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Muscular Dystrophy Presentation (Final)
- 1. MUSCULAR DYSTROPHY CASE STUDY PRESENTATION Matt Reynolds Oxford Brookes University
- 2. Why Muscular Dystrophy? Outpatient Case Study Poorly understood outside Paediatric specialism Rare Overall prevalence of muscle diseases is under 1:1000 Progressive condition leading to: Physical Disability Reduced Independence Reduced Life-Expectancy Significant developments in the management and understanding mean this is improving (Wagner et al., 2007)
- 3. What is Muscular Dystrophy? Heterogeneous group of genetically determined disorders Progressive Degeneration of Skeletal Muscles Increased Disability Reduced Independence Variable Presentations NO cure
- 4. Who’s Affected by MD? 70,000 people in the UK (Muscular Dystrophy UK) Duchenne MD most common 100 boys born with DMD each year 2500 males living with the condition One of which turned up for Neuro Rehabilitation (Muscular Dystrophy UK, 2015)
- 5. Case Study Introduction Age Female Diagnosis in 1986 Stuck to her chair
- 6. Initial Presentation Muscle Weakness Distal > Proximal Reduced ROM Ankles Wrists Lx and Hips Low Tone ++ in Lower Limb Muscle Wastage in Thenar and Hypothenar Eminence Sensations Intact
- 7. Functional Presentation Loss of Independence during STS: Low Chair High Chair = Independent Loss of Independence with Tall Steps Reduced Mobility Decreased walking tolerance Pain in Lx, Hips and Lower Limbs History of Falls Trendelenburg Gait Reduced Dexterity
- 8. Additional Problems Dysarthria ? Dysphagia Incontinence and Constipation PMH: Heart Murmur Epilepsy Spinal Cord Operation (2009)
- 9. Medication and Social History Medication: No condition specific medication Painkillers Paracetamol/ Co-codamol Social History Lives with partner, son and daughter Stairs Stair Rail and Lift Shower with level access and a seat Raised Toilet Seat
- 10. What did we do? Provided advise regarding: Onward Referrals: Occupation Therapist Shower adaptations Adaptive Cutlery Wheelchair Services Powered Wheelchair? Hydrotherapy Heat/ Ice Grip Gloves Prescribed Walking Aid HEP Lx Rolls Hip Flexion Mini Posterior Pelvic Tilts
- 11. Research into Muscular Dystrophy Generally symptoms: • Weakened Muscles • Muscle Cramps • Functional Limitations and Compensatory Adaptations: • STS • Stairs • Mobility • Falls and subsequently methods for getting up off the floor • Gower’s Manouevre • Jumping • Balance • Gait • ‘Waddling’ • Trendelenburg
- 12. Complications/ Variable Symptoms Contractures Pain Inability to Walk Facial Muscle Weakness Ptosis Swallow Impairments Visual Impairments Scoliosis Respiratory Muscle Weakness Dilated Cardiomyopathy Slow or Irregular Heartbeat (Cardiac Arrhythmias)
- 13. What Causes MD? Gene Mutations Structure and Function of Muscle Fibres affected Inheritance Recessive Inherited disorder 1 in 4 chance of MD 1 in 4 chance of being healthy 2 in 4 chance of being healthy, but a carrier Dominant Inherited disorder Sex-linked (X-linked) disorder Spontaneous Mutation
- 14. Diagnosis Initial Investigation of Symptoms Family History Discussion Blood Tests Creatine Kinase Genetic Testing Electromyography (EMG) Muscle Biopsy Symptom Specific Tests
- 15. Types of MD Over 30 known variations Reasons for Variations: Age of Symptom Presentation Affected Areas of Muscle Weakness Disability Life-expectancy Gender (Centers for Disease Control and Prevention, 2016; Norwood et al., 2009; Muscular Dystrophy Association, 2015; Stokes and Stack, 2012)
- 16. Duchenne MD Most Common – 16:100,000 males in NE have DMD or BMD Males Muscle Weakness = before 5 years Muscles Involved First: Upper Arms and Legs Other Areas Affected: Brain Throat Heart Diaphragm/ Respiratory Muscles Stomach Intestines Spine Learning Difficulties/ Developmental Delay
- 17. Myotonic Dystrophy 11:100,000 individuals in NE have MMD Males and Females equally Muscle Weakness = between 10-30 years, ranges to 70 Muscles Involved First: Face, Neck, Arms, Hands, Hips, Lower Legs Other Areas Affected: Eyes Throat Heart Stomach Intestines Hormone-Producing Organs Nerves Skin
- 18. Facioscapulohumeral MD 4:100,000 individuals in NE have FSH MD Males more than Females Muscle Weakness = by 20 years (average = teens) Muscles Involved First: Face, Shoulders (‘winging’ scapula), Upper Arms, Lower Legs Other Areas Affected: Eyes Ears Heart (atrial arrhythmias) Trunk
- 19. Becker MD Closely Related to DMD 16:100,000 males in NE have DMD or BMD Males Muscle Weakness = between 7-12 years Muscles Involved First: Upper Arms and Legs Other Areas Affected: Brain Throat Heart Diaphragm/ Respiratory Muscles Stomach Intestines Spine
