Headache was the presenting symptom in 5 of 6 patients with Chiari type malformation, reported from the Departments of Neurology and Neurosurgery, Trondheim University Hospital, Norway. Patient 1 had migraine headaches that started at age 22 during a first pregnancy. Patients 2 and 3, monozygotic twin daughters of patient 1, had headache and diplopia or vertigo, starting either at puberty or after the birth of a first child at the age of 20 years. Patients 4 and 5, daughters of patients 2 and 3, had pain in the neck and head. The diagnosis was made by MRI and confirmed at the time of surgery in 1 twin. The mother of patient 1 had severe headaches of undetermined cause. Whooping cough at the age of 2 weeks may have accentuated the degree of cerebellar herniation in 1 twin. [1]

COMMENT. Chiari type I malformation should be considered in the diagnosis of headache presenting at puberty or during first pregnancies. Hormonal changes may accentuate the tonsillar herniation and precipitate the occurrence of symptoms. A herniation of at least 5 mm is clearly pathological and 3-5 mm represents a borderline zone. The significance of minor degrees of herniation in adolescents with recurrent migraine type headaches is a concern and requires careful follow-up.

Chiari type I malformation was the cause of a velopharyngeal insufficiency in a 5 year old girl reported from the Hopital Robert Debre, Paris, France [2]. This child had denervation of the IX, X and XI cranial nerves, absent gag reflex, speech problem, but no complaint of headaches was recorded.