Pituitary apoplexy: considerations on a single center experience and review of the literature

PURPOSE

To present a single-center experience on pituitary tumor apoplexy and a review of literature focusing on predisposing and precipitating factors.

METHODS

Clinical presentation of our series of cases. Contemporary published literature is also reviewed.

RESULTS

The definition of this syndrome has not been consistent although now the majority of authors agree to definite it as an acute condition caused by hemorrhage or infarction of a pre-existing pituitary adenoma. Different predisposing and precipitating factors have been described in literature; among these antithrombotic and anticoagulant drugs, seem to play relevant roles. The clinical cases observed in our clinic confirm these data and suggest a probable association between elderly patients taking anticoagulant therapy and pituitary apoplexy adenoma.

CONCLUSION

Pituitary tumor apoplexy remains a challenging disease in relation to difficulties in correct diagnosis and thus in appropriate treatment. Antithrombotic/anticoagulant therapy may have an important role as precipitating factor. When a pituitary disorder is known, great care should be taken in the prescription of anticoagulant therapy.

Combined nicotinic and muscarinic blockade in elderly normal volunteers: cognitive, behavioral, and physiologic responses

Establishing a pharmacologic model of the memory deficits of Alzheimer's disease could be an important tool in understanding how memory fails. We examined the combined effects of the muscarinic antagonist scopolamine and the nicotinic antagonist mecamylamine in eight normal elderly volunteers (age 61.9 +/- 8.3 yrs, SD). Each received four separate drug challenges (scopolamine (0.4 mg i.v.), mecamylamine (0.2 mg/kg up to 15 mg PO), mecamylamine + scopolamine, and placebo). There was a trend toward increased impairment in explicit memory for the mecamylamine + scopolamine condition as compared to scopolamine alone. Increased impairment was also seen for the mecamylamine + scopolamine condition as compared to scopolamine alone in selected behavioral ratings. Pupil size increased when mecamylamine was added to scopolamine, while systolic blood pressure and pulse changed in concordance with ganglionic blockade. These data together with previous brain-imaging results suggest that this muscarinic-nicotinic drug combination may better model Alzheimer's disease than either drug alone.

Dementia Mood Assessment Scale

The behavioral symptoms seen in patients with dementia are diverse, ranging from agitation to hallucinations and paranoid delusions. Many patients with dementia have affective disturbances, including depressed mood. To provide a means of assessing the severity of depression and mood changes in demented patients, the authors and colleagues at the National Institute of Mental Health developed the Dementia Mood Assessment Scale.

Scopolamine effects on the pressor response to thyrotropin-releasing hormone in humans

Thyrotropin-releasing hormone (TRH) produces a marked pressor effect, which may be mediated by central cholinergic neurons, which in turn enhance sympathetic nervous system activity. In this study, 22 subjects (10 patients with Alzheimer's disease and 12 elderly controls) were administered IV scopolamine or placebo prior to administration of IV high-dose TRH (0.5 mg/kg). Systolic blood pressure was less on the day scopolamine was administered prior to TRH administration, as compared with placebo (F[1,20] = 6.12, p < 0.02). Results indicate that the pressor effect of TRH is attenuated by scopolamine, indicating a role of the cholinergic system in this response in humans.

Preliminary results on phosphorus-31 nuclear magnetic resonance evaluation of human uveal melanoma in enucleated eyes

Clinical evaluation of uveal melanomas by nuclear magnetic resonance (NMR) techniques depends on ascertaining how these tumors characteristically appear in NMR images and spectra. The authors have determined NMR characteristics of suspected uveal melanomas by phosphorus-31 (31P) NMR spectroscopy of freshly enucleated human eyes. Nuclear magnetic resonance examination was performed at 8.45 Tesla within 90 minutes after enucleation. Enucleated eyes were maintained at 4 degrees C in tissue culture medium during the 30 minutes required for transport. Nuclear magnetic resonance spectra were obtained within 10 minutes, a clinically acceptable time, using a two-turn 31P surface coil. Spectral parameters included 10-kHz spectral width, 1024 data points, and 0.5-second recycle delay. Phosphorus-31 NMR spectroscopy allowed differentiation of choroidal melanomas from normal ocular structures. Differentiating features include significant peaks in tumor spectra due to the phosphodiesters glycerol 3-phosphoryl ethanolamine (GPE) and glycerol 3-phosphorylcholine (GPC), and the phosphomonoesters phosphorylethanolamine (PE) and phosphorylcholine (PC). These preliminary data are encouraging and suggest that clinical trials at the lower magnetic field strengths available in NMR imaging systems seem feasible and warrant investigation.