Box 1.

Positive clinical features of functional movement disorders

Functional hypokinetic movement disorder	Functional hyperkinetic movement disorders	Functional axial movement disorders
General	Tremor and myoclonus	Gait
Excessive slowness and fatigue	Variable frequency	Knee buckling
Giveway weakness	Entrainment to different frequencies	Excessive slowness
Distractibility and variability	Suppression with contralateral movements	Dragging one leg
Leg Weakness	Dystonia	Resolution with change of pace or direction
Hoover sign*	Fixed at onset	Decreased swaying with distraction
Hip abductor sign**	Inconsistent resistance	Absent or controlled falls
Ability to stand on heels or toes despite supine plantar or dorsiflexion weakness	Lack of sensory trick	Speech
Arm weakness	Lack of overflow	Excessively effortful
Drift without pronation	Tics	Acute onset adult stuttering
Finger abductor sign***	Not stereotypical	Variable foreign accent
Parkinsonism	“Explosive” onset in adulthood of complex tics with lack of simple tics	Swallowing
Slow tapping without speed or amplitude decrement	Lack of premonitory urge	Globus sensation despite not swallowing anything
Inconsistent rigidity	Inability to suppress

*Pressure is felt under the paretic leg when the non-paretic leg is raised. No pressure is felt in the non-paretic leg when the paretic leg is being raised

**Weakness of hip abduction in a paretic leg that resolves with contralateral hip abduction against resistance in the normal leg

***Weakness of fingers abduction that resolves with contralateral finger abduction against resistance