PubMed Health⌕ Search

Biomedical subjects

R D Rose

Publications and source records attributed to R D Rose.

At least 19 recordsLinked to original sources
PubMed1998

Correlation of late intraforaminal screw removal with somatosensory evoked potentials and neurologic improvement.

This case report describes the intraoperative improvement of somatosensory evoked potentials (SEPs) during the removal of a broached pedicle screw that had been placed in an unmonitored procedure 1 month earlier. Postoperatively, there was improved neurologic function and reversal of the neurologic deficit that had been caused by the first procedure. To our knowledge, this is the first report of a correlation of intraoperative SEP improvement with improved postoperative neurologic function after neurologic deficit because of nerve irritation or compression from a pedicle screw. Nerve damage occurs in about 15% of patients who undergo instrumentation after lumbar fusion. The potential utility of neurophysiologic methods during initial screw placement is suggested and supported, as proper use of such intraoperative tools may have prevented the need for the second procedure.

Adult↗
PubMed1998

Removing the antidromically driven sensory component from cervically evoked motor potentials.

The purpose of this paper is to present a model for removing antidromically activated afferent input from cervically elicited neurogenic motor evoked potentials (nMEPs). nMEPs have recently been used clinically, purportedly for monitoring spinal cord motor function, during spine surgery. However, the nMEP response may be due, in part or in whole, to neural signals travelling through sensory rather than motor pathways. This complicates nMEP interpretation and may lead to false conclusions about the status of motor tracts and postoperative motor function. Moreover, transcranial stimulation techniques may also contain similar afferent contamination. Here I suggest a protocol for intraoperative use that should effectively remove such afferent contamination via an afferent action potential collision technique.

Afferent Pathways↗
PubMed1998

Simultaneous somatosensory evoked potential and electromyographic recordings during lumbosacral decompression and instrumentation.

OBJECTIVE: Both motor and sensory neurological deficits have been reported after decompression and instrumentation of the lumbosacral spine. In this report, we describe a simple and effective method by which sensory and motor functions can be monitored simultaneously, using somatosensory evoked potentials (SSEP), spontaneous electromyographic (EMG) activity, and compound muscle action potential monitoring. The concomitant use of these monitoring techniques allows ongoing functional evaluation of the cauda equina and spinal cord during patient positioning, surgery, wound closure, and anesthetic emergence. METHODS: SSEPs were recorded continuously in response to peroneal or tibial nerve stimulation. EMG activity (both spontaneous and evoked) was recorded bilaterally from appropriate lower extremity muscle groups. All recordings (SSEP and EMG activity recordings) were obtained, stored, and reviewed simultaneously. RESULTS: SSEPs and EMG activity were simultaneously recorded for 44 patients. All patients in the study underwent surgical procedures to decompress and stabilize the lumbosacral spine, using pedicle screw instrumentation. In two cases, changes in SSEPs and spontaneous EMG activity were noted and were correlated with postoperative patient complaints. CONCLUSION: This report describes the concomitant use of powerful and simple tools that provide immediate, "early-warning" feedback to the surgical team concerning the sensory and motor functioning of the spinal cord and cauda equina. In addition, compound muscle action potential recording provides a tool for the identification of both levels and structures in the lumbosacral spine.

Action Potentials↗
PubMed1997

Flash visual evoked potential monitoring of optic tract function during macroelectrode-based pallidotomy.

