Gait analysis in a patient with severe Charcot-Marie-Tooth disease: a case study with a new orthotic device for footdrop.

Management of footdrop in severe Charcot-Marie-Tooth (CMT) patients is a challenge owing to the combination of quadriceps muscle weakness, distal muscular atrophy, sensory impairment and poor soft tissue resistance to the placement of an orthotic device. We present a case study of a patient who gradually became unable to use his ankle-foot orthoses because they hampered the compensative movements required to stabilize his knees passively and caused pain. The aim of this report is to describe orthotic management in such a severe CMT case and to present a new orthotic device that we devised for the footdrop in this patient. We provided him with 3 different footdrop devices, each of which was highly elastic to allow knee hyperextension, and left him free to decide which one to use: 1) the silicone-ankle-foot orthoses were rapidly discarded because of pain; 2) the Codivilla support was not used because of discomfort and poor aesthetic appearance; 3) a new device, called the "Soft Footdrop Insert" (SFI), consisting of a sheet of Veolform, a reticulated polyolephinic foam, stuck to the counter of midcalf boots, was found to be effective, comfortable, pain-free and aesthetically acceptable, and was consequently used the vast majority of the time. At a 3-year follow-up, an instrumental gait analysis, in which ordinary shoes were compared with the Codivilla support and the SFI, revealed that both the Codivilla support and the SFI controlled footdrop more effectively than ordinary shoes and increased swing and mean velocity; in addition, the SFI yielded the best gait performances. We think that a soft, invisible device, such as the SFI, may satisfy the needs of CMT patients and improve compliance with orthoses-wearing for footdrop.

Foot drop and plantar flexion failure determine different gait strategies in Charcot-Marie-Tooth patients.

OBJECTIVE: To describe the temporal, kinetic, kinematic, electromyographic and energetic aspects of gait in Charcot-Marie-Tooth patients with foot drop and plantar flexion failure. METHODS: A sample of 21 patients fulfilling clinical, electrodiagnostic and genetic criteria for Charcot-Marie-Tooth disease were evaluated by computerized gait analysis system and compared to a group of matched healthy subjects. Patients were classified as having isolate foot drop (group 1) and association of foot drop and plantar flexion failure (group 2). RESULTS: While it was impossible to detect a reliable gait pattern when the group of patients was considered as a whole and compared to healthy subjects, we observed two distinctive gait patterns when patients were subdivided as group 1 or 2. Group 1 showed a gait pattern with some characteristics of the "steppage pattern". The complex motor strategy adopted by this group leads to reduce the swing velocity and to preserve the step length in spite of a high energy consumption. Group 2 displayed a "clumsy pattern" characterized by very slow gait with reduced step length, a broader support area and great reduction in the cadence. This group of patients is characterized by a low energy consumption and greater energy recovery, due above all to the primary deficit and the various compensatory mechanisms. CONCLUSIONS: Such between-group differences in gait pattern can be related to both primary motor deficits and secondary compensatory mechanisms. Foot drop and plantar flexion failure affect the overall gait strategy in Charcot-Marie-Tooth patients.

Lower limb manual muscle testing in the early stages of Charcot-Marie-Tooth disease type 1A.

Charcot-Marie-Tooth disease (CMT) is a genetically and clinically heterogeneous disorder that affects approximately one in 2,500 individuals. CMT 1A, which is due to a duplication in the area containing the PMP-22 gene on chromosome 17, is the most frequent CMT subtype. To date, there is no consensus among authors about which muscles are weakened in the early stages of CMT, even though this knowledge would be crucial for deciding the most appropriate interventions to restore balance between muscles and prevent the development of deformities. The aim of this study was to evaluate the strength of several lower limb muscles in the early stages of CMT 1A. In a series of 45 patients (age 10-72 years; 21 males, 24 females) affected by CMT 1A, we evaluated 83 non-operated lower limbs that corresponded to the two milder stages of a five-level functional classification. The strength of two foot muscles, seven leg muscles, two thigh muscles, and three pelvic girdle muscles was graded using the manual muscle testing techniques of Daniels and Worthingham; the power of the triceps surae was graded, in the prone position, using a 4-level scale of ability to raise the heel from the floor. Muscle strength was determined on the basis of interobserver agreement estimated by kappa statistics between two observers. The flexor hallucis brevis and lumbricals were very weak in all the limbs; the leg muscles were strong in more than 90% of limbs, except the peronei (strong in 83.13%); all the triceps surae were strong in the prone test, but 16.87% were weak in the standing test; all the proximal muscles were strong. In the large majority of patients in the early stages of CMT 1A, the intrinsic foot muscles are very weak and the leg and proximal muscles are strong.

