Evaluation of headaches in primary brain calcification in Japan

Background: Primary brain calcification (PBC) is a rare neurodegenerative disorder characterized by bilateral calcification in the brain. No nationwide survey on headache has been performed in Japan. Aim A questionnaire survey was performed to clarify the situation of headache in PBC patients. Methods: The first questionnaire survey was conducted on 173 patients diagnosed as having PBC in Japan. Subsequently, the second survey was performed using two types of questionnaire: Headache Impact Test (HIT-6) and Migraine Disability Assessment (MIDAS). Results: In the first survey, 27 of 82 patients had headaches. Only one patient was able to be classified in accordance with the criteria as having migraine without aura. In the second survey, 10 of 17 patients showed a significant score of 50 and higher in HIT-6, and five of 17 patients showed a significant score of 6 and higher in MIDAS. No significant correlation was found between total calcification score and HIT-6 score or MIDAS score in the second survey. All patients carrying the PDGFB variant and two of three patients carrying the SLC20A2 variant showed some effects of headache on their daily life as judged from their MIDAS scores or HIT-6 score. Conclusions: The headaches in PBC patients could not be classified as the primary headache. Those headaches in PBC patients may be of the secondary headache caused by the dysfunction of the blood-brain barrier. This first report on headaches of Japanese patients with PBC will contribute to the understanding of PBC patients' difficulties in their daily lives.