MedicalResearch.com Interview with:
Bradley S. Peterson, MD
Director of the Center for Developmental Neuropsychiatry
Director of the Center for Developmental Neuropsychiatry,
New York State Psychiatric Institute
Suzanne Crosby Murphy Professor in Pediatric Neuropsychiatry,
Columbia University, NY
MedicalResearch.com: What are the main findings of the study?
Dr. Peterson: We detected the presence of lactate in the brains of 13% of 75 participants who had ASD (Autism Spectrum Disorder), compared with 1% of the brains of 96 typically developing control participants. The presence of lactate was especially more common in adults who have ASD. Lactate is a product of anaerobic metabolism, which generally should not occur in healthy, living brains under normal circumstances. The presence of lactate in the brains of persons with Autism Spectrum Disorder therefore suggests the presence of deficient production of energy stores by a component of brain cells called “mitochondria”. We detected lactate most commonly in the cingulate gyrus, a region that supports the higher-order control of thought, emotion, and behavior, and that has been implicated previously in Autism Spectrum Disorder.
MedicalResearch.com: Were any of the findings unexpected?
Dr. Peterson: Diseases of the mitochondria are known causes of Autism Spectrum Disorder, but until now were thought to be responsible for less than 1% of all cases of ASD. Therefore, the large number of individuals in the ASD group who had detectable lactate was surprising. Moreover, this number was almost certainly an underestimate of those who actually had elevated lactate, because measuring lactate in the brains of living people is difficult — available techniques for measuring lactate are not yet very sensitive, which means that they will frequently miss the presence of lactate when it is truly present. Prior studies have reported high rates of lactate in the body tissues of people with Autism Spectrum Disorder, but not in their brains. Therefore, seeing these high rates in the brains of persons with Autism Spectrum Disorder was also surprising. We attribute our success in detecting brain lactate in Autism Spectrum Disorder largely to the use of technical advances that made our brain imaging measures more sensitive than the techniques used to assess lactate in past studies.
MedicalResearch.com: What should clinicians and patients take away from your report?
Dr. Peterson: Our strong evidence for the common presence of mitochondrial dysfunction in persons with Autism Spectrum Disorder suggests that patients should undergo clinical evaluation for the presence of mitochondrial disease. In addition, novel treatments for known mitochondrial diseases are under development and showing promise. These might one day prove helpful in the treatment of mitochondrial dysfunction in persons who have Autism Spectrum Disorder.
MedicalResearch.com: What recommendations do you have for future research as a result of this study?
Dr. Peterson: Large-scale imaging studies that use sensitive techniques for the measurement of lactate in living persons should relate lactate levels to the clinical symptoms, clinical course, and treatment outcomes in Autism Spectrum Disorder. These studies are needed to use the identification of mitochondrial dysfunction for the improvement of clinical care in people who have ASD.
Goh S, Dong Z, Zhang Y, DiMauro S, Peterson BS. Mitochondrial Dysfunction as a Neurobiological Subtype of Autism Spectrum Disorder: Evidence From Brain Imaging. JAMA Psychiatry. 2014;():. doi:10.1001/jamapsychiatry.2014.179.