Spontaneous infarction in pituitary tumors: neurologic and therapeutic aspects.

In addition to progressive endocrine dysfunction and progressive visual loss, pituitary neoplasms may annouce their presence by the more catastrophic alternative of spontaneous tumor infarction. In two patients reported, illness due to the spontaneous infraction of pituitary tumors was heralded by sudden onset of focal headache associated with diplopia. Stupor, confusion, and evidence of increased intracranial pressure occurred without subarachnoid hemorrhage or massive extrasellar extension of tumor. One patient developed inappropriate antidiuretic hormone secretion with spontaneous infarction in a large but clinically silent chromophobe adenoma. In both patients, skull x-rays suggested a long-standing intrasella mass. Both underwent prompt treatment with endocrinologic replacement therapy and subsequent successful transsphenoidal removal of voluminous, infarcted, pituitary masses.

Ambulatory blood pressure monitoring during pregnancy. Establishment of standards of normalcy.

Ambulatory blood pressure monitoring (ABPM) was used as an effective methodology by a primary care physician to assess normalcy of blood pressure (BP) and heart rate during pregnancy. One hundred fifty pregnant women in one of three periods (18 to 22, 30 to 32, and 36 to 38 weeks) of gestation and 30 age-matched nonpregnant women participated in this study. The study was designed to establish ABPM standards of normalcy during critical times of gestation. Twenty-four-hour BP (systolic and diastolic BP) values monitored during gestational weeks 18 to 22 and 30 to 32 were similar to each other and lower than the same values recorded in nonpregnant women. Blood pressures monitored during gestational weeks 36 to 38 were significantly higher than similar values observed during the two earlier gestational periods but not significantly higher than nonpregnancy BP values. Heart rates were significantly elevated during all gestational periods when compared with nonpregnancy heart rates. The results of this study established normalcy BP curves during three different gestational periods. Mean 24-h, daytime, and nighttime BPs were significantly elevated during weeks 36 to 38 when compared with BPs recorded during gestational weeks 18 to 22 and 30 to 32. Ambulatory blood pressure monitoring is a useful tool for the measurement and treatment of BP abnormalities during pregnancy.

The Effects of Cold Acclimation upon the Oxygen Consumption of Two Species of Free-Living Nematodes.

Two species of free-living nematodes, Panagrellus redivivus and Turbatrix aceti, were cultured axenically at control (20 C) and cold (10 C) temperatures. Oxygen consumption of worms from each population was measured manometrically on days 2 through 8 after exposure to these temperatures. In both species, the slope of the oxygen consumption curve for the controls was greater than that of the worms exposed to the cold on day 2. The slope of the curve of the cold-exposed worms gradually increased until day 7. At this time, the slope of the oxygen consumption curve from the cold-exposed worms exceeded or equaled that of the controls. This is taken as an indication of the onset of the cold-acclimated state in both species of worms by day 7.

The NIH consensus development program.

The NIH CDCs are a highly visible, public forum to evaluate controversial medical technologies by synthesizing current medical science data. The consensus statements, although not intended as medical practice guidelines, may form part of the database preceding guideline formulation. It is difficult to assess the effect of the conferences on physician practice, in part reflecting the interference of the many other influences, medical and nonmedical, on physician behavior. Yet the program has had some success in influencing reimbursement policy for some technologies here and abroad and in influencing specialty organization policy, thereby indirectly affecting physician behavior. On the other hand, OMAR's dissemination activities have apparently been so successful that demand for CDC statements has more than doubled over the past five years, prompting OMAR to establish an information service (including fax and the Internet). And finally, the program has spawned consensus conferences throughout the world, including Canada, Western Europe, and Israel (Goodman & Baratz 1990).

Hemifacial spasm and the facial nucleus.

Spontaneous and associated hyperkinetic facial movements and contracture which follow injury to the seventh cranial nerve (postparalytic hemifacial spasm) or arise without known previous injury (cryptogenic hemifacial spasm) are pathological motor phenomena not found in the distribution of other cranial or somatic motor nerves. The commonly expressed hypotheses of pathogenesis--aberrant regeneration and fiber excitation by false synapse formation (ephapses) at the site of injury--cannot account for all aspects of these phenomena or for the uniqueness of such movements to the distribution of the seventh nerve. The suggestion is made that the existing diversity of facial motor behavior, which encompasses voluntary, emotional, and especially automatic, associated, and reflexive movements, is based on a unique central organization that sets it apart from other motor groups. I hypothesize that because of this organization, the changes following axonal injury--which include selective deafferentation, glial response, axonal sprouting, functional reconnection, and hyperexcitability from dendritic spike generation--can unmask and augment automatic, associated, and reflexive movements already present in the facial neuronal network to result in facial hyperkinesia.