Striatal dopamine transporter binding for predicting the development of delayed neuropsychological sequelae in suicide attempters by carbon monoxide poisoning: A SPECT study Kai-Chun Yang a , Hsiao-Lun Ku b , Chia-Liang Wu b , Shyh-Jen Wang c , Chen-Chang Yang d , Jou-Fang Deng d , Ming-Been Lee e,f , Yuan-Hwa Chou b,g, ⁎ a Department of Psychiatry, Taipei Veterans General Hospital Yuanshan Branch, Yilan, Taiwan b Department of Psychiatry, Taipei Veterans General Hospital & National Yang Ming University, Taipei, Taiwan c Department of Nuclear Medicine, Taipei Veterans General Hospital & National Yang Ming University, Taipei, Taiwan d Department of Toxicology, Taipei Veterans General Hospital & National Yang Ming University, Taipei, Taiwan e Department of Health, Taiwan Suicide Prevention Center, Executive Yuan, Taipei, Taiwan f Department of Psychiatry, College of Medicine, National Taiwan University and Hospital, Taipei, Taiwan g Institute of Neuroscience, National Yang-Ming University, Taipei, Taiwan abstract article info Article history: Received 28 September 2010 Received in revised form 22 January 2011 Accepted 14 April 2011 Keywords: Carbon monoxide poisoning (COP) Delayed neuropsychological sequelae (DNS) 99m Tc-TRODAT Dopamine transporter (DAT) Suicide Single photon emission computed tomography (SPECT) Carbon monoxide poisoning (COP) after charcoal burning results in delayed neuropsychological sequelae (DNS), which show clinical resemblance to Parkinson's disease, without adequate predictors at present. This study examined the role of dopamine transporter (DAT) binding for the prediction of DNS. Twenty-seven suicide attempters with COP were recruited. Seven of them developed DNS, while the remainder did not. The striatal DAT binding was measured by single photon emission computed tomography with 99m Tc-TRODAT. The specific uptake ratio was derived based on a ratio equilibrium model. Using a logistic regression model, multiple clinical variables were examined as potential predictors for DNS. COP patients with DNS had a lower binding on left striatal DAT binding than patients without DNS. Logistic regression analysis showed that a combination of initial loss of consciousness and lower left striatal DAT binding predicted the development of DNS. Our data indicate that the left striatal DAT binding could help to predict the development of DNS. This finding not only demonstrates the feasibility of brain imaging techniques for predicting the development of DNS but will also help clinicians to improve the quality of care for COP patients. © 2011 Elsevier Ireland Ltd. All rights reserved. 1. Introduction Suicide by charcoal burning, which results in carbon monoxide poisoning (COP), has increased rapidly in Taiwan, Hong Kong and other Asian countries (Lee et al., 2002; Liu et al., 2007). From 1998 to 2005 in Taiwan, the age-adjusted suicide rates for COP increased by 33-fold in males and 126-fold in females, resulting in COP becoming the most common method of suicide in the young and middle-aged groups (Lin and Lu, 2008). Delayed neuropsychological sequelae (DNS), a striking feature of COP, occur in 10–30% of COP patients who develop neuropsychiatric deficits after a relatively lucid interval of 3 to 240 days following recovery from acute intoxication (Ernst and Zibrak, 1998; Choi and Cheon, 1999; Weaver et al., 2002; Kao and Nañagas, 2005; Weaver, 2009). The most frequent symptoms of DNS include cognitive dysfunctions, personality changes, urine and fecal incontinence, gait disturbance, parkinsonism and other movement problems, depres- sion, anxiety and mutism (Thom et al., 1995; Ernst and Zibrak, 1998; Kao and Nañagas, 2005). Since COP produces multiple pathophysio- logical changes (Ernst and Zibrak, 1998; Hara et al., 2002; Taskiran et al., 2003; Kao and Nañagas, 2005; Weaver et al., 2007; Weaver, 2009), the mechanism for the DNS development is still unknown and urgently needs to be clarified. Several clinical factors have been suggested as predictors of DNS such as age, duration of exposure to carbon monoxide, initial loss of consciousness (LOC) and duration of unconsciousness (Ernst and Zibrak, 1998; Kao and Nañagas, 2005). Our recent study further demonstrated that the scores of the initial Glasgow Coma Scale (GCS) and Mini-Mental Status Examination (MMSE) and positive findings in brain computed tomography (CT) scans would be valuable as predictors for the development of DNS (Ku et al., 2010). Dopamine regulates several brain activities and the dopamine transporter (DAT) plays a crucial role in controlling dopamine transmission (Torres et al., 2003). Alterations of DAT have been reported in patients with neuropsychiatric diseases, such as Psychiatry Research: Neuroimaging 194 (2011) 219–223 ⁎ Corresponding author at: Department of Psychiatry, Taipei Veterans General Hospital, No. 201, Sec 2, Shih-Pai Rd, 112, Peitou, Taipei, Taiwan. Tel.: +886 2 28711290; fax: + 886 2 28768403. E-mail address: c520608@ms64.hinet.net (Y.-H. Chou). 0925-4927/$ – see front matter © 2011 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.pscychresns.2011.04.006 Contents lists available at ScienceDirect Psychiatry Research: Neuroimaging journal homepage: www.elsevier.com/locate/psychresns