MFN2 mutation distribution and genotype/phenotype correlation in Charcot-Marie-Tooth type 2.

Mutations in mitofusin 2 (MFN2) have been reported in Charcot-Marie-Tooth type 2 (CMT2) families. To study the distribution of mutations in MFN2 we screened 323 families and isolated patients with distinct CMT phenotypes. In 29 probands, we identified 22 distinct MFN2 mutations, and 14 of these mutations have not been reported before. All mutations were located in the cytoplasmic domains of the MFN2 protein. Patients presented with a classical but rather severe CMT phenotype, since 28% of them were wheelchair-dependent. Some had additional features as optic atrophy. Most patients had an early onset and severe disease status, whereas a smaller group experienced a later onset and milder disease course. Electrophysiological data showed in the majority of patients normal to slightly reduced nerve conduction velocities with often severely reduced amplitudes of the compound motor and sensory nerve action potentials. Examination of sural nerve specimens showed loss of large myelinated fibres and degenerative mitochondrial changes. In patients with a documented family history of CMT2 the frequency of MFN2 mutations was 33% indicating that MFN2 mutations are a major cause in this population.

Overwork weakness in Charcot-Marie-Tooth disease.

OBJECTIVE: To determine the incidence of overwork weakness in Charcot-Marie-Tooth disease (CMT). DESIGN: Prospective survey. SETTING: Rehabilitation department for CMT in an Italian tertiary care hospital. PARTICIPANTS: A total of 106 outpatients with CMT, selected for absence of other causes of weakness (age range, 11-69y), and 48 healthy volunteers (controls). INTERVENTIONS: The strength of 2 intrinsic hand muscles (abductor pollicis brevis [APB], first dorsal interosseous) in the dominant and nondominant hands was graded by using manual muscle testing and a modified Medical Research Council (MRC) Scale. MAIN OUTCOME MEASURES: The side of the stronger muscle and the difference in strength between the nondominant and dominant muscles. RESULTS: Muscles were stronger on the nondominant side in 65.57% of patients versus 1.04% of controls, and on the dominant side in .94% of patients versus 84.38% controls. The difference in strength for first dorsal interosseous was .51 in patients and -.32 in controls (P>.01). The difference in strength for APB was .65 in patients and -.35 in controls (P>.01). CONCLUSIONS: CMT muscles in the dominant hand are weaker than in the nondominant hand. This may be the result of overwork weakness.

Gait rehabilitation in a patient affected with Charcot-Marie-Tooth disease associated with pyramidal and cerebellar features and blindness.

Charcot-Marie-Tooth (CMT) disease, an inherited neuropathy characterized by length-dependent degeneration of the motor and sensory nerve fibers with consequent distal muscle atrophy and sensory reduction, can be associated with symptoms and signs of involvement of the central nervous system and/or cranial nerves. We present a patient with relatively severe CMT, cerebellar ataxia, pyramidal involvement, and blindness due to Leber's hereditary optic neuropathy. The patient presented with poor standing and gait, with consequent severe disability. Factors responsible for the patient's functional impairment (plantarflexor failure, footdrop, foot rotation, knee flexor contracture, poor proprioception, cerebellar dysfunction, spastic paraparesis, blindness) were identified and addressed by a rehabilitation management, which included, as a main intervention, ankle stabilization by drop-foot boots instead of ankle-foot orthoses. Improved balance and independent ambulation resulted from rehabilitation.

Footdrop, foot rotation, and plantarflexor failure in Charcot-Marie-Tooth disease.

OBJECTIVE: To evaluate the frequency of occurrence of the main causes of poor stance and gait in patients with Charcot-Marie-Tooth disease (footdrop graded as mild or severe, rotation, and plantarflexor failure) both as single and associated problems. DESIGN: Observational. SETTING: A neuromuscular disorders department in a specialized Italian rehabilitation hospital. PARTICIPANTS: One hundred twenty-six nonoperated lower limbs from 64 outpatients. INTERVENTIONS: Ankle angle during active dorsiflexion and heel angle in stance were measured in a photograph; the ability to raise the heel at least 2cm was evaluated. MAIN OUTCOME MEASURES: Frequency of mild footdrop (ankle angle < or =100 degrees ), severe footdrop (ankle angle >100 degrees ), and rotation and plantarflexor failure singularly and in association. RESULTS: Mild footdrop was present in 47.6% of examined limbs and was associated with rotation in 39.7% of limbs; severe footdrop was present in 52.4% of limbs and was associated with rotation in 28.6% of limbs, with rotation plus plantarflexor failure in 21.4% of limbs. CONCLUSIONS: We recommend categorizing problems in the lower limbs into 4 levels of increasing symptom severity, starting with mild footdrop and graduating to the instance where the 3 problems are associated.