Differential Diagnosis for Intermittent Headache Involving C2-C3 Dermatome in a 60-Year-Old

Single Most Likely Diagnosis

• Cervicogenic Headache: This condition is characterized by headaches that originate from the cervical spine, often involving the C2-C3 dermatome. The age of the patient and the specific dermatomal involvement make this a plausible diagnosis, given that degenerative changes in the cervical spine are common in this age group.

Other Likely Diagnoses

• Tension-Type Headache: Although not specifically dermatomal, tension-type headaches can be referred to the neck and scalp areas, potentially involving the C2-C3 dermatome. The intermittent nature of the headache could fit this diagnosis.
• Occipital Neuralgia: Involves the nerves that run from the base of the skull to the scalp, which could include the C2-C3 dermatome. Symptoms include sharp, stabbing pain, which could be intermittent.
• Migraine: Although migraines are typically more widespread and not limited to a single dermatome, they can sometimes present with localized pain, including the neck and scalp areas.

Do Not Miss Diagnoses

• Giant Cell Arteritis: Although less likely due to the specific dermatomal involvement, giant cell arteritis can cause headaches and is a medical emergency due to the risk of vision loss. It's crucial to consider this diagnosis in any older adult with new-onset headache.
• Subarachnoid Hemorrhage or Other Intracranial Bleeds: These conditions can present with sudden, severe headache but might also have a more gradual onset in some cases. The dermatomal distribution might not be a typical presentation, but the potential severity warrants consideration.
• Meningitis: Infection or inflammation of the meninges can cause headache, among other symptoms. While the dermatomal pattern is not typical, the potential for serious consequences if missed makes it a "do not miss" diagnosis.

Rare Diagnoses

• Neoplastic Processes (e.g., Metastases, Primary Tumors): Rarely, headaches can be the presenting symptom of a tumor affecting the cervical spine or the brain, potentially causing localized pain in a dermatomal pattern.
• Inflammatory or Autoimmune Conditions (e.g., Rheumatoid Arthritis, Psoriatic Arthritis): These conditions can affect the cervical spine and cause headaches, though they are less common causes of dermatomally localized pain.
• Vascular Malformations or Fistulas: Abnormal connections between arteries and veins can cause a variety of neurological symptoms, including headaches, though these would be rare causes of dermatomally specific pain.