Diffusion‐tensor MR imaging for evaluation of the efficacy of hyperbaric oxygen therapy in patients with delayed neuropsychiatric syndrome caused by carbon monoxide inhalation

Abstract

The purpose of this study is to assess the efficacy of hyperbaric oxygen therapy (HBOT) in patients with delayed neuropsychiatric syndrome (DNS) caused by carbon monoxide (CO) inhalation using diffusion tensor magnetic resonance (MR) imaging and neuropsychological test. Conventional and diffusion tensor brain MR imaging exams were performed in six patients with DNS immediately before and 3 months after the HBOT to obtain fractional anisotropy (FA) values. Six age- and sex-matched normal control subjects also received MR exams for comparison. Mini-Mental State Examination (MMSE) was also performed in patients immediately before and 3 months after the HBOT. A significantly higher mean FA value was found in control subjects as compared with the patients both before and 3 months after the HBOT (P < 0.001). The mean FA value 3 months after the HBOT was also significantly higher than that before the HBOT in the patient group (P < 0.001). All of the patients regained full scores in the MMSE 3 months after the HBOT. Diffusion tensor MR imaging can be a quantitative method for the assessment of the white matter change and monitor the treatment response in patients of CO-induced DNS with a good clinical correlation. HBO may be an effective therapy for DNS.

White Matter Damage in Carbon Monoxide Intoxication Assessed in Vivo Using Diffusion Tensor MR Imaging

“…[1][2][3][4][8][9][10][11][12][13][14][15] They include hindered executive function and slowed mental processing speed, which are often observed after frontal lobe damage, and altered visuospatial abilities, which are commonly observed after parietal lobe injury. 10 Central executive function involves corticocortical connectivity, 31 which depends mainly on complex WM networks.…”

“…8,[12][13][14][15] Among these techniques, diffusion tensor imaging (DTI) is a quantitative and noninvasive method that permits clinicians to delineate the anatomy of WM pathways by measuring molecular diffusiondriven displacement in restricted organized tissues. The directionality of water diffusivity can be quantified by measuring fractional anisotropy (FA), whereas the apparent diffusion coefficient (ADC) indicates the degree of molecular mean diffusivity.…”

The Role of MR Imaging in Assessment of Brain Damage from Carbon Monoxide Poisoning: A Review of the Literature

“…Most such evaluations have reported low FA values, suggesting a reduction in the directionality of water molecule diffusion because of demyelination, when DTI was performed in the subacute or chronic phases after the appearance of DNS. 49,[54][55][56] Low FA values might continue until 3 months after poisoning, 55 and improvement in FA has correlated with improvement in DNS. 49,56 These changes in FA values should sensitively demonstrate progressive demyelination causing DNS and gradual remyelination while DNS improves.…”

“…Different areas where the region of interest is placed on the CWM might influence the FA values. Lo et al 55 reported FA values measured by using regions of interest placed on the centrum semiovale and explained why they placed regions of interest on these areas as follows. All patients in their study showed abnormalities in the deep WM involving the centrum semiovale on T2-weighted imaging, and areas involving the centrum semiovale were relatively homogeneous WM zones related to worse cognitive performance.…”

Diffusion Tensor Imaging for Predicting the Clinical Outcome of Delayed Encephalopathy of Acute Carbon Monoxide Poisoning

“…Previous studies have described FA measurements in patients with CO poisoning and DEACMP [7,8,9]. Decreased FA suggests that a certain amount of demyelination has occurred in patients with DEACMP.…”