Early gray matter atrophy and neurological deficits in patients with carbon monoxide poisoning

PURPOSE

To investigate early neurological deficits-related change patterns in gray matter (GM) volume in patients with carbon monoxide poisoning (COP) and GM volume differences between patients with and without delayed neurological sequelae (DNS) and those with and without T2 hyperintense lesions after COP.

METHODS

Forty-one COP patients (24 patients with DNS) and 36 sex- and age-matched healthy controls (HC) were enrolled in this study. The neurological assessments were administered within 24 h after MRI scans. Voxel-based morphometry analysis was used to detect regional GM volume change.

RESULTS

The COP group had statistically significant GM atrophy in the bilateral prefrontal and temporal lobes, anterior cingulate (ACC), thalamus, posterior cerebellum, and right hippocampus compared to the HC group. Atrophy in the left medial orbital superior frontal gyrus (SFG), bilateral ACC, and bilateral thalamus were related to lower Mini-Mental State Examination (MMSE) scores and higher Unified Parkinson's Disease Rating Scale subsection III and neuro-psychiatric inventory scores. Atrophy in the hippocampus and posterior cerebellum were also related to decrease MMSE scores. The DNS subgroup had greater GM atrophy in the limbic system than the non-DNS subgroup. Compared to the subgroup without T2 hyperintense lesions, greater GM atrophy in the limbic system, motor and visual cortex, and default network was observed in the subgroup with T2 hyperintense lesions.

CONCLUSION

GM atrophy in the medial orbital SFG, ACC, thalamus, hippocampus, and posterior cerebellum is associated with early neurological deficits in patients with COP. Greater atrophy occurred in patients with DNS and those with T2 hyperintense lesions.

Predicting scale of delayed neuropsychiatric sequelae in patients with acute carbon monoxide poisoning: A retrospective study

OBJECTIVE

To establish and validate a predictive formula for calculating the possibility of developing delayed neurological sequelae (DNS) after acute carbon monoxide (CO) poisoning to facilitate better decision-making about treatment strategies.

METHODS

This study retrospectively enrolled 605 consecutive patients who had been newly diagnosed with CO poisoning from the Central Hospital of Enshi Prefecture between January 1, 2015 and December 31, 2020. The cohort was randomly divided into two subgroups: the development cohort (n = 104) and validation cohort (n = 44). Univariate analysis and backward elimination of multivariate logistic regression were used to identify predictive factors, and a predictive formula was established. The performance was assessed using the area under the curve (AUC), the mean AUC of five-fold cross-validation, and calibration plots.

RESULTS

The formula included four commonly available predictors: initial GCS score, duration of exposure, CK, and abnormal findings on MRI. We next created a formula to calculate the risk score for developing DNS: Risk score = -4.54 + 3.35 * (Abnormal findings on MRI = yes) - 0.51 * (Initial GCS score) + 0.65 * (Duration of exposure) + 0.01 * (CK). Then, the probability of developing DNS could be calculated: Probability of DNS = 1/(1 + e ^{Risk score}). The model revealed good discrimination with AUC, and mean AUC of fivefold cross-validation in two cohort, and the calibration plots showed good calibration.

CONCLUSIONS

This study established a prediction predictive formula for predicting developing of DNS, which could facilitate better decision-making about treatment strategies.

Effects of intravascular laser phototherapy on delayed neurological sequelae after carbon monoxide intoxication as evaluated by brain perfusion imaging: A case report and review of the literature

BACKGROUND

Delayed neurological sequelae (DNS) caused by carbon monoxide (CO) intoxication poses considerable treatment challenges for clinical practitioners. In this report, we used nuclear medicine imaging and the Mini-Mental State Examination (MMSE) to evaluate the effectiveness of intravascular laser irradiation of blood (ILIB) therapy for the management of DNS.

