Summary

We report the case of a 69-year-old married man who presented with features of irritability, characterised by outbursts of anger, short-term memory deficits and clumsiness, which progressed over a period of some 20 years. A detailed review elicited motor and verbal agitation during sleep, a history that was only available from his wife. He had excessive daytime sleepiness. A parasomnia in association with his possible neurological disorder was suspected and a referral made to the sleep disorders clinic. Further investigation with polysomnography determined that the abnormal behaviours during the night were secondary to arousals caused by obstructive sleep apnoea. Treatment with continuous positive airways pressure therapy prevented the abnormal behaviours at night, improved his daytime sleepiness but also led to improvements in his clumsiness, short-term memory and temper, all corroborated by his wife.