Myotonic dystrophy
| Incidental findings | Frontal balding ?patient wearing wig |
| +ve signs | Ptosis, wasting temporalis, myotonia, cataracts, Depressed reflexes |
| Differential diagnosis | Myotonic dystrophy |
| Function | |
| Tests |
BM - diabetes mellitus ECG – conduction abnormalities EMG – waxing/waning of potentials ‘dive-bomber’effect Slit lamp examination – cataracts |
Extensions
- Ask patient to make a fist then open hand quickly
- Open eyes quickly after firm closure
- Percussion myotonia – dimples in muscles fill slowly
Notes
- Other features: cardiomyopathy, conduction defects, respiratory infections (low IgG levels),
- Other causes bilat ptosis: MG, muscular dystrophies
- Myotonia congenita (Thomsen’s disease): Myotonia but no other features of MD, reflexes normal, can have Herculean appearance