Analgesic effect of octreotide in headache associated with acromegaly is not mediated by opioid mechanisms. Case report

Emergence of Pituitary Adenoma in a Child during Surveillance: Clinical Challenges and the Family Members' View in an AIP Mutation-Positive Family

INTRODUCTION

Germline aryl hydrocarbon receptor-interacting protein (AIP) mutations are responsible for 15-30% of familial isolated pituitary adenomas (FIPAs). We report a FIPA kindred with a heterozygous deletion in AIP, aiming to highlight the indications and benefits of genetic screening, variability in clinical presentations, and management challenges in this setting.

PATIENTS

An 18-year-old male was diagnosed with a clinically nonfunctioning pituitary adenoma (NFPA). Two years later, his brother was diagnosed with a somatolactotrophinoma, and a small Rathke's cleft cyst and a microadenoma were detected on screening in their 17-year-old sister. Following amenorrhoea, their maternal cousin was diagnosed with hyperprolactinaemia and two distinct pituitary microadenomas. A 12-year-old niece developed headache and her MRI showed a microadenoma, not seen on a pituitary MRI scan 3 years earlier.

DISCUSSION

Out of the 14 members harbouring germline AIP mutations in this kindred, 5 have pituitary adenoma. Affected members had different features and courses of disease. Bulky pituitary and not fully suppressed GH on OGTT can be challenging in the evaluation of females in teenage years. Multiple pituitary adenomas with different secretory profiles may arise in the pituitary of these patients. Small, stable NFPAs can be present in mutation carriers, similar to incidentalomas in the general population. Genetic screening and baseline review, with follow-up of younger subjects, are recommended in AIP mutation-positive families.

Quantitative evaluation of headache severity before and after endoscopic transsphenoidal surgery for pituitary adenoma

OBJECT The relationship between headaches, pituitary adenomas, and surgical treatment of pituitary adenomas remains unclear. The authors assessed the severity and predictors of self-reported headaches in patients referred for surgery of pituitary adenomas and evaluated the impact of endoscopic transsphenoidal surgery on headache severity and quality of life (QOL). METHODS In this prospective study, 79 patients with pituitary adenomas underwent endoscopic transsphenoidal resection and completed the Headache Impact Test (HIT-6) and the 36-Item Short Form Health Survey (SF-36) QOL questionnaire preoperatively and at 6 weeks and 6 months postoperatively. RESULTS Preoperatively, 49.4% of patients had mild headache severity, 13.9% had moderate severity, 13.9% had substantial severity, and 22.8% had intense severity. Younger age and hormone-producing tumors predisposed greater headache severity, while tumor volume, suprasellar extension, chiasmal compression, and cavernous sinus invasion of the pituitary tumors did not. Preoperative headache severity was found to be significantly associated with reduced scores across all SF-36 QOL dimensions and most significantly associated with mental health. By 6 months postoperatively, headache severity was reduced in a significant proportion of patients. Of the 40 patients with headaches causing an impact on daily living (moderate, substantial, or intense headache), 70% had improvement of at least 1 category on HIT-6 by 6 months postoperatively, while headache worsened in 7.6% of patients. The best predictors of headache response to surgery included younger age, poor preoperative SF-36 mental health score, and hormone-producing microadenoma. CONCLUSIONS The results of this study confirm that surgery can significantly improve headaches in patients with pituitary adenomas by 6 months postoperatively, particularly in younger patients whose preoperative QOL is impacted. A larger multicenter study is underway to evaluate the long-term effect of surgery on headaches in this patient group.

Secondary headaches: secondary or still primary?

The second edition of the International Classification of Headache Disorders makes a distinction between primary and secondary headaches. The diagnosis of a secondary headache is made if the underlying disease is thought to cause headache or if a close temporal relationship is present together with the occurrence of the headache. At first glance, this may allow clearly secondary headaches to be distinguished from primary headaches. However, by reviewing the available literature concerning several selected secondary headaches, we will discuss the hypothesis that some secondary headaches can also be understood as a variation of primary headaches in the sense that the underlying cause (e.g. infusion of glyceryl trinitrate [ICHD-II 8.1.1], epilepsy [7.6.2], brain tumours [7.4], craniotomy [5.7], etc.) triggers the same neurophysiologic mechanisms that are responsible for the pain in primary headache attacks.

