Objective: To describe a patient with specific hypoglycemia rebound migraine.
Background: There is an increased prevalence of headache in persons with diabetes. Although hypoglycemia may precipitate headache in some diabetic (and nondiabetic) patients, it is not a universal pathogenetic mechanism responsible for headache in those individuals or in normal fasting subjects.
Methods: Clinical history, review of past medical records, neurologic examination, follow-up evaluation, electroencephalogram, and computerized tomography of the head.
Results: A 56-year-old man with unstable diabetes mellitus had recurrent monthly episodes of profound hypoglycemia for 40 years. These episodes were followed by severe, global, pulsatile headache after glycemia became normal subsequent to intravenous infusion of glucose and the patient was no longer confused and lethargic. He had no headache preceding or throughout the actual hypoglycemic phase. His neurologic examination was normal when asymptomatic. His baseline electroencephalogram was normal, but showed mild slowing of the background in the immediate posthypoglycemic state. Computerized tomography of the head demonstrated mild atrophic changes. His severe bouts of hypoglycemia and migraine were ameliorated by prophylactic treatment with valproic acid.
Conclusion: Posthypoglycemic migraine may occur exceptionally in patients with unstable diabetes as a rebound phenomenon, caused by an unidentified mechanism.