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Biomedical subjects

M Rappaport

Publications and source records attributed to M Rappaport.

At least 19 recordsLinked to original sources
PubMed1992

An epidemiological study of obsessive-compulsive disorder and related disorders in Israeli adolescents.

Five hundred and sixty-two, 16- to 17-year-old consecutive inductees into the Israeli Army, constituting a random sample of their cohort, were screened for obsessive-compulsive disorder (OCD), Tourette's syndrome, transient tics (TT), chronic multiple tics (CMT), and attention-deficit hyperactive disorder (ADHD). Two child psychiatrists interviewed the subjects, using screening items from structured interviews that implement DSM-III-R diagnostic criteria. For OCD, a point prevalence of 3.6% was found, 3.9% for ADHD, 1.8% for CMT, and 1.6% for TT. For ADHD, TT, and CMT, but not for OCD, there was a significantly higher prevalence for males than for females. Among the OCD individuals, there was an elevation of TT, CMT, and Tourette's syndrome relative to the population rates.

Adolescent↗
PubMed1992

Effects of anesthesia and stimulus intensity on posterior tibial nerve somatosensory evoked potentials.

Under anesthesia peak latencies occurring up to 75 milliseconds after stimulus onset upon somatosensory evoked potential testing of the somatosensory evoked potential testing of the posterior tibial nerve were not affected by stimulus intensity (between 5 and 19 ma) or by length of time under isoflurane and nitrous oxide up to over 2 hours. When pre- and postoperative tests on patients who were not under anesthesia were compared with results under anesthesia, no significant latency differences were found in relation to stimulus intensity for peaks N30, P40 and N50. For peaks P60 and N75, however, significantly increased latencies were seen during anesthesia, more pronounced and consistent for N75. Amplitudes, however, were affected by both stimulus intensity and anesthesia duration. A curvilinear relationship was found during early anesthesia. Maximum amplitudes were found at 7 or 11 ma stimulus intensity levels, depending upon which peak was analyzed, with lesser amplitudes occurring at both lower and higher stimulus intensity levels. Stimulus intensity and anesthesia interacted such that maximum amplitude occurred, in general, at 11 ma after short duration anesthesia (6') and at 7 ma after long duration anesthesia (125'). Under long duration anesthesia amplitudes were significantly diminished, mostly at the 11 ma intensity level. At 15 and 19 ma intensity levels peak amplitudes remained relatively constant regardless of anesthesia duration and therefore are the intensities to use to monitor changes during prolonged surgeries. When preoperative during prolonged surgeries. When preoperative and postoperative tests were compared to tests under anesthesia, there was a decrease in amplitude under anesthesia, greater for long than short duration anesthesia.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Effects of stimulus intensity on posterior tibial nerve somatosensory evoked potentials.

Relationships between stimulus intensity and peak latencies and amplitudes in posterior tibial nerve somatosensory evoked potential patterns were evaluated in ten healthy subjects. Eight intermediate latency peaks between 30 and 125 milliseconds (ms) after stimulus onset and seven amplitudes were analyzed. In general, there was a decrease in latency with each increase in stimulus intensity over a five step intensity range between 5 and 19 milliamps (mA) for most peaks. Similarly, increases in amplitudes generally occurred with increases in stimulus intensity for most peaks. Later peaks N105 and P115 as well as amplitudes P90-N105 and N105-P115 were least sensitive to stimulus intensity changes. The greatest changes in peak latency and amplitude occurred as stimulus intensity was increased from 7 to 11 mA. Beyond 11 mA relatively little change was observed in either peak latencies or amplitudes. Under anesthesia, by contrast, there was no stimulus intensity-peak latency interaction and beyond 11 mA there were decreases in amplitudes. Possible reasons for these findings are discussed.

Adult↗
PubMed1992

Evaluation of coma and vegetative states.

The Coma/Near-Coma (CNC) scale was designed to measure small clinical changes in patients with severe traumatic and nontraumatic brain injuries who were functioning at very low levels characteristic of near-vegetative and vegetative states. In 20 patients followed for 16 weeks the scale identified 25% who ultimately showed modest improvement. Interrater reliability was high (r = .95); validity was supported by significant correlations between CNC- and brain-multimodality evoked potential abnormality scores as well as between scores on the CNC and the Disability Rating Scale. The CNC scale was easily learned and it could be completed quickly and cost effectively. Staff found it useful in recognizing among relatively homogeneous low-level patients those most likely to respond to further rehabilitation care. The CNC appears to be useful for justifying ongoing intensive rehabilitation and for preventing premature transfer to lower levels of care.

