A Screening Tool to Quickly Identify Movement Disorders in Patients with Inborn Errors of Metabolism

Area of Science:

• Neurology
• Metabolic Disorders
• Movement Disorders

Background:

• Movement disorders are frequently observed in patients with inborn errors of metabolism (IEMs).
• These disorders are often underrecognized by non-specialists in movement disorders.
• Early recognition is crucial for timely intervention and management.

Purpose of the Study:

• To develop a user-friendly, rapid screening tool for detecting movement disorders in patients with IEMs.
• The tool is designed for non-movement disorder specialists.
• Focus is on identifying moderate and severe movement disorders in patients aged 4 years and older.

Main Methods:

• Videos of 55 patients with IEMs were evaluated by 12 movement disorder specialists.
• Inter-rater agreement was assessed for the presence and subtype of movement disorders.
• Key tasks (walking, arm observation, spiral drawing) were identified for the screening tool.

Main Results:

• Movement disorders were present in 80% of patients, with high agreement (κ=0.900) for moderate to severe cases.
• Dystonia was the most common phenotype (27.3%).
• Walking, arm observation, and spiral drawing tasks were most informative and included in the tool.

Conclusions:

• A screening tool was developed to aid in recognizing movement disorders in IEM patients.
• This tool can help identify patients needing referral to a movement disorder specialist.
• Improved identification can lead to timely evaluation and treatment.