Internal Medicine

0521779407-08 CUNY1086/Karliner 0 521 77940 7 June 13, 2007 7:47

Glycogen Storage Disease 637

➣Exercise fails to increase lactate, but enhances ammonia

response (IIIa, V, VII)

➣Electromyogram may show generalized myopathy (II, IIIa, V, VII)

➣Electrocardiogram may show ventricular hypertrophy (II, IIIa)

■Abdominal imaging

➣Liver ultrasound, CT or MRI to assess adenoma size and number,

hemorrhage, and malignancy (Type I)

■Tissue biopsy

➣To evaluate glycogen and fat content

➣To assess presence and degree of hepatic fibrosis

➣To assay for putative missing enzyme

Liver (Ia, Ib, Ic, IIIa, IIIc, IV, VI, IX)

Muscle (II, IV, V, VII)

Nerve (IV)

Skin (II, VII)

differential diagnosis

■Other inborn error of metabolism

➣Weakness, exercise-induced myalgias and cramps

Disorders of fatty acid oxidation

Carnitine palmitoyltransferase II deficiency

Long-chain acyl CoA dehydrogenase deficiency

➣Muscular weakness and atrophy

Charcot-Marie-Tooth disease

➣Myoglobinuria

Familial recurrent myoglobinuria

➣Liver disease with hypoglycemia

Galactosemia

Fructose intolerance

management

What to Do First

■Prevent hypoglycemia

➣Nocturnal nasogastric glucose feedings (I, III)

➣Frequent small meals including uncooked cornstarch (I, III)

➣Restrict fructose and galactose (I)

➣Teach home blood glucose monitoring

General Measures

■Avoid strenuous exercise (V, VII)

■Genetic counseling