Adolescent↗
PubMed1991

Passive P300 response in traumatic brain injury patients.

Severe traumatic brain injury (TBI) patients in a vegetative state were exposed to passive P300 (PP300) evoked potential tests under two conditions: two auditory tones (unimodality condition), and a flash and auditory tone (bimodality condition). A third non-P300 condition using a single repetitive auditory tone was also presented. Patients produced PP300 responses under all three conditions, even though the severity of their clinical condition did not allow them to respond to even simple commands. No peak latency differences were found. PP300 amplitude was significantly larger under the bimodality stimulus condition than either the unimodality or non-P300 condition. The PP300 amplitude under the unimodality condition, in turn, was larger than the P300-like response in the non-P300 condition. This replicates earlier findings with normal subjects. PP300 responses appear to be a tool that might find utility in evaluating TBI patients. Results raise questions about the neuropsychological/neurophysiological nature of the PP300 response.

Adolescent↗
PubMed1991

Short and long latency auditory evoked potentials in traumatic brain injury patients.

Short latency auditory nerve and brainstem evoked responses (BAERs) and long latency cortical auditory evoked responses (CAERs) in 75 long-term traumatic brain injury (TBI) cases were compared. CAERs were found to be significantly correlated with clinical disability as measured by the Disability Rating Scale, while BAERs were not. Also, BAER patterns were consistently and significantly less abnormal and less sensitive to overall dysfunction than CAER patterns. Findings support previous observations that BAERs have relatively little utility for evaluating in surviving TBI patients the degree of overall brain impairment. In general, long latency AEP patterns are better able to reflect the extent and severity of brain dysfunction and overall clinical condition than are short latency AEP patterns in long-term severe TBI patients, and these patterns should be obtained routinely in the evaluation of such patients.

Adolescent↗
PubMed1991

Dermatomal somatosensory evoked potentials in brachial plexus injuries.

The dermatomally stimulated somatosensory evoked potential is an essentially painless, noninvasive procedure that can add useful information to the diagnosis of the site and extent of brachial plexus injuries. In this study, 13 patients with unilateral brachial plexus injuries who had previously undergone conventional electromyographic testing underwent somatosensory evoked potential recording with median, ulnar, radial, musculocutaneous nerve and C5, C6, C7, C8 and T1 dermatomal stimulation. There was no significant difference in the peak latencies, interpeak latencies, or amplitudes of the major peaks between the normal values and the values from the affected levels. However, analysis for absence or presence of major peaks from side-to-side was useful in supporting the data from electromyographic and radiologic studies, as well as in providing more specific information as to the level of injury and extent of injury in two of the cases. The accurate diagnosis can provide the information needed to determine patient treatment as well as plan the rehabilitation program of the patient. The dermatomal somatosensory evoked potential can be a useful supplement to the assessment of the patient with a brachial plexus injury.

Adult↗
PubMed1990

P300 response under active and passive attentional states and uni- and bimodality stimulus presentation conditions.

P300 evoked potential patterns were evaluated for two active and two passive attentional states in which stimuli were presented in either one or two sensory modalities. Latency to an infrequent auditory tone was shortest when counting the frequent stimulus, longer when counting the infrequent stimulus, longer still under a passive condition, and longest in a non-P300 condition. P300 amplitudes identifiable in the passive attentional state were enhanced when stimuli were from two, rather than from one, sensory modality. Implications for understanding the mechanism of attention are discussed. Preliminary findings in traumatic brain injury patients suggest that passive P300 responses may be useful in assessing the extent and severity of brain dysfunction.

Adolescent↗
PubMed1990

Effects of stimulus intensity on direct recordings of eighth nerve auditory evoked responses.

