Detection and Management of Factitious Weakness

Introduction to Factitious Disorders

The American Academy of Pediatrics defines factitious disorder as the intentional production of symptoms without obvious external gain, where the motivation is to assume the sick role 1

Hoover's sign is a specific clinical test to detect nonorganic weakness, where the examiner places one hand under the heel of the "weak" leg while asking the patient to push down with the "normal" leg against resistance, and a positive sign is indicated by involuntary downward pressure from the supposedly weak leg 2, 3
Give-way weakness is characterized by inconsistent strength with sudden giving way during resistance testing, which can be an indicator of factitious weakness 1
Drift without pronation can be a sign of nonorganic weakness, as in true hemiparesis, a drifting arm typically pronates 2
Non-anatomical patterns of weakness that don't follow known neurological pathways can be an indicator of factitious weakness 1
Inconsistent performance, with variable strength when tested repeatedly or in different contexts, can be a sign of factitious weakness 4

Somatic symptom disorder is characterized by excessive thoughts, feelings, or behaviors related to somatic symptoms, and can be considered in the differential diagnosis of factitious weakness 5
Conversion disorder, which is characterized by neurological symptoms that are not compatible with recognized neurological diseases but are not intentionally produced, can be considered in the differential diagnosis of factitious weakness 1
Psychogenic Non-Epileptic Seizures (PNES) often co-occur with other functional neurological symptoms, including factitious weakness 1