Improvement of Dialysis Headache After Treatment with ACE-Inhibitors but not Angiotensin II Receptor Blocker: A Case Report with Pathophysiological Considerations

Newman and Solomon (1) were the first to describe headache as a well-recognized complication of haemodialysis treatment. These headaches may newly develop, however, patients suffering from primary headache syndromes before dialysis often have problems with headache of either migraine or tension type. Less often headaches occur which are exclusively associated with the dialysis procedure and are either a completely new event in the patient’s medical history or express a distinctly different quality and nature from any headaches the patient had previously experienced. Only these headaches are classified as dialysis headache. According to IHS-Criteria dialysis headache is classified as a headache beginning exclusively during haemodialysis and rising to a very high intensity without substantial concomitant symptoms (2). Recently a modification of the classification criteria has been proposed (3). Although dialysis headache is considered to be rare, Antioniazzi et al. (4) diagnosed haemodialysis headache according to the IHS-Criteria in 68% of patients developing headache during haemodialysis. The pathophysiology is unknown and the literature on this topic is spare. It has been suggested, that the headache may represent an integral part of the so-called ‘dysequilibrium syndrome’ and be one symptom among its many manifestations (5). Another common concept is, that the headache may be due or is triggered by a rising blood pressure during haemodialysis. In this context Bana et al. (6) reported a positive correlation between the severity of hypertension and the likelihood of the patient to develop a headache of one type or another. The absence of hypertension, however, would not preclude the occurrence of headache during dialysis (6). It is intriguing that nephrectomy or transplantation may prompt a marked improvement in the headache which occurrs during subsequent dialyses. It is also known, that following dialysis the urine production may temporarily increase (7). These findings prompted us to postulate, that the ReninAngiotensin-system may be involved in the pathophysiology of dialysis headache.