Prediction of deficits in behavioral self-regulation among persons with multiple sclerosis

There is evidence that the lesions characteristic of multiple sclerosis (MS) may isolate prefrontal cortex from other regions of the brain. These findings are consistent with neuropsychological data that show many persons with MS to perform poorly on tests thought to assess the executive functions presumably mediated by the prefrontal area. Furthermore, prefrontal lesions have long been associated with the occurrence of various kinds of behavior pathology. These data prompted us to test the hypothesis that deficits in behavioral regulation typical of frontal lobe dysfunction might play a significant role in the occurrence of behavioral disturbances among persons with multiple sclerosis hospitalized for treatment with methylprednisolone and rehabilitation therapies. Twenty-three chronic progressive MS patients were compared with 23 healthy controls matched on age and education. Both groups were administered the Mini Mental State Exam (MMSE) and the Behavioral Dyscontrol Scale (BDS), a test based on Luria's studies of frontal lobe dysfunction that measures the capacity for regulation of purposeful activity. The MS patients performed more poorly than comparison subjects on the BDS, but not on the MMSE. The MS sample was then divided into two groups according to whether patients obtained low (n = 8) or high scores (n = 16) on the BDS. Compared with high-scoring patients, low-scoring patients showed greater behavioral inertia and greater disruption of the ability to regulate purposeful activity in the performance of activities of daily living. Behavioral disturbances in these individuals thus require careful assessment. Among those who show deficient capacity for behavioral control, the most efficacious interventions may involve the use of cueing, provision of structure, supervision, and environmental modifications.