Functional Neurological Symptom Disorder is characterized by what main feature?

• A. Intentional deception for external gain.
• B. Symptoms are exclusively due to medical condition.
• C. Symptoms are caused by substance use.
• D. One or more symptoms of altered voluntary motor or sensory function with incompatibility with known neurological conditions.

Answer: (D)

Functional Neurological Disorder revolves around symptoms of altered voluntary motor or sensory function that do not fit with any known neurological disease. The defining feature is this mismatch or incompatibility: the way the symptoms present and progress isn’t explainable by typical neurological conditions, even though the person truly experiences them and it can cause real distress or impairment. Importantly, these symptoms are not produced on purpose; they’re not due to deliberate deception (malingering) or external gain. So the best description highlights real, involuntary-appearing neuro symptoms that are incompatible with established neurology.