Isolated cerebellar damage caused by carbon monoxide intoxication.

To cite: Hamcan S, Akgun V, Yilmaz O, et al. BMJ Case Rep Published online: [please include Day Month Year] doi:10.1136/ bcr-2013-201647 DESCRIPTION An unconscious 5-year-old girl with convulsions was admitted to emergency department. Her blood carboxyhaemoglobin level was 7.3%. CO intoxication was presumed and she was referred to our department for a brain MRI. In addition to conventional sequences, diffusion-weighted imaging (DWI) was also performed. Whereas there was no pathological signal change on supratentorial images, symmetrical lesions in the grey matter were observed in both cerebellar hemispheres. MRI showed hypointensities on T1weighted image (figure 1A), hyperintensities both on T2-weighted image (figure 1B) and fluid-attenuated inversion recovery image in these affected areas. A diffusion-weighted MRI revealed restricted diffusion pattern due to cytotoxic oedema (figure 2A, B) as well. As a result, CO intoxication with isolated cerebellar damage was confirmed as the final diagnosis based on these MRI findings. CO is a highly toxic gas affecting predominantly the central nervous system. Clinical features of poisoning are generally non-specific and its severity ranges from mild headache to death depending on the concentration of the exposed gas and exposure duration. In CO poisoning, as is in other hypoxic ischaemic central nervous system events, relatively poor vascularisation and ‘watershed’ areas are more vulnerable and affected earlier. The most sensitive