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Biomedical subjects

M L Levy

Publications and source records attributed to M L Levy.

At least 55 records · Page 3Linked to original sources
PubMed1999

Toward a simpler surgical management of Chiari I malformation in a pediatric population.

A wide variety of surgical adjuvants to the standard bony decompression have been advocated in the treatment of the Chiari I malformation, especially when the tonsillar herniation is associated with hydrosyringomyelia. These include various shunting procedures, duroplasty, obex plugging, and resection of the cerebellar tonsils. Our practice has been to avoid these adjuvants and to perform a simple limited occipital craniectomy, C1 laminectomy, and dural opening. The dura mater is left open and overlain with oxidized cellulose. To evaluate the efficacy of this more limited procedure, a retrospective review was performed of the medical records of 31 consecutive patients treated over a 6-year period. Twenty-six (84%) of these patients had an associated spinal cord syrinx; all underwent the same procedure. The follow-up period ranged from 15 to 93 months, with all patients having at least one postoperative magnetic resonance imaging at 6 months. Twenty-three of the 26 patients (88%) who presented with a syrinx had significant resolution of the syrinx on follow-up scans with concomitant improvement of presenting signs and symptoms. Of the remaining 3 patients, 1 had progressive hydrocephalus and received a ventriculoperitoneal shunt, with symptom resolution. In the other 2 patients the syrinx did not diminish; both received syringopleural shunts. Postoperative morbidity includes a 26% incidence of headaches, of which half resolved within 5 days, and only 1 persisted beyond 2 weeks. Nausea and vomiting occurred in 16%. Neither of these figures significantly exceeds those of other large surgical series in which the dura mater was closed with a patch graft. Three patients (10%) did have a postoperative cerebrospinal fluid leak; all responded to bedside suturing without further sequelae. This study indicates that a simple bone removal and open dural decompression of the cervicomedullary junction is a safe, effective operative treatment for Chiari I malformation in children. Shunts, duroplasty, obex plugging, and tonsillar resection offer no benefit regarding the outcome when our series is compared to others in which such adjuvants were used.

Adolescent↗
PubMed1999

A prospective analysis of the use of octylcyanoacrylate tissue adhesive for wound closure in pediatric neurosurgery.

OBJECTIVE: Cyanoacrylate monomers have been developed for use as skin adhesives. Previous studies have demonstrated that using this skin adhesive for the closure of traumatic lacerations results in excellent cosmesis, decreased procedure-related pain and timesavings. SURGICAL TECHNIQUE: Octylcyanoacrylate skin adhesive is applied after the placement of deep fascial sutures with close approximation of the skin edges. The adhesive is applied in liquid form and polymerizes rapidly to solid form. Multiple layers are applied forming a hard impenetrable barrier. RESULTS: This technique was prospectively evaluated in the closure of 102 elective neurosurgical operations with 142 incisions: ventriculoperitoneal shunt insertion/revision (53%) and craniotomy for tumors (10%) were the commonest procedures. There were a total of 83 scalp, 36 abdominal, 8 neck, 6 chest and 6 lumbar incisions. The mean incision length was 5.1 cm (range 0.25-50 cm). Fifty-nine percent of the wounds had previous areas of operative incisions. Complications included 1 poor cosmetic result and 4 cerebrospinal fluid (CSF) leaks. Of the 4 patients with CSF leaks, 2 required operative wound revision, and 1 required ventriculoperitoneal shunting for hydrocephalus. CONCLUSION: Cyanoacrylate skin adhesive is a viable means of obtaining cosmetic wound closure. Its use requires attention to proper skin approximation and hemostasis. In our experience, propensity for CSF leakage especially in reoperative procedures is a relative contraindication.

Adolescent↗
PubMed1999

Does age or other factors influence the incidence of ventriculoperitoneal shunt infections?

