Table 1

Examples of positive signs in functional disorders that can be shared with a patient to explain the diagnosis

Positive finding
Motor symptoms
 Hoover’s sign27 (figure 1)Hip extension weakness that returns to normal with contralateral hip flexion against resistance
 Hip abductor sign28Hip abduction weakness returns to normal with contralateral hip abduction against resistance
 Other clear evidence of inconsistencyFor example, weakness of ankle plantar flexion on the bed but able to walk on tiptoes
 Global pattern of weaknessWeakness that is global, affecting extensors and flexors equally
Movement disorder
 Tremor entrainment test29Patient with a unilateral tremor is asked to copy a rhythmical movement with their unaffected limb: the tremor in the affected hand either ‘entrains’ to the rhythm of the unaffected hand, stops completely or the patient is unable to copy the simple rhythmical movement
 Fixed dystonic posture30A typical fixed dystonic posture, characteristically of the hand (with flexion of fingers, wrist and/or elbow) or ankle (with plantar and dorsiflexion)
 Typical ‘functional’ hemifacial overactivity31 (figure 2)Orbicularis oculis or orbicularis oris over-contraction, especially when accompanied by jaw deviation and/or ipsilateral functional hemiparesis
 Reduced postural sway with distraction32Abnormal sway that resolves during tasks such as assessing numbers written on the back or using a phone
Non-epileptic attacks26
 Prolonged attack of motionless unresponsivenessParoxysmal motionlessness and unresponsiveness lasting longer than a minute
 Long durationAttacks lasting longer than 2 min without any clear cut features of focal or generalised epileptic seizures
 Closed eyesClosed eyes during an attack, especially if there is resistance to eye opening
 Ictal weepingCrying either during or immediately after the attack
 Memory of being in a generalised seizureAbility to recall the experience of being in a generalised shaking attack
 Presence of an attack resembling epilepsy with a normal EEGA normal EEG does not exclude frontal lobe epilepsy or deep foci of epilepsy but does provide supportive evidence
 Visual symptoms33
 Fogging testVision in the unaffected eye is progressively ‘fogged’ using lenses of increasing dioptres whilst reading an acuity chart. A patient who still has good acuity at the end of the test must be seeing out of their affected eye
 Tubular visual fieldThe patient has a field defect of the same width at 1 m as at 2 m