“Striatal Hand Signs” and early diagnosis of Parkinson’s Disease: The “Monkey-Wrench Sign”

Background: Striatal hand signs, first described by Charcot, are reported in 10% of advanced Parkinson’s Disease patients as flexion of the metacarpophalangeal joints, extension of proximal interphalangeal joints, flexion of distal interphalangeal joints and ulnar deviation. Another deformation is the metacarpophalangeal joints flexion and thumb medialization (U shaped - “Monkey-Wrench sign”). We believe that mild hand deformities are present in earlier phases of the disease and may help the diagnosis of PD. Objectives: To identify hand deformities in PD patient. Methods: We evaluated 36 PD patients, according to UKPDS Brain Bank Diagnostic Criteria, side of onset, disease duration, severity by UPDRS part III - left/ right side, hand deformities and the “monkey-wrench sign”. Results: We had 14 patients 10 years. 2/3 had left side onset. 33 patients (91.67%) presented the “Monkey- Wrench sign”, unilaterally or asymmetrically, and it was present in all PD patients > 4 years of disease onset, but it was present only in 78.6% less than 4 years. The “MW” sign was easily detected in the more affected side, with a mean UPDRS score of 31.1 on the side of striatal hand signs compared to the mean score of 24.7 on the less affected side. Conclusions: Striatal hand deformities and the “Monkey-Wrench” sign may be useful to diagnosis PD, if unilateral or asymmetrical signs, as well as, it could be used to differentiate between tremors of PD and other etiologies, in a more visual way.