Posteroventral pallidotomy (PVP) has received renewed interest as an ablative procedure for the symptomatic treatment of Parkinson's disease. In previous reports, the proximity of the optic tract to the lesion target in the globus pallidus internus has resulted in the occurrence of visual field deficits in as much as 14% of patients. The authors have used intraoperative visual evoked potentials (VEPs) during PVP to reduce this risk. All procedures were performed in awake patients. Flash stimuli were delivered to each eye via fiberoptic sources. Baseline flash VEPs were recorded at O1/Cz (left visual cortex to vertex), Oz/Cz (midline visual cortex to vertex), and O2/Cz (right visual cortex to vertex) for OS, OU, and OD stimulation. Epochs were acquired before and after localization, after macroelectrode stimulation, after temporary thermal lesioning, and after permanent thermal lesioning. Forty-seven patients underwent a total of 59 procedures. Visual evoked potentials were recorded reproducibly in all patients. In 11 procedures, VEP changes were reported, including six amplitude changes (10-80%), six latency shifts (3-10 msec), and one report of "variability." In four procedures, VEP changes prompted a change in target coordinates. One false-positive and one false-negative VEP change were encountered. The only confirmed visual deficit was a superior quadrantanopsia, present on formal fields, but clinically asymptomatic. The authors conclude that VEPs may be useful for procedures performed in the awake patient because of the lack of anesthetic-induced variability. The 1.7% visual morbidity reported here (one in 59 patients) compares favorably with other series using microelectrodes. Visual evoked potentials may be a useful monitoring technique to reduce the incidence of clinically significant visual morbidity during pallidotomy, especially during formal lesioning of the ventral pallidum adjacent to the optic tract.

Journal Article↗
PubMed1997

Persistently electrified pedicle stimulation instruments in spinal instrumentation. Technique and protocol development.

STUDY DESIGN: A prospective review was done of a new intraoperative technique developed to detect and prevent neurologic compromise during pedicle screw insertion. OBJECTIVES: To describe in sufficient detail the technique of persistently electrified pedicle stimulation instruments, so that this technique will be available generally to all clinical neurophysiologists and spine surgeons; and to demonstrate the use, typical results, interpretation, and protocol of the technique. SUMMARY AND BACKGROUND DATA: Fusion techniques that use pedicle instrumentation have the potential to cause nerve root injury. Several authors have proposed imaging and neurophysiologic methods to improve outcome. The present method represents a significant theoretical departure and advance from previously reported methods. METHODS: All relevant instruments used during pedicle instrumentation were converted easily, inexpensively, and quickly into monopolar stimulators with appropriate stimulus voltages to identify broaches of pedicle bone via evoked-electromyograms from relevant muscle groups. RESULTS: The persistently electrified pedicle stimulation instrument technique provided accurate intraoperative neurophysiologic information concerning pedicle, integrity in the patients studied. The protocol is standardized and adaptable easily, inexpensively, and quickly to most clinical applications. CONCLUSIONS: The persistently electrified pedicle stimulation instrument technique described here is useful for monitoring instrumented lumbar fusion procedures. The use of this protocol may help confirm intraosseous placement of pedicle screws and prevent neurologic injury.

Bone Screws↗
PubMed1997

Secondary trauma: assessing inter-generational transmission of war experiences with a modified Stroop procedure.

Intergenerational transmission of war experiences was assessed using a modified Stroop task. Adult children of war veterans and those of nonveterans named the colors in which war related words were printed. They also named the colors of neutral, positive, and OCD related words in addition to color naming a series of zeros contained on a control card. All participants completed the MMPI-II PTSD Scale, the Impact of Event Scale, and a demographic questionnaire. A statistically significant difference between the children of veterans and nonveterans was found only on the Stroop card containing war related words. Results suggest that the modified Stroop task is a sensitive measure that may have value in assessing transmission of war experiences from parents to children.

Adolescent↗
PubMed1997

Evaluation with evoked and spontaneous electromyography during lumbar instrumentation: a prospective study.

