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Biomedical subjects

M L Levy

Publications and source records attributed to M L Levy.

At least 37 records · Page 2Linked to original sources
PubMed2000

A prospective population-based study of pediatric trauma patients with mild alterations in consciousness (Glasgow Coma Scale score of 13-14).

OBJECTIVE: Considerable controversy surrounds the appropriate evaluation of children with mild alterations in consciousness after closed head trauma (Glasgow Coma Scale [GCS] score of 13-14). The objective of the current study was to determine the incidence of intracranial lesions in pediatric patients with a field GCS score of 13 or 14 after closed head injuries. METHODS: The current study is a population-based, multicenter prospective study of all patients to whom emergency medical services responded during a 12-month period. The setting was urban Los Angeles County, encompassing a patient population of 2.3 million children, 13 designated trauma centers, and 94 receiving hospitals. RESULTS: In the pediatric age group (<15 yr old), 8488 patients were transported by emergency medical services for injuries. Of these, 209 had a documented field GCS score of 13 or 14. One hundred fifty-seven patients were taken to trauma centers, and 135 (86%) underwent computed tomography. Forty-three patients (27.4%) had abnormal results on computed tomographic scans, 30 (19.1%) had an intracranial hemorrhage, and 5 required an operative neurosurgical procedure for hematoma evacuation. Positive and negative predictive values of deteriorating mental status (0.500 and 0.844, respectively), loss of consciousness (0.173 and 0.809), cranial fracture (0.483 and 0.875, and extracranial injuries (0.205 and 0.814) were poor predictors of intracranial hemorrhage. CONCLUSION: Pediatric patients who have mild alterations in consciousness in the field have a significant incidence of intracranial injury. The great majority of these patients will not require operative intervention, but the implications of missing these hemorrhages can be severe for this subgroup of head-injured patients. Because clinical criteria and cranial x-rays are poor predictors of intracranial hemorrhage, it is recommended that all children with a GCS score of 13 or 14 routinely undergo screening via non-contrast-enhanced computed tomography.

Adolescent↗
PubMed2000

The delta valve: how does its clinical performance compare with two other pressure differential valves without antisiphon control?

OBJECTIVE: The Delta valve is a pressure differential valve with a siphon control device. The valve mechanism is normally closed, but is designed to open in response to positive ventricular pressure, thereby avoiding overdrainage of cerebrospinal fluid (CSF). As a result, the incidence of subdural fluid collections as well as postural symptoms is purportedly reduced. In addition, the valve might reduce the number of obstructions as there would be no negative pressure sucking tissue and debris into the shunt system. In order to assess whether use of the Delta valve reduced the number of shunt-related problems as compared with two other pressure differential valves without an antisiphon component, we performed a retrospective review of all children undergoing CSF diversion procedures at our institution. METHODS: We reviewed the charts of 1, 193 patients. Cases included 2,325 ventriculoperitoneal (V-P) shunt insertions or revisions from January 1, 1985, to December 31, 1994, performed at our institution. The Delta valve and two pressure differential valves without antisiphon function were exclusively inserted during the following time periods: Holter-Hausner (H-H): January 1, 1985, to August, 1987; Heyer-Schulte (H-S): August, 1987, to June, 1991, and Delta: June, 1991, to December 31, 1994. RESULTS: Of the cases reviewed, 475 patients underwent insertion of a V-P shunt at the Childrens Hospital of Los Angeles and had a total of 686 shunt operations. Median follow-up was 3 years and ranged up to 10 years. Kaplan-Meier analysis documented that 67% of H-H, 71% of H-S and 70% of the Delta valves were functioning at 1-year follow-up. At 2-year follow-up, 66% of H-H, 64% of H-S and 65% of the Delta valves were functioning. The difference was not statistically significant. The occurrence rate for symptomatic subdural fluid collections was 0.7% (1/130) for H-H, 2.2% (3/139) for H-S and 1.0% (2/206) for the Delta valve (p = 0.52). The combined breakage/obstruction rate for the series was 7.7% (10/130) for H-H, 2.9% (4/139) for H-S and 4.9% (10/206) for the Delta valve (p = 0.19). No Delta valves malfunctioned secondary to fibrous capsule affecting the antisiphon device. CONCLUSIONS: In conclusion, it appears that performance of the Delta valve was not significantly different from the H-H and H-S valves, two valves without an antisiphon device. There was no significant difference in the occurrence of symptomatic subdural fluid collections based upon valve type, or in the combined valve breakage/obstruction rates based upon valve type.

