Clinical clerkships in neurosurgery and neurology at United States medical schools.

The neurology and neurosurgery clinical clerkship experience (excluding lectures and conferences) of the students in U.S. allopathic medical schools during one of the academic years 1986 to 1987 or 1987 to 1988 was surveyed. Almost all schools have at least some students taking these clerkships. The majority of students (78%) have clinical exposure to neurology, but only a minority (28%) take a neurosurgical clerkship; however, far more schools require their students to take neurology clerkships (54%) than neurosurgical clerkships (12%). A few require that either be taken. Overall, 81% of schools require all students to take at least one of these clerkships. For the most part, students taking a clerkship in either specialty do not do so again. The initial and usually unique exposure averages 3.5 weeks in neurology and 2.4 weeks in neurosurgery. For each specialty, required clerkships tended to be shorter than selective clerkships, which in turn were shorter than elective ones. Furthermore, first clerkships offered in the fourth year, whether they were required, selective, or elective, tended to be longer than the corresponding third-year first clerkships at other schools. Whereas the average length of a first clinical clerkship in neurology is almost as long for schools requiring it (3.4 wk) as for those that offer it as an elective or selective (4.0 wk), required neurosurgical clerkships are much shorter (1.5 wk) than elective or selective rotations (3.1 wk). Schools with residency training programs more frequently required students to a clerkship and, consequently, had greater numbers of students taking a clerkship in the corresponding specialty.(ABSTRACT TRUNCATED AT 250 WORDS)

Feasibility of intracranial surgery in the primate fetus. Model and surgical principles.

A research model for intracranial surgery in the primate fetus was developed and tested in 10 timed-pregnant rhesus monkeys. With general anesthesia and sterile surgical technique, a laparotomy followed by a lower uterine segment hysterotomy was performed at a site avoiding the placenta. The amnion was opened carefully by use of the operative microscope and the fetal head was exposed. A scalp incision was made over the frontal region and a small craniectomy and cortical incision were carried out. In three of the fetuses, ventricular shunts were also placed. A layered closure was performed and the uterus was returned to the peritoneal cavity. Placental integrity and fetal viability were assessed before surgery and 1 week postoperatively by ultrasonography. The survival rates were 100% for the mothers and 80% for the fetuses. One fetus died in utero after an overdose of a sedative to the mother, and another was stillborn. Postmortem examination revealed no intracranial or systemic abnormalities in either case, and the cause of death was attributed to drug overdose and a naturally occurring stillbirth, respectively. Newborns were maintained either with their mothers or in a nursery, where they were observed and evaluated for 3 weeks. Weight, crown-rump length, and occipitofrontal head circumference were measured. General patterns of behavior and neurological assessments were recorded weekly. The eight surviving neonates were normal with respect to all parameters evaluated. Several principles of fetal intracranial surgery are emphasized as important: uterine relaxation by prostaglandin inhibition; low-dose halothane anesthesia supplemented by nitrous oxide in oxygen; perioperative ultrasonography and intraoperative transillumination of the uterus for placental localization; lower uterine segment opening; controlled exposure of the fetal cranium; minimization of amniotic fluid loss; enhancement of fetal anesthesia by injection of a local anesthetic agent at the fetal operative site; and multilayered watertight closure.

Fetal therapy: ethical and legal implications of prenatal intervention and clinical application.

Recent advances in antenatal diagnosis have stimulated interest in the development of techniques for in utero treatment of fetal abnormalities. This article identifies and discusses the ethical and legal problems which emerge from fetal therapy. Is a fetus a patient? Does the fetus have rights? Who should give consent for the unborn? Does the fetus have redress if it is injured? Could a pregnant woman be forced to undergo treatment which could endanger her life and health for the benefit of the fetus? Answers to these questions are not clear and create in themselves additional queries. Until fetal therapy becomes an accepted medical practice, the resolution of the ethical and legal issues that it provokes will probably remain inconclusive and a matter of concern.

CT visualization of ruptured berry aneurysm within hematoma: the flip-flop sign.