Some studies indicate that infants, especially those less than 1 month of age have a higher incidence of ventriculoperitoneal shunt infections. To look at age as well as other variables that might relate to the rate of shunt infection, we reviewed the records of all patients undergoing a ventriculoperitoneal shunt insertion or revision at our institution from January 1, 1985, to December 31, 1994. There were a total of 2,325 ventriculoperitoneal shunting procedures performed on 1,193 patients with a male:female ratio of 678:515. The overall infection rate was 3.2% (74 infections). Analyzed by age, the infection rates were as follows: <1 month 9/223 (4.0%), 1-6 months 16/449 (3.6%), 6-12 months 13/297 (4.4%), 12-18 months 3/122 (2.5%), 18-24 months 7/116 (6.0%) and 24+ months 26/1, 118 (2.3%). There was no statistically significant difference between age groups (p > 0.05). Upon selectively examining premature neonates who developed hydrocephalus secondary to intraventricular hemorrhage from the figures given above, one finds that 2/44 (4.5%) of neonates became infected, which was also not significant. The infection rate was the same irrespective of whether the procedure was to insert or revise the shunt, or whether another operative procedure was done under the same anesthesia. The etiology of the hydrocephalus was not a factor, nor was the presence of an open neural tube defect. The presence of fluid accumulation along the shunt tract or at another neurological operative site was associated with a significant increase in incidence of infection 15/168 (8.9%) when compared to those with no fluid accumulation (p < 0.001). The type of infecting organism was divided roughly in thirds, with relatively equal representation from Staphylococcus epidermidis/coagulase negative and Staphylococcus aureus. The remaining third was comprised of a wide variety of organisms.

Adolescent↗
PubMed1999

Neuropsychiatric symptoms and cholinergic therapy for Alzheimer's disease.

Neuropsychiatric abnormalities, as well as the commonly associated neuropsychological symptoms, are clinical characteristics of Alzheimer's disease (AD), the most common form of dementia. Thus, in addition to a general cognitive and functional decline, neuropsychiatric manifestations, such as agitation, apathy, anxiety, psychoses and disinhibition, are frequently evident in AD patients. Such neuropsychiatric symptoms of AD are the source of considerable patient and caregiver distress, resulting in the prescription of neuroleptics, benzodiazepines or other psychotropic agents, and are a major factor in the decision to transfer the care of patients into nursing homes. Recent evidence suggests that some neuropsychiatric changes associated with AD are related to the cholinergic deficits in the brains of AD patients and that such abnormalities may be responsive to cholinergic therapy. Cholinergic drug therapies indicated for the symptomatic treatment of AD, for example tacrine and the newer cholinesterase (ChE) inhibitors such as donepezil, have been demonstrated to improve memory, language and praxis. Furthermore, although less is known about the effect of ChE inhibitors on the neuropsychiatric symptoms of AD, preliminary evidence suggests that they reduce apathy, anxiety, hallucinations, disinhibition and aberrant motor behaviour. Thus, the newer-generation ChE inhibitors that are well tolerated, easy to administer and show promise in reducing the cognitive, as well as neuropsychiatric disturbances of AD, may emerge as important treatments for some neuropsychiatric symptoms in patients with central cholinergic deficits, including AD.

Acetylcholine↗
PubMed1999

Propofol in the treatment of moderate and severe head injury: a randomized, prospective double-blinded pilot trial.

OBJECT: Sedation regimens for head-injured patients are quite variable. The short-acting sedative-anesthetic agent propofol is being increasingly used in such patients, yet little is known regarding its safety and efficacy. In this multicenter double-blind trial, a titratable infusion of 2% propofol accompanied by low-dose morphine for analgesia was compared with a regimen of morphine sulfate in intubated head-injured patients. In both groups, other standard measures of controlling intracranial pressure (ICP) were also used. METHODS: Forty-two patients from 11 centers were evaluated to assess both the safety and efficacy of propofol: 23 patients in the propofol group (mean time of propofol usage 95+/-87 hours) and 19 patients in the morphine group (mean time of morphine usage 70+/-54 hours). There was a higher incidence of poor prognostic indicators in the propofol group than in the morphine group: patient age older than 55 years (30.4% compared with 10.5%, p < 0.05), initial Glasgow Coma Scale scores of 3 to 5 (39.1% compared with 15.8%, p < 0.05), compressed or absent cisterns on initial computerized tomography scanning (78.3% compared with 57.9%, p < 0.05), early hypotension and/or hypoxia (26.1% compared with 10.5%, p = 0.07). During treatment there was a trend toward greater use of vasopressors in the propofol group. However, the mean daily ICP and cerebral perfusion pressure were generally similar between groups and, on therapy Day 3, ICP was lower in the propofol group compared with the morphine group (p < 0.05). Additionally, there was less use of neuromuscular blocking agents, benzodiazepines, pentobarbital, and cerebrospinal fluid drainage in the propofol group (p < 0.05). At 6 months postinjury, a favorable outcome (good recovery or moderate disability) was observed in 52.1% of patients receiving propofol and in 47.4% receiving morphine; the mortality rates were 17.4% and 21.1%, respectively. Patients who received the highest doses of propofol for the longest duration tended to have the best outcomes. There were no significant differences between groups in terms of adverse events. CONCLUSIONS: Despite a higher incidence of poor prognostic indicators in the propofol group, ICP therapy was less intensive, ICP was lower on therapy Day 3, and long-term outcome was similar to that of the morphine group. These results suggest that a propofol-based sedation and an ICP control regimen is a safe, acceptable, and, possibly, desirable alternative to an opiate-based sedation regimen in intubated head-injured patients.

