Diclofenac Gel in the Treatment of Cervicogenic Headache

Inclusion criteria: 1. 18-90 Years old 2. Subject must be able to consent for themselves 3. Hospitalized at Loma Linda East Campus Rehabilitation Hospital 4. English or Spanish speaking 5. Complain of a headache, caused by a disorder of the cervical spine and/or it's component (i.e. bony, disc and/or soft tissue elements) usually but not invariably accompanied by neck pain (Avijgan et al, 2019)). Exclusion criteria: 1. Primary headache secondary to intracranial pathology (i.e. tumors) a. While TBI and Stroke patients can suffer headaches as a sequalae of their intracranial pathologies, it is not always the case that their headache is primarily secondary to their pathology but due to other etiologies such as cervicogenic headache or myofascial pain syndrome. History and physical examination by the medical team will help aid in determining the headache's etiology. 2. Patients on dual antiplatelet therapy a. Aspirin 81mg daily or Clopidogrel (or antiplatelet monotherapy) is acceptable 3. History of cervical spine procedures a. Spinal cord injury patients with cervical neck injuries that have required operative repair will be excluded from the study. 4. Nerve blocks within past 4 weeks or steroid injections within past 6 months. 5. Patients with fibromyalgia 6. Pregnant women 7. Chronic pain on continuous opiate regimen (use of opioids on most days \>90 days) 8. Discharged in less than 14 days from acute inpatient rehabilitation 9. Any contraindication use per diclofenac gel package insert: 1. Known hypersensitivity to diclofenac or any other components of the drug product 2. History of asthma, uriticaria, or other allergic-type reactions after taking aspirin or other NSAIDs. 3. In the setting of coronary artery bypass graft (CABG) surgery. 10. Development of adverse reaction resulting in discontinuation of diclofenac gel