Case 6. Headache and arm movements during pregnancy
Case
A 27 year old woman who was 31 weeks pregnant presented with a new headache and involuntary movements in her right arm.
The headache had been present since waking 2 days prior on waking. It had been mild at first, but had increased over several hours to a moderate level of intensity. It was accompanied by mild light sensitivity - she could tolerate the room lighting but found it unpleasant. She also noted some visual floaters, and had experienced similar a few times in the past when she had experienced migraines.
She had noticed two episodes in which her right arm began shaking for approximately 2 minutes, after which it was floppy and she was unable to move it, then it would resolve in the following 5-10 minutes with full strength regained.
She had been well in the prior weeks, with an uncomplicated course of pregnancy.
This was her first pregnancy. Her only past medical history was occasional episodic migraines, and she had not had any of these during the pregnancy.
Neurological examination was normal, including no meningism. Systemic and obsetric examinations were also normal.
She had captured footage of the second event with shaking movements using her unaffected left arm to hold her cameraphone - the right arm had rhythmic jerking in elbow flexion and extension lasting around 30 seconds. Similar but lower amplitude movements were visible in the right leg.
Where is the lesion?