Adult↗
PubMed1999

Herpes gestationis in a mother and child.

Herpes gestationis (pemphigoid gestationis) is a rare autoimmune disease that appears during pregnancy or in the immediate postpartum period. We report the cases of a mother and neonate with immunofluorescence confirmed herpes gestationis both of whom had extensive cutaneous involvement.

Autoimmune Diseases↗
PubMed1998

Prenatal diagnosis for keratin mutations to exclude transmission of epidermolytic hyperkeratosis.

Epidermolytic hyperkeratosis (bullous congenital ichthyosiform erythroderma) is an autosomal dominant skin disorder caused by mutations in keratins 1 and 10. We have used direct gene sequencing to ascertain the status of a 15 week fetus of parents whose first child was affected with this disorder. The parents show no clinical signs of epidermolytic hyperkeratosis but were concerned about the possibility of transmitting the disorder due to germline mosaicism. Molecular analysis of the affected son revealed a G to A mutation in codon 156 of keratin 10, resulting in an arginine to histidine substitution within the highly conserved 1A region. Codon 156 has been previously identified as a mutational hot spot and substitutions of this arginine residue are very common in epidermolytic hyperkeratosis patients. Analysis of genomic DNA isolated from amniotic cells showed that the fetus did not harbour this mutation and a healthy infant was eventually born that was unaffected by this disorder.

Amniotic Fluid↗
PubMed1998

Stereoscopic head-mounted display incorporated into microsurgical procedures: technical note.

OBJECTIVE: We have previously evaluated video technologies that have allowed for the use of electronic imaging during microneurosurgical and endoscopic procedures. This stereoscopic camera set and monitor/recording system allows for the use of stereoscopic images during surgery by the primary surgical assistant and ancillary personnel. It also allows for stereoscopic recording and playback using a wide video home system format. We describe a novel prototype of a head-mounted display (HMD) that allows the surgical team to simultaneously visualize the surgical field stereoscopically and includes picture-in-picture, voice control, and stereoscopic recording capabilities. INSTRUMENTATION: A stereoscopic HMD with 640 x 480 (video graphics array) pixel resolution and the ability to display 24-bit images has been designed. This device weighs 900 g. It is interfaceable with common video display formats. RESULTS: This stereoscopic HMD is being evaluated in a prospective multicenter trial of open microsurgical and endoscopic minimally invasive procedures. In our experience to date, there have been no equipment failures or complications attributable to the use of the display system. The equipment was well accepted by users who reported significant benefits in visualization. CONCLUSION: The use of a stereoscopic HMD may result in improved efficiency and safety in both endoscopic and open microsurgical procedures. We have verified that the HMD is comfortable during the course of a surgical procedure, is reliable, and allows for accessibility to the operative field with an excellent field of view and three-dimensional perception. Positioning and dexterity within the operative field are also enhanced. Additional uses relate to surgical training, multimodal information display, and operative rehearsals.

Depth Perception↗
PubMed1998

An institutional experience with cervical vagus nerve trunk stimulation for medically refractory epilepsy: rationale, technique, and outcome.

OBJECTIVE: Intermittent stimulation of the left cervical vagus nerve trunk is emerging as a novel adjunct in the treatment of medically refractory seizures. We sought to evaluate theoretical and practical issues attendant to this concept. We review the anatomic and physiological background arguing for clinical application of vagus nerve stimulation, discuss salient aspects of patient selection and the nuances of surgical technique, and present our observations of and results from application of the method. METHODS: Each of 18 patients with medically refractory epilepsy and at least six complex partial or secondarily generalized seizures per month underwent placement of a NeuroCybernetic Prosthesis pulse generator (Cyberonics, Webster, TX) in the chest, connected to helical platinum leads applied to the left cervical vagus nerve trunk. The patients were then randomized in a double-blinded fashion to receive either high (presumably therapeutic) or low (presumably less therapeutic) levels of vagus nerve stimulation. Reduction in seizure frequency, global assessments of quality of life, physiological measurements, and adverse events were recorded during a 3-month period. Patients in the low group were then crossed over to high-stimulation paradigms during a 15-month extension trial. RESULTS: All operations were successful, uneventful, and without adverse postoperative sequelae. One patient was excluded from analysis because of inadequate seizure calendars. Of the seven patients initially assigned to high stimulation, the mean reduction in seizure frequency was 71% at 3 months and 81% at 18 months. Five (72%) of these patients had a greater than 75% reduction in seizure frequency, and one (14%) remained seizure-free after more than 1.5 years of follow-up. The mean reduction in seizure frequency among the low-stimulation group was only 6% at 3 months. No serious complications, device failures, or physiological perturbations occurred. CONCLUSION: In our experience, vagus nerve stimulation has proven to be a safe, feasible, and potentially effective method of reducing seizures in select patient populations. However, the elements of strict definition for the application of the method require further study.

