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Biomedical subjects

R G Grossman

Publications and source records attributed to R G Grossman.

At least 19 recordsLinked to original sources
PubMed2001

Ischemic injury and faulty gene transcripts in the brain.

The brain has the highest metabolic rate of all organs and depends predominantly on oxidative metabolism as a source of energy. Oxidative metabolism generates reactive oxygen species, which can damage all cellular components, including protein, lipids and nucleic acids. The processes of DNA repair normally remove spontaneous gene damage with few errors. However, cerebral ischemia followed by reperfusion leads to elevated oxidative stress and damage to genes in brain tissue despite a functional mechanism of DNA repair. These critical events occur at the same time as the expression of immediate early genes, the products of which trans-activate late effector genes that are important for sustaining neuronal viability. These findings open the possibility of applying genetic tools to identify molecular mechanisms of gene repair and to derive new therapies for stroke and brain injury.

Animals↗
PubMed2001

Comparison of thalamotomy and pallidotomy for the treatment of dystonia.

OBJECTIVE: Thalamotomy and, more recently, pallidotomy have been used to treat selected patients with intractable dystonia, although few studies have compared the effectiveness of these two surgical procedures. In this study, we compare our results using thalamotomy and pallidotomy to treat patients with different forms of dystonia, and we discuss our results in the context of other published series. METHODS: Thirty-two patients with intractable dystonia underwent thalamotomy (n = 18) or pallidotomy (n = 14). Dystonia was classified according to cause and distribution, and each patient was evaluated postoperatively at two or more time points, using a global outcome scale. RESULTS: Although comparisons are limited by differences between the two surgical groups, including longer follow-up periods for the thalamotomy group, differences in symptom distribution, and more bilateral procedures for the pallidotomy group, patients with primary dystonia who underwent pallidotomies demonstrated significantly better long-term outcomes than did patients who underwent thalamotomies (P = 0.0467). Patients with secondary dystonia experienced more modest improvements after either procedure, with little or no difference in outcomes between the two procedures. CONCLUSION: For patients with primary dystonia, pallidotomy seems to result in better outcomes than does thalamotomy.

Adolescent↗
PubMed2001

Aneurysms of the posterior cerebral artery: classification and endovascular treatment.

BACKGROUND AND PURPOSE: We present a retrospective review of our experience in the endovascular treatment of posterior cerebral artery (PCA) aneurysms. We detail the anatomic location of these aneurysms, the technique of endovascular treatment, morphologic results, and clinical outcome. We also discuss the segmental anatomy of the PCA as it relates to the various neurologic deficits that may result from occlusion of the parent artery. METHODS: From 1993 to 1998, 20 patients (12 female, eight male; mean age, 44 yrs) harboring a PCA aneurysm were treated via an endovascular approach. One patient had two aneurysms, comprising a total of 21 lesions. Fourteen (66%) of 21 aneurysms were saccular in nature, five (24%) were giant serpentine aneurysms, and two (10%) were posttraumatic. All aneurysms were treated using Guglielmi detachable coils (GDC) either by selective obliteration of the aneurysm sac or by parent artery occlusion. RESULTS: Fourteen (66%) of the 21 aneurysms were successfully treated with preservation of the parent artery. In the remaining seven (33%), the parent artery was permanently occluded. The overall complication rate in this series was 15%, with a permanent morbidity rate of 10% and a 0% mortality rate. CONCLUSION: Aneurysms of the PCA are rare compared with other locations in the intracranial circulation. Saccular PCA aneurysms can be treated effectively, by use of GDC, to obliterate the aneurysm yet preserve the parent artery. Fusiform and giant serpentine aneurysms of the PCA can effectively be treated by permanent occlusion of the parent artery; in these cases, thorough knowledge of the PCA segmental anatomy is crucial in order to select the site of occlusion and to avoid major neurologic deficits.

Adult↗
PubMed2000

Long-term efficacy of posteroventral pallidotomy in the treatment of Parkinson's disease.

The authors describe results of unilateral posteroventral pallidotomy (PVP) in 89 patients with PD. At 3 months after surgery, 81.9% of the patients reported marked or moderate improvement in their parkinsonian symptoms. Postoperative Unified PD Rating Scale "off" state mean total motor score improved by 35.5% and the mean activities of daily living score by 33.7% (p <0.001). Improvements in parkinsonian symptoms were maintained in both"off" and "on" states in 62 patients at 12 months after PVP and in 41 patients who were followed for 18 months or longer (mean 26.6 months).

Adult↗
PubMed2000

Phase I study of adenoviral delivery of the HSV-tk gene and ganciclovir administration in patients with current malignant brain tumors.

