Research progress on head imaging features of carbon monoxide poisoning and delayed encephalopathy / 中华劳动卫生职业病杂志

Acute carbon monoxide poisoning and its delayed encephalopathy have obvious damage to the central nervous system. There are different neuroimaging changes in different stages of the disease, and they are relatively specific. This article reviews the clinical research progress on the imaging changes of carbon monoxide poisoning and delayed encephalopathy, including computed tomography (CT) , conventional magnetic resonance imaging (MRI) , diffusion weighted imaging (DWI) , diffusion tensor imaging (DTI) , diffusion kurtosis imaging (DKI) , magnetic resonance spectroscopy (MRS) and other imaging changes reflecting the function and metabolic state of the brain tissue.

Correlation of computed tomography, magnetic resonance imaging and clinical outcome in acute carbon monoxide poisoning / Correlação de tomografia computadorizada, ressonância magnética e resultados clínicos em intoxicação aguda por monóxido de carbono

Abstract Background and objectives: Carbon monoxide is a toxic gas for humans and is still a silent killer in both developed and developing countries. The aim of this case series was to evaluate early radiological images as a predictor of subsequent neuropsychological sequelae, following carbon monoxide poisoning. Case 1: After carbon monoxide exposure, early computed tomography scans and magnetic resonance imaging findings of a 52-year-old woman showed bilateral lesions in the globus pallidus. This patient was discharged and followed for 90 days. The patient recovered without any neurological sequela. Case 2: In a 58-year-old woman exposed to carbon monoxide, computed tomography showed lesions in bilateral globus pallidus and periventricular white matter. Early magnetic resonance imaging revealed changes similar to that like in early tomography images. The patient recovered and was discharged from hospital. On the 27th day of exposure, the patient developed disorientation and memory impairment. Late magnetic resonance imaging showed diffuse hyperintensity in the cerebral white matter. Conclusion: White matter lesions which progress to demyelination and end up in neuropsychological sequelae cannot always be diagnosed by early computed tomography and magnetic resonance imaging in carbon monoxide poisoning.

Resumo Justificativa e objetivos: Monóxido de carbono é um gás tóxico para os seres humanos, além de ser um assassino silencioso tanto em países desenvolvidos quanto em desenvolvimento. O objetivo desta série de casos foi avaliar as imagens radiológicas iniciais como um preditivo de sequelas neuropsicológicas decorrentes de intoxicação por monóxido de carbono. Caso 1: Após exposição ao monóxido de carbono, os achados iniciais em tomografias computadorizadas e ressonâncias magnéticas de uma mulher de 52 anos mostraram lesões em globo pálido bilateralmente. A paciente recebeu alta e foi acompanhada por 90 dias. Recuperou-se sem sequelas neurológicas. Caso 2: Paciente do sexo feminino, 58 anos, exposta ao monóxido de carbono. A tomografia computadorizada mostrou lesões em globo pálido, bilateralmente, e substância branca periventricular. A ressonância magnética inicial revelou alterações semelhantes àquelas em tomografias precoces. A paciente se recuperou e recebeu alta. No 27° dia de exposição, evoluiu com desorientação e perda de memória. Ressonância magnética posterior mostrou hiperintensidade difusa da substância branca cerebral. Conclusão: As lesões da substância branca que progridem para desmielinização e resultam em sequelas neuropsicológicas nem sempre podem ser diagnosticadas em tomografias e ressonâncias iniciais em casos de intoxicação por monóxido de carbono.

Evaluation of outcome after acute carbon monoxide poisoning by brain CT

Of 129 patients with carbon monoxide (CO) poisoning, 62(48.0%) had characteristic computed tomographic (CT) findings. The most common finding, seen in 42 patients, was low-density in the cerebral white matter, and the second characteristic feature, seen in 33 patients, was low-density in both globus pallidi. Abnormal CT findings tended to increase in accordance with the duration of unconsciousness during acute CO poisoning, but such findings occurred even when the mental state was clear during acute illness. The prognosis of acute CO poisoning depended on low-density lesions of the cerebral white matter rather than those of the globus pallidus. There also seemed to be a significant correlation between the cerebral white matter changes in the initial CT scan and the development of delayed neurologic sequelae after acute CO poisoning, particularly in middle age or older patients, but no correlation between the CT findings and the clinical outcome of delayed neurologic sequelae.

Clinical Study on Carbon Monoxide Intoxication in Children

Carbon monoxide intoxication has long been one of the most serious public health problems in Korea. This is mainly due to the wide use of anthracite coal briquettes as domestic fuel for cooking and under-the floor heating. One hundred and seven cases of CO intoxicated children hospitalized at Yonsei Medical center from January 1970 to December 1986 have been investigated clinically. The sex ratio was 1.3:1 (male 60 cases, female 47 cases) with the peak incidence occuring in patients between 12 and 14 years of age (28%). The most common symptoms were vomiting convulsions and headache; and the most frequent signs were altered mental state, increased deep tendon reflex and a positive Babinski sign. The outcome of patients was as follows: 4 cases (3.7%) expired, 77 cases (72.0%) recovered without neurologic sequelae and 26 cases (24.3%) survived with neurologic sequelae. The neurologic sequelae included persistent convulsions (7 cases), cortical blindness (3 cases), peripheral neuropathy (2 cases) and delayed neurologic sequelae (11 cases). Neurologic sequelae occurred most frequently in comatose patients (45.5%) and least often in mentally alert patients (6.1%), more frequently m patients exposed to CO gas for more than 8 hours than in those exposed for less than 8 hours, and in patients who did not receive hyperbaric oxyen therapy(29.4%) than in those who did(19.6%). Delayed neurologic sequelae were mental retardation (72.7%), epilepsy (36.4%), mutism (18.2%) etc. The lucid interval in 11 cases of delayed neurologic sequelae ranged from 2 to 20 days. The results of this study suggest that every patient exposed to CO gas should receive prompt and efficient oxygenation including hyperbaric oxygen therapy and that expeditious reduction of cerebral edema maybe of value. The importance of providing follow-up facilities in anticipation of a relapse of the delayed neurologic sequelae has been established.