DR Medhat MRCP

• Management
Stop antipsychotic
IV fluids to prevent renal failure
Dantrolene* may be useful in selected cases
Bromocriptine( dopamine agonist) may also be used.
*thought to work by decreasing excitation-contraction coupling in skeletal muscle by
binding to the ryanodine receptor, and decreasing the release of calcium from the
sarcoplasmic reticulum.
Mitochondrial diseases
- Whilst most DNA is found in the cell nucleus, a small amount of double-stranded
DNA is present in the mitochondria.
- It encodes protein components of the respiratory chain and some special types of
RNA
Mitochondrial inheritance has the following characteristics:
1) Inheritance is only via the maternal line as the sperm contributes no cytoplasm
to the zygote.
2) All children of affected males will not inherit the disease.
3) All children of affected females will inherit it
4) Generally encode rare neurological diseases
5) Poor genotype :phenotype correlation - within a tissue or cell there can be
different mitochondrial populations - this is known as heteroplasmy)
Histology
Muscle biopsy classically shows 'red, ragged fibres' due to increased number
of mitochondria
Examples include:
Leber's optic atrophy
MELAS syndrome: mitochondrial encephalomyopathy lactic acidosis and stroke-like
episodes
MERRF syndrome: myoclonus epilepsy with ragged-red fibres
Kearns-Sayre syndrome: onset in patients < 20 years old, external ophthalmoplegia,
سؤال retinitis pigmentosa. Ptosis may be seen
Sensorineural hearing loss
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