Differential Diagnosis for Headache Starting at the Base of the Skull on One Side
Single Most Likely Diagnosis
- Occipital Neuralgia: This condition is characterized by inflammation or irritation of the occipital nerves, which can cause pain that starts at the base of the skull and radiates to the side of the head. The pain is typically unilateral and can be triggered by pressure on the nerve.
Other Likely Diagnoses
- Tension Headache: Although tension headaches are usually bilateral, they can sometimes start at the base of the skull and be unilateral. They are often associated with muscle tension in the neck and scalp.
- Cervicogenic Headache: This type of headache is referred from the cervical spine and can start at the base of the skull on one side, often accompanied by neck pain and stiffness.
- Migraine: While migraines can occur on both sides of the head, they can also be unilateral and start at the base of the skull, especially if they involve the occipital region.
Do Not Miss Diagnoses
- Subarachnoid Hemorrhage: Although rare, a headache that starts at the base of the skull and is severe, sudden, and unilateral could be indicative of a subarachnoid hemorrhage, which is a medical emergency.
- Meningitis: Inflammation of the meninges can cause a severe headache that may start at the base of the skull and can be accompanied by fever, neck stiffness, and altered mental status.
- Temporal Arteritis: This condition, also known as giant cell arteritis, can cause unilateral headaches, often in the temporal region but can also involve the occipital area, and is associated with jaw claudication and visual disturbances.
Rare Diagnoses
- Atlantoaxial Subluxation: A rare condition where there is a misalignment of the first and second cervical vertebrae, which can cause a headache that starts at the base of the skull.
- Eagle Syndrome: A condition caused by an elongated styloid process or calcified stylohyoid ligament, which can cause a unilateral headache that starts at the base of the skull, often accompanied by facial pain and dysphagia.
- Neoplastic Processes: Tumors at the base of the skull, such as meningiomas or schwannomas, can cause unilateral headaches due to compression or invasion of surrounding structures.