XI Congresso della Società Italiana di Psicopatologia Psichiatria ...

SIMPOSI TEMATICI
24 FEBBRAIO 2005 - ORE 18.00-19.30
SALA LEONARDO
S79 - Prospettive future degli studi di neuroimmagine
strutturale
Cerebral structure analyzed by Magnetic
Resonance methods
R.S.J. Frackowiak
IRCCS “Santa Lucia”, Roma Italy; DEC, ENS, Paris and
FIL, IoN, UCL London
Voxel based morphometry (VBM) is a new way of
analysing structural MR images. VBM can characterise differences
in structural MRI scans of diseases influenced by
genetic variation. In X-linked Kallmann’s syndrome there is
selective hypertrophy of the pyramidal tract in patients with
mirror movements compared to those without. In a dominantly
inherited, dyspraxic, language-impaired family, gene
penetrance is full and associated with abnormal structure
and function of the caudate nucleus and other areas. Atrophy
of the caudate in affected family members is associated with
task-related hyperactivity, suggesting functional compensation.
Presently unaffected individuals from families of
Huntington’s patients show caudate atrophy that correlates
with genetic status. Caudate atrophy correlates with clinical
score and CAG codon repeats on chromosome 4. Studies
with Turner’s and partial Turner’s patients have identified
focal structural brain abnormalities. Candidate regions on
the X-chromosome have been found that influence amygdala
and orbital frontal cortex development. A structural
amygdala abnormality in patients predicts failure to recognise
fear in photographs of faces; a prediction that is now
confirmed. These studies suggest that imaging is an efficient
way of associating candidate genes with quantitative measures
of brain structure and function and that informative intermediate
phenotypes can be described that predict future
disease in asymptomatic at-risk individuals.
Bibliografia
Krams M, et al. Neurology 1999;52:816-22.
Watkins KE, et al. Brain 2002;125:465-78.
Thieben MJ, et al. Brain 2002;125:1815-28.
Good CD, et al. Brain 2003;126:2431-46.
Good CD, et al. NeuroImage 2002;17:29-46.
White matter morphometry and volume
in schizophrenia
G. Spalletta, G. Bonaviri, N. Ruesch, C. Caltagirone
IRCCS Fondazione “Santa Lucia”, Roma e Dipartimento di
Neuroscienze, Università di Roma “Tor Vergata”
Schizophrenia has been conceptualised as a brain misconnection
syndrome. Structural white matter changes may account
for both cognitive deficits and disturbed emotion regulation
and impulse control. Current research using voxel-
MODERATORI
G. Spalletta, C. Caltagirone
based morphometry and diffusion tensor imaging of cerebral
white matter is rapidly expanding our knowledge on
white matter changes in schizophrenia and correlations with
cognition, impulsivity and suicidality. Here, we present recent
findings of our groups on:
1)white matter changes in schizophrenia especially in areas
responsible for language and hearing processes as compared
to healthy controls (Fig. 1);
2)white matter alterations in the frontal lobes being correlated
with working memory deficits in subjects with
schizophrenia but not in healthy controls (Fig. 2);
3)increased white matter volumes in subjects with schizophrenia
who both have a history of suicide attempts and
show current self-aggression.
These converging findings support the notion that white
matter alterations are at the core of neurobiological alterations
in schizophrenia and are related to deficits central to
this disorder.
Fig. 1.
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