Myotonic Dystrophy & CMT

Prognosis: Myotonic Dystrophy

Progressive, but variable -- good rehab potential for improvement in strength, aerobic capacity, etc. w/ training

_________: most common muscular dystrophy w/ adult onset

Mytonic dystrophy

Myotonic dystrophy is more common in persons of _________ descent

European

Myotonic dystrophy is caused by chromosomal abnormalities and is of autosomal _________ (recessive vs. dominant) inheritance

Dominant (i.e., there is a 50% chance of passing the gene on)

Myotonic dystrophy type _________ is more common overall, with the following subtypes: congenital-onset (in-utero), childhood-onset (birth to adolescence, usually <10), adult-onset (adolescence/early adulthood), and mild (usually >40 (ranges 20-70s))

Type I (chromosome 19 affected)

Which subtype of Myotonic Dystrophy Type I is MOST common? (remember, your options are congenital-onset, childhood-onset, adult-onset, and mild)

Adult-onset

Myotonic Dystrophy type _________ is less common and generally less severe than the other variation. Onset ranges from 20-70 years old.

Type II (chromosome 3 affected)

Myotonic Dystrophy includes which 3 MAIN s/s?

Myotonia, muscle weakness, and early cataracts

_________ (one of the MAIN s/s of Myotonic Dystrophy): inability/difficulty in voluntarily relaxing skeletal muscle

Myotonia

What is the MAIN difference between Myotonic Dystrophy I and Myotonic Dystrophy II?

Type I involves distal > proximal muscles, while Type II involves PROXIMAL > distal muscles!!

Which type of Myotonic Dystrophy may have a reduced lifespan compared to "normal" due to extra problems?

Adult-onset (Type I)

Clinical hx: Myotonic Dystrophy

"recurring ab pain, constipation, obstetric complications," "hx of parent w/ muscle weakness," "difficulty relaxing grip or letting go of shovel/screwdriver"

Clinical exam: Myotonic Dystrophy

Assess for myotonia!! (ex: percussion, grip and release, ankle DF w/ relaxation); refer for an eye exam!!

What is the GOLD STANDARD for a Myotonic Dystrophy diagnosis?

Genetic testing

How does Myotonic Dystrophy present on an EMG?

Characteristic "dive-bombing" sound of muscle activity

Tests & measures: Myotonic Dystrophy

Systems review (including vitals!!), pain & general QOL inventories, neuro screen, no specific outcome measure for the condition (i.e., core outcome measures appropriate -- make sure to assess fatigue as well!!)

Neuro screen: Myotonic Dystrophy

Observation for atrophy, myotonia assessment, MMT or functional strength testing, ROM/ flexibility, gait & balance

PT interventions: Myotonic Dystrophy

Gait training (may require AD, orthoses, or manual/power WC or scooter), strength (mod intensity), stretching/ROM, aerobic training (mod intensity), balance training, functional training, monitor physiologic response to exercise (i.e., Borg, RPE, HR)

Goals: Myotonic Dystrophy

Max. ROM, avoid/min. disuse atrophy, max. functional abilities, energy conservation, prevent secondary injuries

Discharge: Myotonic Dystrophy

When goals met and patient/family able to self-manage. Depending on symptom variability, may be candidates for skilled maintenance therapy.

Is there a cure for Myotonic Dystrophy?

NO!!

Referrals: Myotonic Dystrophy

Neurologist (initial dx and overall monitoring), ophthalmologist (monitoring of eye health/ mgmt. of cataracts), OT (adaptive equipment and strategies for hand fx/ADLs), ST (swallowing or speaking difficulties), cardiology (high incidence of cardiac abnormalities), pulmonologist (if breathing difficulties noted), sleep study (sleep apnea or other REM sleep issues suspected)

_________: hereditary (GENETIC) condition caused by 60 different genes w/ more than 900 mutations!! affects all NERVE-related structures and functions (i.e., myelin, axons)

Charcot-Marie-Tooth (CMT) Disease

CMT is the most frequently inherited _________ (sensory and/or motor) w/ an onset in _________

Peripheral neuropathy, mid-childhood or early adulthood

When it comes to CMT, s/s present _________ and progress _________ (length-dependent)

Distal --> proximal

What might be the FIRST sign of CMT?