The neuroanatomical structures that approximate the bony pedicles of the lumbar spine allow little room for technical error or compromise of the bone during pedicle screw insertion. Currently available neurophysiological monitoring techniques detect compromised bone and nerve root injury after it occurs. The purpose of this prospective study is to evaluate the reliability and efficacy of a unique neurophysiological monitoring technique. This technique provides immediate evaluation of pedicle cortical bone integrity in patients undergoing lumbar fusion with instrumentation by using electrified surgical instruments throughout the pedicle screw fusion procedure. Spontaneous electromyographic (EMG) activity was also monitored. Intraoperative evoked EMG stimulation was performed using a pedicle probe and feeler as monopolar stimulators during the insertion of 164 pedicle bone screws in 32 patients. The EMG response to subthreshold stimulation intensities indicated cortical bone compromise. Immediate and conclusive feedback via evoked EMG activity using stimulating pedicle probes in appropriate muscle groups was successful in identifying pedicle cortical bone compromise in four patients. One false-negative evoked EMG study was noted but was identified via spontaneous EMG activity. Intraoperative EMG monitoring alerted the surgeon that redirection of the pedicle probe or screw was necessary to avoid nerve root irritation or injury and served as an early warning system. Evoked EMG stimulation proved to be reliable and efficacious, especially when used in combination with spontaneous EMG. This technique may provide an added safeguard during implant placement procedures at centers where intraoperative neurophysiological monitoring is routinely performed.

Adult↗
PubMed1996

Sensory component of cervically evoked motor potentials.

The purpose of this paper is to present the hypothesis that cervically elicited motor evoked potentials which have recently gained clinical acceptance for monitoring spinal cord motor function during spine surgery, may be due, in part or in whole, to neural signals travelling through sensory rather than motor tracts. If true, then the interpretation of cervically elicited motor evoked potentials may lead to false conclusions about the status of motor tracts and postoperative motor function.

Electroencephalography↗
PubMed1993

Neural nets identify sensory receptors from somal spikes.

Retrospective analysis of somal electrophysiology from intracellularly recorded, physiologically identified afferents demonstrates that neural nets can be readily trained to identify the type of peripheral receptor supplied. Specifically, cat spinal ganglion somata could be identified as innervating muscle spindles, hairs or high-threshold mechanoreceptors. Further, both hair afferents and high-threshold mechanoreceptors could be separated into three distinct subclasses. The neural net sorting reported here utilizes only the electrophysiological properties of the somata plus conduction velocity and can with this information alone predict the functional properties of the sensory endings. Interestingly, neural net sorting could also distinguish between different types of hair afferents (or nociceptors), even when conduction velocity information was ignored. It is suggested that neural nets, in combination with computer-controlled data-acquisition systems, could greatly increase investigator efficiency and decrease the number of animals needed to demonstrate specific phenomena, such as drug effects on particular cell types. A double-edged sword of increased investigator efficiency and decreased animal usage may be of particular usefulness in the present socio-political research arena.

Action Potentials↗
PubMed1991

Pudendal motor and premotor neurons in the male rat: a WGA transneuronal study.

Anatomical studies using retrograde neuronal tracers were carried out to identify pudendal motoneurons and putative lumbosacral interneurons involved in the generation of penile reflexes in the adult male rat (Sprague-Dawley). In agreement with previous studies, injection of the direct neuronal tracers, horseradish peroxidase or fluoro-gold, into the left M. bulbospongiosus (dorsal division) resulted in direct retrograde labeling of motoneurons only in the ipsilateral dorsomedial (DM) nucleus. In contrast, similar injections of the transneuronal tracer, wheat germ agglutinin (WGA), resulted in direct retrograde labeling of ipsilateral DM motoneurons as well as transneuronal labeling of contralateral DM motoneurons and of bilaterally located putative spinal interneurons. The WGA-labeling was determined to be transneuronal by a series of nerve cut experiments. The direct retrograde WGA-labeling of ipsilateral DM motoneurons and the transneuronal WGA-labeling of contralateral DM motoneurons and bilateral putative spinal interneurons occurred with different time courses. Direct retrograde labeling of ipsilateral DM motoneurons was seen at 20 hours survival and persisted up to 7 days survival. The shortest survival period for detecting transneuronal labeling of contralateral DM motoneurons and putative interneurons was 2 days. Transneuronal WGA-labeling of contralateral DM motoneurons was transient in that the intensity of label increased from 2 to 3 days survival but was markedly reduced at 7 days survival. At the same time, the number of WGA-labeled putative interneurons increased with longer survival times up to 7 days. WGA-labeled putative interneurons were located primarily in regions receiving dendritic projections from WGA-labeled DM motoneurons and, in particular, 1) the ventral gray matter between the DM and dorsolateral nuclei and 2) near the central canal and extending dorsally to the dorsal gray commissure. The rapid and extensive transneuronal transport between DM nuclei suggests that direct synaptic coupling may mediate coordinated, bilateral activation of DM motoneurons.