Headache associated with pituitary tumors

The objective of this study is to analyze the presence of headache in pituitary tumors and their characteristics, the relationship between pituitary tumor size, biological type, local extension and intrasellar pressure (ISP). This is a prospective study, of 64 consecutive patients presenting with primary pituitary masses at Neuroendocrinological Department of General Hospital of Fortaleza from October 2005 to December 2006. We analyzed sex, age, headache (laterality, site, severity, quality, frequency, duration, associated symptoms, time of onset, trigger, alleviating factors and familial history) and tumor characteristics (type, size, quiasmatic compression, cavernous sinus invasion, sella turcica destruction, cystic or solid mass and ISP). We observed a statistic significant factor between pituitary tumor and tumor size, optic compression, sellar destruction, cavernous sinus invasion and ISP. Biochemical-neuroendocrine factors, mainly in prolactinomas, seem to be an important factor in the determination of headache. The presence of headache in pituitary tumor is related to a combination of factors, including ISP, tumor extension, relationship with the sellar structures, patient predisposition, familial history, and functional disturbance within the hypothalamo-pituitary axis.

Analgesic activity of a non-peptide imidazolidinedione somatostatin agonist: in vitro and in vivo studies in rat

Several lines of evidence support an important role for somatostatin receptors (SSTRs) in pain modulation. The therapeutic use of established SSTR peptide agonists for this indication is limited by their broad range of effects, need for intrathecal delivery, and short half-life. Therefore, the goal of the present study was to investigate the analgesic effect of SCR007, a new, highly selective SSTR2 non-peptide agonist. Behavioral studies demonstrated that paw withdrawal latencies to heat were significantly increased following intraplantar SCR007. Furthermore, both intraperitoneal and intraplantar injection of SCR007 significantly reduced formalin- and capsaicin-induced flinching and lifting/licking nociceptive behaviors. Recordings from nociceptors using an in vitro glabrous skin-nerve preparation showed that SCR007 reduced heat responses in a dose-dependent fashion, bradykinin-induced excitation, heat sensitization and capsaicin-induced excitation. In both the behavioral and single fiber studies, the SCR007 effects were reversed by the SSTR antagonist cyclo-somatostatin, demonstrating receptor specificity. In the single fiber studies, the opioid antagonist naloxone did not reverse SCR007-induced anti-nociception suggesting that SCR007 did not exert its effects through activation of opioid receptors. Analysis of cAMP/protein kinase A (PKA) involvement demonstrated that SCR007 prevented forskolin- and Sp-8-Br-cAMPS (a PKA activator)-induced heat sensitization, supporting the hypothesis that SCR007-induced inhibition could involve a down-regulation of the cAMP/PKA pathway. These data provide several lines of evidence that the non-peptide imidazolidinedione SSTR2 agonist SCR007 is a promising anti-nociceptive and analgesic agent for the treatment of pain of peripheral and/or central origin.

Octreotide is not effective in the acute treatment of migraine

The aim of this study was to determine whether subcutaneous octreotide is effective for the treatment of acute migraine. Patients with migraine with and without aura as classified by the International Headache Society were recruited to a double-blind placebo-controlled crossover study. Patients were instructed to treat two attacks of at least moderate pain severity, with at least a 7 day interval, using subcutaneous 100 microg octreotide or matching placebo. The primary endpoint was the headache response defined as: severe or moderate pain becomes mild or nil, at 2 h. The primary endpoint was analysed using a Multilevel Analysis approach. Secondary end-points included associated symptoms and a four-point functional disability score. The study was powered to detect a 30% difference at an alpha of 0.05 and a beta of 0.8. A total of 51 patients were recruited, of whom 42 provided efficacy data on an attack treated with octreotide and 41 with placebo. Modelling the headache response as a binomial determined by treatment, using the patient as the level 2 variable, and considering a possible period effect, and sex and migraine type as other variables of interest, subcutaneous octreotide was not significantly superior to placebo. The two hour headache response rates were 20% for placebo and 14% for octreotide, whilst the two hour pain free rates were 7% and 2%, respectively. Subcutaneous octreotide 100 microg is not effective in the acute treatment of migraine when compared to placebo.

