Introduction

Kearns-Sayre Syndrome (KSS), a rare mitochondrial disorder that affects muscles and energy production in cells, can progressively disrupt multiple body systems, resulting in muscle weakness, visual loss, and even heart and breathing issues.¹

Although incurable at present, physical therapy can play a crucial role in helping individuals with KSS build muscle strength, improve mobility, and maintain independence for as long as possible. Through carefully tailored exercise plans and supportive movement strategies, physical therapy can reduce fatigue, improve balance, and delay progression of muscle weakness and mobility loss.^2,3 

This article examines how targeted physical therapy can help individuals affected by a condition to stay active, manage symptoms, and improve their quality of life in a step-by-step approach.

Understanding mobility challenges in KSS 

What is Kearns-Sayre Syndrome? 

Kearns-Sayre Syndrome (KSS) is a rare genetic (mitochondrial) neuromuscular disorder caused by mitochondrial DNA deletion that impairs the body’s ability to produce energy (ATP). With KSS’s primary effect on muscles, progressive weakness, fatigue, and poor coordination across the eyes, limbs, even heart and breathing muscles can directly lessen mobility and muscle strength as the disease progresses.^1,4

Common motor-related symptoms 

Individuals with KSS typically experience a wide range of motor-related symptoms due to the gradual diminishing of muscle energy production. These can include progressive weakness in the limbs and eye muscles, leading to limb and eye movement difficulties (external ophthalmoplegia) and droopy eyelids (ptosis).¹ 

Fatigue sets in quickly during physical exertion because strength and endurance are reduced by energy deficits, which impair daily functioning. Poor balance and coordination impede walking whilst heightening the risk of falls and injury. Ongoing weakness extending to facial, neck, and trunk muscles can further affect postural control, mobility, and overall stamina.^1,5

The symptoms vary greatly from person to person, ranging from mild limitations to severe disability. In general, symptoms are slowly progressive and require adaptive strategies for functional maintenance.^1,4

Impact on daily life 

The progressive symptoms result in basic tasks, including stair-climbing, standing from a seated position, and even lifting objects, becoming more challenging over time. The loss of independence affects self-care and daily activity participation because mobility declines. Therefore, adaptive strategies are required for functional maintenance.¹ 

Goals of physical therapy in KSS 

Preserve and improve muscle strength

Preserving and improving muscle strength is a key aim of physical therapy in KSS. A personalised exercise plan can maintain existing muscle function, delaying muscle weakness, enhance endurance, and overall improve mobility for daily activities. Targeted gentle muscle training in accordance with patients’ capacity can further prevent deconditioning and atrophy in specific muscle groups. Thus, physical therapy aims to lessen fatigue and empower individuals to remain active and independent as long as possible.^2,3 

Enhance balance and coordination

Enhancing balance and coordination is an essential component of physical therapy for those with KSS. While KKS may affect the cerebellum and result in ataxia, the focus on stability, posture, and controlled movement can reduce the risk of falls and promote safe mobility. Proper balance and coordination training can re-educate muscles and the nervous system to work together for smoother movements, resulting in greater confidence and independence in daily activities despite progressive weakness.^3,6 

Prevent contractures and joint stiffness

Physical therapy in KSS is crucial. While regular stretching and range-of-motion (ROM) exercises can keep joints flexible and muscles elongated to counteract the indirect deconditioning resulting from progressive muscle weakness, to avoid joint stiffness, and even contractures that potentially worsen pain and posture maintenance. The promoted full ROM can further support the comfortable and free movements during daily activities towards the achievement of higher functional independence.^1,2,3 

Minimise fatigue through energy-conserving techniques

Minimising fatigue to delay functional loss through the introduction of energy-conserving techniques is vital in physical therapy for the KSS population. While the teaching of pacing strategies, proper body mechanics, and task modification by therapists can help individuals in managing limited energy reserves and daily activities more effectively, to balance activity with rest, preserve strength and prevent overexertion and symptom flare-ups.^1,7

Maximise independence in daily activities

Maximising independence in daily activities has been the ultimate central aim of physical therapy in KKS. Tailored strengthening, balancing, ROM exercises, and pacing strategies can promote the overall functionality of the KSS population to perform self-care and daily tasks with greater ease and less assistance. This enhances self-confidence, quality of life, long-term functional autonomy, and well-being.^1,7 

Core physical therapy strategies 

Strengthening training

Low-impact strengthening exercises, combined with aerobic activities, are crucial for managing muscle weakness in KSS. Due to mitochondrial energy deficits that cause muscles to tire easily, exercises with low-intensity (light resistance) and short duration, combined with high repetitions, can help build muscle endurance without overloading the mitochondria. While isometric exercises can be a great starting point, simple exercises such as seated leg lifts, arm curls with light weights, light resistance band exercises, tai chi, or water aerobics, that are personalised to patients’ strength and energy level, could improve the quality of life for people with KSS.^1,7 

Stretching and flexibility

Stretching exercises are beneficial to individuals with mitochondrial muscle weakness by improving muscle length and range of motion (ROM), whilst preventing muscle stiffness and contractures. It is essential to begin with gentle exercises, accompanied by adequate warm-up exercises, to prevent overstretching weak or hypermobile joints. Yoga-inspired stretches, pilates, or therapist-guided movements on major muscle groups (for example, hamstrings, calves) can further help to preserve and improve mobility.

