Are amyotrophic lateral sclerosis patients cognitively normal?
BACKGROUND
Patients with ALS are often told that the disease spares cognition; however, recent evidence suggests deficits in frontal executive skills occur in a sizable minority of ALS patients. In many instances, the frontal executive deficits represent the co-occurrence of frontotemporal lobar dementia (FTLD) and ALS.


METHODS
Word generation, a simple frontal task that takes <2 minutes, was tested in 100 consecutive patients with ALS seen in the authors' multidisciplinary clinic. Any patient with a prior dementia diagnosis was excluded from the study. A subset of 44 patients agreed to undergo further neuropsychological testing and clinical interview to confirm or deny a diagnosis of dementia.


RESULTS
Diminished word generation was found in one-third. Of the patients with abnormal word generation who agreed to further evaluation, nearly all were shown to meet research criteria for FTLD. In addition, one-quarter of the patients with normal word generation who agreed to further evaluation met research criteria for FTLD; these patients had new-onset personality changes.


CONCLUSIONS
This study suggests that frontal executive deficits are present in half of ALS patients, many of whom meet strict research criteria for FTLD. Word generation tests are a useful screening tool in this cohort.
Lomen-Hoerth
C
C
Department of Neurology, University of California at San Francisco, 94143, USA.
Murphy
J
J
Langmore
S
S
Kramer
J H
JH
Olney
R K
RK
Miller
B
B
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000690:Amyotrophic Lateral Sclerosis / Q000453:epidemiology* / Q000503:physiopathology; D015331:Cohort Studies; D003704:Dementia / Q000175:diagnosis* / Q000453:epidemiology* / Q000503:physiopathology; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology; D006801:Humans; D015994:Incidence; D008297:Male; D008403:Mass Screening / Q000379:methods; D008875:Middle Aged; D009483:Neuropsychological Tests; D011237:Predictive Value of Tests; D014705:Verbal Behavior