Functional Weakness and Sensory Disturbance
Various signs have been deemed useful indicators of functional or "nonorganic" neurological illness, including:
Collapsing or "give way" weakness Hoover’s sign
Babinski’s trunk-thigh test "Arm drop"
BelleindifférenceSternocleidomastoid sign Midline splitting sensory loss Functional postures, gaits:
Monoplegic "dragging" Fluctuation of impairment Excessive slowness, hesitation "Psychogenic Romberg" sign "Walking on ice"
Uneconomic posture, waste of muscle energy Sudden knee buckling
Although such signs may be suggestive, their diagnostic utility has never been formally investigated in prospective studies, and many, if not all, have been reported with "organic" illness. Hence it is unwise to rely on them as diagnostic indicators.
Lempert T, Brandt T, Dieterich M et al. How to identify psychogenic disorders of stance and gait: a video study in 37 patients. Journal ofNeurology 1991; 238: 140-146
Stone J, Zeman A, Sharpe M. Functional weakness and sensory disturbance. Journal of Neurology, Neurosurgery and Psychiatry 2002; 73: 241-245