Upper limb predominant, multifocal chronic inflammatory demyelinating polyneuropathy.

Chronic inflammatory demyelinating polyneuropathy (CIDP) presents in rare instances with focal or multifocal upper limb involvement. We reviewed the clinical and electromyographic (EMG) characteristics of 10 such patients (UL-CIDP) and compared them with patients with typical generalized CIDP (G-CIDP) and multifocal motor neuropathy (MMN). There were six men and four women, with a mean age of 54 years. Symptoms began in one arm or hand in six patients and in both arms or hands in four and included numbness (n = 10), paresthesias (n = 9), weakness (n = 8), and pain (n = 6). Findings were initially restricted to the ulnar nerve distribution in three patients, and median and axillary nerve in one patient each, and involved multiple nerves in five. Conduction block was detected in the forearm segment of 68% of the median and ulnar motor nerves tested; in contrast to multifocal motor neuropathy, 73% of the sensory nerves tested were abnormal, and none had anti-GM1 antibodies. Aside from a regional onset, there were no clinical or electrophysiological features that distinguished patients with UL-CIDP from those with G-CIDP. However, the magnitude of recovery following treatment was greater in patients with G-CIDP. We conclude that a multifocal variant of CIDP begins with upper extremity sensorimotor symptoms, simulates isolated or multiple mononeuropathies, can be distinguished from MMN, and may have a less favorable response to treatment.