Magnetic resonance spectroscopy in autistic children : relation to severity

الملخص EN

Background : There is strong evidence that autism is associated with abnormal brain development.

Disorders of the amygdaloid-hippocampal region and cerebellum are considered to play an important role in the characteristic cognitive and emotional dysfunction in autism.

Magnetic resonant spectroscopy (MRS) provides a functional image and measures the molecular and metabolic changes thajyxcur in the brain.

AiriB ? to evaluate the neurobiological abnormalities in a sample of Egyptian autrelic children, using MRS technique to evaluate the ratios of the major brain metabolites in the left cerebellum (LC) and left amygdaloid-hippocampal (LH) regions and to assess their relevance to the severity of the disease.

Methods : This cross-sectional study extended over a period of 12 months.

Twenty one autistic children recruited from the Clinical Genetics Clinic, National Research Centre, Egypt were enrolled in the study.

Seven apparently healthy sex and age matched children served as controls.

Enrolled patients and controls were subjected to detailed history taking, clinical examination and pedigree construction.

Rating of the severity of autism using Childhood Autism Rating Scale (CARS} was donerAccording to CARS, patients were classified into, mild, moderate and severe subgroups.

MRS was performed for all autistic patients and controls, evaluating the ratios of major metabolites including N-acetylaspartate/choline (NAA/Cho), N-acetylaspartate/creatine (NAA/Cr), choline/creatine (Cho / Cr) and myb-inositol / creatine (Mi / Cr).

Results: The MRS results revealed that NAA/Cr (LH), NAA/Cho (LC) and Mi/Cr (LH) were significantly lower, while Cho/Cr (LC) was significantly higher among patients and their subgroups compared to controls.

However, other ratios of MRS finding were not significantly different among patients and controls.

The mean values of NAA/Cho (LC), NAA/Cr (LC) and Mi/Cr (LH) were significantly lower among patients with moderate compared to those with mild autism.

Meanwhile, the mean value of Cho / Cr (LC) was significantly higher while, the mean values of NAA/Cho (LC) and NAA / Cr (LC) were significantly lower among patients with severe compared to those with mild autism.

However, there were no significant differences between patients having moderate and those with severe autism regarding the MRS results.

In the left cerebellar region, the NAA/Cr ratio had significant negative correlation while Cho / Cr ratio showed significant positive correlation with the degree of severity of autism according to CARS.

Conclusion : This study highlights the possibility that changes of the major brain metabolites in autistic children are variable and correlate with the severity of the disease and that MRS may be helpful in diagnosis and can be used as a follow up