Headache in recent onset hypothyroidism: Prevalence, characteristics and outcome after treatment with levothyroxine.

Objective The objective of this article is to analyze the features of headache attributed to hypothyroidism (HAH), evaluate the differences between groups with and without HAH, between "overt" and "subclinical" hypothyroidism groups, and evaluate outcomes after levothyroxine treatment. Methods Patients with hypothyroidism were selected in a cross-sectional study, followed prospectively for 12 months, and classified as subclinical or overt hypothyroidism. The patients were divided into two groups: with and without HAH. Results HAH was reported by 73/213 (34%) patients, involving the following areas: fronto-orbital (49%), temporal (37%), and posterior part of the head (15%). The HAH features were as follows: pulsatile (63%), four to 72 hours' duration (78%), unilateral (47%), nausea/vomiting (60%), and moderate-severe intensity (72%). Hypothyroidism symptomatology was similar in both groups, except for a greater frequency of hoarseness in the group with HAH. Migraine history was more frequent in the patients with HAH (53% vs 38%, p < 0.05). The frequency of HAH was similar both in overt and subclinical hypothyroidism. After levothyroxine treatment 78% reported a decrease in HAH frequency. Subclinical and overt hypothyroid patients reported a similar alleviation of their headaches. Conclusion Patients with HAH may present with unilateral, pulsatile, episodic pattern, and nausea/vomiting, which is at odds with the criteria for HAH established by ICHD 3 beta. Not all individuals responded to levothyroxine, and patients with the subclinical form of hypothyroidism benefit from this treatment.