Between December 1996 and September 1998, 13 patients with advanced recurrent malignant brain tumors (9 with glioblastoma multiforme, 1 with gliosarcoma, and 3 with anaplastic astrocytoma) were treated with a single intratumoral injection of 2 x 10(9), 2 x 10(10), 2 x 10(11), or 2 x 10(12) vector particles (VP) of a replication-defective adenoviral vector bearing the herpes simplex virus thymidine kinase gene driven by the Rous sarcoma virus promoter (Adv.RSVtk), followed by ganciclovir (GCV) treatment. The VP to infectious unit ratio was 20:1. Our primary objective was to determine the safety of this treatment. Injection of Adv.RSVtk in doses <==2 x 10(11) VP, followed by GCV, was safely tolerated. Patients treated with the highest dose, 2 x 10(12) VP, exhibited central nervous system toxicity with confusion, hyponatremia, and seizures. One patient is living and stable 29.2 months after treatment. Two patients survived >25 months before succumbing to tumor progression. Ten patients died within 10 months of treatment, 9 from tumor progression and 1 with sepsis and endocarditis. Neuropathologic examination of postmortem tissue demonstrated cavitation at the injection site, intratumoral foci of coagulative necrosis, and variable infiltration of the residual tumor with macrophages and lymphocytes.

Adenoviridae↗
PubMed2000

Corpora amylacea and heat shock protein 27 in Ammon's horn sclerosis.

Increased numbers of corpora amylacea have been observed in the resected mesial temporal lobe of many patients with complex partial seizures (CPS) and Ammon's horn sclerosis (AHS). Several heat shock proteins (HSPs) are induced by seizures and have been suggested as an etiologic factor in the formation corpora amylacea. We quantified corpora amylacea and HSP27-immunoreactive astrocytes in temporal lobe specimens from patients with CPS (28 AHS; 10 non-AHS) and in 5 autopsy controls. Corpora amylacea were increased in each sector of Ammon's horn in the AHS group, significantly so in CA1 and CA3 (p < 0.0001 and p = 0.0097, respectively), compared with the non-AHS group, although there was considerable variability among the specimens. We found HSP27 to be significantly but nonspecifically increased in the resected temporal lobe specimens from all patients with CPS, regardless of the underlying pathology. HSP27 was not, however, expressed within the corpora amylacea, and did not correlate with the number of corpora amylacea in any of the 9 mesial and lateral temporal lobe areas examined.

Adult↗
PubMed2000

Neuropsychological outcome after unilateral pallidotomy for the treatment of Parkinson's disease.

OBJECTIVE: To assess the long term cognitive outcome of unilateral posteroventral pallidotomy (PVP) and the overall efficacy of the surgery. METHODS: Forty two (29 left and 13 right PVP) patients with Parkinson's disease underwent neurological and neuropsychological testing before PVP and at 3 and 12 months after PVP. The neuropsychological testing battery emphasised measures of verbal learning and memory, visuospatial abilities, speed of information processing, executive functioning, and affective functioning. RESULTS: All patients demonstrated motor improvements after surgery during their off state, and 86% of patients also showed improvements in motor functioning in their on state. Repeated measures ANOVA showed significant improvements in confrontational naming, visuospatial organisation, and affective functioning 3 months and 12 months after surgery, with inconsistent improvements in executive functioning 12 months post-PVP. Patients demonstrated a transient impairment in verbal memory, with verbal learning performance returning to baseline 12 months post-PVP after a significant decline 3 months after PVP. When three patients with lesions extending outside of the PVP were excluded from the analysis, a decline in verbal fluency performance after PVP was not found to be significant. Differences due to side of lesion placement were not found on any of the cognitive measures. CONCLUSIONS: In the largest long term follow up study reported to date, the cognitive changes found up to a year after PVP are minimal compared with the robust improvements in motor function. The findings highlight the need to investigate the relation between the specific fibre tracts affected by the lesions and cognitive outcome.

Activities of Daily Living↗
PubMed1999

Simultaneous measurement of cortical potassium, calcium, and magnesium levels measured in head injured patients using microdialysis with ion chromatography.

Potassium, calcium and magnesium were measured in 3717 microdialysate samples in 43 patients with head injury experiencing refractory increased ICP, episodes of jugular venous oxygen desaturation and brain death. Cation analysis was performed with 'ion chromatography'. Potassium levels remained stable until severe physiological deterioration occurred, whereupon they increased 100-400%, usually associated with release of amino-acids including glutamate, aspartate, and taurine into the extracellular space. The magnesium and calcium levels remained unchanged, regardless of the severity of physiological deterioration.

Brain Injuries↗
PubMed1999

Functional recovery after bilateral pallidotomy for the treatment of early-onset primary generalized dystonia.

This report describes the successful treatment of dystonia musculorum deformans with bilateral stereotactic pallidotomy in a 14-year-old girl in whom the dystonia was diagnosed when she was 7 years old. The patient presented with dystonia of the right upper extremity that progressed to generalized dystonia. Preoperatively, she required maximal assistance with all activities of daily living and transfers. She was not a functional ambulator. Postoperatively, she had remarkable functional recovery. At discharge, she was at modified independence level for all basic activities of daily living and required supervision for household ambulation. No postoperative complications were noted. We propose that bilateral stereotactic lysis of globus pallidus interna may be an alternative treatment for dystonia musculorum deformans. The technique of bilateral pallidotomy and theories of its effectiveness are discussed.

Activities of Daily Living↗
PubMed1999

Neuropsychological outcome following unilateral pallidotomy.