- 20. Limb-Girdle MD 2:100,000 individuals in NE have LGMD Males and Females equally Muscle Weakness = ranges from early childhood to late adulthood Muscles Involved First: Shoulders and Hips Other Areas Affected: Heart Diaphragm/ Respiratory Muscles Spine
- 21. Oculopharyngeal MD Less than 1:100,000 individuals in NE have OPMD Males and Females equally Muscle Weakness = after 40 years Muscles Involved First: Face (mostly around eyes), Neck, Upper Arms and Legs Other Areas Affected: Throat
- 22. Emery-Dreifuss MD Less than 1:100,000 individuals in NE have EDMD Males Muscle Weakness = between 5-15 years Muscles Involved First: Upper Arms and Lower Legs Other Areas Affected: Heart Spine
- 23. Treating MD NO Cure Mobility Assistance Breathing Assistance Surgery Medication Swallowing Heart Education/ Health Promotion Alternative Therapies Support Groups
- 24. Mobility Assistance Low Impact Exercise Swimming Walking Hydrotherapy ROM and Stretching Exercises Passive Stretching and Splinting Mobility Aids Wheelchair and Crutches Neater Arm Support Powered Profiling Beds Toilet Frames/ Bathroom Equipment Physical Aids Leg Braces Night Splints AFOs (Aitkens et al., 1993; Ansved, 2003; Geytenbeek, 2002; Hyde et al., 2000; Kilmer et al., 1994; Kilmer, 2002; Lindeman et al., 1995; Muscular Dystrophy UK, 2015; Newham et al., 1986; Scott et al., 1981; Sveen et al., 2008; Stokes and Stack, 2012)
- 25. Breathing Assistance Breathing Exercises Mechanical Assistance NIV Cough Assist IPPB (American Thoracic Society, 2004; Godwin, 2016; Pryor and Prasad, 2008)
- 26. Surgery Postural Deformities Scoliosis Contractures Scapular Fixation (Rhee and Ha, 2006)
- 27. Medication Corticosteroids Prednisone Side-Effects Anti-Convulsants Muscle Spasms Immunosuppressant's Creatine Supplements (American Thoracic Society, 2004; Manzur et al., 2008)
- 28. Swallowing Dietician Speech and Language Therapist Surgery
- 29. Heart ACE Inhibitors Beta-Blockers Irregular Heartbeat (Arrhythmias or Dysrhythmias) Pacemaker Irregular Heartbeat (Duboc et al., 2007)
- 30. Education/ Health Promotion Diet Exercise Sleep (Muscular Dystrophy UK, 2015)
- 31. Alternative Therapies Supported: Massage Green Tea Unsupported: Acupuncture Royal Jelly (Muscular Dystrophy UK, 2015)
- 32. Support Groups National Charities Muscular Dystrophy Campaign Muscular Dystrophy UK Local Support Groups Type Specific National Support Groups: Action Duchenne Myotonic Dystrophy Support Group Becker United DMD Trust Duchenne Family Support Group Muscular Dystrophy Association (USA)
- 33. Current Research Exon Skipping Stem Cell
- 34. Principles of Physiotherapy Rx To maintain muscle strength and retard contracture progression to maximise function To promote or prolong ambulation with appropriate orthoses To delay or control the development of scoliosis To treat promptly any respiratory and cardiac complications
- 35. Benefits of Physiotherapy Maintain muscle strength in order to delay muscle wastage Improve range of movement and flexibility Reducing pain and stiffness Improving posture Improving balance and coordination Maximising mobility Maximising independence with functional activities Improving quality of life
- 36. Pt Assessment Muscle Strength Oxford Grading Scale Joint Range Goniometry Functional Performance Rise from floor STS Gait Analysis Balance Motor Ability Tests The North Star Ambulatory Assessment Timed Tests Timed 10m Walk Lung Function Spirometry (Fisher et al., 1990; Mazzone et al., 2009; Muscular Dystrophy UK, 2009; Wiles et al., 1990)
- 37. Time to Reflect What happened? Presented with an unusual outpatient case, of which I had very little understanding What went well? We were able to correctly advise on referral to OT, Wheelchair Services, and Hydrotherapy each advocate in my research What did not go so well? Initially my poor understanding limited my treatment choices and the direction of my assessment What have I learnt? Greatly increased my understanding of the various conditions, and how their presentation affects treatment goals and expectations Current research, and treatment choices advocated What will I do next time Able to focus my initial assessment towards identifying problems associated with MD Direct my treatment based on current evidence base
