Regional cerebral blood flow in patients with mild hypothyroidism.
Emotional and cognitive abnormalities are common in adult hypothyroidism. Few studies, however, have evaluated cerebral perfusion and metabolism in this disorder. The aims of this study were to compare regional cerebral blood flow (rCBF) between hypothyroid patients and healthy subjects and assess flow during the euthyroid state after treatment.


METHODS
Ten mildly hypothyroid patients, before and after thyroxine treatment, and 10 healthy controls underwent 99mTc-hexamethylpropyleneamine oxime brain SPECT, MRI, and psychometric testing. SPECT images were analyzed using statistical parametric mapping.


RESULTS
Compared with controls, rCBF in patients before treatment was lower in right parietooccipital gyri, cuneus, posterior cingulate, lingual gyrus, fusiform, insula, and pre- and postcentral gyri. Perfusion did not normalize on a return to the euthyroid state.


CONCLUSIONS
Decreased rCBF in mild hypothyroidism is found in regions mediating attention, motor speed, memory, and visuospatial processing, faculties affected in hypothyroidism. Follow-up studies are needed to determine the longer-term persistence of perfusion abnormalities in this disorder.
Department of Medical Biophysics and Nuclear Medicine, Hadassah-Hebrew University Medical Center, Jerusalem, Israel. yodphat@hadassah.org.il
Yodphat
Y
Krausz
Nanette
N
Freedman
Hava
H
Lester
J P
JP
Newman
Gavriel
G
Barkai
Moshe
M
Bocher
Roland
R
Chisin
Omer
O
Bonne
D000328:Adult; D001921:Brain / Q000098:blood supply* / Q000000981:diagnostic imaging* / Q000187:drug effects; D002560:Cerebrovascular Circulation / Q000187:drug effects; D003072:Cognition Disorders / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000188:drug therapy* / Q000209:etiology; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000150:complications / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000188:drug therapy*; D008875:Middle Aged; D011379:Prognosis; D013974:Thyroxine / Q000627:therapeutic use*; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods; D016896:Treatment Outcome
D013974:Thyroxine