For rehab ilitationists, a major goal for functional neuroimaging is to use techniques to visualize the physiologic activity of medications and their potential for modulating cerebral reorganization. A few tantalizing studies in highly selected patients with stroke or TBI suggest that a monaminergic, serotonergic, or cholin-ergic medication, especially when combined with practice, may hasten or incrementally improve motor,183-186 language,187 and cognitive188 outcomes. Well within the experiences of rehabilitationists are the adverse actions of certain drugs on aspects of cognition, especially anticonvulsants such as phenytoin, phenobarbital and topiramate. Other common drugs also may have a negative, although less obvious, impact on functional outcomes.189
The ability to screen drugs for potential positive and negative effects on the rehabilitation of individual patients could have a profound impact on patient management. A few studies have shown that available medications can influence functional networks. Responses to a drug may be state dependent. For example, flenfluramine, which releases serotonin, increased the regional metabolic rate in anterior cingulate and lateral prefrontal cortex in a PET-FDG study of normal young subjects.190 This response is blunted in people diagnosed with an aggressive, impulsive personality dis-order.191 Thus, after TBI, patients with a similar phenotypic behavior may respond to a sero-tonergic agent in different ways, depending on lesion location. Actions of neurotransmitters and modulators (see Chapter 1) can be studied by functional neuroimaging and cortical stimulation techniques.
Was this article helpful?
Metabolism. There isn’t perhaps a more frequently used word in the weight loss (and weight gain) vocabulary than this. Indeed, it’s not uncommon to overhear people talking about their struggles or triumphs over the holiday bulge or love handles in terms of whether their metabolism is working, or not.