OBJECTIVE: To clarify the clinical features and risk factors of cervicogenic headache (CEH; as diagnosed according to the International Classification of Headache Disorders-Third Edition beta) in patients with cervical spine disorders requiring surgery. BACKGROUND: CEH is caused by cervical spine disorders. The pathogenic mechanism of CEH is hypothesized to involve a convergence of the upper cervical afferents from the C1, C2, and C3 spinal nerves and the trigeminal afferents in the trigeminocervical nucleus of the upper cervical cord. According to this hypothesis, functional convergence of the upper cervical and trigeminal sensory pathways allows the bidirectional (afferent and efferent) referral of pain to the occipital, frontal, temporal, and/or orbital regions. Previous prospective studies have reported an 86-88% prevalence of headache in patients with cervical myelopathy or radiculopathy requiring anterior cervical surgery; however, these studies did not diagnose headache according to the International Classification of Headache Disorders criteria. Therefore, a better understanding of the prevalence rate, clinical features, risk factors, and treatment responsiveness of CEH in patients with cervical spine disorders requiring surgery is necessary. METHODS: We performed a single hospital-based prospective cross-sectional study and enrolled 70 consecutive patients with cervical spine disorders such as cervical spondylotic myelopathy, ossification of the posterior longitudinal ligament, cervical spondylotic radiculopathy, and cervical spondylotic myeloradiculopathy who had been scheduled to undergo anterior cervical fusion or dorsal cervical laminoplasty between June 2014 and December 2015. Headache was diagnosed preoperatively according to the International Classification of Headache Disorders-Third Edition beta. The Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire, Neck Disability Index, and a 0-100 mm visual analog scale (VAS) were used to evaluate clinical features, and scores were compared between baseline (ie, preoperatively) and 3, 6, and 12 months post-surgery. RESULTS: The prevalence of CEH in our population was 15/70 (21.4%, 95%CI: 11.8% to 31.0%). The main clinical features were dull and tightening/pressing headache sensations in the occipital region. Headache severity was mild (VAS, 32 ± 11 mm) and only one patient reported use of an oral analgesic. Compared to patients without CEH, patients with CEH had higher frequencies of neck pain (86.7% vs. 50.9%; P = .017), cervical range of motion limitation (ROM) (66.7% vs. 38.2%; P = .049), and higher Neck Disability Index scores (14 vs. 3; P < .001). Among the different cervical spine disorders, the prevalence of CEH was highest in cervical spondylotic myeloradiculopathy patients (60%), being ≤ 20% for all other disorders. Surgical treatments including cervical laminoplasty to relieve abnormal pressure on the spinal cord via a posterior approach, were associated with initial improvements in headache VAS that slightly diminished by 12 months post-surgery (P < .001). CONCLUSIONS: We report a lower prevalence of CEH in patients with cervical spinal disorders requiring surgery than that reported previously. The main clinical features of CEH were mild, dull, and tightening/pressing headache sensations in the occipital region. Potential risk factors for CEH included neck pain, limited cervical ROM, high Neck Disability Index score, and a diagnosis of cervical spondylotic myeloradiculopathy. The further accumulation of patients in a multi-institutional study may be required in order to discuss the diagnostic criteria and pathophysiology of this condition.
OBJECTIVE: To clarify the clinical features and risk factors of cervicogenic headache (CEH; as diagnosed according to the International Classification of Headache Disorders-Third Edition beta) in patients with cervical spine disorders requiring surgery. BACKGROUND:CEH is caused by cervical spine disorders. The pathogenic mechanism of CEH is hypothesized to involve a convergence of the upper cervical afferents from the C1, C2, and C3 spinal nerves and the trigeminal afferents in the trigeminocervical nucleus of the upper cervical cord. According to this hypothesis, functional convergence of the upper cervical and trigeminal sensory pathways allows the bidirectional (afferent and efferent) referral of pain to the occipital, frontal, temporal, and/or orbital regions. Previous prospective studies have reported an 86-88% prevalence of headache in patients with cervical myelopathy or radiculopathy requiring anterior cervical surgery; however, these studies did not diagnose headache according to the International Classification of Headache Disorders criteria. Therefore, a better understanding of the prevalence rate, clinical features, risk factors, and treatment responsiveness of CEH in patients with cervical spine disorders requiring surgery is necessary. METHODS: We performed a single hospital-based prospective cross-sectional study and enrolled 70 consecutive patients with cervical spine disorders such as cervical spondylotic myelopathy, ossification of the posterior longitudinal ligament, cervical spondylotic radiculopathy, and cervical spondylotic myeloradiculopathy who had been scheduled to undergo anterior cervical fusion or dorsal cervical laminoplasty between June 2014 and December 2015. Headache was diagnosed preoperatively according to the International Classification of Headache Disorders-Third Edition beta. The Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire, Neck Disability Index, and a 0-100 mm visual analog scale (VAS) were used to evaluate clinical features, and scores were compared between baseline (ie, preoperatively) and 3, 6, and 12 months post-surgery. RESULTS: The prevalence of CEH in our population was 15/70 (21.4%, 95%CI: 11.8% to 31.0%). The main clinical features were dull and tightening/pressing headache sensations in the occipital region. Headache severity was mild (VAS, 32 ± 11 mm) and only one patient reported use of an oral analgesic. Compared to patients without CEH, patients with CEH had higher frequencies of neck pain (86.7% vs. 50.9%; P = .017), cervical range of motion limitation (ROM) (66.7% vs. 38.2%; P = .049), and higher Neck Disability Index scores (14 vs. 3; P < .001). Among the different cervical spine disorders, the prevalence of CEH was highest in cervical spondylotic myeloradiculopathypatients (60%), being ≤ 20% for all other disorders. Surgical treatments including cervical laminoplasty to relieve abnormal pressure on the spinal cord via a posterior approach, were associated with initial improvements in headache VAS that slightly diminished by 12 months post-surgery (P < .001). CONCLUSIONS: We report a lower prevalence of CEH in patients with cervical spinal disorders requiring surgery than that reported previously. The main clinical features of CEH were mild, dull, and tightening/pressing headache sensations in the occipital region. Potential risk factors for CEH included neck pain, limited cervical ROM, high Neck Disability Index score, and a diagnosis of cervical spondylotic myeloradiculopathy. The further accumulation of patients in a multi-institutional study may be required in order to discuss the diagnostic criteria and pathophysiology of this condition.