Balance, gait, and postural training

Balance exercises and gait (walking) training are of assistance in reducing the effects of muscle weakness in KSS. Exercises, such as standing on one leg and walking heel-to-toe, trigger the body’s continuous adaptation and improve stability, thus reducing the risk of falls through multidirectional movements and weight shifts. Hand-eye coordination training can address vision-related challenges, enhance walking confidence, and reduce fall risk. Postural training, such as pilates or yoga-related activities, aims to stabilise the core and the back, reduce strain on muscles, joints, and the spine, and minimise pain and fatigue. Hence, improve mobility and overall functional abilities.

Breathing exercises

Breathing exercises could be beneficial to some KSS patients because they could have weakened respiratory muscles. Techniques, including diaphragmatic breathing or pursed lip breathing, can improve oxygen utilisation efficiency and reduce fatigue. 

Energy conservation and fatigue management 

Pacing strategies

Pacing strategies for mitochondrial disorders, such as KSS, include the management of energy expenditure to minimise fatigue and maximise function. Pacing includes planning rest, breaking down tasks into smaller, manageable steps, adjusting activities to meet abilities, prioritising essential tasks, delegating and postponing less critical activities to prevent overwhelming the body, and creating an energy-sustainable routine.⁷ 

Listening to body signals

Listening to body signals is crucial for managing fatigue in KSS. The recognition of early signs of tiredness, such as muscle heaviness or shortness of breath, can help prevent crashes in energy. Physical therapy teaches individuals to rest before exhaustion or fatigue sets in, can facilitate sustainable activity levels, reduces the risk of setbacks in strength and mobility, and protects mitochondrial function.^1,7

Avoiding overexertion

Avoiding overexertion is an important fatigue management strategy in KSS because pushing beyond one’s energy and stamina limits can worsen muscle weakness and prolong recovery. Physical therapist guidance on low-intensity activities, activity breakdown, frequent rest breaks, and realistic goal settings can maintain strength and prevent energy crashes throughout the day. 

Coordination with occupational therapy

Coordination with occupational therapy as a multidisciplinary rehabilitation support can enhance energy conservation and fatigue management in KSS. Occupational therapists help adapt daily tasks, recommend energy-saving techniques and ergonomic tools for daily tasks, and reorganise routines to reduce physical strain, such as adopting a seated position for daily tasks to minimise fatigue from unnecessary standing. The collaboration between physical and occupational therapists facilitates a balanced and holistic plan in promoting independence to ensure the manageability of daily activities within the individual’s energy limits. 

A wide variety of adaptive equipment and assistive devices are helpful in enhancing independence and the ease of daily activities. 

Adaptive equipment and assistive devices 

Mobility aids

As muscle weakness in KSS progresses, mobility aids such as canes, walkers, or wheelchairs may be recommended based on the patient's mobility level. These devices can reduce the risk of falls, conserve energy, and improve movement ability. Physical therapists assessing a patient’s condition will recommend the most suitable aid to promote safer and more independent mobility in daily life. 

Orthotics

Orthotics, such as custom ankle-foot-orthosis (AFOs) or shoes, are common supportive devices used in KSS to address foot drop and improve walking stability and alignment. Orthotics could compensate for muscle weakness, prevent joint strain, and reduce the risk of tripping or falling. Customised orthotics, fitted by orthotists, support comfort and mobility, allowing individuals to move around more efficiently with less effort. 

Home modifications

Home modifications can vastly enhance safety and independence for people with KSS. Simple changes, including the use of non-slip mats, rearranging furniture, installing grab bars, stair rails, and stairlifts, can make daily tasks easier and reduce the risk of falling. Physical therapists and occupational therapists work together in assessing and recommending personalised adjustments for mobility support and energy conservation within the home environment. 

Summary 

Physical therapy is the rehabilitative foundation in managing KSS and addresses the unique progressive muscle weakness, fatigue, and mobility challenges resulting from mitochondrial dysfunction. Starting physical therapy as soon as possible can help maintain mobility, muscle strength, and halt functional decline for years. 

A gentle, tailored physical therapy plan, along with occupational therapists, families, and multidisciplinary medical teams, including neurologists and cardiologists, can further improve independence and quality of life. By adopting a comprehensive physical therapy approach, individuals with KSS can still lead an active and fulfilling life despite their progressive muscle weakness and energy deficiency.