Neurologic diagnostic criteria for functional neurologic disorders

Area of Science:

• Neurology
• Neuroscience
• Psychiatry

Background:

• Functional neurologic disorders (FND) present diagnostic challenges.
• Accurate diagnosis is crucial for effective treatment and patient outcomes.
• Existing diagnostic tools for FND subtypes require ongoing evaluation.

Purpose of the Study:

• To review current diagnostic criteria and rating scales for functional/psychogenic sensorimotor disturbances, psychogenic nonepileptic seizures (PNES), and functional movement disorders (FMD).
• To assess the reliability and limitations of available diagnostic signs and scales for these conditions.

Main Methods:

• Literature review of diagnostic criteria and rating scales for FND subtypes.
• Analysis of reported diagnostic signs for sensorimotor disturbances, PNES, and FMD.
• Evaluation of evidence supporting specific diagnostic features and scales.

Main Results:

• A new sensorimotor scale shows promise but has limitations; specific motor and sensory signs are highly reliable.
• Eight signs demonstrate good evidence for differentiating PNES from epileptic seizures.
• Diagnostic criteria for PNES are recently developed; their performance needs evaluation. Normal EEG can suggest PNES.
• FMD diagnosis relies on refined criteria, potentially aided by specific tests. Rating scales for PNES and FMD exist but have limitations.

Conclusions:

• Reliable diagnostic signs and criteria exist for PNES and FMD, aiding clinical differentiation.
• Further validation of new diagnostic criteria and scales is needed for PNES and FMD.
• Despite advancements, challenges remain in the definitive diagnosis and severity assessment of functional neurologic disorders.