Abduction finger sign: A new sign to detect unilateral functional paralysis of the upper limb

Abstract

Objective of this study is testing a new sign to differentiate functional from organic paralysis of the arm. Thirty-six healthy subjects, ten patients with acute functional paralysis of one arm and eleven patients with acute organic paralysis of one arm were enrolled. The test consisted of abduction finger movements of one hand against resistance with a maximal sustained contraction to detect synkinetic abduction finger movements of the contralateral hand. For both hands, contralateral hand synkinesias were observed in healthy subjects. The task performed with the unaffected hand evoked synkinesias of the presumed affected hand in functional patients, but did not evoke synkinesias of the affected hand in organic patients. The abduction finger test had 100% sensitivity and specificity in distinguishing functional from organic paralysis of the upper limb in this cohort of patients. The abduction finger sign may be a reliable bedside test to discriminate functional from organic arm paralysis.

Interobserver agreement and validity of bedside ‘positive signs’ for functional weakness, sensory and gait disorders in conversion disorder: a pilot study

“…Among the seven validated motor signs,6 we thus excluded the abductor sign 8 and the abductor finger sign, 9 as well as motor inconsistency, 10 as we felt the short standardised recording would not allow a proper judgment on these signs. We kept the Hoover's sign, 2 as it is the best validated sign and as it could reveal co-contractions 11 12 (another positive sign) observable on the video recording.…”

Relative or Absolute? Implications and Consequences of the Measures Adopted to Investigate Motor Overflow

“…As discussed throughout this article, behavioral measures of motor overflow also provide information regarding its kinetic characteristics, its relationship with voluntary movement, and the factors that may exaggerate or suppress it (Lazarus & Whitall, 1999;Uttner, Mai, Esslinger, & Danek, 2005). Furthermore, such measures may provide simple yet effective diagnostic tools for conditions such as psychogenic palsy, where a recent study demonstrated 100% sensitivity and specificity in discerning functional from organic paralysis of the upper limb using a finger abduction task (Tinazzi et al, 2008). Nevertheless, behavioral studies have limitations.…”

The elbow flex-ex: a new sign to detect unilateral upper extremity non-organic paresis

“…Tinazzi et al 6 published a method that used synkinetic movements by measuring finger abduction strength simultaneously in both hands. When abducting against maximal resistance using the unaffected hand, it was possible to differentiate between organic and non-organic paresis by detecting any movement in the contralateral (symptomatic) hand.…”

“…There are reports of incorrect diagnoses of functional disorders being made when there is underlying organic pathology 13. There are previously described signs in the upper6 and lower3 4 extremities that appear reliable in making such distinctions. Like these previously published signs, the elbow flex-ex sign is a sensitive and specific tool to detect non-organic paresis.…”

“…Other described tests similarly use this principle of complementary opposition by examining contralateral abduction and adduction at the hip to test for non-organic lower extremity weakness 4 5. Described tests for upper extremity function use synkinesias6 7 instead of complementary opposition. We observed upper extremity contralateral synergistic limb movements during flexion and extension at the elbow.…”