Acute brachial diplegia due to Lyme disease.

OBJECTIVE

to describe acute brachial diplegia as the initial manifestation of Lyme disease.

BACKGROUND

bilateral, predominantly motor, cervical radiculoplexus neuropathy, the "dangling arm syndrome," has not been reported as a complication of acute Lyme infection.

METHODS

retrospective series of 5 patients from 2 tertiary neuromuscular centers.

RESULTS

there were 4 men and 1 woman with an average age of 69 years. One recalled a tick bite, and preceding constitutional symptoms included headache (2) and fever, arthralgias, and fatigue in 1 patient each. Proximal arm weakness and acute pain developed within 3 weeks from onset; pain was bilateral in 3 patients and unilateral in 2 patients, and was described as severe throbbing. Arm weakness was bilateral at onset in 3 patients, and right sided in 2 patients followed by spread to the left arm within days. All the patients had weakness in the deltoid and biceps that was 3/5 or less (Medical Research Council scale), with variable weakness of the triceps and wrist extensors; 1 patient had a flail right arm and moderate (4/5) weakness of the proximal left arm muscles. Light touch was normal in the regions of weakness, and 1 patient had mildly reduced pin sensation over the forearm. Serum IgM Lyme titers were elevated in all the patients and were detected in the cerebrospinal fluid in 4 tested patients. The cerebrospinal fluid protein ranged between 135 and 176 mg/dL with lymphocytic pleocytosis (range, 42 to 270 cells). Electrodiagnostic studies showed normal median and ulnar motor potentials with asymmetrically reduced sensory amplitudes in the median (4), ulnar (3), and radial, and lateral antebrachial cutaneous potentials in 1 patient each. Two patients had acute denervation in the cervical or proximal arm muscles. There was full recovery after antibiotic therapy in 4 patients and considerable improvement in 1 patient after 2 months.

CONCLUSION

acute brachial diplegia is a rare manifestation of acute Lyme infection and responds promptly to antibiotic therapy.