Animals↗
PubMed1991

A versatile test for clustering and a proximity analysis of neurons.

A test for nonrandom patterns in populations of "cells" of binary attributes is formulated for applications in settings where it is impossible or impractical to completely specify the adjacency matrix, as in circumstances involving enormous numbers of cells and/or censored data. Applications are made to problems concerning spatial distributions of specially labeled cells in nervous system research.

Animals↗
PubMed1988

Counting sectioned cells via mathematical reconstruction.

A new method for determining the number of neurons in sectioned tissue is presented. The method does not involve identification of subcellular structures; rather, it uses estimates of the mean diameters of sections of the neuronal somata (with or without nuclei). All such sections are termed profiles. A mathematical model is developed to reconstruct the cell population from a size histogram of the profiles. Although the model is simple, the calculations are numerous and best done on a computer. A program that performs these calculations is provided. We discuss the idealizations on which the model is based and test the method in various ways: on hand- and computer-generated data in which imaginary spheres of known size were sectioned; on two small samples of real cells for which both cell and profile size histograms were available; and on a sample of potatoes, sliced by hand. In every case the estimate was within 10% of the actual number of cells (or potatoes). The method is robust in that it is relatively insensitive to section thickness, sample size, somal morphology, and observer error with respect to missing the small or thin profiles from any given cell. Results from the present model are compared to those obtained by using other cell count correction schemes that are currently employed. We call our method recursive translation.

Animals↗
PubMed1987

Counting sectioned cells via mathematical reconstruction.

A new method for determining the number of neurons in sectioned tissue is presented. The method does not involve identification of subcellular structures; rather, it uses estimates of the mean diameters of sections of the neuronal somata (with or without nuclei). All such sections are termed profiles. A mathematical model is developed to reconstruct the cell population from a size histogram of the profiles. Although the model is simple, the calculations are numerous and best done on a computer. A program that performs these calculations is provided. We discuss the idealizations on which the model is based and test the method in various ways: on hand- and computer-generated data in which imaginary spheres of known size were sectioned; on two small samples of real cells for which both cell and profile size histograms were available; and on a sample of potatoes, sliced by hand. In every case the estimate was within 10% of the actual number of cells (or potatoes). The method is robust in that it is relatively insensitive to section thickness, sample size, somal morphology, and observer error with respect to missing the small or thin profiles from any given cell. Results from the present model are compared to those obtained by using other cell count correction schemes that are currently employed. We call our method recursive translation.

Animals↗
PubMed1986

Somal action potential duration differs in identified primary afferents.

In the present study we examined action potentials recorded from somata in the cat L7 and S1 dorsal root ganglia. We found (i) that there is a characteristic spike duration for each receptor type (e.g. Golgi tendon organ, D-hair) and (ii) that, for a given peripheral fiber conduction velocity, somata whose axons supply low-threshold cutaneous receptors exhibit spikes with shorter durations than those innervating high-threshold cutaneous receptors. These results suggest that there may be significant differences in somal membrane composition which are specific to the physiological receptor types innervated.

Action Potentials↗
PubMed1985

Crossing dendrites may be a substrate for synchronized activation of penile motoneurons.

The morphology of perineal and extensor hindlimb motoneurons in adult male rats was examined using retrograde labelling with wheat germ agglutinin and horseradish peroxidase. Bulbocavernosus and levator ani motoneurons, located in the spinal nucleus of the bulbocavernosus, were organized as distinct clusters of motoneurons in the medial ventral area of the lumbar (L6-L5) spinal cord and possessed prominent contralaterally projecting dendritic arborizations. In similar experiments, laterally located soleus and extensor digitorum longus motoneurons did not exhibit a similar organization. These findings are discussed with respect to their possible role in the synchronized bilateral activation of penile muscles.

Animals↗