Myotonic dystrophy:
- Uncommon
- AD dystrophy
- A triple repeat of MDPK gene
- The pathognomonic feature is the failure of muscle relaxation after contraction.( Myotonic grip ).
- To check, ask the patient to shake hands
Ocular Manifestations :
- Bilateral ptosis
- Cataracts (Christmas tree cataracts or PSCC)
- Orbicularis oculi weakness
- Pigmentary retinopathy (pattern dystrophy centrally, reticular at mid-periphery, and atrophic far periphery)
Systemic 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).
Investigations
- DNA Analysis: confirms the diagnosis.
- ECG: Should be performed annually for conduction abnormalities.
Treatment:
- Multidisciplinary (Neurologist, Cardiologist, Physiotherapist and Speech therapist). Cataract and Ptosis precautious surgery (when symptomatic).