Duchenne Muscular Dystrophy: Gastrointestinal Management

1. Duchenne Muscular Dystrophy:Gastrointestinal Management

2. Introduction • Patients at risk of both undernutrition and being overweight • Range of experts may be needed as condition progresses • Dietician or nutritionist • Swallowing/Speech and language therapist (SLT) • Gastroenterologist • These experts should • Guide the patient to maintain good nutritional status and well-balanced diet (with tube-feeding if necessary) • Monitor/treat swallowing problems (dysphagia) to prevent aspiration and weight loss, and assess/treat delayed speech/language problems • Treat common problems of constipation and gastro-oesophageal reflux with medication and non-medication therapies

3. Nutritional management (1) • Forward planning needed from diagnosis onwards to maintain good nutritional status • Poor nutrition can adversely affect almost every organ system • Patients require a well-balanced diet with a full range of food types • Weight or BMI for age should be maintained between 10th and 85th percentile on national charts

4. Nutritional management (2) • Regular monitoring is required for • Weight • Linear height (ambulatory patients) every 6 months • Arm span/segmental length (non-ambulatory patients) • Refer to expert dietician at diagnosis and steroid initiation • Further referral triggers include • If patient is underweight (<10th age percentile), at risk of becoming overweight (85th-95th age percentile), or overweight (95th age percentile • Unintentional weight loss/gain, or poor weight gain • If major surgery is planned • If patient is chronically constipated, or if dysphagia is present

5. Upon referral • Diet should be assessed for energy, protein, fluid, calcium, vitamin D and other nutrients • Daily multivitamin recommended (including vitamin D and minerals) • If this is not general practice, computer nutrient analysis of diet can provide evidence for possible need for specific foods or supplements • If suspicion of undernutrition/malnutrition and poor intake, serum vitamin concentrations can be obtained and supplements recommended

6. Swallowing management (1) • In later stages, pharyngeal weakness can lead to dysphagia • Can further accentuate nutritional issues/loss of respiratory strength • Can occur gradually and be difficult to spot • Clinical swallowing examination indicated if • Unintentional weight loss of ≥ 10% • Decline in expected age-related weight gain • Referral necessary if any clinical indicators of dysphagia • Prolonged mealtimes (>30 minutes), or mealtimes accompanied by fatigue, excessive spilling, drooling, pocketing • Persistent coughing, choking, gagging, or wet vocal quality during eating/drinking • Swallowing problems necessitating assessment may also be indicated by • Aspiration pneumonia • Unexpected decline in pulmonary function • Fever of an unknown origin

7. Swallowing management (2) • Videofluroscopic study of swallowing (modified barium swallow) necessary for patients with clinical indicators of possible aspiration and pharyngeal dysmotility • For patients with dysphagia, a Speech Language Therapist (SLT) with training/expertise in treatment of oral-pharyngeal dysphagia should be involved • They can deliver an individualised treatment plan of swallowing interventions/compensatory strategies with aim of preserving good swallowing function.

8. Swallowing management (3) • As disease progresses, most patients begin to experience increasing difficulty with chewing, and subsequently exhibit pharyngeal-phase swallowing deficits in young adulthood • Gastric tube placement should be offered when efforts to maintain weight and hydration by oral means are insufficient • Potential risks/benefits should be carefully discussed with family. • A gastrostomy may be placed by endoscopic or open surgery, taking into account anaesthetic considerations and family/personal preferences

9. Gastrointestinal management (1) • Most common conditions in DMD are constipation and gastro-oesophageal reflux • Constipation: typically at older age/after surgery • Laxatives, stool softeners and stimulants necessary for acute constipation or fecal impaction; daily laxatives necessary if symptoms persist • Use of enemas might be needed occasionally • Adequacy of free-fluid intake should be determined and addressed • Increased fibre may worsen symptoms, especially if fluid intake not increased

10. Gastrointestinal management (2) • Gastro-oesophageal reflux (causing heartburn) • Typically treated with proton-pump inhibitors or H2 receptor antagonists • Prokinetics, sucralfate, and neutralising antacids are adjunctive therapies • Acid blockers commonly prescribed to children on steroid therapy or oral bisphosphonates to avoid complications • With increasing survival, other complications are being reported, including • Intestinal swelling related to air swallowing due to ventilator use • More rarely, delayed gastric emptying and ileus

11. Speech and language Management • Delayed acquisition of early milestones common in DMD • Differences in language acquisition and language skill deficits persisting through childhood • Referral to SLT for assessment/treatment necessary on suspicion of difficulties with speech acquisition, or continuing deficits in language comprehension or oral expression • Oral motor exercises and articulation therapy necessary for young boys with hypotonia and older patients with deteriorating oral muscle strengths and/or impaired speech intelligibility • Compensatory strategies, voice exercises, and speech amplification appropriate in older boys if intelligibility deteriorates • Voice Output Communication Aid assessment appropriate at all ages if speech output is limited

12. Oral care • Not yet part of published international consensus. Scandinavian consensus/ TREAT-NMD expert recommendations • Patients should see dentist with extended experience and detailed knowledge of DMD • Preferably at a centralised/specialised clinic • Aware of specific differences in dental/skeletal development in DMD • Will collaborate with well-informed/experienced orthodontist • Should strive for high-quality treatment, oral health and wellbeing, and function as resource for family and boy’s community dentist • Oral/dental care should be based on prophylactic measures to maintain good oral/dental hygiene • As progressive loss of arm function systematically erodes ability for independent tooth brushing, this needs to be specifically addressed as an area for attention to uphold oral hygiene • Specific alerts necessary if on bisphosphonate treatment

13. References & Resources • The Diagnosis and Management of Duchenne Muscular Dystrophy, Bushby K et al, Lancet Neurology 2010 9 (1) 77-93 & Lancet Neurology 2010 9 (2) 177-189 • Particularly references, p186-188 • The Diagnosis and Management of Duchenne Muscular Dystrophy: A Guide for Families • TREAT-NMD website: www.treat-nmd.eu • CARE-NMD website: www.care-nmd.eu