5 - Guest Lecture: Multiple Sclerosis

What is Multiple Sclerosis (MS)?

A demyelination of the Central Nervous System (CNS) disrupting the transmission of nerve impulses.

What is the global prevalence of MS?

Approximately 2.9 million people worldwide have MS.

Which gender is more likely to be diagnosed with MS?

Women are twice as likely to be diagnosed with MS.

What is the average age of diagnosis for MS?

The average age of diagnosis is 32 years.

What is the incidence rate of MS among different ethnicities?

Highest among White and Black individuals, significantly lower for Asian and Hispanic individuals.

Which country has the highest rates of MS?

Canada has the highest rates of MS in the world.

What diagnostic tool is used to identify lesions in MS?

Magnetic Resonance Imaging (MRI).

What does a spinal tap search for in MS diagnosis?

Antibodies (oligoclonal bands) present in cerebrospinal fluid.

How do evoked potentials diagnose MS

Apply an electrical stimulus and measure how fast it travels through the CNS

What are the types of MS?

Clinically Isolated Syndrome (single episode), Relapse Remitting (unpredictable clearly defined attacks which worsen or present new symptoms. Full/partial remission to pre-lapse function), Secondary Progressive (Fewer attacks and less remission than relapse remitting with a

progressive increase in symptoms) and Primary Progressive (No periods of relapses and no remission. Steady worsening of the condition).

What is the focus of current MS treatments?

Slowing progression and maintaining quality of life.

What are some pharmacological options for treating MS?

Several drugs are available to reduce the frequency and severity of relapses.

How can exercise benefit individuals with MS?

It challenges the nervous system and helps maintain strength and aerobic capacity.

what assistive devices are available for treating MS?

Walkers, canes/walking sticks, ankle-foot orthosis

What types of mobility impairments can MS cause?

Impairments in balance, muscle strength, coordination, pain, early fatigue, spasticity, and tremors.

What is the most important aspect of quality of life for people with MS?

Walking ability.

What is circumduction in the context of MS gait patterns?

A gait pattern where one leg is stiff, requiring the walker to rotate about the hip to take a step.

What characterizes ataxia in MS?

A lack of coordination resembling clumsiness or drunkenness.

What causes foot drop in individuals with MS?

Muscle weakness that prevents maintaining dorsiflexion, causing the foot to slap the ground.

What is the Expanded Disability Status Scale (EDSS)?

A neurological examination of functional systems and unassisted walking ability, scored from 0-10 at 0.5 increments.

What is the EDSS score range for determining disability in MS?

0-10, with higher scores indicating greater disability.

What does a score of 0-3.5 on the EDSS indicate?

Determined by the amount of degradation across multiple functional systems.

How is a score of 4.0-6.0 on the EDSS determined?

By unassisted walking distance up to 500 meters.

What does a score of 6.5-7.0 on the EDSS indicate?

Assisted walking distance up to 100 meters.

What does a score of 7.5-9.5 on the EDSS indicate?

Wheelchair to bed bound.

What is the purpose of the 12-item Multiple Sclerosis Walking Scale (MSWS12)?

It is a self-reported questionnaire assessing how MS affects walking and balance abilities over the last two weeks.

What does the Timed 25-foot walk test (T25FW) measure?

The time taken to walk 25 feet (7.6 meters) as fast as possible.

What percentage change in T25FW is considered clinically meaningful?

20% change.

What does the Symbol Digit Modalities Test (SDMT) assess?

Cognitive ability by matching symbols to numbers.

What is the 9-Hole Peg Test (9HPT) used for?

To measure dexterity by placing pegs in holes as fast as possible, repeated twice for both hands.

What are gait assessments used for in MS?

To understand changes in gait metrics that have to do with spatiotemporal, balance, kinematics/kinetics, other stat/non-linear methods

What is a significant change observed in gait quality between people with MS and healthy individuals?

Increased double support time and decreased stride length, walking speed, and single support time.

What is a limitation of current disease monitoring approaches?

They are reactive, with patients visiting neurologists only 1-2 times per year.

What is the Hawthorne effect?

The phenomenon where people alter their behavior when they know they are being observed.

Why is the EDSS criticized?

It is considered insensitive to change, and T25FW is only meaningful when irreversible changes have likely occurred.

What challenges exist in performing regular gait assessments?

They are often expensive, time-consuming, and require complex technologies. Methods require tight-fitting clothing and tape that is irritating to PwMS/does not conform to all body shapes. Treadmill walking is not fully representative of overground walking. Interpretation is difficult

What innovative approach is being used at uOttawa for monitoring gait quality?

Using instrumented shoe insoles to unobtrusively monitor gait quality in people with MS.

What can the uOttawa approach calculate regarding gait metrics?

Over 200 spatiotemporal gait metrics.

What is the Gait Composite Index (GCI)?

A representation of gait quality as a percentage. Makes results more interpretable and relevant to care.

How does continuous monitoring of gait quality benefit healthcare?

It allows for proactive healthcare and evaluation of interventions.

What future directions are suggested for gait analysis in MS?

Phenotyping gait patterns, analyzing more activities, and early warning detection of attacks.

What is the main takeaway regarding MS and gait?

• MS is a neurodegenerative disease that causes a variety of symptoms based on the location of the lesions in the CNS.

• There is no stereotypical set of symptoms impacting PwMS.

• Walking quality is crucial for quality of life, and proactive monitoring can identify trends before attacks occur (such as with uottawa insoles).