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Biomedical subjects

B E Swartz

Publications and source records attributed to B E Swartz.

At least 37 records · Page 2Linked to original sources
PubMed1991

Surface ictal electroencephalographic patterns in frontal vs temporal lobe epilepsy.

The effectiveness of long term EEG monitoring in the localization of the epileptic focus was studied in 37 patients with temporal lobe epilepsy comprising 190 recorded seizures, in 19 frontal lobe epileptic patients with 172 recorded seizures and in 12 additional patients which were classified as fronto-temporal. In the temporal lobe group, 49/190 seizures began focally (26%) and 20/190 seizures exhibited a regional onset (10%). In the frontal lobe group, only 21 out of 172 seizures (12%) had a focal ictal onset. 41/172 seizures began regionally (24%). In the fronto-temporal group, 31/55 seizures disclosed a focal EEG onset (57%). This study demonstrates that there is a two-fold increase in seizures beginning focally in the temporal lobe epilepsy group versus the frontal lobe group.

Electrodes↗
PubMed1991

Memory dysfunction in epilepsy patients as a derangement of normal physiology.

Patients with CPS often display recent memory deficits. Typically, general intelligence, perceptual skills, language, remote memory, and primary memory are all normal. However, the ability to learn new combinations of cognitively complex material is deficient. This deficit may be specific for verbal material (e.g., as a difficulty with learning to recall a response word given an unrelated cue word), for nonverbal material (e.g., as a difficulty in drawing a complex figure from memory), or for both verbal and nonverbal material. Because these characteristics are typical of memory deficits after MTL damage, it is reasonable to suspect that these deficits in patients with epilepsy also reflect MTL damage. In many cases, MTL damage is apparent from neuroimaging studies, whereas seizure semiology suggests MTL onset. In these patients, the same pathology might be the cause of both the ictus and memory deficits. In other cases, memory impairment appears to be secondary to seizures. This suggestion is supported by cases where prolonged complex partial status resulted in a permanent global amnesia. Cases with shorter-lasting memory deficits were also presented. Neuropsychological testing revealed specific recent-memory deficits that cleared 2 weeks after a flurry of CPS and 24 hr after a single seizure. Depth recordings have demonstrated that MTL electrographic seizures can occur without subjective manifestations. When these are evoked by local electrical stimulation, a profound inability to learn new material may be observed during the afterdischarge. Similarly, artificially induced MTL spike-and-wave complexes interfere with the memory for simultaneously presented complex visual scenes. Recent evidence suggests that all of the above phenomena may reflect the engagement by epileptiform processes of the association-cortex (AC)-MTL circuits used in normal human memory. In recent memory tasks, cognitive evoked-potential components N4 and P3 are generated in the MTL and to a lesser degree in related AC regions. The N4/P3 are strongly modulated by familiarity in recent memory. This modulation is eliminated by anterior temporal lobectomy. The typical slow wave following spontaneous MTL interictal spikes has the same MTL voltage topography, and thus probably similar synaptic generators, as the cognitive P3 potential. Furthermore, MTL spike-and-wave complexes can be evoked in recent memory tasks at a fixed latency equal to that of the N4.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1990

Diagnosis of delayed cerebral radiation necrosis following proton beam therapy.

A 27-year-old man developed delayed cerebral radiation necrosis following proton beam therapy to an arteriovenous malformation. Neuroimaging with technetium 99m diethylenetriamine penta-acetic acid and positron emission tomographic scanning with fludeoxyglucose F 18 aided in his evaluation. Significant improvement of his neurologic deficits resulted from corticosteroid therapy. Clinical resolution was corroborated by serial computed tomographic scans demonstrating regression of the abnormality (a mass lesion). Various facets of radiation injury are discussed, including pathogenesis, risk factors, diagnosis, and therapy.

Adult↗
PubMed1990

Multidisciplinary analysis of patients with extratemporal complex partial seizures. II. Predictive value of semiology.

