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Biomedical subjects

R R Goodman

Publications and source records attributed to R R Goodman.

At least 37 records · Page 2Linked to original sources

Third ventriculostomy: post-operative ventricular size and outcome.

Reduction in ventricular size after third ventriculostomy often appears minimal. In order to determine if changes in ventricular size are a reliable measure of a functioning ventriculostomy, and which ventricle is more sensitive to this change, we compared pre-operative lateral and third ventricular diameter with serial post-operative axial CT and/or MRI scans in a series of 27 consecutive third ventriculostomies. Of eleven patients with aqueductal stenosis, fifteen with mass lesions and one with a Chiari I, six patients were shunted before 1 month and two refused radiographic follow-up. In the remaining nineteen patients, with an average follow-up of 20 months, the average (s.d.) third ventricular change was -30 (11)% for twelve improved patients, and +13 (18)% for the seven patients without improvement (p < 0.00001). The average (s.d.) lateral ventricular change was -23 (15)% for improved patients, and +5 (21)% for those without improvement (p < 0.005). A decrease in third ventricular size by a least 15% was seen in all significantly improved patients. Similar results were found in 9 patients with scans performed exactly one month post-operatively. Among the aqueductal stenosis patients, factors associated with failure were age > 70 years associated with symptoms of NPH, symptomatic, shunted hydrocephalus since before age 1 year and a history of meningitis. In the remaining patients, failures occurred with a history of meningitis, subdural hematoma, Chiari I malformation or following open tumor surgery or intraventricular AVM rupture. Although both the lateral and third ventricles change in diameter after third ventriculostomy, the third ventricular diameter is more reliable. As early as one month post-operatively, ventricular diameter reflects the clinical outcome of the operation. A decrease in third ventricular diameter by at least 15% was seen in all successful cases and in none of the failures.

Adolescent↗

Intracartotid amobarbital procedure memory performance and age at first risk for seizures distinguish between lateral neocortical and mesial temporal lobe epilepsy.

PURPOSE: To determine whether intracarotid amobarbital procedure (IAP) memory-performance asymmetries and early risk factors for epilepsy distinguish between lateral neocortical temporal lobe epilepsy (LNTLE) and mesiobasal temporal lobe epilepsy (MBTLE). METHODS: We studied 10 patients with LNTLE and 22 with MBTLE. All LNTLE patients showed (a) presence of temporal neocortical lesion or lateral seizure onset by intracranial recording, and (b) absence of mesial temporal sclerosis (MTS) by histopathologic analysis. All patients with MBTLE showed (a) video-scalp EEG seizures consistent with mesial TLE, and (b) presence of unilateral MTS by histopathologic analysis. All patients had good surgical outcomes (Engel I or II). Unilateral IAP memory performance was defined as percentage of memory items presented during hemispheric anesthesia that was recognized after recovery. IAP asymmetry scores were the differences in memory performance after right and left injections. RESULTS: Mean memory-asymmetry scores were significantly lower in the LNTLE than in the MBTLE group. An IAP memory asymmetry of < 25% correctly classified seven of 10 patients with LNTLE, and an asymmetry of > or = 25% correctly classified 18 of 22 patients with MBTLE. Age at first risk for epilepsy was significantly younger in those with MBTLE than in those with nonlesional LNTLE. Results suggest that both IAP memory performance and age at first risk can help distinguish between MBTLE and LNTLE.

Adult↗

Reversible signal abnormalities in the hippocampus and neocortex after prolonged seizures.

PURPOSE: To investigate the phenomenon of reversible increased signal intensity of medial temporal lobe structures and cerebral neocortex seen on MR images of six patients with recent prolonged seizure activity. METHODS: After excluding patients with known causes of reversible signal abnormalities (such as hypertensive encephalopathy), we retrospectively reviewed the clinical findings and MR studies of six patients whose MR studies showed reversible signal abnormalities. MR pulse sequences included T2-weighted spin-echo coronal views or conventional short-tau inversion-recovery coronal images of the temporal lobes. RESULTS: All six MR studies showed increased signal intensity within the medial temporal lobe, including the hippocampus in five studies. All follow-up MR examinations showed partial or complete resolution of the hyperintensity within the medial temporal lobe and the neocortex. In one patient, results of a brain biopsy revealed severe cerebral cortical gliosis. Temporal lobectomy performed 4 years later showed moderate cortical gliosis and nonspecific hippocampal cell loss and gliosis. CONCLUSION: Significant hyperintensity within the temporal lobe is demonstrable on MR images after prolonged seizure activity, suggestive of seizure-induced edema or gliosis. Damage to medial temporal lobe structures by prolonged seizure activity indicates a possible mechanism of epileptogenic disorders.