- 38. References American Thoracic Society (2004) ‘Respiratory care of the patient with Duchenne muscular dystrophy’, American Journal of Respiratory and Critical Care Medicine, 170(4), pp. 456–465. doi: 10.1164/rccm.200307-885st. Ansved, T. (2003) ‘Muscular dystrophies: Influence of physical conditioning on the disease evolution’, Current Opinion in Clinical Nutrition and Metabolic Care, 6(4), pp. 435–439. doi: 10.1097/01.mco.0000078987.18774.d9. Centers for Disease Control and Prevention (2016) Facts about Muscular Dystrophy. Available at: http://www.cdc.gov/ncbddd/musculardystrophy/facts.html (Accessed: 11 April 2016). Duboc, D., Meune, C., Pierre, B., Wahbi, K., Eymard, B., Toutain, A., Berard, C., Vaksmann, G., Weber, S. and Bécane, H.-M. (2007) ‘Perindopril preventive treatment on mortality in Duchenne muscular dystrophy: 10 years’ follow-up’, American Heart Journal, 154(3), pp. 596–602. doi: 10.1016/j.ahj.2007.05.014. Eagle, M., Baudouin, S.V., Chandler, C., Giddings, D.R., Bullock, R. and Bushby, K. (2002) ‘Survival in Duchenne muscular dystrophy: Improvements in life expectancy since 1967 and the impact of home nocturnal ventilation’, Neuromuscular Disorders, 12(10), pp. 926–929. doi: 10.1016/s0960-8966(02)00140-2. Eagle, M., Bourke, J., Bullock, R., Gibson, M., Mehta, J., Giddings, D., Straub, V. and Bushby, K. (2007) ‘Managing Duchenne Muscular Dystrophy – the additive effect of spinal surgery and home nocturnal ventilation in improving survival’, Neuromuscular Disorders, 17(6), pp. 470–475. doi: 10.1016/j.nmd.2007.03.002.
- 39. References Fisher, N., Pendergast, D. and Calkins, E. (1990) ‘Maximal isometric torque of knee extension as a function of muscle length in subjects of advancing age’, Archives of Physical Medicine and Rehabiliation, 71, pp. 729–734. Godwin, W. (2016) Commissioning policy for cough assist requests. Available at: http://hub.muscular-dystrophy.org/wp-content/uploads/2016/02/Cough-Assist-Commissioning- proforma-draft-FV-180216.pdf (Accessed: 11 April 2016). Hyde, S.A., Fløytrup, I., Glent, S., Kroksmark, A.-K., Salling, B., Steffensen, B.F., Werlauff, U. and Erlandsen, M. (2000) ‘A randomized comparative study of two methods for controlling Tendo Achilles contracture in Duchenne muscular dystrophy’, Neuromuscular Disorders, 10(4-5), pp. 257–263. doi: 10.1016/s0960-8966(99)00135-2. Manzur, A.Y., Kuntzer, T., Pike, M. and Swan, A.V. (2008) ‘Glucocorticoid corticosteroids for Duchenne muscular dystrophy’, The Cochrane Library, . doi: 10.1002/14651858.CD003725.pub3. Mazzone, E.S., Messina, S., Vasco, G., Main, M., Eagle, M., Amico, A. D’, Doglio, L., Politano, L., Cavallaro, F., Frosini, S., Bello, L., Magri, F., Corlatti, A., Zucchini, E., Brancalion, B., Rossi, F., Ferretti, M., Motta, M.G., Cecio, M.R., Berardinelli, A., Alfieri, P., Mongini, T., Pini, A., Astrea, G., Battini, R., Comi, G., Pegoraro, E., Morandi, L., Pane, M., Angelini, C., Bruno, C., Villanova, M., Vita, G., Donati, M.A., Bertini, E. and Mercuri, E. (2009) ‘Reliability of the north star ambulatory assessment in a multicentric setting’, Neuromuscular Disorders, 19(7), pp. 458–461. doi: 10.1016/j.nmd.2009.06.368. Muscular Dystrophy Association (2015) Diseases List. Available at: https://www.mda.org/disease/list (Accessed: 11 April 2016).
- 40. References Muscular Dystrophy UK (2009) North Star Ambulatory Assessment. Available at: http://www.musculardystrophyuk.org/assets/0000/6388/NorthStar.pdf (Accessed: 11 April 2016). Muscular Dystrophy UK (2015) Progress in Research. Available at: http://www.musculardystrophyuk.org/progress-in-research/ (Accessed: 11 April 2016). NHS Choices (2015) Muscular Dystrophy. Available at: http://www.nhs.uk/conditions/muscular- dystrophy/Pages/Introduction.aspx (Accessed: 11 April 2016). National Institute of Neurological Disorders and Stroke (2016) Muscular Dystrophy: Hope Through Research. Available at: http://www.ninds.nih.gov/disorders/md/detail_md.htm (Accessed: 11 April 2016). Newham, D.J., Jones, D.A. and Edwards, R.H.T. (1986) ‘Plasma creatine kinase changes after eccentric and concentric contractions’, Muscle & Nerve, 9(1), pp. 59–63. doi: 10.1002/mus.880090109. Norwood, F.L.M., Harling, C., Chinnery, P.F., Eagle, M., Bushby, K. and Straub, V. (2009) ‘Prevalence of genetic muscle disease in northern England: In-depth analysis of a muscle clinic population’, Brain, 132(11), pp. 3175–3186. doi: 10.1093/brain/awp236. Pryor, J.A. and Prasad, S.A. (2008) Physiotherapy for respiratory and cardiac problems: Adults and paediatrics. Edited by Jennifer A. Pryor. 4th edn. Edinburgh: Churchill Livingstone Elsevier. Rhee, Y.G. and Ha, J.H. (2006) ‘Long-term results of scapulothoracic arthrodesis of facioscapulohumeral muscular dystrophy’, Journal of Shoulder and Elbow Surgery, 15(4), pp. 445–450. doi: 10.1016/j.jse.2005.10.015.
