Reduction of the internal capsule in families affected with schizophrenia.
BACKGROUND
The anterior limb of the internal capsule (ALIC), connecting cortical and subcortical structures, is involved in functional important circuits. To detect volumetric changes in ALIC, including the influence of genetic factors, a magnetic resonance imaging (MRI) study of families affected with schizophrenia was performed.


METHODS
The study sample comprised 22 family members with schizophrenia (FM-SZ), 34 family members without schizophrenia (FM-NSZ), and 43 control subjects. In addition to manual tracing of ALIC, subjects underwent proton magnetic resonance spectroscopy in the left prefrontal cortex, psychopathological rating, and neuropsychological assessment of frontal lobe function.


RESULTS
Compared with controls, a significant reduction of right ALIC volume was seen in all family members (12%-16% reduction, p < .01) and a reduction of left ALIC volume in FM-NSZ (10% reduction, p = .028) was also observed. Both groups of family members showed a bilateral reduction in maximal cross sectional area of the ALIC. FM-SZ performed significantly worse on neurocognitive measures (Subject Ordered Pointing Task [SOPT] and Wisconsin Card Sorting Test), and performance correlated negatively with the ALIC volume (SOPT, r = -.6, p = .03).


CONCLUSIONS
A reduced volume of ALIC in affected families supports the hypothesis of disturbed frontothalamic connectivity in schizophrenia and demonstrates functional relevance by an association with reduced neurocognitive performance.
Wobrock
Thomas
T
Department of Psychiatry and Psychotherapy, University of the Saarland, Germany. twobroc@gwdg.de
Kamer
Thomas
T
Roy
Anand
A
Vogeley
Kai
K
Schneider-Axmann
Thomas
T
Wagner
Michael
M
Maier
Wolfgang
W
Rietschel
Marcella
M
Schulze
Thomas G
TG
Scherk
Harald
H
Schild
Hans H
HH
Block
Wolfgang
W
Träber
Frank
F
Tepest
Ralf
R
Honer
William G
WG
Falkai
Peter
P
D000328:Adult; D000704:Analysis of Variance; D016022:Case-Control Studies; D005192:Family Health; D005260:Female; D006801:Humans; D020772:Internal Capsule / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011569:Psychiatric Status Rating Scales; D012559:Schizophrenia / Q000235:genetics* / Q000473:pathology*; D013223:Statistics as Topic