Neuro scenario 2 (Duchenne's muscular dystrophy)

Question 1

What is Duchenne muscular dystrophy and how is it diagnosed?

Answer 1

Duchenne muscular dystrophy is inherited in an X-linked recessive pattern. Duchenne is caused by a genetic mutation that prevents the body from producing dystrophin, a protein that muscles need to work properly.
Muscle cells without enough of this protein become damaged as muscles repeatedly contract and relax with use. Every time muscle contract, small rips appear in the cell membrane which allows diffusion of molecules into and out the myocyte (calcium ions). Ca ions flow into myocyte and activate calcium dependant enzymes that break down proteins into proteases. In DMD, high level Ca activate too many proteases so break down important and functional proteins as well as killing myocyte. CK leaks out the cell into blood and so less CK means less energy storage can occur, so muscles weaken. As pt gets older, muscles don’t regenerate fast enough to keep up with constant death of myocytes, so instead fat and scar tissue begins to fill the gaps, which can’t contract, so muscle gets weaker.
most DMD patients are now living into their 30s, and some are living into their 40s and 50s.

Diagnosis:
1. Blood test:
a blood sample is taken to measure the amount of creatine kinase. CK is an enzyme that is found in muscle cells. if muscles are damaged, the muscle cells are broken open and their contents enter the bloodstream. Those with DMD always have a high CK level.
2, Genetic testing:
a blood sample is taken and the DNA of the cells is analysed to see whether there is a mutation in the dystrophin gene, and if so, where.
These 2 tests can detect DMD in 95% of patients.
A small number pf patients have a muscle biopsy to confirm the diagnosis
3. Muscle biopsy
modern techniques use the biopsy to distinguish muscular dystrophies from inflammatory and other diseases.

If suspicion of DMD remains high despite negative genetic analysis, dystrophin detection by staining with selective antibodies is carried out in the tissue derived from a muscle biopsy.

Question 2

Suggest some treatment options for the 22-year-old pt with DMD

Answer 2

find out what he wants to achieve
- standing program
encourages good posture and a neutral position.
use of standing frame or exercise bike to mobilise ankles. Standing for a few hours each day, even with minimal weight-bearing, promotes better circulation, healthier bones, and a straight spine.
- Ankle-foot orthoses (AFOs) are sometimes prescribed for night wear to keep the foot from pointing downward and keep the Achilles tendon stretched. Stops contractures occuring.

Back pain caused by lordotic lumbar spine

• cat-cow stretch: strengthens and stretches the spine, stretches hips, abdomen and back and relieves feelings of stress.
• inducing a lumbar lordosis by using a ‘wedge’ on a patient’s seat. This allows patients to tolerate a better lateral load and helps to prevent low back pain from a slumped position.

Reduced proximal muscle strength

• pt uses Gowers maneuver as he lacks strength in proximal muscles of the lower limb.
• place leg out straight on a gym ball and push foot down into it and hold. Isometric strecth with proprioceptive input from the ball which provides visual feedback.

Weight gain

• use of an exercise bike will help reduce his weight as the extra weight will make it harder for him to mobilise.
• hydrotherapy can help protect against muscle strain and injury, while toning, and improving respiratory function. Allows pts to perform exercises they may not be able to do on land as they are supported by the water.

Education

• parents about pressure areas
• deep breathing exercises - helps to fully inflate the lungs and puts the lungs, respiratory muscles and chest wall through a good range of movement.

Question 3

What outcome measures could be used for this pt?

Answer 3

• incentive spirometry
• pt reported outcome measure
  questionnaires measuring the patients’ views of their health status.
• patient-specific functional scale
  Patients are asked to identify up to five important activities they are unable to perform or are having difficulty with as a result of their problem eg putting socks on, shopping.
  Patients are asked to rate the current level of difficulty
  “0” represents “unable to perform” and “10” represents “able to perform at prior level”

Question 4

What is the Gowers manoeuvre?

