Incidence of intracranial arterial dissection in non-emergency outpatients complaining of headache: preliminary investigation with MRI/MRA examinations.

PURPOSE

Headache is recognized as one of the specific signs of intracranial arterial dissection (ICrAD). We clarified the incidence of ICrAD in non-emergency outpatients complaining of headache and the nature of headache observed in case of ICrAD.

PATIENT POPULATION AND METHODS

Consecutive non-emergency outpatients coming to the neurological and neurosurgical departments and who underwent MRI and MRA examinations were included in this study. The diagnosis of ICrAD was made when patients met the following two conditions: (1) pearl-and-string sign, pearl sign, or string sign on MRA, and (2) high arterial wall signal on T1 images or intimal flap on T2 images. If possible, cerebral angiography and/or black blood MRI and/or surface-image MRI was also performed in cases meeting these criteria.

RESULTS

(1) Headache group (172 patients): severe headache was seen in five patients and headache of sudden onset in three. Arterial dissection was diagnosed in eight patients (4.7%, including seven cases of asymptomatic vertebral dissection and one of basilar dissection). The headache noted in most cases of ICrAD was similar to that experienced in daily life. (2) Non-headache group (201 patients): complaints included vertigo/dizziness in 52 patients, gait disturbance in 28, weakness of the arm or leg in 20, and limb numbness in 18, syncope attack in 14, and others in 69. Arterial dissection was diagnosed in six patients (3.0%, including one case of asymptomatic basilar and two of vertebral artery dissection, symptomatic two vertebral and one basilar dissection).

CONCLUSION

We obtained no evidence of significant difference in the incidence of ICrAD in non-emergency outpatients with (4.7%) and without headache (3.0%). The nature of the headache in the cases of ICrAD was similar to that experienced in daily life. ICrAD with nonspecific headache is more common than previously thought.