Glutamate-based magnetic resonance spectroscopy in neuroleptic malignant syndrome
A 55-year-old man was admitted with a history of acute-onset high-grade fever, severe generalized tremors and an altered level of consciousness for the last 2 days. On admission, the patient had a pulse rate of 116 beats/min, blood pressure 140/80 mm Hg, temperature 103.4°F respiratory rate of 32/min, and oxygen saturation of 95% although inhaling room air. The patient was being treated for bipolar disorder for the last year. He was on risperidone (30 mg/day), clonazepam (0.5 mg/day) and olanzapine (7.5 mg/day). Neurological examination revealed Glasgow coma score 12/15, disorientation, lead-pipe rigidity, brisk jerks, and coarse tremors. Examination of the other systems was normal.\nThe patient's treatment was initiated with cooling blankets, intravenous infusion of acetaminophen, and lorazepam. Routine investigations of blood revealed elevated erythrocyte sedimentation rate (100 mm 1st h), raised serum creatinine (1.5 mg/dl), and a very high creatine phosphokinase level (3522 Units/dl). His electrocardiogram and chest X-ray were normal. Bacterial and fungal cultures of blood were negative.\nMagnetic resonance imaging of the brain was obtained with a 1.5T scanner (General Electric, USA). T2 sequences showed mild hyperintensities in basal ganglia bilaterally []. Simultaneously, magnetic resonance spectroscopy was carried out with single [inner green box in ] and multi-voxel regions [outer white box in ] of interest. The regions of interest (ROI) were specified manually. shows a similar image at a different level. shows the presence of increased levels of glutamate in the single-voxel ROI (625 mm2) (arrowhead) with relaxation time (TR) 4200 and excitation time TE 103.8. A heat map of the glutamate concentration was generated [Figure and ], which showed increased levels of glutamate in both the basal ganglia.\nThe contribution of each hemisphere to the clinical scenario was analysed by parallel-beam radon transformation analysis of the heat map generated by magnetic resonance. This was carried out using the image analysis toolbox of MATLAB (MATLAB 2008a, MA, USA). The result showed marked symmetry [], confirming equal participation of both hemispheres.