Frontal and temporal lobe involvement on verbal fluency measures in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) has been associated with changes in frontal and temporal lobe-mediated cognitive and behavioral functions. Verbal fluency, a sensitive measure to these changes, was utilized to investigate phonemic and semantic abilities in 49 ALS patients and 25 healthy controls (HCs). A subset of the ALS patients was classified as ALS-intact, ALS with mild cognitive impairments (ALS-mild), and ALS with fronto-temporal dementia (ALS-FTD) based on a comprehensive neuropsychological evaluation. Clustering and switching, the underlying component processes of verbal fluency, were analyzed using Troyer's (Troyer, Moscovitch, & Winocur, 1997) and Abwender's (Abwender, Swan, Bowerman, & Connolly, 2001) scoring systems. ALS patients exhibited decreased fluency versus HCs. For phonemic fluency, the intact ALS sample generated fewer clusters and more switches than the ALS-mild and ALS-FTD patients using both scoring systems. This suggests temporal involvement in ALS patients, with increasing frontal lobe involvement in patients with greater cognitive dysfunction. For semantic fluency, similar results were obtained with a greater emphasis on declines in clustering or increased temporal lobe dysfunction. These results suggest that verbal fluency measures identify frontal and temporal lobe involvement in the cognitive decline associated with ALS, particularly when the component processes are evaluated. The clinical utility of these scoring systems with ALS patients is also discussed.

[1]  D. White,et al.  Using verbal fluency to detect very mild dementia of the Alzheimer type. , 2006, Archives of clinical neuropsychology : the official journal of the National Academy of Neuropsychologists.

[2]  G. Winocur,et al.  Clustering and switching on verbal fluency: the effects of focal frontal- and temporal-lobe lesions , 1998, Neuropsychologia.

[3]  Sophie Schwartz,et al.  Role of frontal versus temporal cortex in verbal fluency as revealed by voxel-based lesion symptom mapping , 2006, Journal of the International Neuropsychological Society.

[4]  Marcus Meinzer,et al.  Neural Signatures of Semantic and Phonemic Fluency in Young and Old Adults , 2009, Journal of Cognitive Neuroscience.

[5]  Alex Martin,et al.  Word retrieval to letter and semantic cues: A double dissociation in normal subjects using interference tasks , 1994, Neuropsychologia.

[6]  Alex Martin,et al.  Neural systems supporting lexical search guided by letter and semantic category cues: A self-paced overt response fMRI study of verbal fluency , 2010, NeuroImage.

[7]  David P. Salmon,et al.  Cortical and subcortical influences on clustering and switching in the performance of verbal fluency tasks , 1998, Neuropsychologia.

[8]  R. Grossman,et al.  Clustering and Switching in Phonemic Fluency Following Pallidotomy for the Treatment of Parkinson's Disease , 2003, Journal of clinical and experimental neuropsychology.

[9]  P. Schulz,et al.  Cognitive impairment in familial ALS , 2007, Neurology.

[10]  T. Robbins,et al.  Verbal fluency in Huntington’s disease: a longitudinal analysis of phonemic and semantic clustering and switching , 2002, Neuropsychologia.

[11]  E. Kaplan,et al.  The Boston naming test , 2001 .

[12]  R. Heaton.  Wisconsin Card Sorting Test manual , 1993 .

[13]  S. Folstein,et al.  "Mini-mental state". A practical method for grading the cognitive state of patients for the clinician. , 1975, Journal of psychiatric research.

[14]  Emily Calhoun,et al.  The reliability and validity of qualitative scores for the Controlled Oral Word Association Test. , 2007, Archives of clinical neuropsychology : the official journal of the National Academy of Neuropsychologists.

[15]  S H Appel,et al.  Prevalence and patterns of cognitive impairment in sporadic ALS , 2005, Neurology.

[16]  H. A. Leeper,et al.  Cognition, language, and speech in amyotrophic lateral sclerosis: a review. , 1996, Journal of clinical and experimental neuropsychology.

[17]  K. Abe,et al.  Cognitive function in amyotrophic lateral sclerosis , 1997, Journal of the Neurological Sciences.

[18]  Manel Salamero,et al.  Clustering and switching in semantic fluency: predictors of the development of Alzheimer's disease , 2008, International journal of geriatric psychiatry.

[19]  A Chatterjee,et al.  Neurocognitive contributions to verbal fluency deficits in frontotemporal lobar degeneration , 2009, Neurology.

[20]  H. Tanila,et al.  Verbal fluency activates the left medial temporal lobe: A functional magnetic resonance imaging study , 2000, Neurobiology of Aging.

[21]  D. Tulsky,et al.  WAIS-III WMS-III Technical manual , 1977 .

[22]  M. Kosmidis,et al.  Disproportionate impairment in semantic verbal fluency in schizophrenia: differential deficit in clustering , 2005, Schizophrenia Research.

[23]  G. Winocur,et al.  Clustering and switching as two components of verbal fluency: evidence from younger and older healthy adults. , 1997, Neuropsychology.

[24]  L. Leach,et al.  Diagnostic utility of abbreviated fluency measures in Alzheimer disease and vascular dementia , 2004, Neurology.

[25]  M. Molinari,et al.  Phonological grouping is specifically affected in cerebellar patients: a verbal fluency study , 2000, Journal of neurology, neurosurgery, and psychiatry.

[26]  M. Freedman,et al.  Consensus criteria for the diagnosis of frontotemporal cognitive and behavioural syndromes in amyotrophic lateral sclerosis , 2009, Amyotrophic lateral sclerosis : official publication of the World Federation of Neurology Research Group on Motor Neuron Diseases.

[27]  M. Kosmidis,et al.  The verbal fluency task in the Greek population: Normative data, and clustering and switching strategies , 2004, Journal of the International Neuropsychological Society.