Introduction 

What happens when those muscles we rely on to speak and swallow are weakening slowly, silently, and progressively? How can therapy support communication and eating more safely and effectively? 

These are some pressing questions faced by the population with Kearns-Sayre Syndrome (KSS), a rare mitochondrial disorder that affects multiple body systems, including weakness to the nerves and muscles responsible for speech and swallowing. 

As the disease progresses, individuals may often develop trouble speaking (dysarthria, a motor speech disorder) and trouble swallowing (dysphagia) that significantly disrupt communication, nutrition, and quality of life. Speech-language therapy (SLP) becomes critical to help identify, manage, and support these challenges. 

By exploring the common speech and swallowing difficulties commonly encountered in KSS, this article will outline the therapeutic strategies and tips that help to maintain their speech and swallowing abilities and independence as long as possible. Keep reading to discover how the specialised SLP care can make a life-changing difference to those affected. 

What is Kearns-Sayre Syndrome? 

Kearns-Sayre Syndrome (KSS) is a rare neuromuscular, mitochondrial disorder that typically onset before age 20, affecting cell energy (i.e. ATP) in multiple body systems. It is characterised by progressive external ophthalmoplegia, pigmentary retinopathy, and additional complications like muscle weakness, breathing difficulties, heart problems, and various neurological complications.¹

When mitochondrial DNA deletion accumulates over time, more nerve cells (neurons) are impaired by the loss of the cell's powerhouses' capacity, exacerbating the potential involvement and impact on the central nervous system (CNS) (i.e., cranial nerves and brainstem nuclei for speech and swallowing). Hence, resulting in progressive speech and swallowing difficulties. 

Impact of speech and swallowing in KSS

Weakness of the jaw, lips, tongue, velum, and pharyngeal muscles leads to trouble speaking and swallowing in KSS.²

Speech difficulties 

In KSS, trouble speaking (dysarthria) develops progressively due to weakening of muscles responsible for voice production, resonance and articulation, with varied severity upon the extent of powerhouse dysfunction in peripheral muscles, brainstem nuclei and cranial nerves. 

Common signs and symptoms 

• Slow, slurred and mumbling speech (weakened articulatory muscles)
• Quiet, weak, or breathy/hoarse voice (laryngeal muscle fatigue)
• Nasal speech (hypernasality caused by poor velopharyngeal closure)
• Imprecise articulation
• Monotone voice (vocal muscle stiffness or fatigue)
• Speech fatigue – Deteriorated clarity and volume with prolonged speaking

Impact on daily life

Daily life impact includes communication barriers, social withdrawal, frustration, and emotional distress. Functional limitations to daily tasks like phone calls, group discussions, or emotional expressions become more challenging, resulting in increased caregiver dependency, which can further deplete self-esteem. 

Swallowing difficulties 

Trouble swallowing (dysphagia) in KSS emerges gradually from progressive weakness and fatigue of muscles involved in the mouth (oral cavity), throat (pharyngeal), and occasionally oesophageal stages of swallowing. This can lead to serious nutritional, respiratory, and quality of life concerns. 

Common signs and symptoms 

• Slow or effortful chewing
• Difficulty initiating swallowing
• Food residue in the mouth or throat
• Coughing or choking while eating or drinking
• Liquid exiting through the nose
• Wet or gurgly voice after swallowing
• Frequent throat clearing
• Unexplained weight loss
• Recurrent respiratory infections (due to aspiration)

Impact on daily life

Swallowing challenges can pose a significant impact on daily life. While individuals may avoid certain food textures due to the exceptional effort needed in managing their mealtime anxiety and fatigue. Mealtime becomes extended with dependency on caregivers, and hence, more socially isolated. Health risks, like malnutrition, dehydration, even silent aspiration or aspiration pneumonia, may also occur, requiring medical attention. 

Role of speech therapy in KSS 

Speech therapy (ST) or speech and language therapy (SLTs), led by speech and language pathologists (SLPs), aiming to assess and treat communication and swallowing through targeted exercises and strategies, is crucial for KSS patients with their speech and swallowing. 

While enhancing the clarity, strength, and endurance of speech for better communication, improving swallowing safety, efficiency, and effectiveness to promote nutritional intake and reduce choking. Individuals’ confidence and independence in social settings and eating are fostered. 

SLPs’ work can also be beneficial to KSS as a multisystem disease by collaborating with other healthcare professionals like neurologists, dietitians, and even families and caregivers to create tailored treatment plans for intervening in the progressive symptoms early. 

