Charcot-Marie-Tooth Disease Case Study

Original Editors - Holly Henderson as part of the Queen's University Neuromotor Function Project

Top Contributors - Katharina Fehr, Erin Gorchinsky, Holly Henderson, Clare Murphy, Teresa Raso, and Piera Rooke

Abstract

Charcot Marie Tooth disease is a common progressive form of peripheral neuropathy affecting motor and sensory systems. This fictional case study presents a 23-year-old male diagnosed with Charcot Marie Tooth disease (CMT1A). The subjective and objective findings are stated at initial assessment and at 3 month follow up to monitor his progress with physiotherapy. Physiotherapy interventions are aimed at improving aspects of the patient's body structure/function, activity, and participation following the ICF model. Goals are patient-centered, and treatment aims to improve ROM, strength, balance, endurance and pain management. An interdisciplinary team approach is taken to manage various aspects of this case, including referral for podiatrist, pharmacological interventions, and OT. The patient is motivated to slow the progression of the disease and based on the outcome measure scores it is evident that the patient is able to maintain, if not improve, their functional status and quality of life with physical therapy intervention.  

Introduction

This case will examine a 23-year-old male diagnosed with CMT1A. This genetically inherited neuromuscular disorder affects over 2.6 million people worldwide and is the most common form of peripheral neuropathy . Genetic mutations can be autosomal dominant, autosomal recessive or X-linked. There are 6 subtypes of CMT (CMT1A, CMT1B, CMT2, CMT3, CMT4, CMTX1) differentiated by either demyelination or progressive axonal degeneration. Between different subtypes common symptoms may include altered sensation, impaired motor function and atrophy beginning in the distal lower extremity (feet, ankles) prior to the upper extremity due to long nerves affected first and reduced deep tendon reflexes. Due to this presentation, patients with CMT often have altered gait and foot deformities (pes cavus). Concomitant diabetes or acute/chronic inflammatory demyelinating polyradiculoneuropathy leads to a more severe disease progression .  

The purpose of this case study is to inform readers about the presentation of CMT in a previously active and young person with mild severity and how physiotherapy can assist in moderating quality of life and functional activities in this progressive disease. The case will act as an easily accessible, free, online resource for healthcare professionals and families to reference. Severity and presentation of this disease will differ among individuals and even between family members, ranging from no/mild symptoms to severe impairments requiring a wheelchair or respiratory failure requiring assisted ventilation . This case study will allow physical therapists to differentiate the needs of a patient’s specific progression and the appropriate interventions and goals to maintain or improve quality of life.

Client Characteristics

The patient is a 23-year-old male, who is a recent Teacher’s College graduate now working as a high school teacher in a medium-sized city in Ontario. His hobbies include playing and coaching badminton, riding his bike with his partner on the weekends. Patient has been attending physio for 4 months and was referred to us after a diagnosis from his family doctor Type 1a of CMT. His main complaints are inability to stand for long hours at work and that he is no longer available to participate in sports. He has noticed he had balanced issues due to losing sensation in his feet.

Examination Findings

Subjective

History of Present Illness

A 23-year-old male was diagnosed by neurologist 4 months ago with demyelinating Charcot Marie Tooth Disease (CMT1A) based upon family history, nerve conduction testing, and exclusion of diabetic neuropathy. They initially presented to their family physician reporting the following difficulties over the previous year: persistent pins and needles in the feet bilaterally, balance disturbances, pain in the lower extremities and muscle cramping. They fractured their wrist due to a fall 1 year ago and received physiotherapy for a sprained ankle 1.5 years ago but is otherwise healthy. They are not currently on any medications. They have been referred to physiotherapy for treatment.  

Functional Status

The patient lives alone in a 1-bedroom apartment with an elevator, is independent in all activities of daily living, and does not use a mobility device for ambulation. They were previously active, but currently walks approximately 1 km once a week. They present to physiotherapy describing difficulties ambulating over snow and uneven terrain, inability to run or jump, and chronic ankle rolls. Currently the patient is unable to play badminton along his students and would like to be able to actively participate in the sport rather than just observing.  

Objective

Observation

Spinal alignment appears normal. Atrophy and hypotonia is noted bilaterally in the plantar flexors and tibialis anterior. No atrophy is apparent in the upper extremity. The feet exhibit pes cavus and mild hammer toe is noted bilaterally. Skin appears normal and intact.  

