22nd June 2023

A 34-year-old man is brought in by ambulance after an episode of weakness in his left side

A 34-year-old man is brought in by ambulance after an episode of weakness in his left side.

In the A&E clerking, it is documented that his partner reports that at home the patient was feeling well until he suddenly had rhythmic jerking of the right fingers, then right hand and then right arm that lasted for 30 seconds. He also had some lip smacking at the same time. He was awake throughout and didn’t notice the episode happening.

The left-sided weakness developed soon after the episode and lasted a few minutes until just after the ambulance crew arrived.

When you examine the patient, he has no focal neurology, including resolved normal power in the left arm and the left leg. The CT head you ordered is reported as showing nothing acute.

What is the most likely cause of the patient’s presentation?