CASE SUMMARY

A 51-year-old woman presented to our medical center experiencing progressive bradykinesia, rigidity of limbs, gait disturbance, and cognitive impairment. Based on her neurological deficits, laboratory tests and imaging findings, the patient was diagnosed with delayed neurological sequelae of CO intoxication. She received intensive rehabilitation and ILIB therapy during 30 sessions over 2 mo after diagnosis. Brain single-photon emission computed tomography was performed both prior to and after ILIB therapy. The original hypoperfusion area in bilateral striata, bilateral frontal lobe, right parietal lobe, and bilateral cerebellum showed considerable improvement after completion of therapy. The patient’s MMSE score also increased markedly from 6/30 to 25/30. Symptoms of DNS became barely detectable, and the woman was able to carry out her daily living activities independently.

CONCLUSION

ILIB therapy could facilitate recovery from delayed neurological sequelae in patients with CO intoxication, as demonstrated by improved cerebral blood flow and functional outcomes in our patient.

Clinical predictors of delayed neurological sequelae in charcoal-burning carbon monoxide poisoning

BACKGROUND

The main objective of the treatment of acute carbon monoxide (CO) poisoning is to prevent delayed neurological sequelae (DNS). However, today there is still no objective screening tool to identify patients at high risk of developing DNS. The aim of this study was to identify clinical factors that could predict DNS after acute charcoal-burning CO poisoning.

METHODS

This prospective observational study was conducted from September 1, 2019 to August 31, 2020 in a single academic medical center. Patients older than 18 years of age suffering from charcoal-burning CO poisoning were included in the study. After acute recovery, patients were followed up for six weeks to investigate for DNS development. The clinical predictors of DNS were determined using a multivariate logistic regression model.

RESULTS

Of the 217 patients-113 males (52.1%), median age 37.0 (27.5-51.5) years-included, 49 (22.6%) developed DNS. The multivariate logistic regression analysis revealed the independent predictors of DNS as a lower initial Glasgow Coma Scale (GCS) score (adjusted odds ratio (AOR): 0.73, 95% confidence interval (CI): 0.62-0.87), a longer duration of CO exposure (AOR: 2.18, 95% CI: 1.65-2.88), and the presence of acute brain lesions with high signal intensity on diffusion-weighted imaging (AOR: 5.22, 95% CI: 1.50-18.08). The created multivariate regression model predicted DNS development with high accuracy (area under the curve: 0.93, 95% CI: 0.89-0.97).

CONCLUSION

A low initial GCS score, longer exposure to CO and abnormal findings on diffusion-weighted magnetic resonance imaging can assist in the early identification of patients at high risk of DNS development.

Demographic characteristics and delayed neurological sequelae risk factors in carbon monoxide poisoning

AIM

Carbon monoxide (CO) is a colorless, odorless gas and tasteless. CO poisoning (COP) is one of the most frequently encountered inhalation poisonings. The most common cause of morbidity in COP is delayed neurological sequelae (DNS). DNS is the occurrence of neuropsychiatric findings within 2-240 days after discharge of patients with COP and there are no definitive diagnostic criteria. The aim of our study is; to determine the risk factors and incidence of DNS.

METHOD

Our study is a retrospective, observational study. Patients with the diagnosis of COP in the emergency department between 2015 and 2016 were included in the study. Patients age, gender, findings in the initial physical examination (PE) and neurological examination (NE), blood carboxyhemoglobin (COHb) level, relation between hyperbaric oxygen (HBO) treatment and DNS were assessed.

RESULTS

Total of 72 patients were included in the study. Mean age was 33.43 ± 20.89. It was determined that pathological findings in the initial NE are a significant predictive factor for DNS (Odds ratio 18.600, p:0.004). Significant relation between NE and HBO treatment was present (p:00.1). There was no statistically significant relationship between initial COHb level and receiving HBO treatment (p:0.9). Median COHb level of patients with DNS was 30 (min:10, max: 43), median COHb level of patients without DNS was 25 (min:10, max:44) and there was no statistically significant relationship between the two groups according to COHb levels (p:0.7).