Neurological Assessment

Superficial Sensations

Light touch  

• Decreased sensation in feet and ankle beginning at the midpoint between the ankle and knee joint  

Pinprick

• Absent at the first metatarsal joint and medial and lateral malleolus
• Diminished at the midpoint between the ankle and knee joints on the anterior and posterior surfaces bilaterally
• Normal in the lower leg tested 5 cm proximal to the medial and lateral femoral condyles  
  

Deep Sensations

Proprioception  

• Decreased position sense bilaterally at the ankle and 1st MTP joint  

Vibration perception (tested with a 128 Hz tuning fork)

• Absent sensation at the first metatarsal joint bilaterally
• Impaired sensation at the medial malleolus bilaterally

Upper Motor Neuron Reflexes

Negative Babinski and Hoffman

Vitals

Pedal and radial pulses are strong and regular

Deep Tendon Reflexes (DTR)
	Right	Left
Biceps	2 (normal)	2 (normal)
Triceps	2 (normal)	2 (normal)
Patellar	2 (normal)	2 (normal)
Achilles	1 (diminished)	1 (diminished)

Range of Motion

Active range of motion (AROM): hip extension 5 degrees bilaterally and 10 degrees ankle dorsiflexion bilaterally. All other AROM is within normal limits.  

Passive range of motion (PROM) of the upper and lower extremities are within normal limits. End-feels are normal.  

Manual Muscle Testing (MMT)
	Right	Left
Dorsiflexion	4	4
Plantar flexion	4	4
Inversion	4	4
Eversion	4-	4-
Knee extension	4	4
Knee flexion	4	4
Hip flexion	5	5
Hip extension	4+	4+
Shoulder flexion	5	5
Shoulder extension	5	5
Elbow flexion	5	5
Elbow extension	5	5
Wrist flexion	4+	4+
Wrist extension	4+	4+

Observational Gait Analysis

• Decreased stride length and cadence.  
• Mild foot drop with increased contact in early stance, reduced plantar flexion at toe-off and increased hip and knee flexion in mid swing phase.

Outcome Measures

Charcot Marie Tooth Disease Neuropathy Score: score of 9 indicating mild disease severity.

10 minute walk test: performed in 9 seconds, with a rate of 1.1m/s indicating community ambulation.

Hand dynamometer: performed bilaterally 3 times with an average score of 38 kg for the right hand and 34 kg for the left.

Community Balance and Mobility Scale: score of 72 indicating ability to function with mild impairment within the community and with more complex functional tasks.

Fatigue Severity Scale: score of 23 indicating mild fatigue with functional activities.

Neuropathic Pain Symptom Inventory: score of 24 indicating some neuropathic pain within the lower extremity.

Charcot-Marie Tooth Health Index: self-reported score of 30, indicating disease has some effect on quality of life but not debilitating.

Clinical Impression

Analysis

A 23-year-old male reported to their family physician experiencing lower extremity sensory and balance deficits 1 year ago and was diagnosed with Charcot Marie Tooth Disease (CMT1A) by a neurologist 4 months ago. Disease severity is determined to be mild as evaluated by the CMTNS and the patient reported QoL measure is optimistic. Impairments predominantly affect the lower legs bilaterally. DTR are reduced at the Achilles, but otherwise normal. Sensory deficits are evident in the distal leg which increase the risk of foot sores. Strength deficits are observed in all directions at the ankle and may increase the risk of falls, ankle injuries, and lower limb contractures. The patient demonstrates a mild foot drop with a minor steppage gate. Walking speed is below age-matched healthy control but is currently within the limits of safe community ambulation. If disease severity increases above a CMTNS score of 11 the patient may benefit from foot orthosis and should be referred as appropriate. The patient can usually maintain balance on even terrain, but indicates he has challenges over complex, uneven terrain and in dynamic environments. There is no current need for a gait aid, however this may be considered with disease progression. Minimal impairments in the upper extremity are observed, however grip and wrist strength measures were below average values. May require referral to an occupational and/or hand therapist dependent on changes in future disease status. The patient lives alone but has adequate social supports. They are unable to safely run and jump but reports no major occupational limitations and is independent in all ADLs.  The patient is suitable for PT treatment in maintaining and improving strength and balance, preventing LE contractures and sores, reducing risk of falls, monitoring disease progression and maintaining functional independence.

Prognosis

They have a relatively good prognosis as there are no impairments affecting the upper limbs, they were previously active, and are otherwise healthy. Disease is progressive, but slow therefore the patient should be continually monitored and reassessed at regular intervals particularly over the next 10 years.

Problem List

• Sensory deficits in distal lower extremities and risk of foot sores
• Reduced Achilles reflex  
• Increased falls risk due to strength deficits in ankle (all directions), proprioceptive deficits and drop foot  
• Reduced ankle dorsiflexion ROM
• Decreased walking speed for age
• Balance deficits with uneven terrain  
• Neuropathic pain in lower extremities, somewhat affecting functional activities
• Mild fatigue with completing ADL’s