[Is cognitive change related to hypothyroidism reversible with replacement therapy?].
OBJECTIVE
Although cognitive impairment related to hypothyroidism has been investigated, issues regarding treatment have been less extensively studied. The aim of this study was to assess cognitive function in patients with hypothyroidism just before treatment and after hypothyroidism had resolved.


METHODS
Standardized psychometric assessment (including ten tests) was done in 30 outpatients with biochemical evidence of hypothyroidism (TSH = 92.1 mU/L, range: 11.4-400) and in 30 control subjects matched for age and gender with normal thyroid function. These tests were repeated twice before treatment and after hypothyroidism had been cured. Statistical analysis was done using the Mann-Whitney U test.


RESULTS
The baseline characteristic of patients with hypothyroidism showed that attention, motor speed, memory and visual-spatial organization were significantly impaired. Cognitive decline was significantly greater with increasing age. Cognitive impairment significantly decreased after hypothyroidism had been cured, reaching values obtained in age-matched control subjects.


CONCLUSIONS
Attention, motor speed, memory and visual-spatial organization are significantly impaired in hypothyroidism, particularly in the elderly, suggesting that ageing could have potential effects on cognitive functions. Hormone-replacement therapy leads to normalization of the cognitive functions.
Capet
C
C
Service de médecine interne-gériatrie, CHU, Rouen, France.
Jego
A
A
Denis
P
P
Noel
D
D
Clerc
I
I
Cornier
A C
AC
Lefebvre
H
H
Lévesque
H
H
Chassagne
P
P
Bercoff
E
E
Doucet
J
J
D000367:Age Factors; D000368:Aged; D001288:Attention; D003072:Cognition Disorders / Q000188:drug therapy* / Q000209:etiology*; D005260:Female; D020249:Hormone Replacement Therapy; D006801:Humans; D007037:Hypothyroidism / Q000175:diagnosis / Q000188:drug therapy* / Q000523:psychology*; D007361:Intelligence Tests; D008297:Male; D008568:Memory; D008609:Mental Status Schedule; D008875:Middle Aged; D011594:Psychometrics; D011597:Psychomotor Performance; D012016:Reference Values; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000627:therapeutic use*
D013972:Thyrotropin; D013974:Thyroxine