Effects of auditory stimulus intensity on auditory nerve and brainstem evoked potential patterns recorded simultaneously from the scalp and directly from the eighth nerve were compared for an anesthetized patient undergoing surgery for macrovascular decompression. Replicable robust potentials were readily obtained from a recording electrode on the eighth nerve less than half a second after as few as 15 stimulations. Less robust and less readable evoked potential patterns were obtained from scalp recordings after 30 seconds and about 900 stimulations. It was observed in the direct auditory evoked response (DAER) that there is a systematic decrease in peak latencies with each 10 dB increase in stimulus intensity between 60 and 90 dB nHL. Also, with each 10 dB increase in stimulus intensity there is an increase in amplitude of the DAER action potential between 70 and 90 dB nHL but not between 60 and 70 dB.

Acoustic Stimulation↗
PubMed1990

Intermediate and long latency SEPs in relation to clinical disability in traumatic brain injury patients.

Intermediate (0-60 ms) and long latency (0-500 ms) somatosensory evoked potential (SEP) patterns were compared in terms of their relationship to degree of clinical disability in severe traumatic brain injury patients. Long latency (LL) SEP patterns correlated significantly with clinical disability as measured by the Disability Rating scale while intermediate latency (IL) SEP patterns did not. Evoked potential abnormality (EPA) scores based upon LL SEP patterns appear better able to reflect extent and severity of brain dysfunction and overall clinical condition than do IL SEP patterns for severe traumatic brain injury patients.

Adolescent↗
PubMed1989

Head injury outcome up to ten years later.

Head injury outcome was studied in 63 severe traumatic brain-injured (TBI) victims up to ten years after injury. Extent of improvement and residual deficits in physical and mental impairment and mood and frustration tolerance changes are reported. The impact of these changes upon ability to work and to establish living situations is presented. It was found that long-term outcome is related significantly both to elapsed time between injury and admission to an intensive rehabilitation hospital program and to level of disability at admission. Major problems and needs at follow-up are reported. Thirteen demographic and clinical profile parameters are suggested to permit meaningful comparisons of long-term outcome among different groups of TBI victims.

Adult↗
PubMed1988

Somatosensory evoked responses to dermatomal stimulation in cervical spinal cord injured and normal subjects.

This exploratory study investigates dermatomal evoked potential patterns in the upper extremities of normal and spinal cord injured subjects. Fifteen normal subjects without neurologic deficits and twelve patients with partial or complete spinal cord injuries were tested at dermatomal levels C5, C6, C7, C8, and T1, and also at median and ulnar nerve sites. Responses were recorded at the scalp. Analyses of evoked response patterns included measurement and comparison of peak and interpeak latencies and amplitudes as well as blind ratings of the degree of abnormality of evoked potential waveforms. Analyses were also made of relationships between evoked potential data and neurological findings on clinical examination. There appeared to be a fairly consistent SEP response among normals when dermatomes C6 through C8 are stimulated. Less consistent responses are observed when C5 and T1 are stimulated. In general, spinal cord injured subjects as compared to normal subjects had evoked responses with less consistent peaks, more amplitude diminution, and greater diffuseness and overall pattern abnormality even at dermatomal levels that were intact on clinical neurologic examination. There was also a distinct progression of overall SEP abnormality in dermatomes with impaired vibration, light touch, and position sense. There were no consistent differences in interpeak latencies between SEPs of normal and spinal cord injured subjects at intact dermatomes, but there were significant differences in EP abnormalities (EPA scores). Possible reasons for the differences in the SEP responses between normals and spinal cord injured subjects include spinal cord injury not detectable by clinical exam. Difficulty in obtaining objective and accurate sensory reports also contributes to data unreliability. In conclusion, we believe that stimulation of specific sensory dermatomes merits further study, as it has a number of possible clinical uses. These include: (1) surgical monitoring at more specific levels than monitoring with mixed nerve root stimulation, (2) for study of specific nerve root injury, and (3) as an aid in examining the neurological status in acutely injured spinal cord patients who are unable to cooperate adequately during examination, such as the very young or those with lowered levels of awareness associated with head injury. Additional information which could be useful to obtain is cervical dermatomal stimulation with spinal recording sites.

Adolescent↗
PubMed1988

Neuropsychiatric assessment of a spinal cord injury patient with sudden recovery.

Reported here is the case of a 23-year-old man who, presenting as a spinal cord injury patient with paraplegic and bilateral sensory impairments in the legs, made a rather dramatic recovery after receiving a trivial jolt while moving about in his wheelchair. In addition to clinical findings, both hypnotic and somatosensory evoked potential test results were used to help determine whether there was or was not actual spinal cord injury and whether there was or was not a psychologic overlay involving either malingering or a conversion disorder. In this case, evidence pointed to malingering in the presence of a minor spinal cord injury documented by somatosensory evoked potential patterns.

