Phenotype-specific diagnosis of functional (psychogenic) movement disorders

Area of Science:

• Neurology
• Psychiatry
• Movement Disorders

Background:

• Current diagnostic criteria for functional (psychogenic) movement disorders (FMDs) rely on psychiatric symptoms and historical data, leading to uncertainty.
• Probable and possible FMD categories lack the precision to definitively diagnose or exclude the condition, limiting their clinical utility.

Purpose of the Study:

• To propose phenotype-specific diagnostic criteria for clinically definite functional movement disorders (FMDs).
• To enhance diagnostic reliability and reduce misdiagnosis by focusing on core clinical features.

Main Methods:

• Identifying unequivocal and reliably incongruent or inconsistent clinical features specific to each FMD phenotype.
• Prioritizing core, mandatory examination findings over supportive but less sensitive historical and psychiatric data.

Main Results:

• A handful of consistent clinical features can establish a definite FMD diagnosis, irrespective of psychiatric symptoms.
• The proposed criteria aim to improve inter-rater reliability in diagnosing FMDs.

Conclusions:

• Phenotype-specific criteria for definite FMD diagnosis are more reliable than current methods.
• Focusing on objective clinical signs minimizes false-positive diagnostic errors in functional movement disorders.