Treatment of myotonia
Grete Andersen, MD
Intr
od
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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
cise
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10 weeks
8
Exer
cise
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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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tmen
t Fitness
Exer
cise
as
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tmen
t Questionnaire of myotonia
Exer
cise
as
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tmen
t Functional myotonia testsSe
con
ds
Seco
nd
s
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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as t
reat
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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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Lam
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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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atm
ent
*
Questionnaire of myotonia
Reduced myotonia
Functional myotonia testsLa
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as t
reat
men
t
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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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atm
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
rsp
ect
ive
sPatients:
• Easy accessible medicine
• Inexpensive
• Fewer side-effects
Doctors:
• Two validated medicines
Pe
rsp
ect
ive
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