Eight patients were diagnosed as having extratemporal seizures based on their ictal electroclinical manifestations. The correlation between the focus based on semiology and that based on intracranial electrographic recording and surgical excision was excellent in five, good in three. The electroclinical manifestations of seizures are important data to consider in the diagnosis and treatment of extratemporal seizure foci.

Electroencephalography↗
PubMed1990

Altered patterns of dynorphin immunoreactivity suggest mossy fiber reorganization in human hippocampal epilepsy.

Dynorphin A(1-17), an opioid peptide that is normally present in the hippocampal mossy fiber system, was localized immunocytochemically in the hippocampal formation of control autopsy and temporal lobe epilepsy (TLE) specimens. In control tissue, dynorphin-like immunoreactive (Dyn-IR) structures were confined to the mossy fiber path and were most highly concentrated in the polymorph (hilar) region of the dentate gyrus. Very few Dyn-IR structures were present in the molecular and granule cell layers of the dentate gyrus. In contrast, in all TLE specimens, Dyn-IR elements were present in these layers. The extent of aberrant staining varied among the TLE specimens, and 2 major patterns were observed. The first was a relatively wide band of reaction product in the inner one-third to one-fourth of the molecular layer (8 cases), and the second was a more limited distribution of immunoreactive fibers and presumptive terminals in the granule cell and immediately adjacent supragranular regions (2 cases). The extent of aberrant Dyn-IR structures appeared to be related to the amount of cell loss in the polymorph and CA3 fields and to dispersion of the granule cell somata. Specimens processed with the Timm's sulfide silver method for heavy metals provided independent evidence for the distribution of mossy fibers. In both control and TLE specimens, the patterns of labeling were virtually identical to those of dynorphin localization. These findings suggest that sprouting of mossy fibers or their axon collaterals has occurred in hippocampal epilepsy and that the reorganized fibers contain at least one of the neuropeptides that are normally present in this system. Such fibers could form recurrent excitatory circuits and contribute to synchronous firing and epileptiform activity, as suggested in studies of experimental models of epilepsy.

Cell Survival↗
PubMed1988

Staff surgery--the inevitable question.

The results of a survey of 450 plastic surgeons regarding the practice of operating on their staff members is presented. An overwhelming majority (85 percent) of responding surgeons do operate on their staff. Whether surgery is a "right" of employment or a "reward" for service was addressed. Seventy-two percent felt surgery was a "reward," while only 8 percent felt it was a "right." The results found complications to be relatively minor but numerous (23.5 percent). The need for an office policy is stressed to help eliminate misunderstandings with other employees, and a model office policy is presented and endorsed.

Attitude of Health Personnel↗
PubMed1988

Barbiturates depress currents through human brain calcium channels studied in Xenopus oocytes.

Barbiturates have had wide use as sedatives, anesthetics and anticonvulsants. Among the sites implicated in the membrane action of barbiturates are the gamma-aminobutyric acidA receptor, receptors for excitatory amino acids and Ca and potassium channels. The expression in Xenopus oocytes of various ligand- and voltage-gated channels offers the opportunity for more-detailed studies of such neuroactive substances as the barbiturates. Using RNA from human temporal cortex, we obtained the expression of an omega-conotoxin-sensitive, dihydropyridine-resistant Ca channel in Xenopus oocytes. Under voltage clamp, barbiturates depressed both the peak current and the steady-state current through this Ca channel. Barbiturates had no effect on the shape of the current-voltage relation, nor did they cause a shift in the voltage-dependence of channel activation. However, both the rate of inactivation of open Ca channels, as well as the proportion of channels inactivated at steady state were increased by barbiturates. The IC50 for these effects was about 0.25 mM for the more potent barbiturates tested. These results are consistent with the hypothesis that sedative and anesthetic effects of barbiturates can be mediated in part by an action to depress Ca currents.

Animals↗
PubMed1986

Individual modifications in body contour surgery: the "limited" abdominoplasty.

