Neurologic complications of graft-versus-host disease.

BMT has become an important therapy for many hematologic disorders. Following BMT, the recipient may develop GVHD when it appears that immunocompetent donor lymphocytes react to host antigens. Acute and chronic GVHD represent two distinct syndromes. Acute GVHD has not been associated with primary neurologic involvement. Polymyositis has been reported in 12 patients with chronic GVHD, with the most common underlying illness being aplastic anemia. The clinical, serologic, and muscle biopsy features of the myositis in GVHD have been similar to those observed in idiopathic polymyositis. Weakness was moderate to severe and responded to prednisone, sometimes with the addition of azathioprine. Prognosis depended upon the underlying disease and not on the severity of the myositis. MG occurs rarely in chronic GVHD. Most patients with MG and GVHD have had aplastic anemia; those with aplastic anemia are more likely to have anti-AchR prior to BMT. The clinical manifestations of GVHD MG have not differed from classic autoimmune MG; each patient had elevated antiacetylcholine receptor antibodies titers. All patients have responded well to cholinesterase inhibitors but have received other immunosuppressants. These observations suggest that aplastic anemia is an important host factor in the development of the autoimmune disorders seen with chronic GVHD, certainly of myositis and MG. Herpes zoster peripheral nerve infections have occurred in patients with chronic GVHD. One patient had mononeuritis multiplex. In both acute and chronic GVHD, CNS impairment is usually caused by metabolic encephalopathy or infection. Primary CNS involvement has not been recognized.