Memory in myasthenia gravis: neuropsychological tests of central cholinergic function before and after effective immunologic treatment.

There are reports of central cholinergic deficits in myasthenia gravis (MG) describing impaired performance on a variety of tests of memory with varying benefits from plasmapheresis. We tested 11 patients with symptomatic MG at the start of a trial of immunosuppressive treatment (prednisolone plus azathioprine or placebo) and again when in remission. The tests included the Logical Memory and Design Reproduction parts of the Wechsler Memory Scale, the Rey Auditory Verbal Learning Test, Peterson-Peterson task, and an auditory vigilance task. Muscle strength improved significantly over the period of treatment, but overall performance on tests of memory or attention did not. These results fail to substantiate reports of functionally significant and reversible central deficits in myasthenia gravis.