Stretching of the abdominal wall and skin following pregnancy or excessive weight gain may be limited to the infraumbilical area. In these patients, abdominal repair may be accomplished with a shorter incision and without the necessity for relocating the umbilicus with its attendant visible scar. Forty patients are presented in whom excellent aesthetic repairs were effected through short curvilinear, low abdominal incisions with removal of a modest amount of excess skin. Fascial plication from pubis to umbilicus or above is facilitated by buried figure-of-eight sutures. Suction-assisted lipectomy may be employed as an adjunct. Recovery is facilitated by the reduced incision line length, reduced undermined area, and absence of tension in the midline skin incision, such as may occur in a standard abdominoplasty in which large amounts of panniculus and skin are removed with a complete repair of the abdominal wall. The limited abdominoplasty may be safely performed with ketamine-diazepam anesthesia in an office surgical center. Major complications are few and generally reflect the unpredictable nature of the elasticity of the abdominal skin.

Abdomen↗
PubMed1985

Resolution of late-developing periprosthetic breast infections without prosthesis removal.

Based on prior experience with implant exposure, an aggressive regimen to eradicate periprosthetic infections has proven successful in delayed gram-positive and gram-negative bacterial infections and in atypical microbacterial infections. The objective of the "salvage" procedure is to retain a prosthesis, to maintain breast contour, and to avoid psychological and physical consequences of prosthesis removal. The "salvage" procedure involves topical antisepsis, contracture release if needed, systemic and topical antibiotics with intermittent or continuous irrigation, and reinforcement of incision lines in selected cases using local tissue flaps.

Breast↗
PubMed1984

Effects of intracellular antibodies to cGMP on responses of cortical neurons of awake cats to extracellular application of muscarinic agonists.

Intracellular injection of specific antibody to cyclic 3',5'-guanosine monophosphate (cGMP-Ab) produced substantial decreases in input resistance (Rm) selectively in neurons of the motor cortex that had responded with increased resistance to prior application of muscarinic agents. Intracellular injection of nonspecific immunoglobulins (IgG) did not produce this effect. (Some nonspecific effects on spike production occurred in cells given IgG or cGMP-Ab.) The decrease in Rm may be interpreted as being consequential to a reduction in baseline amounts of active cGMP due to binding of cGMP with the injected antibody. In cells which demonstrated a prior increase in Rm following extracellular application of the muscarinic agonist, aceclidine, or acetylcholine, injection of antibody to cGMP also resulted in suppression of the increase in Rm to subsequent applications of these muscarinic agents. Some increases in firing rate to these agents continued to be observed after injection of cGMP-Ab. The results support the hypothesis that cGMP mediates effects of muscarinic neurotransmission on the conductances of neurons of the motor cortex of awake cats. Intracellular injection of antibodies to specific cellular elements is shown to be feasible in cortical neurons of awake cats and may prove a useful adjunct to future studies of neurotransmitter mechanisms.

Acetylcholine↗
PubMed1984

Anton's syndrome accompanying withdrawal hallucinosis in a blind alcoholic.

During alcohol withdrawal, a man totally blind following ocular trauma experienced formed visual hallucinations ("alcoholic hallucinosis"), the unreality of which he recognized. During these same periods, however, he believed that his vision had been restored, and confabulated descriptions of his surroundings (Anton's syndrome). He was otherwise mentally normal. Anosognosia for blindness can occur episodically or chronically, and with either peripheral or central visual loss; dementia nearly always coexists. The basis of the syndrome is obscure, and its occurrence during alcohol withdrawal, in association with readily acknowledged visual hallucinations and otherwise preserved mentation, has not been previously reported.

Blindness↗
PubMed1981

The new Davol dermatome.

The Davol dermatome, which was introduced in 1965, had several shortcomings in clinical application. In order to increase the efficiency of this machine, changes in the motor and drive linkages of the power handle have been made. In the clinical use of the new dermatome, ;we have found significant improvement in its application. The stalling characteristics of the dermatome have been improved and more satisfactory grafts are now obtainable. This article presents some of the technical data involved in the new drive linkage and motor complex.

Dermatologic Surgical Procedures↗