Quiz Form

Question Date: 25/10/2023

Question: A 29-year-old woman with multiple sclerosis presents because of a new-onset tremor in her right arm that she first noted upon awakening that morning. The tremor is quite disabling, and she is distressed by the symptom as it interferes with her ability to hold utensils to eat. On examination, a large-amplitude tremor is evident in the patients right arm, which is present at rest and worse when her right arm is held out in front of her body. It also clearly worsens as she approaches a target<br><br>Which of the following is the most likely localization of the lesion that is causing the tremor?

Options:

• Left inferior cerebellar peduncle
• Right inferior cerebellar peduncle
• Left superior cerebellar peduncle
• Right superior cerebellar peduncle

Correct Answer: Right superior cerebellar peduncle

Explaination: This patient has multiple sclerosis and presents with an acute-onset tremor in the right arm that is present at rest but also has postural and intention features. This type of tremor is known as a rubral or Holmes tremor and has traditionally been attributed to lesions in the ipsilateral red nucleus (hence the term rubral tremor). However, the tremor can also occur with lesions that interrupt cerebellar outflow to the red nucleus via the superior cerebellar peduncle, as well as with posterior thalamic lesions.

Reference: Edwards MJ, Deuschl G. Tremor syndromes. Continuum (Minneap Minn). 2013 Oct19(5 Movement Disorders)1213-24. doi 10.121201.CON.0000436153.01167.a6. PMID 24092287.