Razdan et al. Journal of Medical Case Reports 2011, 5:77 http://www.jmedicalcasereports.com/content/5/1/77 Page 2 of 3 Figure 1 Computed tomography scan of the head, revealing diffuse, dense calcification of the cerebellum, tentorium, and falx. and the serum phosphorus level, from 6.8 to 8.0 mg/dl (NR, 2.5 to 4.5 mg/dl). His serum parathormone level was 321.1 pg/ml (NR, 15 to 68.3 pg/ml). His arterial blood gas analysis revealed no hypoxemia or hypercap- nia. The rest of his investigations were unremarkable. We continued with maintenance hemodialysis and started him on a low-phosphorus diet. Sevelamer, a phos- phate binder, was started, with a dosage of 800 mg thrice daily. We uptitrated its dose to 1600 mg thrice daily. We also administered tablets containing vitamin D and cal- cium. His serum calcium level increased to 8.6 mg/dl, and the serum phosphate decreased to 5 mg/dl. He reported a remarkable improvement of his headache but would still have an occasional mild to moderate headache. Discussion Headache with onset at an elderly age is a prominent symptom in as many as one in six persons and often has a more serious import than a headache in a younger person. Although around 40% of the elderly have tension head- ache, in the majority of them, a wide variety of diseases are responsible for the headache [2]. These include space- occupying lesions, temporal arteritis, trigeminal neuralgia, postherpetic neuralgia, cerebrovascular disease, hypoxia and hypercapnia, cervical spondylosis, Paget’s disease, systemic disease (for example, anemia), hypocalcemia, hyponatremia, renal failure, post-traumatic headache, or severe hypertension [1-3]. In our patient, a controlled hypertension, no history of significant trauma, the absence of scalp tenderness and jaw claudication, and only a mildly accelerated erythrocy- tic sedimentation rate and normal serum alkaline phos- phatase level rule out severe hypertension, trauma, temporal arteritis, or Paget’s disease as causes of his headache. There was evidence of a space occupying lesion on CT scan of head. There was no history of neur- algias and cerebrovascular disease. Absence of response to antidepressants, various anticonvulsants, and NSAIDs would rule out, to a large extent, tension headaches and primary headaches. The most likely cause of headache in our patient was CRF and disturbances of calcium and phosphorus metabolism associated with it, because the headache improved remarkably with the correction of these metabolic abnormalities. Other conditions asso- ciated with CRF that can cause headache include severe anemia, hyponatremia, severe hypertension, and dialysis. Dialysis headaches are frontal, start within a few hours of the procedure, and are not persistent [1,4]. Our patient had controlled hypertension, mild anemia, and normal sodium levels. His headache was global, persistent, and improved despite continued dialysis. Inadequately treated hyperphosphatemia in CRF leads to secondary hyperpar- athyroidism and extraosseous calcification of soft tissues [5,6]. Ingested calcium is deposited in extraosseous sites, possibly because it cannot be deposited in bones [7]. Our patient had increased serum parathormone levels with diffuse dense calcification of the cerebellum, falx, and tentorium. This calcification appears to be a silent bystander, rather than a contributor to the headache, because the headache improved despite the persistence of the calcification. Nevertheless, it is a powerful clue to the possible existence of hyperphosphatemia. Conclusions In conclusion, if an elderly patient presents with a head- ache for the first time, an underlying cause other than primary and tension headaches should be sought. In a patient with new-onset headache and a comorbidity like renal failure, comorbidity should be blamed first as a cause, identified precisely, and treated specifically before looking for other causes. Consent Written informed consent was obtained from the patient for publication of this case report and accompanying images. A copy is available for review by the Editor- in-Chief of this journal.