[Myotonic dystrophy Curschmann-Steinert]

Myotonic dystrophy Curschmann-Steinert is a multisystemic disorder inherited as an autosomal dominant trait. Characteristic clinical findings are muscular weakness and distal atrophy of the extremities, myotonia and myopathic facies. Ophthalmological symptoms may include cataract, ptosis and intraocular hypotension. Cardiac conduction defects, endocrine disturbances, respiratory insufficiency and gastrointestinal affection appear quite often in the course of the disease. Because of the great diversity of symptoms and the variable clinical presentation the disease may be overlooked.

In January 2006, a 58-year-old woman presented with progressive vision loss on both eyes, lumbal discomfort and pain, as well as a gradual weakness of the right leg. Ophthalmological evaluation revealed a star-shaped posterior subcapsular cataract, subtle ptosis on both eyes and weakness of the eyelid closure. Morphologically we observed a lack of facial expression manifesting as a myopathic facies and a moderate cachexia. Neurological findings included muscle weakness and atrophy in the extremities as well as of the sternocleidomastoid and temporal muscles a slight dysarthrophony and gait disturbance. Furthermore, an increase of the creatine kinase levels in the blood was detected. Electromyography (EMG) showed signs of a myopathic process in the proximal muscles of the lower extremities (right and left vastus medialis muscle). Although no typical myotonic discharges were recorded in the EMG, molecular testing confirmed the clinical suspicion of myotonic dystrophy type Curschmann-Steinert.

The combination of a myotonic muscle disorder with ophthalmological, and probably cardiac, abdominal and pulmonary symptoms, especially respiratory insufficiency and sleep apnoea should lead to the suspicion of a myotonic dystrophy. Due to the high incidence of ocular manifestations, especially of the typical myotonic cataract, an ophthalmological investigation is essential for a straightforward diagnostic procedure.