title: Reversible Changes of Brain Perfusion SPECT for Carbon Monoxide Poisoning-Induced Severe Akinetic Mutism.
abstract: OBJECTIVE
  This study aimed to characterize changes in regional cerebral blood flow (rCBF) in patients who experienced carbon monoxide (CO) poisoning and subsequently developed severe delayed neuropsychiatric sequelae (DNS) with akinetic mutism. We determined whether these changes were reversible in parallel with improvements in neuropsychological function in response to treatment, including hyperbaric oxygen therapy.
  
  
  METHODS
  Patients who developed severe DNS with akinetic mutism after acute CO intoxication between 2007 and 2011 were enrolled. Tc-ECD brain SPECT findings were compared between the patients with severe akinetic mutism and age-matched control subjects to characterize the pattern of rCBF. Perfusion SPECT was correlated with clinical outcomes after treatment with statistical parametric mapping (SPM8); the height threshold was P < 0.01 at peak level, and the corrected false discovery rate was P < 0.05 at the cluster level.
  
  
  RESULTS
  Seven patients with akinetic mutism were analyzed. All patients had neurological symptoms caused by acute CO exposure, and all recovered to nearly normal daily function after initial treatments. In all cases, after a "lucid interval," DNS progressed to akinetic mutism. The SPECT images acquired at the onset of akinetic mutism demonstrated variable hypoperfusion in frontal-temporal-parietal regions, with the greatest severity in the left temporal-parietal regions. In parallel, we performed functional neuropsychiatric tests. After treatment, the brain SPECT showed significantly fewer hypoperfusion regions, and neuropsychiatric tests showed dramatically improved function.
  
  
  CONCLUSIONS
  Our findings demonstrated both cerebral cortical and subcortical injuries in patients with CO-induced akinetic mutism. Improvement in rCBF correlated well with functional recovery after treatment.
authors.affiliation: From the Departments of *Hyperbaric Medicine and †Neurology, Cardinal Tien Hospital, New Taipei City; ‡School of Medicine, Fu-Jen Catholic University, New Taipei City; §Graduate Institute of Aerospace and Undersea Medicine and ∥Department of Neurology, Tri-Service General Hospital, National Defense Medical Center, Taipei; ¶Department of Radiology, Buddhist Tzu Chi General Hospital, Taichung Branch, Tanzih Township, Taichung County; and **Department of Nuclear Medicine, Cardinal Tien Hospital, New Taipei City, Taiwan, Republic of China.
authors.forename: Shao-Yuan
authors.initials: SY
authors.lastname: Chen
authors.forename: Chun-Chieh
authors.initials: CC
authors.lastname: Lin
authors.forename: Yi-Te
authors.initials: YT
authors.lastname: Lin
authors.forename: Chung-Ping
authors.initials: CP
authors.lastname: Lo
authors.forename: Chen-Hsu
authors.initials: CH
authors.lastname: Wang
authors.forename: Yu-Ming
authors.initials: YM
authors.lastname: Fan
mesh_terms: D000328:Adult; D000368:Aged; D000405:Akinetic Mutism / Q000000981:diagnostic imaging* / Q000209:etiology; D002249:Carbon Monoxide Poisoning / Q000150:complications / Q000000981:diagnostic imaging*; D002560:Cerebrovascular Circulation; D003545:Cysteine / Q000031:analogs & derivatives; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015609:Organotechnetium Compounds; D055420:Perfusion Imaging; D019275:Radiopharmaceuticals; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; C059659:technetium Tc 99m bicisate; D003545:Cysteine