Acute hemicranial pain accompanied with a pearl and string type dissection of intracranial vertebral artery: Consideration for the time when to finish the medical observation

Abstract

The International Classification of Headache Disorder (ICHD) clearly guides the suspicion of intracranial vertebral artery dissection (ICVAD) in headache patients, but guidelines on how observational or imaging studies should be performed to detect dangerous progression early are unclear. Fifty-six cases with pearl and string type intracranial vertebral artery dissection were divided into 3 groups: 39 in the headache group, 6 in the infarction group, and 11 in the hemorrhagic group. Clinical and angiographic data were analyzed and compared. Most headaches resolved within 2 weeks and did not exceed 8 weeks. Of the 33 patients (84.6%) who underwent continuous follow-up imaging, 18 (54.5%) returned to normal, but 3 (9%) had deteriorated. All the patients survived without subsequent bleeding or infarction. Image changes started before 3rd month and ended after 6 to 7 months. In acute ICVADs, image changes occur at the same time as the headache resolves and continue for several months after the headache has subsided. Since the dissection is likely to worsen even after the headache disappears, the image changes continue over several months, and prediction of rupture of unruptured ICVAD is unpredictable, it is desirable to conduct continuous imaging studies regularly after the initiation of dissection until stabilization is confirmed.

Figure 1.

Flow chart showing the case selection procedure and follow-up results.

Figure 2.

Kaplan–Meier analysis of the headache resolution rate. Most headaches relieved within 2 weeks in both the headache and infarction groups, and all disappeared within 8 weeks.

Figure 3.

Kaplan–Meier curve showing the cumulative rate of detection of the first image change. The image changes occur steadily for 7 months in both headache and infarction group, after which new imaging changes rarely begin.

Figure 4.

Kaplan–Meier curve showing cumulative rate of stabilization of image changes. Most image changes that started within a 7-month period usually end within the same period. Therefore, this period can be regarded as the period during which most pathophysiological changes occur.

Figure 5.

Relationship between the headache resolution period and the image change period. Note the 4 to 8 weeks that the 2 periods overlap. Image changes occur at the same time as the headache resolves and continue for several months after the headache has subsided.