Role of brain magnetic resonance spectroscopy in the evaluation of suspected mitochondrial diseases in children: Experience in 30 pediatric cases

Introduction: Mitochondrial diseases are a group of inherited disorders caused by derangement of mitochondrial respiration. MR spectroscopy (MRS) has been shown to detect abnormal accumulation of lactate in brain parenchyma and CSF in patients with mitochondrial disorders, but the frequency of detection is largely unknown. Aim of the work: To evaluate the role of brain MR spectroscopy in the assessment of suspected mitochondrial diseases in the pediatric age group. Patients and methods: Thirty children with suspected mitochondrial diseases were examined by MRS. Examination was done using multisection technique and multiple echo times mainly short (35 ms) and intermediate (144 ms). Mitochondrial disease criteria scoring system was used to confirm the suspected diagnosis. Results: All patients showed elevated lactate peak with the CSF being the most sensitive (100%). Among the 30 patients, 26 (86.7%) had elevated levels of blood lactate/pyruvate ratio. Conventional MRI showed highly suggestive features in 15 patients while non specific findings were detected in 11 patients and 4 showed normal appearing brain. Conclusions: MRS provides a noninvasive tool for the diagnosis of mitochondrial diseases, especially in children with non specific findings on MRI, normal appearing MRI or a normal blood lactate/pyruvate ratio