- 41. References Muscular Dystrophy UK (2009) North Star Ambulatory Assessment. Available at: http://www.musculardystrophyuk.org/assets/0000/6388/NorthStar.pdf (Accessed: 11 April 2016). Muscular Dystrophy UK (2015) Progress in Research. Available at: http://www.musculardystrophyuk.org/progress-in-research/ (Accessed: 11 April 2016). NHS Choices (2015) Muscular Dystrophy. Available at: http://www.nhs.uk/conditions/muscular- dystrophy/Pages/Introduction.aspx (Accessed: 11 April 2016). National Institute of Neurological Disorders and Stroke (2016) Muscular Dystrophy: Hope Through Research. Available at: http://www.ninds.nih.gov/disorders/md/detail_md.htm (Accessed: 11 April 2016). Newham, D.J., Jones, D.A. and Edwards, R.H.T. (1986) ‘Plasma creatine kinase changes after eccentric and concentric contractions’, Muscle & Nerve, 9(1), pp. 59–63. doi: 10.1002/mus.880090109. Norwood, F.L.M., Harling, C., Chinnery, P.F., Eagle, M., Bushby, K. and Straub, V. (2009) ‘Prevalence of genetic muscle disease in northern England: In-depth analysis of a muscle clinic population’, Brain, 132(11), pp. 3175–3186. doi: 10.1093/brain/awp236. Pryor, J.A. and Prasad, S.A. (2008) Physiotherapy for respiratory and cardiac problems: Adults and paediatrics. Edited by Jennifer A. Pryor. 4th edn. Edinburgh: Churchill Livingstone Elsevier. Rhee, Y.G. and Ha, J.H. (2006) ‘Long-term results of scapulothoracic arthrodesis of facioscapulohumeral muscular dystrophy’, Journal of Shoulder and Elbow Surgery, 15(4), pp. 445–450. doi: 10.1016/j.jse.2005.10.015.
Notes de l'éditeur
- (Wagner et al., 2007) Initial interest came after being presented with a really interesting outpatient case study involving a AGE year old woman, who I’ll introduce next. With that in mind, I decided to look into the condition. After brief initial research it quickly became apparent that: The condition(s) are rare, with an overall prevalence is around 1:1000. The knowledge of the conditions tends to be poor, particularly outside the specialist area of paediatric care. But their affects often lead to physical disability and subsequently reduced independence and life-expectancy. Surely something can be done to help with this? Indeed, significant developments in the understanding of genetics and molecular biology over the last decade have resulted in improved management strategies in recent times, resulting in more affected children surviving to middle age, where previously they would have died. Thus increasing the likelihood of us receiving Muscular Dystrophy patients outside the paediatric setting.
- A diverse group of genetically determined disorders associated with progressive degeneration of skeletal muscles, and leading to physical disability and reduced independence. The presentation of MD is variable, and has resulted in the discovery of over 30 different types, some of which I’ll introduce later. At present there is NO cure for MD, but current research is focused on discovering one.
- (Muscular Dystrophy UK, 2015) In the UK, more than 70,000 people have MD or a related condition. Of these, Duchenne MD is by far the most represented type: Which is demonstrated by the focus of research into the conditions, with studies predominantly looking at the conditions affects on DMD patients. Around 100 boys are born each year with the condition. And roughly 2500 males are living with the condition in the UK at any one time. I’ll explain why mainly boys later….. But as I said, the main reason it caught my attention was because one such patient turned up in our very own Neuro Rehabilitation Gym.
- The patient in question is a AGE year old female, who was diagnosed with the condition in 1986. She was referred to Helen and myself 3 weeks ago by her GP after a recent decline in her symptoms, Particularly affecting her ability to get out of a chair. Her difficulties with this quickly became apparent to Helen and myself when she simply could not get out of her chair within the rehab gym, and eventually required the assistance of both of us to help her do so.
- So, how did she present? Well, by far the most pronounced symptom was her Muscle Weakness: With her Distal muscles < Proximal muscles (which will become more relevant later on when I introduce the different types of MD) In the Upper Limbs this presented with: Her Elbow, Wrist, and Grip strength predominantly only strong enough to resist gravity at best. While at her Shoulder she could work against resistance, but not through full range. In the Lower Limbs a similar pattern presented, with: Her Knee and Ankle strength only strong enough to record a 2 or 3/5 on the Oxford Grading Scale. While her Hip Flexion scored 4/5 We never actually assessed the remaining movements of the hip, but her functional capabilities suggested a potential bilateral weakness of her glutes as well. She also had Reduced ROM at her Ankles, Wrists, Lx Spine and Hips. Meaning at her ankles she couldn’t achieve plantar grade. And in her Lx Spine and Hips she was severely limited by muscle stiffness and pain in all directions. She also had global low tone, particularly affecting her Lower Limbs and her Thenar and Hypothenar Eminence on both hands. However, her sensations remained intact.