Adult↗
PubMed1987

The novel anticonvulsant MK-801: a potent and specific ligand of the brain phencyclidine/sigma-receptor.

MK-801 (5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine maleate) is a novel anticonvulsant agent reported to antagonize certain N-methyl-D-aspartate (NMDA)-mediated effects non-competitively. The question arises of the mechanism underlying the anti-NMDA and anticonvulsant effects of MK-801. In the present study MK-801 is shown to be an extremely potent inhibitor of the binding of N-[3H] (1-[2-thienyl]cyclohexyl)piperidine ([3H]TCP) to brain phencyclidine (PCP)/sigma-receptors. Its IC50 value of 3.8 +/- 0.8 nM in this assay ranks it as the most potent known ligand of brain PCP/sigma-receptors. Addition of MK-801 altered the apparent Kd but not the apparent Bmax values for [3H]TCP binding, indicating a competitive interaction. The specificity of action of MK-801 is supported by the finding that MK-801 strongly inhibited the binding of (+)-N-[3H]allylnormetazocine ((+)-[3H]SKF 10,047) to the PCP/sigma-receptor but its effect on (+)-[3H]SKF 10,047 binding to the non-PCP, haloperidol-sensitive sigma-binding site was weaker by several orders of magnitude. Furthermore, MK-801 exerts PCP-like antagonistic effects upon NMDA-induced [3H]norepinephrine release. These findings support the concept that the anticonvulsant and anti-NMDA effects of MK-801 result from its being the most potent known ligand of PCP/sigma-receptors.

Animals↗
PubMed1987

A method for comparing two systems of acute 24-hour psychiatric care.

A quasi-experimental method was developed to evaluate the cost-effectiveness of a public system of 24-hour acute psychiatric care in Santa Clara County, California, before and after a new treatment setting was introduced. The original system relied on a 54-bed psychiatric unit in a county general hospital; the new system consisted of a 20-bed unit in the general hospital plus a 45-bed nonhospital psychiatric health facility. The study demonstrated that the per diem cost of the psychiatric health facility was approximately 60 percent that of the original general hospital unit, but the average difference in cost per episode between the two systems was only about +25, primarily due to longer lengths of stay in the new system. In addition, patients treated in the new, combined system appeared sicker at discharge than those treated in the old system. The findings suggest the importance of simultaneously evaluating both cost and treatment effectiveness to make sure that one element does not dominate program direction at the expense of the other.

Acute Disease↗
PubMed1986

The acute effect of sublingual nifedipine and isosorbide dinitrate on plasma viscosity in patients with acute myocardial infarction.

The effect of sublingual nifedipine 10 mg (pierced capsule) and isosorbide dinitrate (ISDN) 5 mg on plasma viscosity (Pl.V) was investigated in 60 consecutive patients 7-10 days after hospitalization for acute myocardial infarction (AMI), who were randomized for either nifedipine (30 patients) or ISDN (30 patients). Pl.V, hematocrit (Htc), and erythrocyte sedimentation rate (ESR) were measured 20 minutes before and thereafter at 5, 10, and 30 min after drug administration while in the recumbent position. Blood pressure (BP) and heart rate (HR) were determined before each blood sample. In 18 patients (60%) Pl.V decreased by greater than 0.05 centipoise (Cp) after nifedipine (0.0953 +/- 0.033 Cp p less than 0.001 vs. initial values). After ISDN, Pl.V decreased by greater than 0.05 Cp (0.0933 +/- 0.036 Cp) in only 7 patients (23%). Systolic blood pressure (SBP) fell by 11.7 +/- 14.6 mmHg after nifedipine and by 16 +/- 14 mmHg after ISDN (nifedipine vs. ISDN = NS). Diastolic blood pressure (DBP) fell by 8 +/- 9.6 mmHg after ISDN and by 6.6 +/- 19.3 mmHg after nifedipine (nifedipine vs ISDN = NS). HR, ESR, and Htc did not change after drug administration. It is thus concluded from our study that nifedipine 10 mg sublingual has a significant Pl.V-lowering activity compared to sublingual ISDN 5 mg in patients with AMI.

Adult↗