Writer’s clamp or musician spasm are focal task-specific acquired forms of restricted dystonia
Who is most commonly affected?
Writers clamp affect Men and women equally. The age group most commonly affected is between the ages of 20 and 50 years.
Seen in professionals such as telegraphers, doctors, musicians playing piano or fingering the violin, etc.
What are symptoms one may experience?
- In the most common form, writer’s cramp, the patient observes, upon attempting to write, that all the muscles of the thumb and fingers either go into spasm.
- One may experience feelings of stiffness and pain or hampered in some other inexplicable way. It can also involve the forearm or even the upper arm and shoulder.
- Occasionally they may display a tremor that interferes with the execution of cursive movements.
- An important characteristic is that spasm disappears immediately upon cessation of writing.
- Most often neurological examination is normal with normal execution of motor activities.
How it occurs?
Scientists have shown a reduction of sensory feedback to control motor response is resp[oncible for excessive and persistent motor activity.
Studies also have shown the reduced volume of gray matter on the side affected in the sensorimotor cortex, thalamus, and cerebellum corresponding to the affected hand.
Botulinum toxin injection:
It is the most widely used treatment. A botulinum toxin is injected into specifically involved muscles of the hand and forearm in cases of writer’s cramp. EMG detection of specific muscles involved can help to improve the success rate.
Transcutaneous electrical stimulation (TENS) of the forearm in 20-minute sessions has a modest effect.
Lifestyle modification including reduction in writing, change in griping pen may have some benefits.