- As I’ve already mentioned, functionally she required AO2 to stand from a low chair. However, she was able to raise from a slightly higher chair, but did so using an unusual compensatory pattern. This involved her: Placing both hands to one side.. Extending, and locking her knees… Rotating… And climbing up into standing using her upper limbs and surrounding furniture for support. She also required AO1 or an aid to climb tall steps, such as a pavement curb. And had reduced mobility due to: A decreased walking tolerance of under 5 minutes, caused by the onset of what she described as 10/10 pain at worst in her Lx Spine, Hips, and down both her legs. Additionally she had a history of falls, And a Trendelenburg gait, affecting her left side during both the stance and swing phase, suggesting weakened glute med and min muscles. Finally her dexterity also appeared affected, as she reported having difficulty with buttons, peeling vegetables, and fastening her bra strap. And she was really tender on palpation of her Lx and Hip musculature.
- Some additional problems for consideration included: Dysarthria Bladder and Bowel impairments, and… ? Dysphagia, ? because she is still awaiting an appointment with her Speech and Language Therapist. She also has a history of: Epilepsy, but not for 10 plus years now. She had a Spinal Cord Operation in 2009. And she's had a Heart Murmur in the past, but not at present.
- Medication wise she currently takes no nothing to help with directly her condition. However, she has previously been prescribed with steroids, but doesn’t take them due to concerns regarding the side-effects. She does occasionally use painkillers if her pain is particularly bad however. At home she lives with her family, including her partner, son and daughter, with the 23 year old son in particular helping out with ADL limitations previously mentioned. The house includes stairs, equipped with a stair rail and a stair lift, which she uses when needing to carrying things upstairs.
- So what did we do? Well, presented with an uncommon condition… During her first session she was only provided with advise regarding: The use of heat and ice to help alleviate her painful and tender Lx and hip musculature… And the benefit of grip gloves to assist with fine movements of the hand… But also concerning the potential use of onward referrals in the future to: An OT for adaptations at home… A Wheelchair Service for the provision of a powered wheelchair… And hydrotherapy, the benefits of which I will touch upon later. During her second session she was prescribed a pair of Fisher crutches, after finding them more beneficial than a pair of walking sticks because they provided extra support at her weak elbows. Finally she was given a few exercises aimed at increasing her ROM, and reducing her pain, at her Lx and hip. But to date, that is all we’ve done for her, and her symptoms haven’t really changed.
- So with all this in mind, I set about researching into the current recommendations regarding her condition. As I’ve said previously, there are over 30 different known types of MD to date, each with varying presentations. But generally MD patients are known to present with: Weakened Muscles, of varying presentation, depending on the type of MD. Muscle Cramps And functional limitations and subsequent compensatory adaptations involving: STS Stairs Mobility Falls and the subsequent need to get up off the floor Gower’s Manouevre – required due to progressive hip and knee extensor weakness, it aims to bypass the need for these muscle by locking the knees into extension, and then using the arms to push off from the thighs with the hand or forearms, enabling the patient to ‘climb’ up their own legs. Jumping Balance Gait Waddling gait – due to hip adductor weakness causing an inability to hold the pelvis level during the stance phase of each leg. Basically the Trendelenburg sign!
- Secondary complications can develop, and other variable symptoms are common depending on the type of MD. Contractures are common in the majority of types, as weakened muscles become fixed in shorten positions, making them even more weaker functionally, and eventually leading to contractures and reduced joint ROM. Such long term shortening of muscles can potentially lead to the development of scoliosis, if not appropriately managed. Scoliosis can directly inhibit respiratory function, causing respiratory muscles to fatigue and weaken. Pain can present in a number of different ways, but commonly due to contracture development and muscle weakness. Weakness of the lower limb muscles can progress to the point where ambulation becomes impossible without the use of aids, and often patients with MD require a wheelchair to maintain independence during latter life. Facial muscle weakness can cause Ptosis, and impairments of the individuals swallow and vision in some rare types of MD. Finally, the heart is also susceptible to the condition, with some types on MD resulting in the patient developing cardiac arrhythmias and cardiomyopathy. It’s at this point, where a patients heart or respiratory function is compromised, that life-expectancy is reduced, and death due to MD may occur.
