Neuropsychological test performance and affect in myasthenia gravis

Neuropsychological test performance, including memory, and affect were investigated in 16 patients with myasthenia gravis (MG) and in a matched control group. Clinical electroencephalograms (EEGs) were recorded from MG patients. Cognitive measures included the Randt Memory Test and a number of tests from the computerized Neurobehavioral Evaluation Battery which included a test of motor speed. Affect was assessed by means of an anxiety questionnaire (IPAT) and a computer based questionnaire similar to the Profile of Mood States (POMS). There were no significant intergroup differences in memory performance and only an isolated significant finding in a timed measure in symbol-digit comparison. The MG group revealed significantly reduced finger tapping. Significantly higher levels of anxiety, tension, anger, fatigue and confusion were associated with the MG group. Abnormal EEGs occurred in 35% of the MG patients, mostly mid-moderate diffuse slowing, but in one case epileptogenic activity was present. The failure to confirm memory deficits in this study appeared not to be related to age or whether patients had generalized or ocular MG. Medication was suggested as a possible factor. These, and other variables, need to be evaluated in further studies.