Headache in Patients with Cervical Spondylotic Myelopathy

Table 1

Classification of the subjects according to whether there is headache preoperatively and postoperatively.

Type	Preoperative headache	Postoperative headache	N (male/female) (cases)
1	−	−	48 (36/12)
2	−	+	3 (3/0)
3	+	−	10 (4/6)
4	+	+	13 (11/2)

−: absence, +: presence. When headache completely disappeared postoperatively, it showed − (type 3). On the other hand, when headache still existed or improved but partly remained postoperatively, it showed + (type 4).