Postcontrast CT of the head may be a useful screening technique for identifying an aneurysm within an intracerebral hematoma. This could avoid unnecessary angiography with its attendant morbidity in inoperable situations and obviate initial arteriography in patients whose surgery is to be delayed.

Feasibility of intracranial surgery in the rat fetus: model and surgical principles.

The feasibility of intracranial surgery in the rat fetus is demonstrated by the use of a microsurgical model. In utero craniotomy and cerebral incision have been performed successfully without compromise of the fetal-maternal unit. Maternal and fetal survival rates of 95 and 93%, respectively, are reported. Several principles of fetal surgery have been established and are discussed. These include the inhibition of uterine contraction, monitoring of physiological variables, timing of operation, microsurgical technique, and preservation of amniotic fluid. The fetal rat model is amenable to antenatal research because it fulfills certain criteria, including accurately timed pregnancies, littermate controls, inexpensiveness, and animal availability.

Experimental spinal cord trauma: potentiation by alcohol.

The effect of alcohol on the injured spinal cord in cats is assessed by use of a standardized trauma model at both nonparaplegic and paraplegic trauma forces. Prior administration of an intoxicant dose of ethyl alcohol resulted in a potentiation of the trauma response at the 100 gm-cm and 260 gm-cm contusion levels. No significant changes were noted at the higher trauma grades. The results suggest that alcohol acts synergistically with mechanical injury of the spinal cord to amplify the trauma response by increasing edema formation within the contused tissue. The mechanism by which this potentiation may occur ar possibly in the areas of antidiuresis and fluid retention from increased tissue hydration in alcohol-treated animals.

Correlation of cerebrospinal fluid serotonin and altered spinal cord blood flow in experimental trauma.

Serotonin levels in the cerebrospinal fluid (CSF) were determined at various time intervals following experimental spinal cord trauma and correlated with alterations in the intramedullary blood flow. At one hour after injury, a significant elevation of CSF serotonin was noted to parallel a marked reduction in white matter perfusion. The correlation between elevated CSF serotonin and decreased blood flow in the traumatized spinal cord suggests that serotonin may have pathogenetic importance relative to posttraumatic alterations in the intramedullary microcirculation. The possible role of serotonin in the pathophysiology of blood flow changes following experimental spinal cord injury are discussed as are the therapeutic implications.

Norepinephrine, dopamine and serotonin in experimental spinal cord trauma: current status.

The status and function of monoamines in experimental spinal cord trauma remains a subject of controversy and continued debate. The norepinephrine hypothesis has been severely weakened by its lack of reproducibility. Dopamine results are too variable to draw meaningful conclusions. The role of serotonin, particularly with reference to its vasoactive properties and the physiological importance of its effects, remains to be determined.

The effect of antifibrinolytic therapy in experimental spinal cord trauma.

The efficacy of antifibrinolytic therapy with epsilon aminocaproic acid (EACA) in experimental spinal cord injury is assessed by use of a standardized trauma model at both nonparaplegic and paraplegic trauma doses. Evaluation of neurologic parameters, cortical evoked response and histopathology of the injured spinal cord demonstrated that within the contusion range studied, EACA has no significant therapeutic effect. The ability of the animal to walk was the most reliable criterion indicative of functional recovery, and was closely paralleled by return of the cortical evoked response. Spinal cord cavitation in excess of 60% uniformly resulted in paraplegia. The data from this experiment show no evidence of a significant secondary injury occurring after spinal cord trauma that is amenable to posttraumatic antifibrinolytic therapy.

A dominant form of adult neuronal ceroidlipofuscinosis (Kufs' disease) with an associated occipital astrocytoma: early diagnosis by cortical biopsy.

A patient with a dominantly inherited form of Kuf's disease and an associated occipital astrocytoma is presented. This is the first reported case in which the diagnosis of Kufs' disease was made by a cortical biopsy several years before its expected clinical onset. The nosology of this disease, and its clinical, genetic, and histopathological characteristics are discussed. The establishment of an early diagnosis by cortical biopsy and its implications are considered.