Long-term effects of octreotide on pituitary gigantism: its analgesic action on cluster headache

We report the case of 19-year-old man with pituitary gigantism due to growth hormone-producing pituitary macroadenoma. The patient complained of recurrent headache and excessive growth spurt since age 15. Octreotide administration was initiated following transsphenoidal pituitary adenomectomy. Octreotide injection for 4 years efficaciously reduced the size of remnant adenoma as well as serum growth hormone levels. Notably, octreotide exhibited a potent analgesic effect on his intractable cluster headache that has continued even after reduction of the adenoma volume. The analgesic effect lasted 2 to 6 hours after each injection and no tachyphylaxis to octreotide appeared during 4-year treatment. To characterize the headache and the pain intensity, analgesic drugs including octreotide, lidocaine, morphine and thiopental were tested using a visual analogue scale (VAS) evaluation, with the result that octreotide exhibited a prompt and complete disappearance of the headache. Headache relief was in part reproduced by morphine injection (56% reduction) but not by lidocaine or thiopental. The present case suggests that the intractable headache associated with pituitary gigantism is possibly related to the endogenous opioid system. Thus, the headache control by octreotide is clinically helpful for continuation of the self-injection regimen.

The association between calcitonin gene-related peptide (CGRP), substance P and headache in pituitary tumours

OBJECTIVES

To determine if the differential expression of calcitonin gene-related peptide (CGRP) or substance P (SP) in a range of pituitary tumours was related to the presence or absence of headache.

METHODS

Using recognised immunohistochemical techniques we examined twenty-six consecutive pituitary adenoma specimens for the presence of CGRP and SP. We included one normal post mortem pituitary specimen for comparison. A separate observer divided the patients into two groups: headache and non-headache. The association between the presence of CGRP, SP and headache was observed.

RESULTS

We observed CGRP in seven specimens (27%) and SP in six tumour specimens (23%), with cytoplasmic staining being the predominant morphological picture. CGRP and SP were co-expressed in the same tumour specimen in five cases. There was no significant association between the presence of CGRP and headache (chi(2) 0.86; P = 0.35). We did not observe CGRP or SP in the control specimen. There was no correlation between tumour subtype and the presence of CGRP or SP.

CONCLUSIONS

The mechanism of pituitary tumour-associated headache remains undetermined. The significance of the presence of CGRP and SP in pituitary tumours is unknown but does not appear to be related to headache or endocrine activity of the tumour.

Somatostatin analogs as primary medical therapy for acromegaly

Acromegaly is a debilitating disease usually caused by a growth-hormone secreting pituitary adenoma. Therapeutic goals include improvement of symptoms, reduction in tumor mass, biochemical normalization, and preservation of pituitary function. Treatment options include transsphenoidal surgery, radiation, and pharmacotherapy. In view of the good cure rate, surgery remains the therapeutic modality of choice for most patients with microadenomas or well-circumscribed macroadenomas. In contrast, >40% of patients with invasive macroadenomas (who make up the majority of patients with acromegaly) will have residual disease following surgery, and require additional therapeutic intervention. Somatostatin analogs result in biochemical normalization in >60% of non-operated patients, and are well tolerated. Therefore, somatostatin analogs have emerged as a rational first-line treatment for the appropriately selected patient with acromegaly.

