‘Presentation—3 years old’

Alice is referred by her general practitioner (GP) for a paediatric neurology opinion with a history of episodes of her legs giving way. The referral letter from her GP mentions that when Alice is picked up when she has one of these episodes, she cannot control her legs, which move abnormally.

Alice is seen by the registrar. Her parents' say that these episodes are occurring at a frequency of one every month, and they describe non-rhythmic jerky movements involving her legs lasting approximately 20 min. She falls and cannot walk or stand when these happen. Recovery occurs without intervention. She has experienced a total of five episodes, and they all occurred in the evening following exertion. Her consciousness is not impaired during these events, and between the episodes Alice is well.

The prenatal and perinatal history are normal, and her development is in keeping with her chronological age.

An interesting aspect of Alice's family history is the fact that her father had experienced similar episodes when he was 8 years old, and they had lasted until he was 13. He described episodic paroxysmal movements involving both his upper and lower limbs, and he recalled needing to sit down when these episodes occurred. He had been given the diagnosis of Sydenham's chorea by his GP.

Alice's head circumference and neurological examination are normal.

The paediatric registrar discusses Alice with the neurology consultant, and given the history of Alice's father having similar episodes in childhood, they consider the possibility of a familial movement disorder such as a ‘Benign hereditary chorea.’ Since Alice is clinically well, the decision is made not to investigate further at that point but to keep her under review. The neurologist suggests a video recording of the event should it happen again.