Treatment of myotonia

Grete Andersen, MD

Intr

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ion

• Background

What is myotonia?

What course myotonia?

• Exercise as treatment of myotonia

• Lamotrigine as treatment of myotonia

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• Myotonia is delayed relaxation of

voluntary muscle movements.

• Myotonia can affects all muscles in

the body

• Symptoms vary, from almost

asymptomatic to invalidating

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Bac

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dMyotonia congenita

- Becker myotonia

- Thomsen myotonia

Paramyotonia congenita

Sodium channelChloride channel

Ion channel mutations

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Na+

K+

Cl–

Rest Movement Relaxation

Normal muscle potential

Treshold

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Na+K+

Cl–

Na+

K+

Cl–

Thomsen and Becker myotonia

Paramyotonia

Intr

od

uct

ion

• Background

• Exercise as treatment of myotonia

The idea of the study

Results

Perspectives

• Lamotrigine as treatment of myotonia

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Regular training enhance sodium-potassium channels.

Rest Movement Relaxation

Na+

K+

Cl–

Exer

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10 weeks

8

Exer

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• 3 days at week

• 30 minutes per day

• 75 % of maximal

performance

Training program

Exer

cise

as

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t 1. Fitness test

1. Questionnaire of myotonia

1. Functional myotonia tests

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Exer

cise

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t Fitness

Exer

cise

as

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t Questionnaire of myotonia

Exer

cise

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t Functional myotonia testsSe

con

ds

Seco

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Normal time

Exer

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Perspectives

• Persons with Thomsen and Becker myotonia can increase fitness

• None of the myotonia tests changed by enhanced fitness

• Maybe other types of exercise can reduce myotonia

Intr

od

uct

ion

• Background

• Exercise as treatment of myotonia

• Lamotrigine as treatment of myotonia

The idea of the study

Results

Perspectives

MexiletineLa

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Bac

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dSodium channel blockers

Na+K+

Cl–

Na+

K+

Cl–

Thomsen and Becker myotonia

Paramyotonia

Mexiletine LamotrigineLa

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Aim:

Is Lamotrigin an efficiency

treatment for myotonia?

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Study design

A randomized, double-blinded, placebo-controlled crossover study.

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Group 1

Group 2

Test-day Test-dayTest-dayTest-day

Outcome measures:

• Questionnaire of myotonia

• Functional myotonia tests

• Questionnaire of general health

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Participants:La

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Excluded

1412

Thomsen and Becker myotonia Paramyotonia

Not included: due to mild myotonia, < 18 years, or no genetic test.Excluded: due to contraindications of lamotrigine treatment.

Lam

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*

Questionnaire of myotonia

Reduced myotonia

Functional myotonia testsLa

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reat

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**

*

*

Questionnaire of HealthLa

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General health increased (max 100 %)from 65 to 70 % (CI: 3–7, P=0·002)

The domains of:physical functioning

(CI: 10–15%, P=0·001)role limitations due to physical health

from 43 to 58 % (CI: 10–21%, P=0·04)social function

(CI: 3–9%, P=0·02)

Side effects

• No serious event occurred

• The most common side effects reported were

headache, fatigue, and skin rash.

• Side effects were recorded in 8% of days on

lamotrigine and 6% of days on placebo.

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Lam

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ent Lamotrigine reduces myotonia

1) Symptoms of myotonia decreased

2) Daily physical functions improved

3) The quality of life increased

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Pe

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sPatients:

• Easy accessible medicine

• Inexpensive

• Fewer side-effects

Doctors:

• Two validated medicines

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sFuture research could be…

- Other types of training may reduce myotonia

- The long-term effect and side effects of

Lamotrigine.

- Combined treatment of Lamotrigine and

Rufinamide