CONCLUSION

Pathological findings in the initial neurological examination had a predictive value for delayed neurological sequelae in patients with carbon monoxide poisoning.

Myocardial injury was associated with neurological sequelae of acute carbon monoxide poisoning in Taiwan

BACKGROUND

Carbon monoxide (CO) poisoning has recently become a serious health problem in some Asian countries, including Taiwan. The aims of this study are to evaluate the changing trend of CO poisoning and to demonstrate the association between myocardial injury and neurological sequelae of CO poisoning in Taiwan between 1990 and 2011.

METHODS

This retrospective cohort study included all eligible patients with acute CO poisoning reported to the Taiwan National Poison Control Center during the study period. The changing trend of CO poisoning and its impacts on the primary outcomes, i.e., persistent neurological sequelae (PNS) and delayed neurological sequelae (DNS), were then assessed.

RESULTS

786 CO poisoned cases were reported. Among them, 467 cases were intentional. Intentional CO exposure started to become the major cause of CO poisoning in Taiwan in 2002. Increase in the number of intentional CO poisoning significantly correlated with the increase in the overall number of CO poisoning (r = 0.972, p < 0.001). Patients who took tranquilizer (OR = 3.89; 95% CI:1.94-7.77), had myocardial injury (OR = 1.70; 95% CI:1.03-2.82), had been stayed in intensive care unit (OR = 2.03; 95% CI:1.13-3.62), presented with GCS less than 9 (OR = 4.05; 95% CI:2.32-7.08) and had abnormal brain image (OR = 14.46; 95% CI:5.83-35.83) had a higher risk of PNS. Moreover, patients who were older age (OR = 1.04; 95% CI:1.02-1.07), had psychiatric disorder history (OR = 2.82; 95% CI:1.35-5.89), had myocardial injury (OR = 1.33; 95% CI:1.16-1.53), and presented with GCS less than 9 (OR = 3.23; 95% CI:1.65-6.34) had a higher risk of DNS.

CONCLUSION

The pattern of CO poisoning had changed markedly during the study period, with a significant increase in both the numbers of intentional and overall CO poisoning. Moreover, intentional CO poisoning was associated with a higher risk of neurological sequelae, which was mediated by various indicators of poisoning severity such as myocardial injury and GCS less than 9.

Plasma copeptin as a predictor of intoxication severity and delayed neurological sequelae in acute carbon monoxide poisoning

The present study was designed to assess the usefulness of measuring plasma levels of copeptin (a peptide co-released with the hypothalamic stress hormone vasopressin) as a biomarker for the severity of carbon monoxide (CO) poisoning and for predicting delayed neurological sequelae (DNS). Seventy-two patients with CO poisoning and 72 sex and age matched healthy individuals were recruited. Plasma copeptin levels were measured on admission from CO poisoning patients and for healthy individuals at study entry by using a sandwich immunoassay. The CO poisoning patients were divided into two groups according to severity (unconscious and conscious) and occurrence of DNS. The mean plasma copeptin levels (52.5±18.5 pmol/L) in the unconscious group were significantly higher than in the conscious group (26.3±12.7 pmol/L) (P<0.001). Plasma copeptin levels of more than 39.0 pmol/L detected CO poisoning with severe neurological symptoms e.g. unconsciousness (sensitivity 84.6% and specificity 81.4%). The plasma copeptin levels were higher in patients with DNS compared to patients without DNS (52.2±20.6 pmol/L vs. 27.9±14.8 pmol/L, P<0.001). Plasma copeptin levels higher than 40.5 pmol/L predicted the development of DNS (sensitivity 77.8%, specificity 82.1%). Plasma copeptin levels were identified as an independent predictor for intoxication severity [odds ratio (OR) 1.261, 95% confidence interval (CI) 1.112-1.638, P=0.002] and DNS (OR 1.313, 95% CI 1.106-1.859, P=0.001). Thus, plasma copeptin levels independently related to intoxication severity and were identified as a novel biomarker for predicting DNS after acute CO poisoning.