Differential Diagnosis for Sudden Symmetric Headache Paroxysms

• Single Most Likely Diagnosis
  • Cluster headache: Characterized by severe, unilateral (though can be bilateral in rare cases) orbital, supraorbital, or temporal pain lasting 15-180 minutes, occurring in clusters or cycles. However, given the symmetric nature of the headache, this might not perfectly fit, but it's a common cause of severe headache paroxysms.
• Other Likely Diagnoses
  • Migraine: Although typically unilateral, migraines can sometimes present with bilateral or symmetric headache, especially in the aura phase or in certain variants like familial hemiplegic migraine.
  • Tension-type headache: Often described as a band or a squeezing sensation around the forehead, back of the neck, or both, which can be symmetric and might present in paroxysms, especially if exacerbated by stress or other triggers.
  • Chronic daily headache: This includes a variety of headache disorders that occur 15 days or more per month, which can have a symmetric presentation and may have paroxysmal exacerbations.
• Do Not Miss Diagnoses
  • Subarachnoid hemorrhage: A life-threatening condition that can present with a sudden, severe headache (often described as "the worst headache of my life"), which may be symmetric. It's crucial to consider this diagnosis due to its high morbidity and mortality if missed.
  • Meningitis: Inflammation of the protective membranes covering the brain and spinal cord, known as the meninges, which can cause severe, symmetric headache, along with fever, neck stiffness, and other symptoms.
  • Cervicogenic headache: Though typically unilateral, in rare cases, it can present bilaterally and is caused by referred pain from the cervical spine or soft tissues of the neck.
• Rare Diagnoses
  • Hypnic headache: A rare headache disorder that occurs in older adults, characterized by recurrent, severe headaches that awaken the patient from sleep, which can be bilateral or unilateral.
  • Short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) or short-lasting unilateral neuralgiform headache attacks with cranial autonomic features (SUNA): Although typically unilateral, these rare headache disorders can present with severe, brief paroxysms of pain and might, in rare instances, have a symmetric component or be misinterpreted as such due to their severity and associated autonomic features.
  • Trigeminal neuralgia: Characterized by intense pain along a branch of the trigeminal nerve, which can be severe and paroxysmal but is usually unilateral. However, in rare cases or certain variants, it might be perceived as symmetric due to the radiation of pain or involvement of both sides in separate episodes.