Misdirected attentional focus in functional tremor.

Area of Science:

• Neurology
• Movement Disorders
• Cognitive Neuroscience

Background:

• Functional neurological disorder (FND) symptoms often correlate with attention levels.
• Attentional phenomena are implicated in FND, but their specific role in functional tremor remains unclear.
• Understanding attentional focus in functional tremor is crucial for developing effective interventions.

Purpose of the Study:

• To investigate if attentional focus is misdirected in functional tremor.
• To determine if this misdirection is detrimental or compensatory.
• To compare attentional strategies in functional tremor, organic tremor, and healthy controls.

Main Methods:

• Compared attentional focus during reaching movements in 17-28 participants with functional tremor, organic tremor, and healthy controls.
• Assessed motor performance under varying attentional conditions (visual feedback, no feedback, speed, accuracy).
• Measured trajectory length and movement duration as indicators of motor performance.

Main Results:

• Functional tremor patients disproportionately focused on visual feedback, unlike controls.
• Motor performance deteriorated across all groups with attention to visual feedback, accuracy, or slow movements.
• Motor performance improved in functional tremor patients when movement was unimportant or performed quickly, and in all groups without visual feedback.

Conclusions:

• Altered attentional allocation, specifically excessive focus on visual feedback, is characteristic of functional tremor.
• This altered focus may contribute to tremor by interfering with automatic movement processes.
• Distraction can improve motor performance in functional tremor, highlighting a potential therapeutic avenue.