To characterize clinical and neuroimaging manifestations in acute carbon monoxide (CO) poisoning by analyzing etiology, symptomatology, laboratory profiles, and neuroimaging features.

Clinical characteristics analysis: each patient's exposure history, neurological symptoms, and laboratory tests were carefully analyzed and compared. Imaging analysis: each patient underwent cranial MRI to evaluate the intracranial imaging features and dynamics following acute CO poisoning.

Among the 5 patients with acute CO poisoning (1 severe case, 4 mild cases), COHb levels were significantly elevated. Patients with mild poisoning manifested clinical symptoms such as dizziness, transient consciousness disturbances, and limb convulsions, while the severe case exhibited persistent consciousness disturbances. Some patients showed elevated levels of laboratory indicators, including white blood cells, alanine aminotransferase, creatine kinase, troponin, and brain natriuretic peptide. Notably the severe patient demonstraed significantly lower mini-mental state examination (MMSE) and Montreal cognitive assessment (MoCA) scores compared to the normal range, indicative of notable cognitive impairment. In terms of imaging, MRI of the severe case revealed abnormal signals (long T1 and long T2) in the bilateral cerebral peduncle and globus pallidus, and CT of the head showed low-density lesions in the bilateral globus pallidus. For the mild cases, cranial MRI displayed widespread high signals in the diffusion weighted imaging (DWI) sequence along the cortex, which gradually disappeared after treatment, likely reflecting ischemic and hypoxic changes.

Early diagnosis and prompt treatment are imperative for patients with acute CO poisoning. In severe acute cases, imaging typically shows abnormal symmetrical signals in the globus pallidus and cerebral peduncles, whereas mild cases primarily exhibit hypoxic-ischemic changes in the cerebral cortex. Timely initiation of hyperbaric oxygen therapy during the acute phase is crucial for preventing delayed encephalopathy caused by CO poisoning and improving prognosis.