Systematic review of movement disorders mislabeled as functional: when incongruence misleads

Daniel S Marín-Medina1,2, Joselyn Miño Zambrano2, Alberto J Espay3

  • 1Edmond J. Safra Fellow in Movement Disorders, FLENI, Buenos Aires, Argentina.

Journal of Neurology
|April 8, 2026
PubMed
Abstract

Insights

Misdiagnosing functional movement disorders (FMD) often stems from focusing on incongruence. Relying on at least two signs of neurological inconsistency significantly reduces FMD misdiagnosis rates.

Area of Science:

  • Neurology
  • Clinical Medicine
  • Diagnostic Accuracy

Background:

  • Misdiagnosis of functional movement disorders (FMD) is a persistent clinical challenge.
  • Understanding features contributing to FMD misdiagnosis is crucial for improving patient care.

Purpose of the Study:

  • To review phenomenology and clinical features linked to FMD misdiagnosis.
  • To identify diagnostic criteria associated with higher or lower rates of FMD misdiagnosis.

Main Methods:

  • Systematic review of case reports, case series, and observational studies of adults with FMD.
  • Searched PubMed for studies reporting features of inconsistency, incongruence, and low validity.
  • Analyzed isolated (iMD) and mixed (mMD) movement disorders separately.

Main Results:

  • Gait disturbance and dystonia were common isolated FMDs; jerks and rigidity were common mixed FMDs.
  • Incongruence with known diseases, psychological factors, and symptom variability were key misdiagnosis factors.
  • Applying incongruence alone or neither criterion yielded high misdiagnosis rates (49%); inconsistency alone yielded low rates (13.7%).

Conclusions:

  • Misdiagnosis of FMDs, especially gait disorders and dystonia, frequently resulted from using incongruence as a primary diagnostic criterion.
  • Ascertaining at least two positive neurological signs of inconsistency was associated with the lowest FMD misdiagnosis rates.