Myotonic dystrophy

☝triple repeat of MDPK gene

☝pathognomonic feature is failure of muscle relaxation after contraction.

✅Myotonic dystrophyOcular manifestation

☝bilateral ptosis

☝cataracts (Christmas tree cataracts or PSCC)

☝orbicularis oculi weakness

☝pigmentary retinopathy

• pattern dystrophy centrally

• reticular at mid-periphery

• atrophic far periphery

Myotonic dystrophySystemic manifestation

☝mournful facies ( miserably sad)

☝dysphasia

☝dysphagia

☝muscle weakness with delayed relaxation (myotonic grip)

☝testicular atrophy

☝frontal baldness

☝Dropped IQ

☝cardiomyopathy and conduction abnormalities (may lead to fatal cardiac failure).

✅Myotonic dystrophyInvestigations

☝DNA analysis: confirms diagnosis.

☝ECG: should be performed annually for conduction abnormalities.

✅Myotonic dystrophy Treatment

☝Multidisciplinary (neurologist , cardiologist , physiotherapist and speech therapy) .

☝cataract and ptosis precautious surgery (when symptomatic).

Myotonic dystrophyNB

☝General anaesthesia may unmask subclinical respiratory failure.