Dysphagia Knowledge Hub — 吞嚥困難知識庫

Multiple Sclerosis and Dysphagia in Hong Kong: Managing a Relapsing-Remitting Swallowing Condition

Multiple sclerosis (MS) is an autoimmune condition in which the immune system attacks myelin — the protective sheath surrounding nerve fibres in the central nervous system. In Hong Kong, MS is less prevalent than in Western countries (estimated 2–4 per 100,000 population), but it disproportionately affects working-age adults and presents complex management challenges, particularly for conditions that fluctuate with disease activity.

Dysphagia in MS is more common than many clinicians and patients realise, occurring in approximately 30–40% of people with MS at some point in their disease course. Its most distinctive feature — the one that most separates it from dysphagia in other neurological conditions — is its relapsing-remitting nature: swallowing ability can worsen significantly during a relapse and recover partially or fully during remission. This means dietary management must be dynamic, not static.

How MS Causes Dysphagia

Demyelination of Brainstem and Corticospinal Tracts

Swallowing is coordinated by a complex neural network involving the brainstem (particularly the medulla and pons), the cerebral cortex, and the cerebellum. MS lesions in these regions directly disrupt swallowing.

Brainstem demyelination — particularly in the medulla — affects the nucleus tractus solitarius and nucleus ambiguus, which coordinate the pharyngeal phase of swallowing (laryngeal elevation, epiglottic deflection, pharyngeal constriction, upper oesophageal sphincter relaxation). Lesions here can cause delayed pharyngeal swallow, incomplete laryngeal closure, and reduced pharyngeal clearance.

Corticospinal tract lesions affect voluntary swallowing initiation and oral phase control — leading to slowed tongue movement, reduced bolus propulsion, and difficulty coordinating the transition from voluntary to reflex swallowing.

Cerebellar involvement (common in MS) causes ataxia that extends to swallowing musculature — resulting in irregular, dyscoordinated swallowing patterns that do not follow the predictable timing seen in other neurological dysphagia.

What This Looks Like Clinically

People with MS-related dysphagia may experience:

The Relapsing-Remitting Nature: Diet Cannot Be Static

This is the most important principle in MS dysphagia management. Unlike Parkinson’s disease (slow progression) or stroke (one-time event with recovery trajectory), MS dysphagia can change dramatically — in either direction — within days.

During a relapse: New or existing demyelinating lesions may cause sudden onset or worsening of dysphagia. A patient who safely managed IDDSI Level 6 may, within a week, require Level 4 or thickened liquids. This change can occur without the patient reporting dysphagia — they may simply eat less, lose weight, or develop aspiration pneumonia.

During remission or after steroid treatment: Swallowing function may partially or fully recover. Continuing an unnecessarily restrictive diet texture is associated with reduced caloric intake, nutritional decline, reduced quality of life, and social isolation. IDDSI level should be reviewed upward (toward regular diet) when function improves.

Practical implication: Every new MS relapse should prompt reassessment of dysphagia status. Caregivers and patients should know the key signs of worsening swallowing (increased coughing at meals, voice changes, longer mealtimes, more fatigue during eating) and know to contact the medical team immediately rather than waiting for a scheduled appointment.

Fatigue Management at Mealtimes

MS-related fatigue is central nervous system fatigue — qualitatively different from the tiredness of a busy day. It is not relieved by rest in the short term and may worsen unpredictably. Fatigue directly amplifies dysphagia: swallowing muscles tire, response speed slows, and laryngeal protection becomes less precise.

Timing meals for best function:

Meal pacing:

Energy conservation:

Uhthoff Phenomenon: Heat Worsening Symptoms

Uhthoff phenomenon — temporary worsening of neurological symptoms with elevated body temperature — is well recognised in MS. It directly affects swallowing. Causes of temperature elevation include:

During Uhthoff worsening:

Practical strategies:

Spasticity and Its Effect on Swallowing

MS causes spasticity — increased muscle tone — in affected muscle groups. While most attention focuses on limb spasticity, pharyngeal and oesophageal spasticity also occur and can cause dysphagia symptoms that are distinct from those caused by weakness:

Medications used to manage MS spasticity (baclofen, tizanidine) may have secondary effects on swallowing — both positive (reducing pharyngeal spasticity) and negative (sedation increasing aspiration risk). Review with the treating neurologist if swallowing symptoms worsen after medication changes.

Hospital Authority Neurology Services in Hong Kong

MS in Hong Kong is primarily managed through the Hospital Authority’s neurology services at:

Queen Mary Hospital (QMH), HKU West Cluster: The largest neurology unit in Hong Kong, with MS specialist clinics and access to disease-modifying therapies (DMTs). SLP services are available for inpatients and can be arranged for outpatients through the neurology clinic.

Prince of Wales Hospital (PWH), CUHK New Territories East Cluster: Neurology department with MS clinic. Allied health services including SLP and dietetics accessible through outpatient referral.

Other cluster hospitals: Neurology departments at Pamela Youde Nethersole Eastern Hospital, Queen Elizabeth Hospital, and Princess Margaret Hospital see MS patients; complex cases are typically referred to QMH or PWH for specialist assessment and DMT initiation.

For SLP referral within the HA system: the treating neurologist or the general outpatient physician can make an SLP referral. During a relapse admission, inpatient SLP assessment should be requested.

MS Society of Hong Kong

The MS Society of Hong Kong (多發性硬化症香港協會) provides patient support, peer counselling, and information for people with MS and their families. They can assist with:

Contact and current resources: mshk.org.hk

When to Request SLT Reassessment After Relapse

Request an urgent SLP assessment after any MS relapse if:

After steroid treatment for a relapse and subsequent clinical improvement, request an SLP review to assess whether the IDDSI diet level can be stepped up. Over-restriction of diet texture is a quality-of-life issue that should be actively addressed during remission.

Advance Care Planning

MS follows a highly variable course — some people have minimal disability after decades, while others progress to severe disability relatively quickly. Advanced care planning is relevant even in early disease, particularly regarding:

In Hong Kong, advance directives (預設醫療指示) have legal standing under the Mental Health Ordinance. The social work teams at HA Neurology clinics can assist with advance care planning discussions.

Summary

MS-related dysphagia is characterised by its fluctuating course, fatigue amplification, and sensitivity to temperature through the Uhthoff phenomenon. Key management principles in the Hong Kong context: