Sensory trick phenomenon in cervical dystonia: a functional MRI study

Area of Science:

• Neurology
• Neuroimaging
• Movement Disorders

Background:

• Idiopathic cervical dystonia (CD) is a movement disorder characterized by involuntary neck muscle contractions.
• Sensory tricks, or simple maneuvers, can sometimes provide temporary symptom relief in CD patients.
• The neural mechanisms underlying the effectiveness of sensory tricks in CD remain unclear.

Purpose of the Study:

• To investigate brain functional connectivity patterns using fMRI in CD patients with and without effective sensory tricks.
• To compare brain activity during resting state, sensory trick execution, and sensory trick imagination.
• To elucidate the role of sensorimotor networks and cerebellar involvement in sensory trick efficacy.

Main Methods:

• Recruited 17 CD patients (9 with effective sensory tricks [CD-trick], 8 without [CD-no-trick]) and 15 healthy controls.
• Utilized resting-state fMRI, fMRI during sensory trick execution, and fMRI during sensory trick imagination.
• Assessed cervical range of motion and sensory trick effect using validated instruments.

Main Results:

• CD-no-trick patients exhibited increased sensorimotor network functional connectivity compared to controls at rest.
• CD-trick patients showed decreased sensorimotor network connectivity during sensory trick execution.
• During sensory trick imagination, CD-trick patients demonstrated increased bilateral cerebellar activation compared to CD-no-trick patients.

Conclusions:

• CD is associated with altered sensorimotor network connectivity, particularly in patients without effective sensory tricks.
• Effective sensory tricks in CD patients are linked to reduced sensorimotor network connectivity during performance.
• The cerebellum may play a crucial role in modulating cortical activity for sensory trick efficacy in CD.