Pes cavus --> peroneal weakness and inability to walk on heels

In CMT, atrophy, weakness, and then sensory loss of distal segments of _________, THEN _________ (note: SYMMETRICAL weakness is common)

LE --> UE

What are other s/s of CMT (besides those already discussed)?

Decreased muscle tone, reduced/absent DTRs, loss of proprioception and decreased sensation in distal LE, pain (neuropathic), sleep and respiratory function affected in some cases, foot deformities (pes cavus, claw toes, calcaneal inversion, adduction of forefoot, hammer toes)

Functional limitation: CMT

Steppage gait to compensate for weakness (due to foot slap and hypotonia), marked reduction of aerobic capacity, intolerance to exercise and fatigue, difficulty manipulating small objects or using utensils, frequent tripping/falls

Diagnostic age: CMT

Usually diagnosed in childhood -- NO GOLD STANDARD FOR TESTING (too many genes)

Diagnostic tests: CMT

NCV (confirms neuropathy, but is NOT CMT-specific), EMG, family hx, genetic testing, observation for foot deformities and peripheral weakness, blood tests, nerve biopsy, PFTs

Prognosis: CMT

NO CURE!!--slowly progressive, but is usually NOT life-threatening

Medical mgmt.: CMT

Symptomatic/palliative --> surgical correction of foot/toe deformities (i.e., triple arthrodesis, tendon transfers, soft tissue release, osteotomy) & pharmacologic tx (meds for neuropathic pain, neurotrophin-3)

What is the GENERAL focus of rehab for CMT?

Max. independence and QOL by managing progression through self-help/compensatory strategies and preserving muscle strength as flexibility w/ a MULTIDISCIPLINARY approach

Multidisciplinary team: CMT

Neurologist, genetic counselor, ortho surgeon, physiatrist, pulmonary specialist, PT and OT, social work

Tests & measures: CMT

Systems review (including vitals!!), pain inventories, neuro screen, core outcome measures, CMT neuropathy scale, 9-hole peg test (hand dexterity), grip strength, ankle DF strength

Neuro screen: CMT

Observation for atrophy, motor and sensory testing, DTRs, MMT or functional strength testing, ROM/flexibility testing, gait analysis & balance assessment

As a reminder, what are our "core outcome measures"?

6MWT, 5XSTS, Berg, FGA, ABC, 10MWT

Which 2 measures are the MOST responsive to change and clinically relevant over 2-year period for individuals w/ CMT?

Grip strength & ankle DF strength

Goals: CMT

Improve muscle strength, prevent joint deformities/contractures, improve functional mobility/balance, prevent falls, improve hand fx, prevent/treat pain, prevent foot ulcers

Discharge: CMT

When goals met and patient/family able to self manage -- NOTE: less likely to have a skilled maintenance program due to less variation & fluctuations

Interventions: CMT

Gait training (AD, orthoses (i.e., AFOs, SMOs) or footwear mods, manual/power WC or scooter), balance, strength (mod intensity), stretching/ROM, aerobics (mod intensity), functional training, monitor physiologic responses to exercise (i.e., Borg, RPE, HR)

_________ (intensity) exercise is safe/effective and leads to improvement in walking and LE strength in CMT

Mild to moderate

In individuals w/ CMT, avoid _________ resistance due to risk of overexertion and muscle damage

Maximum

In individuals w/ CMT, improvement of _________ strength will help delay fatigue of hip flexors and decrease gait compesnations

Proximal muscle strength (ex: core, glutes, hamstrings)

In individuals w/ CMT, aerobic exercise may help improve aerobic capacity, BUT observe for _________

Rare respiratory insufficiency

_________: heterogenous group of inherited disorders (i.e., GENETIC condition) that is characterized by PROGRESSIVE muscle weakness and degeneration (i.e., a MUSCLE-level condition)

Muscular Dystrophy

How is Muscular Dystrophy classified?

Based on mode of inheritance, age at onset, rate of progression, muscles involved, morphology of muscle, and genetic markers

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