What is the Difference Between Paroxysmal Hemicrania and Hemicrania Continua?

Paroxysmal Hemicrania and Hemicrania Continua are both primary headache disorders that affect one side of the face and head. They share many clinical features and both show a complete response to indomethacin, a key criterion for their diagnosis. However, there are some differences between the two:

1. Duration of pain: Hemicrania continua causes persistent headaches that rarely or never go away, while paroxysmal hemicrania causes repeated, sudden headaches. People with paroxysmal hemicrania usually have no pain between attacks, whereas those with hemicrania continua always have some level of pain.
2. Pain characteristics: A study found that paroxysmal hemicrania and hemicrania continua were similar in terms of pain characteristics and autonomic features, but paroxysmal hemicrania had higher pain severity.
3. Transformation: Some patients have experienced a transformation from paroxysmal hemicrania to hemicrania continua and vice versa, suggesting that these conditions may be related.

Despite these differences, it can be challenging to distinguish between the two disorders. Hemicrania continua is a rare but treatable headache disorder that comes with a continuous headache, while paroxysmal hemicrania is characterized by brief episodes of unilateral pain.

Comparative Table: Paroxysmal Hemicrania vs Hemicrania Continua

Paroxysmal Hemicrania (PH) and Hemicrania Continua (HC) are both primary headache disorders belonging to the group of trigeminal autonomic cephalalgias (TACs) and are sensitive to indomethacin. However, there are some differences between the two conditions:

Despite their similarities, PH and HC have distinct clinical presentations and responses to indomethacin. PH is characterized by intense, lateralized headaches, while HC is characterized by a continuous, strictly unilateral headache with superimposed exacerbations. Both conditions show a remarkable response to therapeutic doses of indomethacin, but the specific diagnostic criteria for each condition differ.