Brachial plexopathy: a clinical and electrophysiological study.

BACKGROUND

A retrospective study to evaluate the clinical and electrophysiological profile of brachial plexus lesions in a tertiary care center of India.

METHODS

Thirty eight patients with brachial plexopathy (idiopathic or traumatic) with detailed electrophysiological studies were sampled. This included detailed motor and sensory nerve conduction studies of the conventional median, ulnar and radial nerves of the upper limbs, CMAP from deltoid, biceps and triceps on stimulating the ERB's point, needle EMG in the appropriate muscles and paraspinal muscles. The electrophysiological studies were performed on both sides irrespective of the clinical involvement and were recorded within 1.61 +/- 2.89 months in idiopathic group and 2.11 +/- 2.65 months in traumatic plexopathy group. The severity of involvement was assessed on MRC scale. ADL scale was used to assess the disability at presentation and subsequent follow up.

RESULTS

12 patients (11 male and 01 female) had idiopathic brachial plexopathy and 26 patients (all male) had traumatic brachial plexopathy. In the idiopathic group the lesion was localized to upper trunk in 58.3% of patients and middle trunk (posterior cord) in 41.66% and none had lower trunk or diffuse involvement. 25% had bilateral involvement. Two patients (16.6%) with idiopathic plexitis had recurrence involving the opposite side during the follow up. In the traumatic group the lesion was localized to the upper trunk in 11.53%, middle trunk (posterior cord) in 57.69% and 30.76% of patients had diffuse involvement. All the patients in traumatic plexopathy group had severe disability while in idiopathic group 91.66% had severe disability and 8.33% had moderate disability. Low amplitude CMAP and F wave abnormality were seen in 16.6% of patients in idiopathic group. On needle EMG 83.3% had fasciculation or fibrillations while none had paraspinal EMG abnormality. In traumatic group low to absent CMAP was seen in 69.2% and 76.92% had F wave abnormality. SNAPs were not recordable in 53.8%. On Needle EMG all the patients showed fasciculation or fibrillations and only 6 (23.0%) had paraspinal muscle fibrillations. Root avulsion could be documented in only four of these cases on MR imaging.

CONCLUSIONS

Recovery in the traumatic group correlated well with the electrophysiological abnormalities while no such correlation was evident in the idiopathic group.