Despite the findings of significantly improved motor functioning following pallidotomy for the treatment of Parkinson's disease, the cognitive sequelae following surgery have yet to be clearly defined. With increasing knowledge of the surgery's effect on frontostriatal circuits, the cognitive processes potentially affected by the procedure require further exploration to evaluate fully the efficacy of the treatment. We reviewed 10 studies on the neuropsychological outcome after pallidotomy that were published in peer-reviewed journals. A general agreement exists that pallidotomy is a relatively safe and effective treatment for ameliorating the motor symptoms of Parkinson's disease, with relatively few cognitive changes reported following surgery. However, a number of conceptual and methodological concerns, including diverse selection criteria, small sample sizes and short follow-up periods, limit the interpretation and generalizability of these findings. These concerns are discussed in detail, along with a summary of the current neuropsychological literature, suggested guidelines for the conduct of research and future research directions. The neuropsychological findings are critically reviewed and tabulated by study, cognitive domain and follow-up period, with particular emphasis on hemisphere-specific cognitive changes.

Affect↗
PubMed1999

Prevention of secondary ischemic insults after severe head injury.

OBJECTIVE: The purpose of this study was to compare the effects of two acute-care management strategies on the frequency of jugular venous desaturation and refractory intracranial hypertension and on long-term neurologic outcome in patients with severe head injury. DESIGN: Randomized clinical trial. SETTING: Level I trauma hospital. PATIENTS: One hundred eighty-nine adults admitted in coma because of severe head injury. INTERVENTIONS: Patients were assigned to either cerebral blood flow (CBF)-targeted or intracranial pressure (ICP)-targeted management protocols during randomly assigned time blocks. In the CBF-targeted protocol, cerebral perfusion pressure was kept at >70 mm Hg and PaCO2 was kept at approximately 35 torr (4.67 kPa). In the ICP-targeted protocol, cerebral perfusion pressure was kept at >50 mm Hg and hyperventilation to a PaCO2 of 25-30 torr (3.33-4.00 kPa) was used to treat intracranial hypertension. MEASUREMENTS AND MAIN RESULTS: The CBF-targeted protocol reduced the frequency of jugular desaturation from 50.6% to 30% (p = .006). Even when the frequency of jugular desaturation was adjusted for all confounding factors that were significant, the risk of cerebral ischemia was 2.4-fold greater with the ICP-targeted protocol. Despite the reduction in secondary ischemic insults, there was no difference in neurologic outcome. Failure to alter long-term neurologic outcome was probably attributable to two major factors. A low jugular venous oxygen saturation was treated in both groups, minimizing the injury that occurred in the ICP-targeted group. The beneficial effects of the CBF-targeted protocol may have been offset by a five-fold increase in the frequency of adult respiratory distress syndrome. CONCLUSIONS: Secondary ischemic insults caused by systemic factors after severe head injury can be prevented with a targeted management protocol. However, potential adverse effects of this management strategy may offset these beneficial effects.

Adolescent↗
PubMed1998

Pallidotomy for generalized dystonia.

We systematically evaluated the efficacy of both unilateral and bilateral stereotactic pallidotomy in eight patients with generalized dystonia. Six patients had a marked improvement in dystonic movements and motor function; the other two patients also benefited from the procedure but to a lesser extent. The severity of dystonia was assessed before and after surgery by the Burke-Marsden-Fahn Dystonia Scale (BMFDS), the Unified Dystonia Rating Scale (UDRS), and the Activity of Daily Living Scale (ADL). The BMFDS scores decreased by 59.0%, UDRS by 62.5%, and ADL by 47.8% postoperatively. Adverse events were limited to a transient weakness in one patient. We conclude that pallidotomy is a safe and effective treatment in medically refractory cases of generalized dystonia.

Activities of Daily Living↗
PubMed1998

Quality improvement: an overview.

Clinicians are being held accountable for the quality of the care they provide in an unprecedented way. Quality improvement (QI), a scientifically based method, can help health care managers and clinicians improve health care through the elimination of waste and inefficiency. QI is a comprehensive approach that is based on an understanding of variation and uses tools specifically designed to help professionals understand and improve processes. The article gives an overview of quality improvement as a useful method for improving the process of clinical practice. Improving the process of care is an important step toward achieving quality outcomes for all health care customers.

Humans↗
PubMed1998

Alignment correction algorithm for transformation of stereotactic anterior commissure/posterior commissure-based coordinates into frame coordinates for image-guided functional neurosurgery.

OBJECTIVE: The goal was to describe an alignment correction algorithm for the transformation of stereotactic atlas-derived anterior commissure/posterior commissure-based coordinates into frame coordinates for image-guided functional stereotactic neurosurgery. TECHNIQUE: The algorithm was developed for the calculation of targets that are referenced to the intercommissural line. It corrects for deviations of the axis of the intercommissural line in relation to the stereotactic frame (x, y, and z coordinates). The algorithm is easily implemented on a personal computer with a spreadsheet program. The calculation is fast and effective. CONCLUSION: The procedure is universally applicable for functional stereotactic neurosurgery, and it can be used with different stereotactic frames, different imaging techniques, and different workstations.

Algorithms↗