Somatostatin infusion withdrawal: a study of patients with migraine, cluster headache and healthy volunteers

Migraine and cluster headache are the most common disabling primary headache syndromes and are typically episodic. A reliable method of triggering such headache attacks facilitates the study and treatment of these disorders. There is sufficient clinical and laboratory evidence to suggest that somatostatin withdrawal may be a useful way of triggering headache. We studied 15 subjects, eight migraineurs, four cluster headache sufferers and three healthy controls. Each subject had a standard somatostatin infusion, 250 microg/h for 3.5h. Subjects were followed for 24h post-infusion. Growth hormone was suppressed in each subject demonstrating a biologically active infusion of somatostatin. None of the non-headache sufferers had pain. Seven of eight migraine sufferers had no immediate headache and no delayed headache. One migraineur experienced short lasting headache with no migrainous features. Three of four patients with cluster headache had no significant pain with the infusion, while one had pain after 1h. The results suggest that somatostatin infusion is not a reliable way to produce headache in experimental settings in either migraine or cluster headache. The data do not exclude a role for somatostatinergic mechanisms in primary headache.

Prolactinomas, dopamine agonists and headache: two case reports

Headache is a common problem in patients with pituitary tumours. Small pituitary lesions can cause debilitating headache, suggesting that the size of the pituitary tumour may not be the only causal factor in pituitary-related headache. We present two cases of prolactinoma-associated headache. The first case has a clinical diagnosis of short-lasting unilateral headache attacks with conjunctival injection and tearing (SUNCT). The second case has a clinical diagnosis of hemicrania continua and idiopathic stabbing headache. In each case, the administration of dopamine agonists has led to an exacerbation of symptoms. We review the relevant literature to understand the pathophysiological implications of these cases.

Acromegaly

Acromegaly is a slow developing disease caused by hypersecretion of growth hormone and insulin-like growth factor 1. Increased morbidity and mortality associated with the disease make early diagnosis and treatment crucial. This article reviews the etiology, clinical manifestations, and diagnosis of acromegaly, with an emphasis on newly available therapeutic options.

The palliative effects of octreotide in cancer patients

Octreotide is an extremely useful compound for palliative care physicians. It appears to be active in a number of different pain states and may be given by the spinal and intraventricular route. Its actions in reducing gut motility and secretions make it a valuable adjunct in the management of inoperable bowel obstruction. The same actions make it a potent antidiarrheal agent. Octreotide will often succeed where other antidiarrheal agents fail. Its ability to reduce gut secretions has led to its use in the treatment of fistulae. It has also been proposed as a useful drug in the management of cachexia and ascites. Most of the existing evidence is based on small numbers of case reports and further larger trials are necessary.

Somatotropinoma infarction during octreotide therapy leading to bilateral cavernous sinus syndrome

The cyclic somatostatin analog, octreotide, forms the mainstay of medical treatment for acromegaly. In addition to lowering circulating growth hormone levels and shrinking tumor size, octreotide may provide symptomatic relief of headaches associated with growth hormone secreting tumors. The majority of reported complications of octreotide therapy are gastrointestinal and metabolic. The present case illustrates the development of acute bilateral cavernous sinus syndrome with loss of eye movement bilaterally during octreotide therapy. Serial MRI examination suggest tumor infarction as the etiology. The symptoms resolved over 2 months as the tumor shrunk in size and growth hormone was dramatically reduced.

The role of octreotide in palliative care

Octreotide, an analogue of somatostatin with a more favorable pharmacokinetic profile, is a new drug that may offer some advantages in the palliative care setting. It has been used with favorable results in the management of some gastrointestinal disorders, such as gastrointestinal hemorrhage, diarrhea, short-bowel syndrome, fistula, and intestinal occlusion in the palliative care setting. These favorable results occurred without important side effects, underlining the potential role of this drug. The cost-benefit ratio of this expensive drug must be considered, however.

Octreotide dependency and headache: a case report

We report on headache induced by a somatostatin octapeptide analog (octreotide) used for the treatment of acromegaly. This "rebound" headache has severe tension-type characteristics and occurs every 6-8 h. It resolves dramatically within minutes with octreotide administration. This is the first report of headache developing under treatment with octreotide.