A case of delayed neurological manifestation following carbon monoxide poisoning in Sri Lanka: epidemiology of exposure and literature review

Delayed neuropsychiatric sequelae due to long-term effects of carbon monoxide poisoning in Ethiopia: A case report

Background

One emergency that occurs frequently and has high morbidity is carbon monoxide poisoning. After a time of lucidity, some victims who recover from the incident of acute carbon monoxide exposure may later suffer delayed neuropsychiatric sequelae (DNS), which can include cognitive impairments, a wide range of neurological abnormalities, and affective disorders. Below, we report the first documented incident of DNS after carbon monoxide poisoning in Ethiopia.

Case presentation

A 40-year-old male patient who developed a coma after he was exposed to burning charcoal in a closed room was admitted to Debre Tabor Comprehensive Specialized Hospital in the northwest region of Ethiopia. He stayed for 12 days during his first admission and was discharged with improvement. One month after discharge, he developed delayed neuropsychiatric sequelae, which manifested as bizarre behavior, being unable to walk unsupported, loss of concentration, and failure to control urine and feces. Brain MRI showed bilateral periventricular and frontoparietal deep white matter subcortical abnormal T1 and T2 prolongation with no restriction of diffusivity, possibly due to demyelinating disorders. He was managed with fluid therapy, benzhexol, risperidone, and rehabilitation therapy. He stayed for two weeks in our hospital and was discharged with improvement.

Conclusion

Despite the paucity of delayed neuropsychiatric sequelae from carbon monoxide poisoning, physicians should be highly suspicious in the right situations. The precise mechanisms of delayed toxic effects, prevention measures, and treatment modalities have not yet been determined; therefore, more research and attention are required.

A patient with toxic encephalopathy associated with acute carbon monoxide poisoning–A clinical case

Carbon monoxide (CO) is a colorless, odorless, and lacking in irritative properties gas. It has a higher affinity towards hemoglobin than oxygen and thus the complex carboxyhemoglobin develops. Acute CO poisoning leads to poly-organic insufficiency and the organs that suffer the most are the ones with higher oxygen needs- the brain, the heart and the kidneys. We present a clinical case of 49-year-old woman with a sudden appearance of complaints of dizziness, stiffness throughout the entire body, inability to move. Subsequently she was found by her relatives with disorientated and “foaming around her mouth”. Earlier she had been using a gasoline generator because of a power outage. Her laboratory results came out with higher carboxyhemoglobin (40%), nitrogen waste products and mixed type acidosis. From the conducted brain MRI there were changes, correlating to toxic encephalopathy after acute CO poisoning.

Two similar carbon monoxide poisoning cases with different outcomes: evidence from longitudinal fMRI

Prognosis after carbon monoxide (CO) poisoning is difficult to assess using structural images. Functional connectivity provided by functional magnetic resonance imaging (fMRI) may explain the mechanism of differential prognosis. We report here two cases of carbon monoxide poisoning with simultaneous coma. They were nearly normal on days 7-8, but diagnosed with delayed neurological sequelae (DNS) with cognitive and motor impairments on days 22-29. Similar Methylprednisolone pulse therapy and hyperbaric oxygen therapy were given to them. The movement disorder of case 1 improved slightly during the recovery stage, while the movement disorder of case 2 worsened significantly. In case 1, the function of supplementary motor area decreased first and then increased, and the function of pallidum increased first and then decreased. Case 2 showed a reduction in the supplementary motor area and small changes in the pallidum after DNS, but both were reduced during recovery stage. The cognitive ability of case 1 remained poor, while that of case 2 improved during the recovery stage. FMRI showed damage to the right and bilateral hippocampus in case 1 and partial damage to the left hippocampus in case 2. Taken together, fMRI can be a useful method to study functional connectivity abnormalities corresponding to different prognoses.

Investigation of the relationship between MBP gene polymorphisms and delayed encephalopathy after acute carbon monoxide poisoning

Increasing evidence reveals that delayed encephalopathy after acute carbon monoxide poisoning (DEACMP) results from the combined effects of environmental and genetic factors. The main pathological feature of DEACMP was generalized demyelination of cerebral white matter. Myelin basic protein (MBP) levels in cerebrospinal fluid (CSF) and serum samples from DEACMP patients were elevated. This study investigated the association of MBP single nucleotide polymorphisms(SNPs) (rs470555, rs470724, rs4890785, rs595997, rs76452994, and rs921336) with DEACMP. We genotyped 416 DEACMP patients and 785 age, educational level, and sex-matched ACMP patients for rs470555, rs470724, rs4890785, rs595997, rs76452994, and rs921336 SNPs using the Agena MassArray. There were no significant differences in the allele frequency distribution, four genetic models, and genotype distributions between the DEACMP and ACMP groups for rs470555, rs470724, rs4890785, and rs595997. However, significant differences were observed for rs76452994 and rs921336. This study revealed that the MBP polymorphisms, rs470555, rs470724, rs4890785, and rs595997, were not associated with DEACMP. Based on the codominant, dominant, and overdominant genetic inheritability patterns, the MBP rs76452994 and rs921366 polymorphisms were associated with DEACMP. Furthermore, the G allele of rs76452994 and T allele of rs921336 could lead to higher DEACMP risk.

DELAYED NEUROPSYCHIATRIC SYNDROME AFTER CARBON MONOXIDE POISONING

arbon monoxide (CO) is an odorless, tasteless, colorless and nonirritating gas 1. In Spain, most of the accidents due to CO poisoning are caused by water heaters2,3,4. CO binds to hemoglobin with much greater affinity than oxygen, for- ming carboxyhemoglobin (COHb) and resulting in impaired oxygen transport and utilization.XS In up to 40 percent of patients with significant CO exposure, a delayed neuropsy- chiatric syndrome (DNS) can arise 3 to 240 days after appa- rent recovery, characterized by cognitive deficits, personality changes, movement disorders, and focal neurologic deficits, which may persist for a year or longer.

Delayed brain injury post carbon monoxide poisoning

A 66-year-old male was found unresponsive and diagnosed with acute carbon monoxide poisoning, with pathognomonic findings on radiological imaging. During his first day's the patient underwent acute neurological deterioration; however, this was followed 2 weeks later with a subsequent improvement to near baseline. The improvement back to baseline was short-lived, and the patient quickly worsened and underwent neurological decompensation. These findings were consistent with delayed post hypoxic leukoencephalopathy, serious sequelae of carbon monoxide poisoning. This case report shows the importance of recognition of carbon monoxide toxicity and aims to improve accurate diagnosis of the sequelae that may follow using computed tomography and magnetic resonance imaging sequences, magnetic resonance spectroscopy in order to prevent or ameliorate further neurological decline.