Myasthenic syndrome and small cell cancer of the lung. Variable response to antineoplastic therapy.

Myasthenic syndrome secondary to small cell lung cancer has been studied in five patients who achieved complete remission with chemotherapy. The relationship between response or relapse of the neoplasm to therapy and the activity of the myasthenic syndrome is variable. This inconsistent clinical correlation between the cancer and its paraneoplastic syndrome is examined in view of current data on the immunologic basis of myasthenic syndrome.

An improved technique to facilitate transcervical thymectomy for myasthenia gravis.

We have used the transcervical method of thymectomy in patients with myasthenia gravis and believe that complete thymectomy is accomplished with minimum morbidity. For the past eight years we have used an improved technique for the transcervical approach, employing a specially designed sternal retractor that permits improved visualization of the anterior mediastinum. We have reviewed 65 patients operated on between 1977 and 1986. Patients were assessed using a modified Osserman classification (0 = asymptomatic; 1 = ocular signs and symptoms; 2 = mild generalized weakness; 3 = moderate generalized weakness; 4 = severe generalized weakness, respiratory dysfunction, or both). The mean grade for all patients at the time of thymectomy was 2.7. At most recent follow-up, the mean clinical grade was 0.5. In addition, 85% of patients were free of generalized weakness, 95% had improved by at least one grade, and 86% had improved by two or more grades. Comparing these results with those reported following thymectomy through a sternotomy reveals that the transcervical approach gives equivalent results.

Measurement of human skeletal muscle acetylcholine receptor antibodies using monkey receptors.

Human skeletal muscle acetylcholine receptor (AChR) antibodies were assayed by a double immunoprecipitation technique using 125I-alpha-bungarotoxin as the label. Monkey AChRs were found to be superior to those from diabetic humans for analytical and practical reasons. The analytical sensitivity is 0.05 nmol alpha-bungarotoxin/L serum. The between-run and within-run precision (1 c.v.) of the assay are 13% and 3%, respectively. The normal range is 0-0.2 nmol alpha-bungarotoxin/L. There was no correlation between the antibody concentration and the clinical severity of myasthenia gravis. The clinical sensitivity and specificity of the assay for generalized myasthenia gravis are 79% and 96%, and for ocular myasthenia gravis 29% and 96%, respectively.

Plasma exchange therapy for severe penicillamine-induced myasthenia gravis.

Two rheumatoid patients with typical D-penicillamine-induced myasthenia gravis, both resistant to anticholinesterase therapy, were treated with intensive plasma exchange. With this therapy, both patients quickly regained normal muscle power. Plasma exchange therapy may benefit penicillamine-induced myasthenic patients who develop life-threatening weakness despite withdrawal of D-penicillamine and the use of anticholinesterase medication.

Toronto General Hospital controlled trial data plasma exchange therapy in Guillain-Barré' syndrome.

The mechanism by which plasma exchange (PE) may benefit patients with acute Guillain-Barre' syndrome (AGBS) is unclear. It is possible, therefore, that the response of patients with AGBS is influenced by the choice of replacement solution (whole plasma vs. albumin or similar protein-containing solution). This report compares the outcome in 57 patients with AGBS treated at the Toronto General Hospital (TGH) using conventional therapy (27), PE with plasma replacement (15) and PE with albumin replacement (15). Fifteen patients (5 treated conventionally, 8 by PE with plasma replacement, 2 by PE with albumin replacement) were treated before the Baltimore coordinated multicenter trial. Forty-two patients (22 treated conventionally, 7 by PE with plasma replacement and 13 by PE with albumin replacement) were then entered at the TGH into the multicenter trial. The best outcome was observed in those patients (9) in whom PE was started within 14 days of the first neuropathic symptoms and plasma was used as replacement. The mean improvements in clinical grade in this subgroup of patients of 1.11 at four weeks after starting treatment and 1.71 at six weeks were significantly better than the corresponding improvements in the conventionally treated group of 0.35 (p less than 0.01) and 0.94 (p less than 0.05). The response of patients (9) exchanged within 14 days of onset, but replaced with albumin (grade change of 0.67 at four weeks and 0.86 at six weeks), was not significantly different from that of the conventionally treated patients. These data support the need for a randomized trial to compare PE using plasma replacement and PE using albumin replacement in patients with AGBS.(ABSTRACT TRUNCATED AT 250 WORDS)