Dysphagia Knowledge Hub — 吞嚥困難知識庫

Multiple Sclerosis and Dysphagia: A Practical Guide

Multiple sclerosis (MS) is a chronic neurological condition in which demyelination and axonal damage in the central nervous system disrupt communication between the brain and body. Dysphagia is more common in MS than many people — including clinicians — realise: studies report prevalence ranging from 30% to over 40%, with rates rising as disability accumulates and in progressive MS subtypes. Because swallowing difficulties often develop gradually and patients may not spontaneously report them, active screening is essential.

How MS Causes Swallowing Difficulties

Swallowing requires precise coordination between the cortex, brainstem, and peripheral nerves. MS lesions affecting any of these pathways can disrupt the swallowing sequence. Common underlying mechanisms include:

• Brainstem lesions: affecting cranial nerve nuclei and the central pattern generators that coordinate pharyngeal swallowing
• Corticobulbar tract damage: reducing voluntary control of the oral and pharyngeal phases
• Cerebellar involvement: causing incoordination and timing errors during swallowing

The result may be delayed pharyngeal swallow trigger, reduced pharyngeal constriction, incomplete laryngeal elevation and closure, or impaired cricopharyngeal opening — all increasing aspiration risk. Silent aspiration (aspiration without cough reflex) is common in neurological dysphagia, making clinical vigilance especially important.

The Role of Fatigue

MS fatigue — one of the most prevalent and disabling symptoms of the condition — has a direct impact on swallowing safety. Even patients who swallow safely at the beginning of a meal may aspirate by the end as fatigue sets in. This means:

• Assessment should replicate real-world eating conditions, including testing after sufficient quantity to reveal fatigue effects
• Meal size, pace, and duration should be managed — smaller, more frequent meals are often preferable to large portions
• High-demand foods (tough meats, dry crumbly textures) should be avoided at times of greatest fatigue
• Rest before meals can reduce fatigue-related risk

Recognising Dysphagia in MS

Patients and carers should know the warning signs:

• Coughing or throat-clearing during or after eating or drinking
• A wet or gurgly voice quality after swallowing
• Sensation of food or liquid sticking in the throat or chest
• Taking much longer than usual to finish a meal
• Avoiding particular foods or drinks without a clear reason
• Recurrent chest infections (which may indicate silent aspiration)
• Unexplained weight loss

MS relapse can cause acute worsening of swallowing. Any sudden deterioration warrants prompt SLT review and consideration of instrumental assessment.

Assessment and Monitoring

RCSLT guidelines recommend regular dysphagia screening for all people with MS, particularly those with significant disability, brainstem involvement, or bulbar symptoms. A validated screening tool (such as the EAT-10 questionnaire) can be used in clinic or community settings to flag those needing full SLT assessment.

When clinical signs suggest aspiration risk, instrumental evaluation — VFSS or FEES — is recommended to characterise the mechanism of dysfunction and guide intervention. Instrumental assessment is particularly important before prescribing specific swallowing manoeuvres or texture modifications, as treatment must match the underlying physiological impairment.

Management Approaches

Compensatory strategies modify how swallowing occurs without changing the underlying physiology. Examples relevant to MS include:

• Chin tuck (chin-down posture): reduces premature spillage into the pharynx before swallow trigger
• Head turn: redirects the bolus away from a weaker side
• Small sips and small bites: reduces bolus size and pharyngeal demand
• Double swallow and effortful swallow: clears residue and increases pharyngeal pressure

Texture modification using the IDDSI framework may be required for food and/or liquids when aspiration risk is confirmed on instrumental assessment. Thickened liquids should not be prescribed without evidence of need, as they can reduce fluid intake and patient satisfaction.

Exercise-based therapy targets the underlying swallowing musculature. Expiratory muscle strength training (EMST), tongue pressure exercises, and the Mendelsohn manoeuvre have evidence in neurological populations including MS. Programme intensity should account for fatigue — exercises designed for high-repetition frequency may not suit patients with significant MS fatigue, and session timing should be planned around the individual’s energy patterns.

Practical Day-to-Day Advice

• Sit upright at 90 degrees for all eating and drinking; remain upright for at least 30 minutes after meals
• Eliminate distractions at mealtimes — focus reduces aspiration risk
• Choose appropriate IDDSI food and liquid levels as prescribed by your SLT
• Avoid alcohol before eating, as it impairs swallowing coordination and cough reflex
• Keep regular dental hygiene — good oral health reduces bacterial load and aspiration pneumonia risk

When to Seek Help

People with MS and their carers should know when to contact their MS nurse, GP, or SLT:

• New or worsening swallowing symptoms
• Any episode of suspected aspiration or aspiration pneumonia
• Significant unintentional weight loss
• Increasing mealtime duration or meal avoidance

Dysphagia in MS is manageable. With proactive monitoring, timely assessment, and tailored intervention, most people with MS can continue to eat safely and enjoyably.