Adolescent↗

Effects of coregistration of MR to CT images on MR stereotactic accuracy.

Coregistration of different modality imaging serves to increase the ease and accuracy of stereotactic procedures. In many cases, magnetic resonance (MR) stereotaxis is supplanting computerized tomography (CT). The advantages of increased anatomical detail and multiplanar imaging afforded by MR, however, are offset by its potential inaccuracy as well as the more cumbersome and less available nature of its hardware. A system has been developed by one of the authors by which MR imaging can be performed separately without a stereotactic fiducial headring. Then, immediately prior to surgery, a stereotactic CT scan is obtained and software is used to coregister CT and MR images anatomically by matching cranial landmarks in the two scans. The authors examined this system in six patients as well as with the use of a lucite phantom. After initially coregistering CT and MR images, six separate anatomical (for the patients) and eight artificial (for the phantom) targets were compared. With coregistration, in comparison to CT fiducial scans, errors in each axis are less than or equal to 1 mm using the Cosman-Roberts-Wells system. In fact, the coregistered images are more accurate than MR fiducial images, in the anteroposterior (p = 0.001), lateral (p < 0.05), and vertical (p < 0.03) planes. Three-dimensional error was significantly less in the coregistered scans than the MR fiducial images (p < 0.005). The coregistration procedure therefore not only increases the case of MR stereotaxis but also increases its accuracy.

Brain↗

Seizure outcome after lesionectomy for cavernous malformations.

Cavernous malformations that are associated with seizures are often treated by surgical resection consisting of lesion removal, "lesionectomy," alone. Through retrospective analysis the authors have examined some factors that may predict failure to eradicate seizures by such a procedure. A group of 51 patients were examined who had been treated for supratentorial cavernous malformations with preoperative seizures and received postoperative follow up lasting at least 1 year. There was one mortality in the group. Of the remaining 50 patients, 15 (30%) had continued postoperative seizures despite therapeutic levels of antiepileptic medications. Variables that were significantly associated with continued seizures postoperatively included increasing duration of preoperative seizure history (p = 0.03), increasing number of preoperative seizures (p < 0.003), and female sex (p < 0.04). One hundred percent of patients with only one preoperative seizure or a seizure history lasting less than 2 months were seizure free following lesionectomy: approximately 75% to 80% of all patients with two to five seizures, or a seizure history lasting 2 to 12 months, were seizure free; and only 50% to 55% of those with more than five seizures or with preoperative seizure histories lasting more than 1 year were seizure free postoperatively. This investigation indicates that patients with shorter seizure histories and fewer preoperative seizures can be effectively treated by lesionectomy alone, whereas those with longer histories and more seizures are not effectively treated by this procedure and may require more extensive resections.

Adolescent↗

Magnetic resonance imaging-directed stereotactic endoscopic third ventriculostomy.

Third Ventriculostomy has been proposed as the procedure of choice for many patients with acquired obstructive hydrocephalus. Various techniques have been used to perform this procedure. This report describes the use of magnetic resonance images to guide the performance of a stereotactic third ventriculostomy with a rigid endoscope, allowing continuous direct visualization. This procedure has been performed on three patients, yielding clinical improvement without the need for extracranial shunting. Magnetic resonance imaging allows accurate identification of the important anatomical landmarks (i.e., foramen of Monro and interpeduncular cistern), with axial, coronal, and sagittal images, and is readily used in conjunction with the Cosman-Roberts-Wells stereotactic apparatus.

Adult↗

Stereotaxic implantation of autologous adrenal medulla into caudate nucleus in four patients with parkinsonism. One-year follow-up.

Four patients with levodopa-responsive parkinsonism (aged 26, 35, 45, and 49 years) received autologous adrenal medullary implants into or near the left caudate nucleus by stereotaxic implantation after flank adrenalectomy. All patients had an immediate response to implantation lasting several days, during which parkinsonian signs and symptoms decreased. This period was followed by a gradual reappearance of symptoms in all but one patient. This patient had had a dramatic increase in "on" time without dyskinesias and a decrease in the severity and duration of "off" time. He died of multifocal glioblastoma 1 year after transplantation. Autopsy revealed no surviving adrenal cells. In one case, the stereotaxic implantation missed the basal ganglia, resulting in the placement of the adrenal medullary tissue into the medial thalamus and near the third ventricle; the patient did not improve. In the other two cases, a modest but definite increase in "on" time without dyskinesia and a reduction in the severity and duration of "off" time has been observed. The role of autologous adrenal medullary transplantation in patients with parkinsonism remains to be determined. Patients with a family history of cerebral malignancy may be at increased risk for the development of transplant-induced malignancy.

