26 age- and sex-matched healthy controls. Clinical examination includes the House-Brackmann Facial Nerve Grading System and Medical Research Council (MRC) scale for trapezius and masseter muscles. Electrophysiological study of facial, spinal accessory, and blink reflex (BR) was done.

Results: Majority of patients (80.77%) had a typical CIDP diagnosis. The motor latencies of facial and spinal accessory nerves in the patient group were noticeably longer than the controls. Similarly, the patients have significantly longer BR R1, iR2, and cR2 latencies. The disease duration and cR2, as well as spinal accessory motor latencies, were found to positively correlated. The spinal accessory and facial motor latencies were abnormal in 41 and 40 nerves, respectively in patients with normal clinical examination.

Conclusions: Patients with CIDP exhibited multiple cranial palsies. Subclinical involvement of cranial nerves was evident in 3 quarters of the patients. Disease duration had favourable relationship with BR and spinal accessory parameters.