Oculogastrointestinal Muscular Dystrophy

At a glance

Very rare form of muscular dystrophy that affects females more often than males. Clinically, patients are affected with ptosis, external ophthalmoplegia, and absence of intestinal peristalsis that leads to abdominal pain, diarrhea, constipation, malabsorption, and progressive intestinal pseudoobstruction.

Synonyms

Intestinal Pseudoobstruction with External Ophthalmoplegia Syndrome; Familial Visceral Myopathy with Ophthalmoplegia.

Incidence

Extremely rare. Fewer than 30 patients described. No new descriptions since 1997.

Genetic inheritance

Autosomal recessive.

Pathophysiology

Primary myopathic lesions affect the smooth muscles (musculi propria) of the stomach, jejunum, and colon, while the neurogenic structures (vagus nerve and myenteric plexus) are intact. This disorder leads to progressive intestinal pseudoobstruction with malnutrition. Ocular manifestations, such as ptosis and ophthalmoplegia, are associated with the disorder because of occasional myopathic changes (atrophy) of the striated muscles and involvement of the peripheral nerves and central nervous system, characterized by demyelinating and axonal neuropathy and focal spongiform degeneration of the posterior columns.

Diagnosis

Early onset is characterized by ptosis and ophthalmoplegia during childhood, gastrointestinal symptoms in teenage and early adulthood years; death occurs before age 30 years. Late onset has a milder course with ocular and gastrointestinal manifestations during the fourth and fifth decades of life. Jejunal manometry, gastrointestinal contrast roentgenograms (gastric atony with delayed gastric emptying, hypomotility and dilatation of the small bowel with jejunal and ileal diverticula, megaduodenum, possibly megacolon), and gastrointestinal biopsy (degeneration and fibrosis of the intestinal muscle involving mainly the longitudinal layer) contribute to the final diagnosis. In cases of associated muscular weakness, electromyography shows delayed motor nerve conduction velocities, and sural nerve biopsy may reveal loss of large myelinated fibers and axonal loss. Striated muscle biopsies show myopathic changes involving both fiber types. Creatine kinase levels are often normal.

Clinical aspects

Bilateral ptosis and external ophthalmoplegia (limitation of eye movements in all directions) are associated with gastrointestinal manifestations of chronic diarrhea and symptoms of chronic intestinal pseudoobstruction leading to malnutrition. Some cases of associated neuromuscular impairment (facial, proximal, and distal limbs weakness with decreased deep tendon reflexes, limb hypesthesia) have been described. Mitral valve prolapse may coexist. The main differential diagnosis is oculopharyngeal muscular dystrophy, which consists of an autosomal dominant transmission, ptosis, and ophthalmoplegia. The digestive tract involvement consists only of difficulty in swallowing (no gastrojejunal lesions) or a mitochondrial disease-like myopathy with peripheral neuropathy, encephalopathy, and gastrointestinal disease (MNGIE or ☞POLIP Syndrome).

Precautions before anesthesia

Obtain a full history of gastrointestinal symptoms, “early” versus “late” onset of the disease, associated neuromuscular manifestations, and/or mitral valve prolapse (echocardiogram). Evaluate patient’s volume status, electrolyte levels, and obtain a hemoglobin level. If on total parenteral nutrition (TPN), evaluate albumin, ...