Adrenal Medulla↗

Acoustic schwannoma and epidermoid cyst occurring as a single cerebellopontine angle mass.

The case of a 66-year-old man with a 3-year progressive hearing loss and a homogeneous left cerebellopontine angle mass on magnetic resonance imaging scan is described. At surgery, the major portion of the mass was a typical encapsulated, solid, acoustic schwannoma, but the most rostral portion was a distinct, flaky, cystic mass without a well-defined capsule, typical of an epidermoid cyst. The radiographic and operative findings of this unique coexistence of two different benign cerebellopontine angle masses are presented.

Aged↗

Surgical management of pain.

This article presents an overview of the neuroanatomical, neurochemical, and neurophysiological substrates of nociception relevant to the neurosurgical treatment of chronic pain. Consideration is given to the various procedures currently employed in the treatment of patients suffering from medically intractable chronic pain of both benign and malignant diseases, including their indications, techniques, and results. Particular attention is given to the modern neuroaugmentative methods, such as electrical stimulation and CNS drug infusion, that are progressively overshadowing the previously developed ablative procedures.

Chronic Disease↗

Quantitative autoradiographic distribution of meptazinol-sensitive binding sites in rat brain.

1. Meptazinol is an interesting opioid-producing naloxone-reversible analgesia with few cardiovascular and respiratory effects. Recent studies indicate that mu 1 opioid receptors mediate meptazinol analgesia. Using a computerized autoradiographic subtraction technique, we have examined the regional distribution of meptazinol-sensitive [3H][D-Ala2,MePhe4,Gly(ol)5]enkephalin (DAGO) binding and compared this with the distribution of mu 1 binding determined by competition with low [D-Ala2,D-Leu5]enkephalin (DADL) concentrations. 2. Meptazinol and DADL lowered [3H]DAGO to similar extents in most brain regions studied. The greatest levels of inhibition were observed in the periaqueductal gray, interpeduncular nucleus, thalamus, hypothalamus, and hippocampus. Low levels of inhibition were found in the temporal and frontal cortex. The correlation between the inhibition of [3H]DAGO binding by meptazinol and that by DADL was high (r = 0.83), consistent with the binding of meptazinol to mu 1 sites.

Analgesics↗

Treatment of amyotrophic lateral sclerosis with the TRH analog DN-1417.

Thyrotropin-releasing hormone has been reported to increase strength in patients with amyotrophic lateral sclerosis (ALS). DN-1417 is an analog of thyrotropin-releasing hormone, which has less endocrinologic activity, but more anterior horn cell stimulating effect (with no "autorefractory state"). However, 2 mg DN-1417, IM twice a day for 1 month in an open-label trial, produced no objective improvement of strength in nine patients with ALS. No patient entered the double-blind, placebo-controlled phase of the trial.

Adult↗

Autoradiographic analysis of mu1, mu2, and delta opioid binding in the central nervous system of C57BL/6BY and CXBK (opioid receptor-deficient) mice.

The recent development of in vitro autoradiography techniques has enabled investigators to determine the distribution and relative levels of multiple ligand binding sites in discrete anatomical areas. In this study we used semi-quantitative in vitro autoradiography to compare the levels of binding to central mu1, mu2, and delta opioid sites in two strains of mice, C57BL/6BY and CXBK. The CXBK strain is known to be deficient in whole brain opioid binding sites and to be less sensitive than the C57 strain to the analgesic and locomotor stimulatory effects of opiates and opioids. Delta sites were visualized using [3H](D-Ala2-D-Leu5]-enkephalin (DADL) plus a low concentration of morphine, total mu sites (mu1 and mu2) were visualized using [3H] dihydromorphine (DHM), and mu2 sites were visualized using [3H]DHM plus a low concentration of DADL. Binding to mu1 sites was determined by subtracting mu2 binding from total mu binding. We found that the two strains did not consistently differ in the levels of delta site; in some areas the CXBKs had lower levels but in many areas they had levels equal to or greater than those for the C57s. The CXBK strain, however, either had less or the same amount of mu binding as the C57 strain in all areas studied. The CXBK strain was especially deficient in mu1 binding, particularly in areas involved in pain processing.

