Magnetic resonance imaging of the thalamus and adhesio interthalamica in twins with schizophrenia.
BACKGROUND
Abnormalities of the thalamus are thought to be central to the pathophysiology of schizophrenia. These abnormalities include altered structure and shape of the thalamus itself and possibly changes to the adhesio interthalamica (or massa intermedia), the gray matter bridge connecting the 2 thalamic lobes. However, it is not clear to what extent these abnormalities are determined by the genetic liability for schizophrenia.


OBJECTIVE
To investigate thalamic volume and the presence of the adhesio interthalamica in monozygotic (MZ) twins concordant or discordant for schizophrenia.


METHODS
Study of MZ twins.


METHODS
Patients were drawn from inpatient and outpatient clinics. Twin controls were recruited from a volunteer twin register and through media advertisements.


METHODS
A total of 123 twins participated: 19 MZ twin pairs concordant for schizophrenia, 15 MZ schizophrenic twins and 16 MZ nonschizophrenic twins drawn from 17 pairs discordant for schizophrenia, and 27 MZ twin pairs without schizophrenia. Groups were matched for age, sex, handedness, level of education, parental socioeconomic status, and ethnicity.


METHODS
The volume of the thalamus (including right and left hemispheres) was measured (in cubic centimeters) and the presence of the adhesio interthalamica was ascertained from structural magnetic resonance images.


RESULTS
Concordant twin pairs displayed significantly reduced thalamic volume compared with control twins, even when covarying for effects of whole-brain volume, age, and sex. There was a significant linear decrease in thalamic volume (control greater than discordant nonschizophrenic greater than discordant schizophrenic greater than concordant). In all groups, right thalamus was larger than left thalamus. There was no difference across groups in the frequency of the adhesio interthalamica.


CONCLUSIONS
Volumetric thalamic abnormalities in schizophrenia occur in twin pairs concordant for schizophrenia. These abnormalities may mark the substantial genetic contribution to the illness seen in concordant twin pairs, whereas the adhesio interthalamica is unlikely to be affected in schizophrenia.
Ettinger
Ulrich
U
Centre for Neuroimaging Sciences, Division of Psychological Medicine, Institute of Psychiatry, King's College London, London, England. u.ettinger@iop.kcl.ac.uk
Picchioni
Marco
M
Landau
Sabine
S
Matsumoto
Kazunori
K
van Haren
Neeltje E
NE
Marshall
Nicolette
N
Hall
Mei-Hua
MH
Schulze
Katja
K
Toulopoulou
Timothea
T
Davies
Nadia
N
Ribchester
Tracy
T
McGuire
Philip K
PK
Murray
Robin M
RM
D000328:Adult; D001284:Atrophy; D004200:Diseases in Twins / Q000235:genetics* / Q000473:pathology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000706:statistics & numerical data*; D008297:Male; D009434:Neural Pathways / Q000473:pathology; D012559:Schizophrenia / Q000235:genetics* / Q000473:pathology* / Q000503:physiopathology; D012737:Sex Factors; D013788:Thalamus / Q000473:pathology* / Q000503:physiopathology; D014430:Twins, Monozygotic / Q000235:genetics