Pseudohypoglycemia Manifesting as Complex Partial Seizures in a Patient with Type III Glycogen Storage Disease

This chapter illustrates the case of a man diagnosed with complex partial seizures, pseudohypoglycemia and asymptomatic type III glycogen storage disease. The diagnosis of type III glycogen storage disease distracted his physicians from the diagnosis of seizures. Although some of his symptoms were potentially compatible with hypoglycemia, he had no biochemical evidence of hypoglycemia associated with spells, his symptoms were unaffected by eating, and his spells were too sudden in onset and too brief to be attributable to hypoglycemia. He was initially treated with levetiracetam at a dosage titrated up to 500 mg po BID. After 5 months of no seizures, the patient reduced his dosage of levetiracetam to 250 mg po BID. He has remained free of seizures for an additional 7 months. Establishing the diagnosis of partial seizures is often a diagnostic challenge for physicians, particularly when the seizures occur infrequently. A careful history is essential for establishing the possibility of partial seizures, but patients often are unable to provide sufficient details. Additional history obtained from family members and friends can provide a more complete description of the spells, as it did in this case.