Cognitive impairment in familial ALS.
BACKGROUND
ALS is a progressive neurodegenerative disorder that affects upper and lower motor neurons. Recent reports demonstrate cognitive impairment in patients with sporadic ALS (sALS).


OBJECTIVE
To test whether patients with familial ALS (fALS) have cognitive impairment and whether it is of the same type and degree as observed in sporadic ALS.


METHODS
Thirty-seven consecutive patients with fALS underwent comprehensive neuropsychological testing. Cognitive impairment was categorized by 1) cluster analysis of non-timed, non-motor dependent neuropsychological tests, 2) cutoff scores, and 3) clinical impression.


RESULTS
By cluster analysis, 23 of 37 (62%) patients with fALS and 190 of 392 (48.5%) patients with sALS had cognitive impairment (difference not significant). Similar rates of impairment were found using clinical diagnostic criteria and cutoff score analysis. Neither motor scores nor the site of symptom onset correlated with cognitive impairment. Only age differed between the affected and unaffected fALS groups.


CONCLUSIONS
The prevalence and pattern of cognitive impairment in familial ALS (fALS) is similar to that of sporadic ALS. For patients with fALS, the site of symptom onset did not correlate with cognitive impairment, but age did. Future studies will determine whether cognitive impairment in fALS correlates with specific genetic mutations or polymorphisms.
Wheaton
M W
MW
Department of Neurology, NB-302, Baylor College of Medicine, 6501 Fannin, Houston, TX 77030, USA.
Salamone
A R
AR
Mosnik
D M
DM
McDonald
R O
RO
Appel
S H
SH
Schmolck
H I
HI
Ringholz
G M
GM
Schulz
P E
PE
D000328:Adult; D000367:Age Factors; D017668:Age of Onset; D000368:Aged; D000690:Amyotrophic Lateral Sclerosis / Q000453:epidemiology* / Q000235:genetics / Q000523:psychology; D016000:Cluster Analysis; D003072:Cognition Disorders / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology; D015897:Comorbidity; D004185:Disability Evaluation; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D008875:Middle Aged; D016472:Motor Neuron Disease / Q000453:epidemiology* / Q000235:genetics / Q000523:psychology; D009483:Neuropsychological Tests; D015995:Prevalence