Neuropsychology of Post‐Polio Syndrome

The sparse literature concerning the psychology of PPS is easy to summarize. Some psychopathology can be observed in PPS, but it is not clear whether it is a reaction to PPS or a by‐product of a concurrent but unrelated disorder. Psychopathology does not seem to be responsible for the onset or intensity of new PPS symptoms. A relationship may exist between the perception of stress, an inability to handle stress, and perceived fatigue in PPS. Neuropsychological studies have been equivocal with patients performing well on some tests and more poorly on others compared to controls. An attempt has been made to link reticular formation and hypothalamic involvement in PPS to decreased attention and arousal and increased fatigue. Higher levels of fatigue have been associated with the presence of hyperintensities on MRI scanning. Unfortunately, a variety of methodological problems are present with most of these studies and indicate that caution should be used in their interpretation (see section on Methodological Considerations). Future studies should adapt more stringent controls in subject selection so that non‐PPS factors that might affect behavior or cognition can be factored out (e.g., hypertension or exogenous depression). Tests specifically designed to evaluate components of attention and motor control can be used to test hypotheses regarding fatigue, arousal, and attention. Our experience is that patients carefully selected to have pure PPS without concurrent medical disease have few complaints about cognition or altered mood. Before we pronounce neuropsychological deficits in PPS patients, more carefully designed studies are required.