A Clinical Observation of Delayed Neurologic Deterioration Following Carbon Monoxide Poisoning

Abstract

Some patients with anoxic exposure develop new neurologic deficits after periods of delay when they recover from the initial anoxia. This Delayed Neurologic Deterioration(DND) is most commonly seen following carbon monoxidelf'O) poisoning. This study was done to further describe the clinical features of this interesting but rare entity. We reviewed the records and brain scans of 37 patients who were admitted to Seoul National University Hospital because of DND following CO poisoning during the period January 1980 to December 1986. On reviewing the data, we were able to see certain patterns. Age may be important in the development of DND. Most patients were in their 40's to 60's. Patients with severe CO poisoning may be at higher risk of developing DND. However many patients with DND had brief periods of unconsciousness during acute poisoning. The lucid interval was usually 1-4 weeks. Long lucid interval may predict good prognosis. Global encephalopathy was the most common. Post-CO Parkinsonism was diagnosed in 5. Parkinsonism was part of global encephalopathy. They improved with L-dopa better than with anticholinergics. Low density in the globus pallidus may not be associated with Parkinsonism. Diffuse brain atrophy was the most common radiological finding.