Which tremor is seen in cerebellar pathway disorders such as multiple sclerosis?

• A. Resting Tremor
• B. Postural Tremor
• C. Intention Tremor
• D. Oral-Facial Dyskinesias

Answer: (C)

Tremor type reflects which brain circuit is disrupted, and cerebellar pathways produce a tremor that reveals itself during movement. When the cerebellum isn’t coordinating well, the signal that corrects ongoing motion is impaired, so the tremor appears as you try to move toward a target. This is called an intention (or kinetic) tremor: there is little to no tremor at rest, but as you perform a deliberate movement—like reaching to touch a target or performing a finger-to-nose test—the tremor grows worse as you approach the endpoint. In multiple sclerosis, demyelinating lesions can involve cerebellar circuits, leading to this characteristic intention tremor along with signs of ataxia and dysmetria.

This differs from resting tremor, which is typical of Parkinson’s disease and occurs when the limb is stationary. Postural tremor occurs when holding a position and is often seen in essential tremor or physiologic tremor. Oral-facial dyskinesias are involuntary, non-tremor movements rather than tremor per se, so they don’t fit the pattern seen with cerebellar pathway involvement.