This is a 39 year-old male who first started having problems in the fifth grade of intermittent weakness. The patient's typical events include arm weakness, difficulty walking, right footdrop, dry mouth, and possibly arrhythmias. His triggers are mostly a high-salt diet, but can include beer, high carbohydrate meals, and extra exercise. Normally, he has mild events every two to three months, lasting 24 to 48 hours, with occasional events that last longer, even some requiring admission to the hospital. In between events, he does not describe any permanent weakness.
The patient presents to the ER today after eating a very large piece of ice cream cake. This is a typical episode, but wishes to be seen while the symptoms are present in case it makes a diagnostic difference.
The work-up to date has included a normal EMG with no evidence of myotonia, a normal muscle biopsy that did not show any deficiencies in myophosphorylase or CPT (Carnitine Palmitoyl Transferase), normal TSH, normal CPK, and negative acetylcholine receptor antibodies.
Family History: Negative for similar disease, and he has one biological daughter who is healthy at age 13.
Social History: Works at a local supermarket. He has a 13-year-old daughter, two adopted children, and one stepson on his wife's side.