OBJECTIVE: Neurodevelopmental models of schizophrenia imply that a more
severe early brain lesion may produce earlier onset of psychotic symptoms.
The medial temporal lobes have been proposed as possible locations for such
a lesion. The authors tested this hypothesis in a group of children and
adolescents with childhood-onset schizophrenia who had severe, chronic
symptoms and who were refractory to treatment with typical neuroleptics.
METHOD: Anatomic brain magnetic resonance imaging scans were acquired with
a 1.5-T scanner for 21 patients (mean age=14.6 years, SD=2.1) who had onset
of schizophrenia by age 12 (mean age at onset=10.2, SD=1.5) and 41 normal
children. Volumes of the temporal lobe, superior temporal gyrus, amygdala,
and hippocampus were measured by manually outlining these structures on
contiguous 2-mm thick coronal slices. RESULTS: Patients with
childhood-onset schizophrenia had significantly smaller cerebral volumes.
With no adjustment for brain volume, no diagnostic differences were
observed for any temporal lobe structure. Unexpectedly, with adjustment for
total cerebral volume, larger volumes of the superior temporal gyrus and
its posterior segment and a trend toward larger temporal lobe volume
emerged for the patients with schizophrenia. These patients lacked the
normal (right-greater-than-left) hippocampal asymmetry. CONCLUSIONS: These
findings do not indicate a more severe medial temporal lobe lesion as the
basis of very early onset schizophrenia.