Cerebrospinal Fluid Shunts↗
PubMed2000

Causes, epidemiology, and risk factors of chronic subdural hematoma.

Chronic subdural hematoma is an important reversible cause of dementia and disability in the elderly. A sufficiently high level of clinical suspicion and prompt radiographic evaluation may allow for timely treatment to avoid poor outcomes. Thankfully, the routine use of computed tomographic scanning in most emergency facilities has made the diagnosis of these lesions commonplace.

Adult↗
PubMed1999

Concurrent three dimensional neuroendoscopy: initial descriptions of application to clinical practice.

Applications of endoscopic technique neurosurgery are becoming increasingly popular as greater evidence of the safety and efficacy of these techniques is reported. Nevertheless, significant technical limitations need to be solved before neuroendoscopy can achieve widespread popularity. One limitation is the surgeon's difficulties in becoming anatomically oriented in a two-dimensional (2-D) environment. The lack of appropriate visual cues to orient oneself in three-dimensional (3-D) space makes relatively simple anatomical regions difficult to navigate. The authors describe an endoscopy system that allows for stereoscopic visualization during minimally invasive procedures and that acts as an adjunct to conventional open craniotomies. Four cases are described in which stereoendoscopy was used as either a primary means of visualization or as an adjunct to the operating microscope in conventional open neurosurgical procedures. The authors believe that stereoendoscopic vision is a significant advance in endoscope technology and will play a large role in the popularization of minimally invasive techniques in neurosurgery.

Journal Article↗
PubMed1999

Virtual endoscopic environments in modern neurosurgical practice.

Modern radiographic techniques have allowed the creation of high-definition planar images that can provide important anatomical as well as physiological data. Planar imaging sets can be reformatted into three-dimensional (3-D) data sets that can then be manipulated to demonstrate important anatomical or gross pathological features. Three-dimensional data sets have been used with success in modern image-guided or frameless stereotactic surgery. Another potential application is so-called "virtual endoscopy" or "scopeless endoscopy," in which a 3-D anatomical data set is reformatted into a volume-rendered image that can then be viewed. By reformatting images in this way, a "surgeon's-eye" view can be obtained, which can aid in presurgical planning and diagnosis. The use of virtual endoscopy has the potential to increase our understanding of the appropriate anatomy and the anatomical relationships most apparent during neurosurgical approaches. In so doing, virtual endoscopy may serve as an important means of planning for therapeutic interventions. On the other hand, one must always be cognizant of the technical limitations of these studies regardless of the quality of the reconstructed images. Prospective, correlative, clinical studies in which the anatomical advantages of virtual-based endoscopy are evaluated in large cadaver or patient series must be performed. Until then, the only potential ways to compensate for errors that exist in the algorithms and reconstructions of 3-D endoscopic images are based on the surgeon's understanding of the clinical state of the patient and prior experience with the anatomy in the region of question.

Journal Article↗
PubMed1999

Apolipoprotein E genotype and noncognitive symptoms in Alzheimer's disease.

BACKGROUND: The apolipoprotein E (ApoE) epsilon 4 allele confers significant risk for Alzheimer's disease and is associated with a greater amyloid burden in the brain. Future treatments may target molecular mechanisms associated with this allele, and it is important to define any phenotypic characteristics that correspond to this genotype. We sought to clarify the relationship between ApoE status and noncognitive symptoms in Alzheimer's disease patients. METHODS: Possible and probable Alzheimer's disease patients from a clinical trial (n = 605) were assessed with the 10-item Neuropsychiatric Inventory cross-sectionally prior to treatment, and their ApoE genotype was determined. Among the population studied, the following numbers with specific genotypes were studied: 23-2/3, 17-2/4, 209-3/3, 288-3/4, 68-4/4. RESULTS: When correlations were controlled for the patient's level of cognitive impairment, there was no relationship between epsilon 4 dose and any of the 10 noncognitive symptoms assessed, including psychosis, mood changes, and personality alterations. CONCLUSIONS: Among patients with comparable disease severity, the epsilon 4 allele does not confer additional psychiatric morbidity.

Aged↗
PubMed1999

PHACE: a neurocutaneous syndrome with important ophthalmologic implications: case report and literature review.

OBJECTIVES: To introduce PHACE syndrome (Posterior fossa malformations, Hemangiomas, Arterial anomalies, Coarctation of the aorta and other cardiac defects, and Eye abnormalities) to the ophthalmologic literature; to report the first case of PHACE syndrome associated with congenital glaucoma; and to review the ocular and systemic findings that may occur in this entity. DESIGN: Case report and literature review. METHODS: The authors report a child with PHACE syndrome and congenital glaucoma and review the ophthalmologic and systemic manifestations of this syndrome. RESULTS: A 9-month-old girl with PHACE syndrome was treated. She had a large right facial hemangioma, central nervous system (CNS) abnormalities, and cardiac anomalies. Glaucoma was detected in her left eye, and she underwent glaucoma surgery. She did well following two glaucoma procedures, and the facial hemangioma is responding to medical treatment. CONCLUSIONS: Ophthalmologists who examine children with large facial hemangiomas should consider PHACE syndrome in the differential diagnosis and should obtain appropriate CNS imaging studies and cardiac evaluation when the diagnosis is suspected. Congenital glaucoma should be added to the list of PHACE-associated ocular anomalies.

Abnormalities, Multiple↗
PubMed1999

Granuloma faciale in a child successfully treated with the pulsed dye laser.

Granuloma faciale, a rare, chronic, cutaneous disorder, is uncommon in children. Numerous treatment modalities have been used to treat granuloma faciale but none are consistently effective. In addition, many of the previously used therapies have unwanted side effects or are not well tolerated by children. We report a case of granuloma faciale in an 11-year-old child successfully treated with the pulsed dye laser. To our knowledge, this is the first report of this treatment modality for granuloma faciale.

Child↗
PubMed1999

Three new cases of transient bullous dermolysis of the newborn.

We present 3 new patients with transient bullous dermolysis of the newborn (TBDN), which is a form of dystrophic epidermolysis bullosa. TBDN may be diagnosed by electron microscopy showing a sublamina densa cleavage; immunofluorescence antigenic mapping demonstrating bullous pemphigoid antigen, laminin- 1, and type IV collagen along the epidermal roof of subepidermal clefts; and indirect immunofluorescence with monoclonal antibodies revealing intraepidermal type VII collagen. Although intraepidermal type VII collagen has been reported in other forms of dystrophic epidermolysis bullosa, we believe that the presence of type VII collagen in a striking intraepidermal granular array is a finding unique to TBDN. Our cases demonstrate the importance of immunodermatologic studies in the diagnosis of bullous disorders that are seen at birth because accurate diagnosis carries prognostic implications. This variant of epidermolysis bullosa, in contrast to other forms of dystrophic epidermolysis bullosa, is a benign, self-limited disease.

Autoantigens↗
PubMed1999

Present and future management of asthma and COPD: proceedings from WONCA 1998.

On 15 June 1998, a workshop on asthma and chronic obstructive pulmonary disease (COPD) was held at the WONCA conference in Dublin. Based on the current guidelines for diagnosis and treatment of asthma and COPD, new developments and present and future research projects were discussed. Based on these guidelines and the research findings, new developments were positioned. The final conclusion of this workshop was that there is a need to continue exchanging ideas at an international level. So an initiative to start a Scientific Group of Primary Care Research within the European Respiratory Society has been taken.

Asthma↗
PubMed1999

Pathogenesis and pharmacological strategies for mitigating secondary damage in acute spinal cord injury.

OBJECTIVE: Experimental models and clinical observations of acute spinal cord injury (SCI) support the concepts of primary and secondary injury, in which the initial mechanical insult is succeeded by a series of deleterious events that promote progressive tissue damage and ischemia. Whereas the primary injury is fated by the circumstances of the trauma, the outcome of the secondary injury may be amenable to therapeutic modulation. This article reviews the pathogenetic determinants of these two phases of injury and summarizes the pharmacological manipulations that may restore neurological function after SCI. METHODS: Experimental models of SCI and their inherent limitations in simulating human SCI are surveyed. The pathogenesis of primary and secondary injury, as well as the theoretical bases of neurological recovery, are examined in detail. The effects of glucocorticoids, lazeroids, gangliosides, opiate antagonists, calcium channel blockers, glutamate receptor antagonists, antioxidants, free radical scavengers, and other pharmacological agents in both animal models and human trials are summarized. Practical limitations to inducing neural regeneration are also addressed. RESULTS: The molecular events that mediate the pathogenesis of SCI are logical targets for pharmacological manipulation and include glutamate accumulation, aberrant calcium fluxes, free radical formation, lipid peroxidation, and generation of arachidonic acid metabolites. Enhancement of neural regeneration and plasticity comprise other possible strategies. CONCLUSION: Pharmacological agents must be given within a narrow window of opportunity to be effective. Although many therapeutic agents show potential promise in animal models, only methylprednisolone has been shown in large, randomized, double-blinded human studies to enhance the functional recovery of neural elements after acute SCI. Future therapy is likely to involve various combinations of these agents.

Acute Disease↗
PubMed1999

The development of anatomic art and sciences: the ceroplastica anatomic models of La Specola.

Anatomic models are important heuristic aids for surgeons in training. They are uniquely able to convey the three-dimensional relationships of anatomic structures with a physical immediacy not allowed by any other media. We examine the conceptual development of the anatomic model in light of the history of neuroanatomic understanding and coexistent artistic movements. The teaching anatomic model traces its ancestry to the work of Gaetano Zumbo in the late 17th century, on the heels of important anatomic discoveries made in the preceding 100 years of investigation. The anatomic model reached its peak expression in the late 18th century with the founding of the ceroplastica laboratory in Florence. We discuss the technological, artistic, and scientific origins of the anatomic wax model and the conditions that allowed it to flourish in the late 18th century.

Anatomy, Artistic↗
PubMed1999

Integration of a variable action suction adapter into ultrasonic aspirators.

PURPOSE: Use of ultrasonic aspirators has become a mainstay in the neurosurgical armamentarium. The handpiece design and ultrasonic parameters have evolved to maximize its safe and efficacious use. Despite these modifications, continuous suction through the tip of the aspirator can result in neurovascular damage, especially when the aspirator is working in the cavernous sinus region or cerebellopontine angle. CONCEPT: We describe the integration of a variable suction adapter into the existing handpiece of an ultrasonic aspirator to minimize potential injury from the continuous forceful suction normally associated with the use of these devices. RATIONALE: The integration of such an adapter can reduce the potential for suction injury to cranial nerves or microvascular structures or smaller-caliber arteries and veins. DISCUSSION: This variable action suction adapter can decrease suction injuries to cranial nerves or the microvasculature.

Brain Neoplasms↗
PubMed1999

Identification of sporadic mutations in the helix initiation motif of keratin 6 in two pachyonychia congenita patients: further evidence for a mutational hot spot.

Pachyonychia congenita (PC) is a rare, autosomal dominant, ectodermal dysplasia characterized most distinctly by the presence of symmetric nail hypertrophy. In the Jadassohn-Lewandowsky form, or PC-1, additional cutaneous manifestations may include palmoplantar hyperkeratosis, hyperhidrosis, follicular keratoses, and oral leukokeratosis. Mutations have previously been identified in the 1A helix initiation motif of either keratin 6 or keratin 16 in patients with PC-1. In the current study, we have identified 2 sporadic, heterozygous mutations in the 1A helix region of the K6 isoform (K6a). The first mutation identified was a 3 base pair deletion (K6adelta N171). The second mutation was a C-to-A transversion resulting in an amino acid substitution (K6a N171K). These data, in combination with previous reports, provide further evidence that this location is a mutational hot spot.

Amino Acid Sequence↗
PubMed1999

Intraoperative angiography in the management of pediatric vascular disorders.

We reviewed our experience with intraoperative angiography in the management of 7 cerebral aneurysms and 15 arteriovenous malformations (AVMs) in children over the past 5 years. The patients ranged from 4 months to 18 years of age with a mean age of 9 years. In 4 of the 22 cases, angiography provided information that led to changes during surgery. In 3 cases, the intraoperative angiogram revealed residual AVMs that were then completely resected. In 1 patient with an anterior circulation aneurysm, intraoperative studies revealed findings which resulted in clip repositioning. Intraoperative angiography added a mean of 43 (+/-19) min to the operative time, with a mode of 40 minutes. There was 1 complication, a groin hematoma that readily resolved. Intraoperative angiography prolongs to operative course; however, it is a useful adjunct to the management of vascular disorders in children. We now routinely use and recommend intraoperative angiography to assist with the surgical management of vascular malformations in children.

Adolescent↗