Language as a Predictor of Motor Recovery: The Case for a More Global Approach to Stroke Rehabilitation

Abstract

Stroke is the third leading cause of death in the developed world and the primary cause of adult disability. The most common site of stroke is the middle cerebral artery (MCA), an artery that supplies a range of areas involved in both language and motor function. As a consequence, many stroke patients experience a combination of language and motor deficits. Indeed, those suffering from Broca's aphasia have an 80% chance of also suffering hemiplegia. Despite the prevalence of multifaceted disability in patients, the current trend in both clinical trials and clinical practice is toward compartmentalization of dysfunction. In this article, we review evidence that aphasia and hemiplegia do not just coexist, but that they interact. We review a number of clinical reports describing how therapies for one type of deficit can improve recovery in the other and vice versa. We go on to describe how language deficits should be seen as a warning to clinicians that the patient is likely to experience motor impairment and slower motor recovery, aiding clinicians to optimize their choice of therapy. We explore these findings and offer a tentative link between language and arm function through their shared need for sequential action, which we term fluency. We propose that area BA44 (part of Broca's area) acts as a hub for fluency in both movement and language, both in terms of production and comprehension.

Keywords: Broca; aphasia; hemiparesis; language; rehabilitation; stroke.