Altered Spontaneous Brain Activity in Schizophrenia: A Meta-Analysis and a Large-Sample Study

Area of Science:

• Neuroscience
• Psychiatry
• Medical Imaging

Background:

• Altered spontaneous brain activity is implicated in schizophrenia, but findings on amplitude of low-frequency fluctuations (ALFF), fractional ALFF (fALFF), and regional homogeneity (ReHo) lack consensus.
• Understanding regional alterations in these brain activity measures is crucial for elucidating schizophrenia's pathophysiology.

Purpose of the Study:

• To clarify regional alterations in ALFF, fALFF, and ReHo in schizophrenia through a meta-analysis and large-sample validation.
• To provide a more definitive map of brain activity changes associated with schizophrenia.

Main Methods:

• A meta-analysis using activation likelihood estimation (ALE) was performed on ten studies reporting abnormal foci in schizophrenia.
• A large-sample study compared 86 schizophrenia patients and 89 healthy controls to validate the meta-analysis findings.
• Analysis focused on spontaneous brain activity measures: ALFF, fALFF, and ReHo.

Main Results:

• Meta-analysis revealed consistent distribution patterns for ALFF and ReHo alterations in schizophrenia.
• Decreased ALFF/fALFF and ReHo were predominantly observed in the somatosensory cortex, posterior parietal cortex, and occipital cortex.
• Increased ALFF/fALFF and ReHo were mainly localized to the bilateral striatum, medial temporal cortex, and medial prefrontal cortex.
• The large-sample validation study confirmed the findings from the meta-analysis.

Conclusions:

• The study provides a clearer understanding of regional spontaneous brain activity alterations in schizophrenia.
• Findings support and refine pathophysiological hypotheses of schizophrenia.
• The results can guide future neuroimaging research and therapeutic target identification in schizophrenia.