Animals↗

Autoradiographic distribution of mu1 and mu2 opioid binding in the mouse central nervous system.

Several types of opioid binding sites have been differentiated using biochemical and pharmacological criteria. We have used quantitative in vitro autoradiography to compare the levels of mu1 and mu2 opioid binding in the mouse central nervous system. Mu1 sites have a high affinity for all labeled opioids studied to date and have been associated with their analgesic effects, whereas mu2 sites have a high affinity only for opiate alkaloids and have been associated with their respiratory depressant effects. We used [3H]dihydromorphine (DHM) to visualize total mu sites (mu1 and mu2) and [3H]DHM plus a low concentration of [D-Ala2-D-Leu5]enkephalin (DADL) to visualize mu2 sites. Levels of mu1 binding were determined by subtracting mu2 binding from total mu binding. This mu1 distribution was confirmed in selected regions by an alternate method using [3H]DADL. High ratios of mu1 to mu2 binding were noted in frontal cortex, nucleus accumbens, rostral striatum, ventral pallidum, ventral periaqueductal gray matter, and laminae I and II of the spinal cord. The observation of high densities of mu1 binding in certain pain processing areas correlates with behavioral and pharmacological studies suggesting that analgesia from opiates and opioids is mediated primarily by mu1 sites. In other areas, such as the limbic system, dorsal nucleus of the vagus nerve, and nucleus of the solitary tract, either a low ratio of mu1 to mu2 binding or no mu1 binding was observed. This differential regional localization of mu1 and mu2 binding provides further evidence for the distinctness of these sites.

Animals↗

Regional differences in mu 1-binding of [3H][D-Ala2,D-Leu5]-enkephalin: comparisons of thalamus and cortex in the rat.

Typically, mu 1-sites represent approximately 25-35% of binding in rat brain homogenates. Competition studies indicated that approximately 60% of [3H][D-Ala2,D-Leu5]-enkephalin ([3H]DADLE) binding in the thalamus was inhibited by low concentrations of morphine (2-5 nM). This high proportion of mu 1-binding was anticipated based upon the low levels of delta-sites and the high levels of mu 1-sites in this region observed in autoradiography studies. In contrast, morphine lowered [3H]DADLE binding by only approximately 5-15% in the cortex, a region known to possess large amounts of delta- and few mu 1-receptors. These results support previous autoradiography studies and illustrate the advantages of using tissue regions in the characterization of opiate receptor subtypes.

Animals↗

Increased analgesic potency of morphine and increased brain opioid binding sites in the rat following chronic naltrexone treatment.

Implantation of rats with prolonged-release naltrexone pellets increased both morphine's analgesic potency in the tailflick assay and radiolabeled opioid binding in the brain. The increases in both radiolabeled opioid binding and morphine potency were time-dependent. Implantation for 24 hours did not increase binding, whereas increases of approximately 45% were seen following 8 days of implantation. Similarly, morphine's analgesic potency, measured as ED50 values, was increased by 50% following 8 days of exposure to naltrexone while a 24 hour exposure had no significant effect.

Animals↗

Visualization of mu1 opiate receptors in rat brain by using a computerized autoradiographic subtraction technique.

We have developed a quantitative computerized subtraction technique to demonstrate in rat brain the regional distribution of mu1 sites, a common very-high-affinity binding site for both morphine and the enkephalins. Low concentrations of [D-Ala2, D-Leu5]enkephalin selectively inhibit the mu1 binding of [3H]dihydromorphine, leaving mu2 sites, while low morphine concentrations eliminate the mu1 binding of [3H][D-Ala2, D-Leu5]enkephalin, leaving delta sites. Thus, quantitative differences between images of sections incubated in the presence and absence of these low concentrations of unlabeled opioid represent mu1 binding sites. The regional distributions of mu1 sites labeled with [3H]dihydromorphine were quite similar to those determined by using [3H][D-Ala2, D-Leu5]enkephalin. High levels of mu1 binding were observed in the periaqueductal gray, medial thalamus, and median raphe, consistent with the previously described role of mu1 sites in analgesia. Other regions with high levels of mu1 binding include the nucleus accumbens, the clusters and subcallosal streak of the striatum, hypothalamus, medial habenula, and the medial septum/diagonal band region. The proportion of total specific binding corresponding to mu1 sites varied among the regions, ranging from 14% to 75% for [3H][D-Ala2, D-Leu5]enkephalin and 20% to 52% for [3H]dihydromorphine.

Animals↗