Ataxia Prevalence in Primary Orthostatic Tremor

Area of Science:

• Neurology
• Movement Disorders
• Neuroscience

Background:

• The pathophysiology of primary Orthostatic Tremor (OT) remains unclear, with proposed cerebellar pathway involvement.
• Clinical evidence of ataxia in OT patients is debated.
• This study aimed to prospectively investigate ataxia in OT.

Purpose of the Study:

• To systematically assess the prevalence and characteristics of ataxia in primary Orthostatic Tremor (OT).
• To compare ataxia symptoms between OT patients and healthy controls.
• To evaluate the potential role of the cerebellum in OT pathophysiology.

Main Methods:

• A prospective, multinational study enrolled 34 EMG-confirmed primary OT patients and 21 spousal controls.
• Neurological examinations included semiquantitative ataxia assessments: Detailed Limb Coordination (DLC), Detailed Stance and Gait (DS), and Brief Ataxia Rating Scale (BARS).
• Intra- and inter-rater reliability for ataxia assessments were confirmed as satisfactory.

Main Results:

• 88% of OT patients exhibited abnormal BARS items.
• OT subjects showed significantly higher rates of appendicular and truncal ataxia compared to controls, evidenced by DLC, DS, and BARS scores.
• No statistically significant differences in ocular ataxia or dysarthria were observed between groups.

Conclusions:

• Mild-to-moderate ataxia, particularly appendicular and truncal, is more prevalent in primary OT than previously recognized.
• These findings support the hypothesis of cerebellar involvement in the pathophysiology of OT.
• Further research and clinical considerations for ataxia in OT management are warranted.