Encoding and retrieval are differentially processed by the anterior cingulate and prelimbic cortices: a study based on trace eyeblink conditioning in the rabbit.

A growing body of literature suggests that structures along the midline of the prefrontal cortex (mPFC), including Brodmann's area 32 (prelimbic cortex) and area 24 (anterior cingulate cortex) in the rabbit play a role in retrieval of learned information. The present studies compared the effects of post-training lesions produced either immediately or 1-week following learning, to either prelimbic (area 32) or anterior cingulate (area 24) cortex on trace eyeblink (EB) conditioning. Further, because recent evidence suggests that the mPFC may play an even greater role in learning and memory when emotional arousal is low, these studies compared the effects of lesions in groups conditioned with either a relatively low-arousal corneal airpuff, or a more aversive periorbital eyeshock unconditioned stimulus (US). A total of six groups were tested, which received selective ibotenic acid or "sham" control lesions to either area 32 or 24, immediately or 1-week following asymptotic learning, and conditioned with an eyeshock US or an airpuff US. Results showed that the greatest lesion deficits were found when conditioning with the less aversive airpuff US. Further, lesions produced to area 32 one-week, but not immediately following learning, caused significant deficits in performance, while lesions produced to area 24 immediately, but not 1-week following learning, caused significant deficits in performance. These findings add to the body of evidence which shows that area 32 of the mPFC regulates retrieval, but not acquisition or storage of information, while area 24 mediates a less specific reacquisition process, but not permanent storage or retrieval of information during relearning of memories abolished by mPFC damage. These findings were, however, specific to those experiments in which the relatively non-aversive airpuff was the US.

Decompressive bifrontal craniectomy in the treatment of severe refractory posttraumatic cerebral edema.

OBJECTIVE: The management of malignant posttraumatic cerebral edema remains a frustrating endeavor for the neurosurgeon and the intensivist. Mortality and morbidity rates remain high despite refinements in medical and pharmacological means of controlling elevated intracranial pressure; therefore, a comparison of medical management versus decompressive craniectomy in the management of malignant posttraumatic cerebral edema was undertaken. METHODS: At the University of Virginia Health Sciences Center, 35 bifrontal decompressive craniectomies were performed on patients suffering from malignant posttraumatic cerebral edema. A control population was formed of patients whose data was accrued in the Traumatic Coma Data Bank. Patients who had undergone surgery were matched with one to four control patients based on sex, age, preoperative Glasgow Coma Scale scores, and maximum preoperative intracranial pressure (ICP). RESULTS: The overall rate of good recovery and moderate disability for the patients who underwent craniectomies was 37% (13 of 35 patients), whereas the mortality rate was 23% (8 of 35 patients). Pediatric patients had a higher rate of favorable outcome (44%, 8 of 18 patients) than did adult patients. Postoperative ICP was lower than preoperative ICP in patients who underwent decompression (P = 0.0003). Postoperative ICP was lower in patients who underwent surgery than late measurements of ICP in the matched control population. A statistically significant increased rate of favorable outcomes was seen in the patients who underwent surgery compared to the matched control patients (15.4%) (P = 0.014). All patients who exhibited sustained ICP values above 40 torr and those who underwent surgery more than 48 hours after the time of injury did poorly. Evaluation of the 20 patients who did not fit into either of those categories revealed a 60% rate of favorable outcome and a statistical advantage over control patients (P = 0.0001). CONCLUSION: Decompressive bifrontal craniectomy provides a statistical advantage over medical treatment of intractable posttraumatic cerebral hypertension and should be considered in the management of malignant posttraumatic cerebral swelling. If the operation can be accomplished before the ICP value exceeds 40 torr for a sustained period and within 48 hours of the time of injury, the potential to influence outcome is greatest.

Attitudes, activities, and involvement in nursing research among psychiatric nurses in a public-sector facility.

The purpose of this descriptive study was to explore attitudes, activities, and involvement in nursing research among psychiatric nurses practicing in a public-sector facility. A convenience sample of 90 nurses was asked to complete the Probe Nursing Research Questionnaire (PNRQ) and the Selby Research Attitude Inventory (SRAI). Nurses demonstrated positive attitudes toward nursing research by SRAI scores. The findings indicated that the education level was positively correlated (p = .003), whereas years of employment reflected an inverse relationship with SRAI scores (p = .013). Nurses with a high school diploma as their highest level of education scored lowest; those with an advanced education level scored highest. Nurses employed longer at the public-sector facility scored lower on the SRAI than those recently hired. The cross-product of age/employment with SRAI scores found that nurses who were older and employed for a greater number of years had lower research attitude scores (p = .003). Strategies are offered to enhance nursing research activities and involvement in public-sector facilities.

The Traumatic Coma Data Bank: a nursing perspective, Part II.

The Traumatic Coma Data Bank (TCDB) was a collaborative project undertaken to study the nature and course of severe head injury. Evolution of nursing goals includes collection of data, communication, new clinical observations, designing future research projects, education and legislative impact. Management issues inherent in the collaborative research project are defining, collecting, entering, and analyzing and publishing results.

The Traumatic Coma Data Bank: a nursing perspective, Part I.

The Traumatic Coma Data Bank (TCDB) was a collaborative project undertaken to study the nature and causes of severe head injury, allowing patients similar in age, severity of insults and neurological and physical symptoms to be compared in terms of outcome. Systematic uniform data were collected during the prehospital, acute and rehabilitative phases on 581 patients from 6 centers during the pilot phase of the TCDB, June 1, 1979 through May 31, 1982. The pilot phase successfully determined that a collaborative approach to studying head injury was feasible and additional information gained was incorporated into the main phase April, 1983 through April, 1988. A description of the TCDB population as of this writing (730 patients) is included here.