No effect of obstetric complications on basal ganglia volumes in schizophrenia

Background

Heterogeneous findings have been reported in studies of basal ganglia volumes in schizophrenia patients as compared to healthy controls. The basal ganglia contain dopamine receptors that are known to be involved in schizophrenia pathology and to be vulnerable to pre- and perinatal hypoxic insults. Altered volumes of other brain structures (e.g. hippocampus and lateral ventricles) have been reported in schizophrenia patients with a history of obstetric complications (OCs). This is the first study to explore if there is a relationship between OCs and basal ganglia volume in schizophrenia.

Methods

Thorough clinical investigation (including information on medication) of 54 schizophrenia patients and 54 healthy control subjects was undertaken. MR images were obtained on a 1.5 T scanner, and volumes of nucleus caudatus, globus pallidum, putamen, and nucleus accumbens were quantified automatically. Information on OCs was blindly collected from original birth records.

Results

Unadjusted estimates demonstrated a relationship between increasing number of OCs and larger volume of nucleus accumbens in schizophrenia patients and healthy controls. No statistically significant relationships were found between OCs and the basal ganglia volumes when controlled for intracranial volume, age, and multiple comparisons. There were no effects of typical versus atypical medication on the basal ganglia volumes. The patients with schizophrenia had larger globus pallidum volumes as compared to healthy controls, but there were no case–control differences for accumbens, putamen, or caudate volumes.

Conclusion

The present results do not support the hypothesis that OCs are related to alterations in basal ganglia volume in chronic schizophrenia.     

Is there an association between spatial access to parks/green space and childhood overweight/obesity in Calgary, Canada?

Background  

The recent increase in childhood obesity is expected to add significantly to the prevalence of chronic diseases. We used multivariate multilevel analysis to examine associations between parks/green space and childhood overweight/obesity across communities in Calgary, Canada, a city characterized by intensified urban sprawl and high car use.     

Effects of intensity variations on auditory processing in aphasia. II. Different intensities at each ear

A neurologic extinction model was applied to the auditory-processing disorders evidenced by 10 persons with aphasia. This model suggests that messages travel faster to the intact hemisphere, where they are more differentiated and articulated, than to the affected hemisphere. This leads to extinction and interference of the message. To overcome this extinction, the stimulus intensity was raised by 15 or 30 dB to one ear at a time. The stimuli were a cortical auditory-evoked response (AER) measure, a nonverbal intensity sequencing test (NVIST), a minimally varied phoneme-in-word discrimination and sequencing test (MVPT). and a semantic-syntactic level test (RTT). The results suggest that intensity can be traded for time in quantities large enough to overcome the extinction interference of auditory stimuli. Although some statistically significant results and meaningful trends toward improved performance were evident on the NVIST and the MVPT, a unilateral increase of stimulus intensity did not prove to be a potent mechanism for improving auditory comprehension. Sentence length material was not affected in either direction by selective amplification. The role of the left ear/right hemisphere as a facilitator of processing for linguistic and nonlinguistic material was suggested by the results of this study.     

Prism adaptation can improve contralesional tactile perception in neglect

The authors show that prismatic adaptation can reduce tactile inattention in stroke patients with unilateral neglect. Four patients with visuospatial neglect and tactile extinction underwent 10-minute application of 20 degrees right-shifting prismatic lenses during pointing. This improved contralesional tactile perception in all patients, even for a task requiring no exploration or spatial motor responses. This finding suggests a potential role for prismatic adaptation in the rehabilitation of multiple sensory modalities in patients with neglect.