The patient is an 86-year-old right-handed female who presents for evaluation of tremor and episodic stiffness. She had attacks of muscle stiffness since about age 9. Attacks have a prodrome of tongue heaviness and difficulty in speaking, followed by abnormal sensation in bilateral upper extremities. She remains fully conscious during the episodes. The actual episodes consist of dystonia of trunk associated with unilateral or bilateral upper and lower extremity chorea. About a quarter of the attacks are unilateral. There is complete resolution of symptoms between attacks except for persistent mild horizontal and vertical head tremor as well as action tremor of both extremities, also with onset at age 9. Hence she was able to play baseball and basketball at this age. There is an extensive family history of similar episodes but not tremor inherited in autosomal dominant fashion.
Psychological stress can trigger episodes, as a few have occurred just after medical appointments and phlebotomy. Caffeine exacerbates her condition. She refuses to drink coffee and only rarely drinks tea, both of which can cause attacks. She is able to handle a half a cup of hot chocolate with milk each morning. She does not drink alcohol. Surprisingly, evening diazepam did not prevent episodes and daytime as needed diazepam did not abort episodes. She will try clonazepam as that was reported to be more effective in PNKD.
The frequency of attacks was about once a month, but two and a half years ago it has escalated to once a day. Duration of attacks increased from half an hour to two hours. In addition, amplitude of action tremor of the hands as well as persistent horizontal and vertical head tremor worsened at that time. Two years ago she was diagnosed with breast cancer (3.3 cm Grade III infiltrative ductal carcinoma, Her2Neu positive, negative lymph node biopsy), which was treated with excision and localized radiation. Her episode frequency and length slowly returned towards baseline after treatment was completed.
In addition, she believes that her current exercise regimen utilizing 1 kg weights helps reduce frequency of attacks. This is in stark contrast to paroxysmal exercise induced dystonia (PED) and paroxysmal kinesigenic choreoathetosis/dyskinesia (PKC/PKD), which are episodic disorders triggered by exercise and sudden movements, respectively.