Synopsis
Make and communicate a rule-in diagnosis of functional neurological disorder, distinguish new emergencies and comorbidity, and support multidisciplinary rehabilitation without implying feigning or diagnostic closure.
- FND is a disorder of neurological functioning and is diagnosed through positive clinical features, not simply because imaging or laboratory tests are normal.
- Internal inconsistency means a function changes with task, attention or automatic movement; it does not mean the person is deliberately inconsistent.
- Examples include Hoover or hip-abductor signs, distractible or entrainable tremor, and specialist recognition of functional-seizure semiology.
- Explain the diagnosis clearly, name it, show a positive sign with permission and emphasise that symptoms are real and potentially reversible.
- FND can coexist with epilepsy, multiple sclerosis, migraine, Parkinsonism or other neurological disease; new symptoms are assessed normally.
- Treatment is individualised rehabilitation, commonly involving neurology, specialist physiotherapy, occupational therapy and psychological expertise.
- Trauma, stress, anxiety or depression may be relevant but are not required to diagnose FND and should not be presumed.
- Functional seizures require driving advice: the person must stop driving and notify DVLA, with relicensing determined by current standards and specialist review.
Key red flags
Sudden persistent focal deficit, aphasia, visual loss or severe imbalance requires time-critical stroke assessment regardless of previous FND.
A first seizure-like episode, status, cyanosis, significant injury, pregnancy or failure to regain baseline needs acute medical evaluation.
Progressive objective neurological signs, cognitive decline, systemic illness or a substantially different event pattern should reopen the differential.
Suicidal intent, repeated injury, unsafe driving, severe self-neglect or safeguarding vulnerability requires urgent coordinated action.
Investigation priorities
Identify reproducible signs characteristic of functional weakness, movement or sensory disturbance within a complete relevant examination.
Management branches
An appropriate neurological assessment identifies a recognised positive functional sign.
- Name FND and validate that the symptom is real, involuntary and produced by altered nervous-system functioning.
- With permission, demonstrate the positive sign and explain that preserved capacity under different conditions creates a rationale for retraining.
- Check understanding, address concerns about missed disease and provide a written plan for rehabilitation, comorbidity and new symptoms.