Utilizing Cerebral Perfusion Scan and Diffusion-tensor MR Imaging to Evaluate the Effect of Hyperbaric Oxygen Therapy in Carbon Monoxide-induced Delayed Neuropsychiatric Seqeulae- A Case Report and Literature Review.

PURPOSE Detection of regional cerebral blood flow (rCBF) and/or brain magnetic resonance imaging (MRI) has been used to investigate functional defect of brain caused by carbon monoxide (CO) poisoning. In this report, we attempted to demonstrate the correlation of changes in brain singlephoton emission computed tomography (SPECT) and diffusion-tensor MR image (DTI) with functional improvement of severe delayed neuropsychiatric sequelae (DNS) after CO intoxication during the treatment of hyperbaric oxygen therapy (HBOT). CASE REPORT The patient had normal activities of daily life after he recovered from acute CO poisoning. One month later, he presented symptoms of declined cognitive functioning, aphasia, apraxia, dysphagia, muscle rigidity, urine and fecal incontinence. After one course of HBOT, these symptoms improved significantly and the patient could regain most of his previous functioning. The patient's improvement was evidenced by increased rCBF in Brodmann areas 7, 8, 11 and 40, as well as higher mean fractional anisotropy (FA) value of DTI. CONCLUSION Although the efficacy of HBOT in DNS patients is still needed to be evaluated in large clinical study, these data suggest that HBOT may be the choice to improve DNS efficiently and shorten the duration of suffering with favorable outcome.