The strategies used to perform a verbal fluency task appear to be reflective of cognitive abilities necessary for successful daily functioning. In the present study, we explored potential differences in verbal fluency strategies (switching and clustering) used to maximize word production by patients with relapsing-remitting multiple sclerosis (RRMS) versus patients with secondary progressive multiple sclerosis (SPMS). We further assessed impairment rates and potential differences in the sensitivity and specificity of phonological versus semantic verbal fluency tasks in discriminating between those with a diagnosis of MS and healthy adults. We found that the overall rate of impaired verbal fluency in our MS sample was consistent with that in other studies. However, we found no differences between types of MS (SPMS, RRMS), on semantic or phonological fluency word production, or the strategies used to maximize semantic fluency. In contrast, we found that the number of switches differed significantly in the phonological fluency task between the SPMS and RRMS subtypes. The clinical utility of semantic versus phonological fluency in discriminating MS patients from healthy controls did not indicate any significant differences. Further, the strategies used to maximize performance did not differentiate MS subgroups or MS patients from healthy controls. 1. Introduction Multiple sclerosis (MS) is a chronic, debilitating, autoimmune disease of the nervous system that usually presents with a relapsing-remitting, and then later a progressive, course. Both the course of the illness and the presentation of motor and cognitive symptoms in terms of type and severity can vary significantly from one individual to another [1]. The disease has been classified as a frontal-subcortical dementia, as it causes demyelination of neurons mainly in frontal and subcortical regions [2]. It has been estimated that approximately 60% of patients with multiple sclerosis present with cognitive deficits [3]. Consistent with the locations of disease-induced lesions, subsequent functional impairments comprise problems with attention, information processing speed, memory, and executive functioning, all of which limit the individual’s ability to perform within the context of work and social relationships and may even compromise the safety of daily activities such as driving [4]. Although the cognitive effects of MS have been repeatedly documented in previous studies [3], it is not clear whether cognitive deficits are exclusively the result of neurological damage or could also be the product of
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