Schizophrenic Brain Tries to Heal Itself

Megan Brooks

June 10, 2016

The brains of patients with schizophrenia have the capacity to reorganize and perhaps counter the effects of the disease, a neuroimaging study suggests.

Although schizophrenia is generally associated with a widespread reduction in brain tissue volume, the new study found a subtle increase in brain tissue in certain regions.

"This provides us hope to consider strategies that can harness brain's plasticity in treating this illness and reversing some features that are, so far, considered irreversible with current medical and psychological treatments," lead investigator Lena Palaniyappan, MBBS, PhD, of the Lawson Health Research Institute London, Ontario, Canada, told Medscape Medical News.

The study was published online May 26 in Psychological Medicine.

Noticeable Remodeling

It is now well established that MRI reveals reductions in the thickness of gray matter in patients with schizophrenia, indicating either a developmental or an acquired deficit in the amount of brain tissue, Dr Palaniyappan explained.

"These reductions are seen both in treated and untreated patients, suggesting that current treatments do not reverse the process of tissue loss. We wanted to study if subtle increase in brain tissue also accompanied this reduction."

The researchers followed 98 treated, clinically stable patients with schizophrenia (80 males, 18 females) and compared them to 83 patients without schizophrenia. They used MRI and covariance analysis to measure changes in cortical thickness.

"We observed that across the group of 98 medicated patients, reduced thickness was consistently accompanied by subtle but nevertheless noticeable increases in thickness," said Dr Palaniyappan. Of note, a pattern of cortical amelioration or normalization (assessed by reduced deviation from control patients) was observed with a longer duration of illness, particularly in the occipital cortex.

This suggests that a "compensatory remodeling process might contribute to the cortical thickness variations in different stages of schizophrenia," the researchers write.

"The most important message is that in patients with schizophrenia, the brain changes are not simply a downhill one-way traffic lane. There is small but perhaps crucial 'gain of structure' that often goes unnoticed by the prevailing focus on 'loss of structure.' This may be a reminder for us to acknowledge the compensatory mechanisms that are in action alongside pathological processes that contribute to symptoms of schizophrenia," said Dr Palaniyappan, medical director at the Prevention and Early Intervention Program for Psychoses at the London Health Sciences Centre (LHSC).

"These findings are important not only because of their novelty and the rigor of the study but because they point the way to the development of targeted treatments that potentially could better address some of the core pathology in schizophrenia," Jeffrey Reiss, MD, LHSC site chief of psychiatry, said in a press statement. "Brain plasticity and the development of related therapies would contribute to a new optimism in an illness that was 100 years ago described as premature dementia for its seemingly progressive deterioration," Dr Reiss added.

Dr Palaniyappan urged caution in interpreting the findings from this single cross-sectional study and said that several questions remain unanswered.

"It is not clear if the subtle increase is a compensatory effect or an additional pathological phenomenon. This needs to be clarified in future studies. Further, while clinicians do not often see a full reversal of the diagnostic features of schizophrenia in many patients, there exists a sizable subgroup of patients who recover completely and never come back to see a psychiatrist. We really need to understand the brain mechanisms that underlie such resilience. This, in my opinion, is the most important piece of puzzle on which, unfortunately, not enough effort has been spent to date," Dr Palaniyappan told Medscape Medical News.

Cyrus Raji, MD, PhD, University of California, Los Angeles, who reviewed the study for Medscape Medical News, said this study "demonstrates the utility of cortical thickness MRI in suggesting a reorganization of brain structure in schizophrenia. While earlier studies on schizophrenia highlighted frontal lobe atrophy, this study reminds us that the parahippocampal gyrus ― affected in other disorders, such as Alzheimer's ― also plays a role in schizophrenia."

The study had no commercial funding. The authors have disclosed no relevant financial relationships.

Psychol Med. Published online May 26, 2016. Abstract

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