Adult↗
PubMed1998

The internet as a pediatric neurosurgery information resource.

The Internet is evolving as a powerful source of medical information for patients, family members, and health care providers; however, critical analyses of this information are generally lacking. This investigation was carried out to ascertain the sources, nature, and accuracy of information acquired via searches on the Internet for ten common pediatric neurosurgical topics. Thirteen source types and nine categories of information were characterized and examined. With few notable exceptions, the educational information was highly accurate. It is concluded that the Internet represents an important new pediatric neurosurgery educational resource for the layman and health care providers. Guidelines are offered to assist in the use of this new medium.

Computer Communication Networks↗
PubMed1998

Familial occurrence of an arteriovenous fistula with a giant perimedullary pseudoaneurysm of the thoracic spinal cord in 2 young siblings.

Two siblings, a sister at age 3 years and a brother (15 years later) at 4 years of age, both presented with similar clinical pictures consisting of back pain, progressive gait difficulty, lower extremity weakness and hyperreflexia. Imaging studies in both cases showed the presence of a perimedullary mass with expansion of the bony spinal canal at T10-T12. Angiography demonstrated almost identical vascular lesions that in each case was being fed by a single left-sided T8 fistulous vessel that expanded into a giant perimedullary venous pseudoaneurysm. Each malformation was successfully obliterated using endovascular techniques, balloon occlusion of the feeding vessel in the first case and coil embolization of the pseudoaneurysm in the second. Following treatment the neurologic deficits resolved in both patients. These young siblings represent the first known case of familial occurrence of very similar giant perimedullary venous pseudoaneurysms of the thoracic spinal cord.

Adolescent↗
PubMed1998

A method of cranioplasty using coralline hydroxyapatite.

INTRODUCTION: Current cranioplasty materials include autologous or homologous bone grafts, wire mesh and methyl methacrylate, either alone or in combination. However, each material has its own unique disadvantages. Although hydroxyapatite has been used extensively in other specialties as a bone substitute, the coralline form has rarely been used to repair cranial bone defects. Coralline hydroxyapatite, similar to that found in bone, provides a matrix on which living tissue can form and grow. Because it is an ideal bioimplant, a method of cranioplasty using coralline hydroxyapatite was employed. METHODS: The hydroxyapatite granules are mixed with Avitene and autologous blood to form a paste which can be contoured as needed. RESULTS: Over the past few years, we have used hydroxyapatite either alone or in combination with tantalum mesh in 19 pediatric patients for a variety of conditions. The cosmetic results were good to excellent. Furthermore, postoperative CT scans have documented bony substitution of the hydroxyapatite granules. Follow-up ranged from 1 to 43 months with a mean of 26 months. CONCLUSION: In neurosurgical procedures when a bone substitute is needed, hydroxyapatite is an effective alternative to other currently available materials.

Bone Substitutes↗
PubMed1998

Apathy is not depression.

If depression is associated with apathy, then they should be expressed together in different dementia syndromes and should co-occur at varying levels of disease severity. The authors performed a cross-sectional comparison of neuropsychiatric symptoms in 30 Alzheimer's disease, 28 frontotemporal dementia, 40 Parkinson's disease, 34 Huntington's disease, and 22 progressive supranuclear palsy patients, using a standardized rating scale (the Neuropsychiatric Inventory). Apathy did not correlate with depression in the combined sample; apathy (r = -0.40, P < 0.0001), but not depression, correlated with lower cognitive function as measured by the Mini-Mental State Examination. The relationship of apathy to depression also varied across diagnostic groups. Apathy is a specific neuropsychiatric syndrome that is distinct from depression. Distinguishing these two syndromes has therapeutic implications.

Adult↗
PubMed1998

The use of oxidized regenerated cellulose in neurosurgical procedures.

The following paper discusses a number of issues relevant to the use of topical hemostatic agents in neurosurgical procedures. We initially describe the basic application of such products and review their relative benefits in neurosurgical interventions, emphasizing the use of oxidized, regenerated cellulose. We then discuss their role in specific operations, such as cortical debridement, cavernous sinus, and other skull base approaches, and aneurysms and arteriovenous malformations of the brain.

Journal Article↗