- What causes MD? Well MD is caused by mutations in the genes responsible for the structure and functioning of a patients muscles, particularly their muscle fibres. How? Well, the muscle fibre membranes contain a group of proteins called the dystrophin-glycoprotein complex, which prevent damage to the fibres as they contract and relax. But when this protective membrane is damaged, muscles fibres begin to leak a protein called Creatine Kinase (which is needed for the chemical reactions that produce energy for muscles to contract), and take on excess calcium, which causes further harm. Affected muscle fibres eventually die from this damage, leading to the progressive muscle degeneration seen within the condition. The gene mutations are often inherited from an individuals parents, and depending on the type of MD, the condition can be either: Recessive Inherited disorder – where both mum and dads allele are affected, resulting in: 1 in 4 chance of MD developing 1 in 4 chance of being healthy 2 in 4 chance of being healthy, but a carrier Dominant Inherited disorder – where one parents allele is affected (either as a carrier or an MD sufferer), but the other’s is not, resulting in a 50% chance of any child inheriting MD. Sex-Linked disorder – where only boys are at risk of developing the condition. This is due to the fact males have one X and one Y chromosome, while females have two X chromosomes. As males only have one copy of each gene on their individual X chromosome, any mutation of that gene results in the development of MD, as no second copy of that same gene is available to mask the negative effects. Spontaneous Mutation – can also occur for no apparent reason, developing as a new event in the family tree, but this is very rare. As a result, a person family history plays a key part in diagnosing MD.
- Many different methods can be used to diagnose the various types of MD. Diagnosis will involve some, or all of the following stages: Initial Investigation of Symptoms – involves looking into reasons for why a patient might have newly developed functional difficulties. Family History Discussion – looks to establish the presence of a family history of MD. Blood Tests Creatine Kinase – is usually found in muscle fibres, but as previously mentioned, when damaged, these muscle fibres release CK into the blood stream in abundant numbers, that shown up on blood tests. Genetic Testing – looking directly for gene mutations. Electromyography (EMG) – examine the electrical activity of nerves and muscles at rest and during contractions, to determine whether the underlying problems is residing from the CNS, the PNS, or the muscles themselves, as with MD. Muscle Biopsy – where small tissue samples from potentially affected muscles are removed and tested for the presence of proteins, such as dystrophin in DMD, or for differences in muscle fibre structure. Symptom Specific Tests – include: MRI – looking directly for muscle damage Chest X-Ray – looking for signs of respiratory complications. Electrocardiogram (ECG) – that study the hearts electrical activity, and highlight the presences of an irregular heartbeat, or heart palpitations. Echocardiogram – to examine the hearts structure using sound waves to uncover cardiomyopathy. Lung Function Tests – that also identify respiratory function impairments such as reduced PEFR required for coughing.
- (Centers for Disease Control and Prevention, 2016; Norwood et al., 2009; Muscular Dystrophy Association, 2015; Stokes and Stack, 2012) As I’ve said, there are over 30 different know variations of MD currently. Each presents differently, with reasons for variations including: Age of symptom presentation – predominantly MD symptoms present from birth or during early childhood in the majority of types, while in some they don’t develop until late adulthood. Affected Areas of Muscle Weakness – the presentation can vary greatly, reflecting the wide range of different types of MD. Disability – whether the condition progresses to cause disability or not. Life-Expectancy Gender – the two most well understood types predominantly affect boys, due to Sex-Linked Inheritance mentioned earlier.
- (Centers for Disease Control and Prevention, 2016; Norwood et al., 2009; Muscular Dystrophy Association, 2015) By far the most common, and has the biggest evidence base regarding its management. It is a sex-linked disorder, meaning it usually affects boys, particularly during early childhood, with individuals going on to live into their 20s or 30s. Muscles around the pelvis and thighs are usually affected first, before the upper arm and shoulder also become involved. DMD children can also present with delayed motor milestones and learning difficulties, which lead to global developmental delay later on. The children often need a wheelchair by the time they’re 8-14 years old, causing Scoliosis to become a common problem as a result of early wheelchair dependency. Dilated Cardiomyopathy and an Irregular Heartbeat may also develop during their late teens, alongside respiratory muscle weakness, which eventually leads to breathing difficulties that lead to early death.
- (Centers for Disease Control and Prevention, 2016; Norwood et al., 2009; Muscular Dystrophy Association, 2015; Stokes and Stack, 2012) Myotonic Dystrophy is the 2nd most common, and can develop at any age, and generally progresses slowly. It is considered a Dominant Inherited disorder. Characterised by an inability to relax muscles at will following contractions, and myotonia, or muscle stiffness, especially affecting the hands. Myotonia is demonstrable by asking the patient to clench their fist, and then let go quickly, with the patient having to release their grip using the other hand. Often the smaller muscles are affected first, such as those in the face, jaw, and neck. The large weight-bearing muscles of the legs and thighs are much less affected. Life-expectancy isn’t always shortened, although people with a severe form may have shortened lives. It’s severity can increase as it’s passed down through the generations. Other problems include: Cataracts Excessive Sleeping Dysarthria Dysphagia Frontal Balding Cardiac Arrhythmias
- (Centers for Disease Control and Prevention, 2016; Norwood et al., 2009; Muscular Dystrophy Association, 2015; Stokes and Stack, 2012) A type of MD that can develop in childhood or adulthood, generally progresses slowly, and isn’t usually life-threatening. It affects men slightly more than women, although the reason for this is unclear. It’s considered an dominant inherited disorder. As the condition progresses, it usually affects the muscles in the face, shoulders, and upper arms first, as the name suggests. But it can also affects the trunk and calves, with around half of all people with FSH MD developing weakness in their leg muscles, and 1-10 eventually needing a wheelchair.
