Dynamometry of intrinsic hand muscles in patients with Charcot–Marie–Tooth disease

Abstract

Abstract-Background: Several problems are associated with manual muscle testing and dynamometry in the hands of patients with Charcot-Marie-Tooth (CMT) disease. Objective: To evaluate the efficacy of the Rotterdam Intrinsic Hand Myometer (RIHM) to directly measure intrinsic hand muscle strength in CMT disease. Methods: We measured hand muscle strength and hand function in 41 patients with CMT disease. Results: RIHM measurement of intrinsic strength had excellent reliability. We found overlapping RIHM strength values in Medical Research Council grades 3 to 5. High grip and pinch strength could be found in patients with severe intrinsic muscle weakness. RIHM measurements were more strongly correlated with fine motor skills of the hand than grip and pinch strength. Conclusions: The Rotterdam Intrinsic Hand Myometer is a reliable instrument to measure intrinsic hand muscles strength in patients with CharcotMarie-Tooth disease, providing more detailed information than manual muscle testing and a more direct assessment of intrinsic muscle loss than grip and pinch dynamometers.

Hand function and Disability of the Arm, Shoulder and Hand in Charcot-Marie-Tooth disease

“…A formula [32] is applied to the scores for all items to calculate a DASH score ranging from 0 (no disability) to 100 (severest disability) [25]. The optional sections of the DASH (four items concerning sports/music and four items on work activities) were omitted in the present study, in accordance with Selles et al [10].…”

“…The construct validity of DASH in persons with CMT has been evaluated. DASH was strongly correlated to the muscle strength of the wrist flexors and extensors [10] and to an activity test, the Jebsen test [11], but its correlations to grip strength and sensation have not been evaluated.…”

“…The lower limbs are usually more and earlier affected than the upper limbs and symptoms from the lower limbs have previously been the main focus of research and clinical practice [6,7]. Hand function has nevertheless been addressed recently [8][9][10][11][12][13]. Most patients indeed develop hand weakness and loss of manual dexterity [7,14], although little is still known about the extent of the reduction of hand function and especially of its impact on disability in persons with CMT.…”

“…Research on hand function in CMT has mainly focussed on this dimension including strength [7,13,19], sensory function [20][21][22], dexterity [2] or combinations of tests [8][9][10][11][12]. To obtain an overall picture of a patient's hand function at the dimension of impairment, the three important aspects of strength, sensory function and dexterity might be summarised in a total score.…”

Reliability and validity of the Manual Ability Measure-36 in persons with Charcot-Marie-Tooth disease

“…9-11 People with CMT typically have 50-67% of the grip strength of healthy adults; 9,12 however, weakened intrinsic muscles of the hand do not appear to predict impaired grip strength, presumably due to the compensatory recruitment of extrinsic hand muscles during grip. 11 Overall manual dexterity is also diminished, as people with CMT manipulate one-inch wooden cubes (Box and Block Test) much slower than controls and require 50% more time, on average, to place and remove onequarter-inch diameter wooden dowels in a peg board (Nine-Hole Peg Test). 12 Diminished sensation, including pain, temperature, vibration, and proprioception, is also a typical symptom of CMT.…”