Assessing short-term recognition memory with forced-choice psychophysical methods.

The rationale and methodology for using computer-controlled forced-choice psychophysical methods to assess short-term recognition memory in human subjects are presented. Here, we use non-verbal computer-synthesized auditory and visual stimuli with an adaptive psychophysical procedure. Sequence-length thresholds (SLTs, span lengths) for randomly generated binary auditory and visual-sequential patterns and simultaneous visual-spatial patterns are determined to assess short-term memory capacity. The SLTs can also be used to equate for initial retention level for delayed matching-to-sample (DMS) or delayed matching-to-non-sample (DMNS) tasks which assess memory decay. The DMS/DMNS tasks have also been modified for use with the forced-choice paradigm. In contrast to many verbal paradigms requiring immediate ordered recall, non-verbal stimuli in a forced-choice paradigm provide a more direct measure of sensory memory because long-term memory, complex encoding/decoding processes, and motor-sequencing factors are minimized or avoided. Furthermore, the forced-choice recognition memory tasks are applicable over a broad age range, are less sensitive to socio-economic factors and educational level, and avoid complex instructions. Taken together, these factors enhance the applicability of these tasks in children and adults with CNS lesions, particularly where cognitive status may be compromised.

Use of hydroxyapatite bone cement to prevent cerebrospinal fluid leakage through the frontal sinus: technical report.

OBJECTIVE: To test the efficacy of a simple technique of frontal sinus obliteration during low frontal craniotomy using hydroxyapatite cement instead of more traditional methods, such as pericranial flaps, free muscle or adipose grafts, lumbar drainage, or fibrin glue. METHODS: Eight patients undergoing low frontal craniotomy for intradural surgery had the frontal sinus obliterated by careful removal of mucosa followed by filling of the sinus with hydroxyapatite bone cement. No other adjuncts for preventing cerebrospinal fluid leakage through the sinus were used. RESULTS: At an average follow-up of 9 months, there were no cerebrospinal fluid leaks, infections, instances of resorption, or cosmetic deformities. CONCLUSION: Hydroxyapatite bone cement seems to be a simple and effective method for frontal sinus obliteration and prevention of cerebrospinal fluid leakage.

Eclampsia: a pediatric neurologic problem.

Eclampsia is a syndrome of hypertension, proteinuria, edema, and neurologic manifestations such as seizures, focal deficits, or blindness occurring during pregnancy, mainly in primigravidas. Although it is not seen often in the pediatric population, it occurs with greater frequency among pregnant patients under the age of 15 than in the general population. Serious sequelae can be prevented with prompt and adequate treatment, including termination of pregnancy.

Chronic renal failure presenting as proximal muscle weakness in a child.

A 13-year old boy presented with a three-year history of slowly progressive proximal muscle weakness, particularly involving the lower extremities. Chronic renal failure was uncovered in the course of his evaluation. Urologic investigation showed small and poorly functioning kidneys with a BUN of 118 mg/dL and a creatinine of 10.7 mg/dL. There were no anomalies of the proximal or distal collecting systems or history suggestive of recurrent urinary tract infection. The neurologic examination revealed proximal muscle weakness primarily of the lower extremities and especially of the proximal musculature of the pelvic girdle. Nerve conduction studies were normal. The electromyogram (EMG) showed high-voltage polyphasic potentials consistent with neurogenic muscle disease. A biopsy of the right quadriceps muscle demonstrated type II muscle fiber atrophy with histochemical staining. The patient's clinical findings, EMG studies, and muscle biopsy were not specific for either neurogenic or myopathic disease. Following a period of home peritoneal dialysis and renal transplantation, there was significant clinical improvement of the muscle weakness.

Report of congenital anaplastic astrocytoma discovered in a newborn.

Reports of congenital anaplastic astrocytoma have been rare, representing less than 2% of all brain tumors. We present a case of a congenital anaplastic astrocytoma discovered during the first 24 hours after delivery. A recent literature review found 12 additional cases since 1972. The presenting signs, most common findings on neuroimaging, treatment, and outcome are examined.

Gradenigo syndrome as presenting sign of T-cell lymphoma.

Gradenigo syndrome is an uncommonly observed neurologic complex consisting of cranial nerve VI palsy associated with the loss of the sensory component of cranial nerve V. We report a patient whose presentation with Gradenigo syndrome led to the unexpected diagnosis of T-cell lymphoma and briefly discuss Gradenigo syndrome and intracranial lymphomas.

The beginnings of urban ambulance service in the United States and England.

Urban ambulance systems emerged in the second half of the 19th century as an outgrowth of military experiences in both Europe and America. Developing first in cities such as Cleveland and New York, these systems quickly adapted to the urban environment, and modifications in ambulance construction and procedures soon followed. Since first-aid texts for urban ambulances were rare, military texts on battlefield medicine were adapted to emergency medicine in civilian accidents.

Treatment of the epileptic patient in the dental office.

Epilepsy is a relatively common problem in children, adults and the elderly. Dentists need to be familiar with the various manifestations of the disease, the anticonvulsant medications (AEDs) the patients are taking, and the complications and side effects of these drugs. In this article the types of seizures and AEDs in common use are described. Guidelines for treatment planning are given. Recommendations are made for managing the patient who has a seizure in the dental office.

"The artful science:" medicine's self-image in the 1890's.

Carried on the coattails of the century's scientific and technological revolution, Anglo-American medicine acquired a self-image and sense of purpose that belied its fragile roots. The growth of the laboratory, the popularity of the inductive method, the beginnings of government and private support for medical education, the envy of the German university experience and the new-found importance of medical societies fell in easy step with Victorian pride and the national imperative. America's medical education system grew at a slower pace, inhibited by a laissez-faire bias which reinforced the weaker aspects of its egalitarian society. The fabric for America's medical reform lay in the European clinical experience of its better educated physicians, and the transference of their enthusiasm and reform zeal into the university and medical society environment. By the 1890s, the artful science of medicine had combined the benefits of a century's scientific endeavors with the age-old instinct for useful application.