- (Centers for Disease Control and Prevention, 2016; Norwood et al., 2009; Muscular Dystrophy Association, 2015) Becker MD is closely related to DMD in the presentation of its muscle weakness in the Upper Arms and Legs first, and that it affects males but not females. It differs because it develops later in childhood, and is less severe. As a result, life-expectancy isn’t usually affected. People with BMD often eventually need a wheelchair by the time they reach 40-50 years old, although this is highly variable.
- (Centers for Disease Control and Prevention, 2016; Norwood et al., 2009; Muscular Dystrophy Association, 2015) Limb-Girdle MD represents a group of disorders that usually develop in later childhood, or early adulthood, depending on the specific type. Some can develop quickly and be life-threatening, whereas others develop slowly. Males and females are equally affected. Its can be either a Dominant or Recessive Inherited disorder, again depending on the specific type. The big pectoral and pelvic girdle muscles are predominantly affected. While the muscles of the face are generally unaffected.
- (Centers for Disease Control and Prevention, 2016; Norwood et al., 2009; Muscular Dystrophy Association, 2015) Oculopharyngeal MD doesn’t usually develop until a person is 50-60 years old, and doesn’t tend to be life-threatening. It is considered a Dominant Inherited disorder. It affects the muscles of the eyes and throat, as the name suggests. But it can also affect muscles in the neck, upper arms and legs. Variable symptoms include: Ptosis Diplopia Dysphagia
- (Centers for Disease Control and Prevention, 2016; Norwood et al., 2009; Muscular Dystrophy Association, 2015) Emery-Dreifuss MD is the least common of the 7 types I’ve touched upon, and usually develops in childhood or early adulthood. Its has both a Sex-Linked form, and an Autosomal Dominant disorder form. Hallmarks that make it unique are that it usually causes asymmetric muscle weakness, early development of contractures before the development of any muscle weakness, and a cardiac block, caused by disruption of the cardiac conduction system, rather than the cardiac muscle itself. In the early stages people usually develop muscle contractures, commonly affecting the arms, neck, and ankles. Then, as with all other types of MD, progressive muscle weakness begins to affect the shoulders, upper arms and lower legs. Due to the risk of serious heart and respiratory problems, life-expectancy is often shortened, however, most people will live on until their middle-aged.
- There is NO cure, but a range of treatments can help with the physical disabilities and problems that may develop. Each of these will be touched upon in the following slides, with a focus on the areas important to physiotherapy.
- (Aitkens et al., 1993; Ansved, 2003; Geytenbeek, 2002; Hyde et al., 2000; Kilmer et al., 1994; Kilmer, 2002; Lindeman et al., 1995; Muscular Dystrophy UK, 2015; Newham et al., 1986; Scott et al., 1981; Sveen et al., 2008; Stokes and Stack, 2012) The first of which is Mobility Assistance. Very few controlled studies have looked into the effect of exercise in neuromuscular disease, and many are not disease specific. However, for many MD conditions, management strategies are considered transferable, and knowledge of the most frequently seen conditions will be relevant even to the rarest. Most of the research advocates the use of low-to-moderate intensity exercise to help maintain strength, mobility, and general health. Indeed aerobic exercise has been shown to be well tolerated by patients with BMD, with improvements in the aerobic capacity and strength observed (Sveen et al., 2008). While the results of mild to moderate resistance exercise programmes have shown limited increases in strength, but with no negative effect on muscle function either (Ansved, 2003). Other studies have however highlighted that high loads and possibly even eccentric contractions should be avoided, as they may increase the risk of muscle fibre damage. Eccentric muscle training can cause appreciable morphological damage to muscle fibres (Newham et al., 1986), and damage of this nature is commonly seen in the muscles of patients with myopathic disease. So in summary, low-moderate impact aerobic exercise should be encouraged wherever possible, with examples of including swimming and walking. However, high loading resistance training should be avoided, especially eccentric exercises. Hydrotherapy has also been found to be particularly popular among MD patients themselves, with benefits found in reducing pain, relaxing weakened muscles, and increasing mobility and range of movement. The maintenance of full joint range of motion is essential for optimal muscle function. The force-generating ability of a muscle is influenced by the length at which it contracts, and thus the strength of a muscle held in a shortened position is reduced. With this in mind, the majority of studies have looked into the use of passive stretch and splinting. Two studies have evaluated the effects of both, and concluded that a sustained programme of night splinting and passive stretching together during early stage DMD can retard the development of lower limb contractures. In addition they concluded that that passive stretch alone is less affective (Hyde et al., 2000; Scott et al., 1981). AFOs are not always recommended. Mobility Aids are often required as the condition progresses, to help maintain an individuals function and independence. Obviously wheelchairs, crutches, and home adaptations can be used, much in the same way as any other condition requiring their use. But more specialist equipment available includes the Neater Arm Support, and Powered Profiling Beds. The Neater Arm support is a powered height adjustable arm support that helps patients with weak shoulder muscles to maintain function in their elbow, wrist, and hands. It is operated using a simple switch, and also enables the shoulder itself to be moved through range and reduced the chance of joint deterioration associated with immobility. Powered profiling beds are useful when a patient has mobility difficulties when in bed. This may included enabling them to raise the height of the bed to make STS easier; OR adjusting different parts of the bed to make mobility in the bed itself much easier. As such the need for assistance from carers is reduced, and independence can be maintained.