Speech therapy techniques for speech and swallowing 

Initial assessment 

The initial speech therapy assessment for Kearns-Sayre Syndrome (KSS) has a vital role in identifying the nature and severity of speech and swallowing difficulties. Typically lasts between half an hour and one hour, it includes the evaluation of articulation, voice quality, oral muscle strength, and coordination. As well as the assessment for swallowing safety and effectiveness through clinical meal observations or instrumental methods like videofluoroscopic study (VFSS) or fiberoptic endoscopic evaluation of swallowing (FEES) for early implementation of individualised interventions and progress monitoring.^3,4

Targeted exercises and management for speech difficulties 

ST/SLT in KSS focuses on maintaining communication abilities and delaying speech decline through addressing both muscle weakness and fatigability.  

Articulation and oral motor exercises 

Articulation and oral motor exercises can help to enhance imprecise articulation and speech clarity through improving the range of motion that strengthens and coordinates the weakened tongue, lips, and jaw muscles. 

With exercises like lip rounding and retraction, tongue elevation, lateralisation, and resistance, jaw opening and closing against gentle resistance, plus the repetition of specific sounds or words (e.g., pa-ta-ka). 

A cautious introduction that prevents fatigue and overexertion can support clearer and more effective speech production. 

Vocal strengthening 

Vocal (functional) strengthening exercises can help improve voice volume, quality, and breathing control during speech in KSS. 

Voice therapy techniques include sustained vowel sounds, pitch glides, diaphragmatic breathing, and controlled exhalation during speech. These exercises support stronger vocal fold closure and more voice strength and quality stability.^5,6

Pacing strategies

Given that easy fatigue is a hallmark of KSS, pacing strategies can be particularly effective in handling speech fatigue and maintaining clarity. 

With techniques like speaking slowly, pausing between phrases, limiting sentence length, and planning rest breaks during conversations. These methods conserve energy, reduce slurring, whilst improving listeners' comprehension, making communication less physically demanding, clearer clarity and effective. 

Augmentative and alternative communication 

Augmentative and alternative communication (AAC) can support communication for severe cases of KSS where speech becomes too unclear and unintelligible. These may include alphabet boards, picture cards, writing tools, speech-generating devices (SGDs), potentially with assistive technologies. 

They can reduce frustration, foster independence while ensuring the effectiveness of communication, even during severe fatigue or advanced stages of disease when verbal speech is no longer reliable. 

Swallowing therapy exercises and management 

In KSS, swallowing therapy aims at improving swallowing function, reducing the risk of choking or aspiration, and promoting overall safety and enjoyment for eating and drinking⁷. 

Swallowing muscle-strengthening exercises 

Swallowing exercises aim to improve and maintain the strength of the tongue, lips, and pharyngeal muscles. Common techniques such as tongue presses, Masako manoeuvre, shaker and laryngeal elevation exercises, plus effortful swallowing, can help maintain and improve muscle tone, support swallowing safety, and eventually reduce the risk of aspiration as weaknesses progress.  

Coordination exercises

Swallowing coordination techniques enhance the timing and sequencing of muscle actions during swallowing. These include the Mendelsohn manoeuvre, supraglottic swallow, even repetitive dry swallowing, and sensory stimulation, which help improve airway protection, reduce food residue, whilst promoting smoother and more efficient swallowing, especially targeting fatigue-related discoordination in mitochondrial conditions like KSS.  

Posture training

Postural adjustments can vastly improve swallowing safety and efficiency. Depending on individuals’ swallowing deficits or issues, proper head or neck positioning techniques like chin tuck, head turn, or head tilt can help redirect the food bolus, protect the airway, and compensate for muscle weakness for safe and efficient swallowing.  

Dietary modifications

For more complex cases, dietary changes are tailored to reduce the risk of choking and aspiration. While modifications may include smaller bite sizes, soft or pureed textures, and thickened liquids, associated with the least distractions. These can also be combined with muscle strengthening, coordination exercises, and other secure swallowing techniques to maintain nutrition and hydration. 

Role of caregivers and family support

Caregivers and family members of KSS are vital in supporting smooth communication and safe swallowing. While they can assist with therapy routine under collaboration and education from SLTs, monitoring progress and changes in speech and eating ability, and providing emotional reassurance during dismaying moments. Encouraging rest breaks, using simple, handy communication tools and adapting meals with the least distractions to make daily tasks easier. 

Not only can the involvement of family members help reduce stress, prevent choking and aspiration, as well as maintain social connection. Caregivers also serve as advocates, ensuring the individual is receiving proper and consistent care across medical and therapeutic settings. 

Summary 

Speech therapy is critical in improving speech clarity, swallowing safety, and overall quality of life for individuals with Kearns-Sayre Syndrome (KSS). Through comprehensive assessment, targeted exercises, and supportive tools, patients can maintain communication and nutritional health safely despite progressive muscle weakness. 

While small and consistent effort guided by speech and language pathologists can lead to meaningful and lasting progress. Timely professional care and family support can still facilitate the safety, confidence, and dignity of communication and eating for the KSS population.