Pituitary volume and headache: size is not everything.

BACKGROUND Pituitary tumors are commonly associated with disabling headache. The accepted mechanisms for headache are dural stretch and cavernous sinus invasion. OBJECTIVE To determine if there is a relationship between pituitary tumor size and the report of headache. DESIGN We prospectively studied 63 patients who were initially seen with pituitary tumors. Clinical headache scores, pituitary tumor volume, and the extent of cavernous sinus invasion were obtained for each patient. RESULTS The prevalence of headache was 70%. There was no positive correlation the between clinical headache score and pituitary volume (r = -0.32, P =.01, Spearman rank correlation). There was also no association between cavernous sinus invasion and headache. There was a strong association between pituitary-associated headache and a family history of headache (chi(2) = 8.36, P =.004). CONCLUSIONS These data suggest that a pituitary tumor-associated headache may not simply be a structural problem. Other factors such as family history of headache, and the endocrine activity of the tumor may be equally important determinants of headache. Elucidating these mechanisms will aid in the treatment of these patients and further our understanding of other headache syndromes.