- (American Thoracic Society, 2004; Godwin, 2016; Pryor and Prasad, 2008) Chest infections are a serious complication to vulnerable patients with respiratory muscle weakness, and a poor cough. As such they need to be identified and treated as soon as possible. I don’t want to go into detail about what each of these do, as they’re used in exactly the same way as other conditions. But the use of Cough Assist and IPPB have been studied in Muscular Dystrophy to positive effect. And NIV is particularly prevalent to compensate for respiratory muscle weakness as the disease progresses, particularly at night. As a general rule, if FVC is found to be less than 50% of that expected for an individuals height, or if there’s a greater drop than 20% FVC when a patient lies flat, sleep hypoventilation should be suspected and a sleep study should be arranged.
- (Rhee and Ha, 2006) There are no trials evaluating the effectiveness of surgery to manage postural deformities. But Rhee and Ha (2006) found scapular fixation to be beneficial to patients with Facioscapulohumeral MD, so long as the surgery is performed before a patients respiratory function has been compromised. In terms of contractures, surgery has been used to lengthen or release effected tendons.
- (American Thoracic Society, 2004; Manzur et al., 2008) Corticosteroids have been shown to improve muscle strength and function and respiratory function for between 6 months to 2 years. Whilst they also help to slow the progression of muscle weakness (American Thoracic Society, 2004; Manzur et al., 2008). Their use should also be weighed up against the risk of common side effects however, such as Osteoporosis, weight gain, and excessive hair growth. Anti-Convulsants can used to help target muscle spasms. While Immunosuppressant's may help delay some damage to dying muscle cells. The use of Creatine supplements has also been shown to improve muscle strength in some people with MD, whilst also causing very few side-effects (Alternative Therapies, Muscular Dystrophy UK).
- (Duboc et al., 2007) A pacemaker can be lifesaving if installed before respiratory compromise develops, particularly with Myotonic or Emery-Dreifuss MD.
- (Muscular Dystrophy UK, 2015) Dietary changes haven’t been shown to slow the progression of MD, but a high-fibre, high-protein, and low-calorie diet may help when combined with recommenede fluid intake.
- (Alternative Therapies, Muscular Dystrophy UK) No studies confirming any long term benefits from acupuncture, with only short term relief from pain observed. Royal Jelly is a natural substance made by bees for the nourishment of the queen bee, and is sold as a nutritional supplement, usually in the form of capsules. It is rich in vitamins, antioxidants, enzymes, hormones and amino acids. But no evidence current exists regarding its use in MD. A study is taking place, but to date has found no benefits. Massage is supported to relax tight/ weakened muscles, and aid pain relief, much in the same way its used elsewhere. A recent study has shown that a high intake of Green Tea may have potential for warding off muscle cell death and deterioration in mice. Researchers found that the equivalent of 7 cups a day may have antioxidant effects to compact oxidative stress seen in MD.
- Useful to help people come to terms with their condition. Many also provide advice and support to whose who care for people with MD. I’ve found the Muscular Dystrophy UK website a particularly useful tool for health professionals, full of latest news regarding research into the condition. They have also devised a Physiotherapy eLearning Module that has been advocated by the CSP in the last year, and works in much the same way as Stroke Stars, and CPD accredited.
- New research is looking into ways of repairing the genetic mutations and damaged muscles associated with MD. There are currently promising clinical trials for DMD regarding Exon Skipping and Stem Cell implantation. Exon Skipping – Investigating ways of ‘skipping’ additional exons in the dystrophin gene, resulting in potentially increasing the amount of dystrophin produced, and subsequently reducing the severity of symptoms. Stem Cell research aims to discover if implanted stem cells can be used to produce new muscle cells and regenerate damaged muscle tissue.
- (Fisher et al., 1990; Mazzone et al., 2009; Muscular Dystrophy UK, 2009; Wiles et al., 1990) The key aspects of PT assessment are measurement of muscle strength and functional performance, plus lung function when appropriate. The North Star Ambulatory Assessment has been devised specifically for assessing mobility in MD, and has been found to shown excellent inter-observer reliability (Mazzone et al., 2009). It consists of 17 separate motor activities, biased towards lower limb activities, and each rated on a 3-point scale: 2 = ‘Normal’ – no obvious modification of activity. 1 = Modified method, but achieves goal independent of physical assistance from another. 0 = Unable to achieve independently.