Question category: Tropical medicine
A 12 year old is brought to his GP. He has been unwell for the last few days with a fever, coryza, diarrhoea and a dry cough. On examination there is evidence of small red spots with a white speck in the centre opposite the second molar on the buccal mucosa. There is also evidence of an erythematous rash on the forehead and neck. Given the most likely diagnosis, from which of the following is the most common neurological sequelae?