Answer 4

pt uses their hands and arms to “walk” up their own body from a squatting position due to a lack of hip and thigh muscle strength. Indicates weakness of proximal muscles, especially in the LL.

Question 5

The pt is currently on prednisone and deflazacort. What are these?

Answer 5

Prednisone - anti-inflammatory agent. Synthetic corticosteroid that is generally prescribed to delay the progression of muscle weakness

Deflazacort - corticosteroid used to treat MD. Thought to help improve muscle strength and slow the progression of the disability.

It is thought that the steroids decrease inflammation and may influence the repair of weakened muscle cell membranes.
Corticosteroids are natural or synthetic hormones that act on metabolism and tissue inflammation. They reduce inflammation by inhibiting the formation of inflammatory mediators

Question 6

How would you measure rom of the trunk?

Answer 6

FLEXION:

• occurs in the sagittal plane, no normal value.
• can measure fingertips to floor but this is more a meaurement of hamstring flexibility
• pt stands with feet shoulder-width apart and shoes off
• demo first - chin to chest and roll back down, hands to floor
• 2 measuring spots:
• C7 - base of neck
• S1 - find iliac spine (L3/L4), move down spinous processes, L4,L5,S1
• hold tape measure at both points and record difference

EXTENSION:

• occurs in sagittal plane, no normal value
• pt stands with hands-on hips and focus on spot on the wall. arch back and stop neck extending
• 2 measuirng spots:
• C7
• S1
• record difference

SIDE FLEXION:
- occurs in frontal plane, goniometer normal value = 0-35dgerees
- pt to slide arm down leg as far as possible
- do not lift opposite foot or bend the leg
- tape measure:
measure from distal end of the finger and record difference
- goniometer:
fulcrum on S1
stat arm perp to floor
moving arm follows C7

ROTATION:
- occurs in transverse plane, normal range 0-45 degrees
- pt sat on stool with no back support, cross arms over chest.
- goniometer:
fulcrum on center of head
stat arm parallel to iliac crests or acromiom processes
moving arm parallel to 2 acromiom processes

Question 7

How would you assess sitting posture?

Answer 7

2 types of posture:

1. Dynamic posture: how you hold yourself when moving
2. Static posture: how you hold yourself when not moving. muscle groups wok statically to counteract gravity and other forces.

To assess sitting posture, pt must be:

• sat with feet flat on floor
• angle of elbows, hips and knees is approx 90
• shoulders relaxed and forearms parallel to floor

1. Head alignement:
   - look from tip of nose, down the middle of the chin to the manibrum
2. Shoulder symmetry
   - level of shoulders and both clavicles
3. Arm length
   - level of olecranons from posterior
4. Ankle joints
   - level of both medial malleolus
5. Sagittal plane posture
   - lateral plumb line - line from earlobe to humeral head
6. Lateral shifts indicating scoliosis
   - sacpula spines, inferior angles and distance of medial borders from the spine
7. Pelvic symmetry
   - compare both iliac crests and check both PSIS
   - compare levels of ASIS and PSIS for pelvic tilt

Question 8

What exercises can help with trunk ROM and strength?

Answer 8

1. Cow-cat stretch
   - inhale and arch back, press chest towards floor and bring head up.
   - inhale and round your back and push shoulders away to make ‘angry cat pose’
   - strengthens and stretches spine
   - stretches hip, abdomen and back
   - relieves stretch
2. Open book stretch
   - begin by lying on one side, knees bent and arms in front of you with palms together. bring top hand over and follow with head until all the way over. Hold for a few breaths
   - improves rotation in the TSp
3. Gym ball sitting
   - if pt becomes quickly fatigues with exercise, this is a good low-level alternative. it engages the core and also gives them feedback about their posture. provides proprioceptive input.
4. Posterior tilt
   - lie on back with knees comfortably bent. on expiration, gently draw your belly button down towards your spine to contract your lower abdominals (muscles you use to cough or laugh). tilt your pelvis and press your lower back into the mat. relax on inspiration