CHRONIC INFLAMMATORY DEMYELINATING POLYNEUROPATHY - CLINICAL-FEATURESAND RESPONSE TO TREATMENT IN 67 CONSECUTIVE PATIENTS WITH AND WITHOUTA MONOCLONAL GAMMOPATHY

We report the clinical and EMG details of 67 consecutive patients with strictly defined chronic inflammatory demyelinating polyneuropathy (C IDP) during a 4-year period and compare responses to treatment in pati ents with idiopathic CIDP (CIDP-I) and CIDP with monoclonal gammopathy of uncertain significance (CIDP-MGUS). Patients were examined an aver age of 28 months after first symptoms. There were several variant pres entations that still conformed to the clinical and electrophysiologic definitions of CIDP, including a pure motor syndrome (10%), sensory at axic variant (12%), mononeuritis multiplex pattern (9%), paraparetic p attern (4%), and relapsing acute Guillain-Barre syndrome (16%). Pain w as more frequent than in previous studies (42%). Conduction block was the commonest EMG abnormality (detected in at least one nerve in 73% o f patients), but only 31% had a pure demyelinating neuropathy and the majority had some degree of axonal change. Patients with CIDP-MGUS had less severe weakness, greater imbalance, leg ataxia, vibration loss i n the hands, and absent median and ulnar sensory potentials, but were as likely as CIDP-I patients to respond to plasma exchange. Seventeen of 44 patients (39%) with idiopathic CIDP improved for at least 2 mont hs with an initial therapy. Although the response rates among plasma e xchange, IVIG, and steroids were similar, functional improvement (Rank in score) was greatest with plasma exchange. Of 26 patients who failed to respond to an initial therapy, 9 (35%) benefited from an alternati ve treatment, and of the 11 who required a third modality 3 (27%) impr oved. Overall, 66% responded to one of the three main therapies for CI DP.