Duchenne Muscular Dystrophy: Gastrointestinal Management

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

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 10 th and 85 th percentile on national charts

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 (<10 th age percentile), at risk of becoming overweight (85 th -95 th age percentile), or overweight (95 th 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

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

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

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.

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

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

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

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

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

References & Resources The Diagnosis and Management of Duchenne Muscular Dystrophy, Bushby K et al, Lancet Neurology (1) & Lancet Neurology (2) – Particularly references, p The Diagnosis and Management of Duchenne Muscular Dystrophy: A Guide for Families TREAT-NMD website: CARE-NMD website: