Functional Neurological Symptoms After Mild Traumatic Brain Injury: A Scoping Review and Framework for...

Area of Science:

• Neuroscience
• Neurology
• Psychiatry

Background:

• Persistent post-concussion symptoms (PPCS) following mild traumatic brain injury (mTBI) are prevalent and disabling.
• Symptom persistence in PPCS shows weak correlation with injury severity or structural brain abnormalities.
• There is a recognized, yet poorly synthesized, overlap between PPCS and functional neurological disorder (FND).

Purpose of the Study:

• To systematically review and synthesize evidence linking mTBI with functional neurological symptoms.
• To refine conceptual models by proposing a framework for differentiating functional and organic contributions to persistent post-concussion presentations.

Main Methods:

• A scoping review with narrative synthesis was conducted.
• Searches yielded 120 records, with 57 studies undergoing full-text review.
• Included studies encompassed various research designs, focusing on functional neurological symptoms in the context of mTBI.

Main Results:

• Substantial phenomenological overlap exists between PPCS and FND across multiple domains (cognitive, motor, sensory, etc.).
• Functional neurological symptoms can arise post-concussion, associated with psychiatric comorbidity, dissociation, trauma, and maladaptive beliefs.
• Objective neurological impairment and injury severity have weak associations with symptom persistence.

Conclusions:

• Functional neurological symptoms are a significant, under-recognized contributor to persistent symptoms after mTBI.
• A functional-organic differentiation framework acknowledging dynamic interactions is needed, moving beyond binary models.
• Improved screening, diagnostic communication, and stratified management can enhance outcomes for PPCS patients.