Changes in cortical relative power in patients submitted to a tendon transfer: a pre and post surgery study

Silva, Julio Guilherme; Knackfuss, Irocy Guedes; Portella, Cláudio Elidio; Machado, Sérgio; Velasques, Bruna; Bastos, Víctor Hugo; Queiroz, Ricardo de Andrade; Neves, Marco Antônio Orsini; Pacheco, Mariana; Vorkapic, Camila Ferreira; Cagy, Maurício; Piedade, Roberto; Ribeiro, Pedro

doi:10.1590/s0004-282x2007000400016

Cited by 3 publications

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References 28 publications

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“…Several studies have focused on understanding the basic aspects of leprosy, such as genetics [ 6 , 7 ], physiology of the bacilli [ 8 , 9 ], biological markers [ 10 ], kinesiology and biomechanical factors [ 11 , 12 , 13 ], and public health concerns [ 14 , 15 ]. Until recently, however, there has been little discussion about the relationship between the peripheral upper-limb dysfunction caused by leprosy and changes in the motor cortex [ 16 , 17 ]. This phenomenon, known as plasticity, refers to the physiological and structural changes that occur in the central nervous system over time.…”

Section: Introductionmentioning

confidence: 99%

Primary Motor Cortex Representation of Handgrip Muscles in Patients with Leprosy

et al. 2015

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BackgroundLeprosy is an endemic infectious disease caused by Mycobacterium leprae that predominantly attacks the skin and peripheral nerves, leading to progressive impairment of motor, sensory and autonomic function. Little is known about how this peripheral neuropathy affects corticospinal excitability of handgrip muscles. Our purpose was to explore the motor cortex organization after progressive peripheral nerve injury and upper-limb dysfunction induced by leprosy using noninvasive transcranial magnetic stimulation (TMS).MethodsIn a cross-sectional study design, we mapped bilaterally in the primary motor cortex (M1) the representations of the hand flexor digitorum superficialis (FDS), as well as of the intrinsic hand muscles abductor pollicis brevis (APB), first dorsal interosseous (FDI) and abductor digiti minimi (ADM). All participants underwent clinical assessment, handgrip dynamometry and motor and sensory nerve conduction exams 30 days before mapping. Wilcoxon signed rank and Mann-Whitney tests were performed with an alpha-value of p<0.05.FindingsDynamometry performance of the patients’ most affected hand (MAH), was worse than that of the less affected hand (LAH) and of healthy controls participants (p = 0.031), confirming handgrip impairment. Motor threshold (MT) of the FDS muscle was higher in both hemispheres in patients as compared to controls, and lower in the hemisphere contralateral to the MAH when compared to that of the LAH. Moreover, motor evoked potential (MEP) amplitudes collected in the FDS of the MAH were higher in comparison to those of controls. Strikingly, MEPs in the intrinsic hand muscle FDI had lower amplitudes in the hemisphere contralateral to MAH as compared to those of the LAH and the control group. Taken together, these results are suggestive of a more robust representation of an extrinsic hand flexor and impaired intrinsic hand muscle function in the hemisphere contralateral to the MAH due to leprosy.ConclusionDecreased sensory-motor function induced by leprosy affects handgrip muscle representation in M1.

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