PubMed Health⌕ Search

Biomedical subjects

M L Levy

Publications and source records attributed to M L Levy.

At least 19 recordsLinked to original sources
PubMed2005

Multidirectional projectional rigid neuro-endoscopy: prototype and initial experience.

INTRODUCTION: The role of neuro-endoscopy is emerging. Traditional endoscopy is complicated by limited 2D views that make surgical interventions difficult. We have developed a rigid endoscope with a variable direction view that provides 3D visualization. MATERIALS AND METHODS: A prototype of the EndActive endoscope was used to examine 2 brain/intraventricular models. A 360-degree view is controlled via integrated joystick. Alternatively, the computer can volumetrically capture the ventricular surface. The captured video image can be viewed later or processed to create a flat projection map. The performance of this endoscope was compared to standard endoscopy with fixed directions of view. To simulate endoscopy, the center of the first brain model had eight labeled projections. The model was inspected with the multidirectional endoscope, standard rigid endoscopes (0-, 30- and 70-degree), and via a projection map. Ten neurosurgeons proficient in neuro-endoscopy were recruited for the experiments. The second brain model was labeled with 32 intraventricular tumors. RESULTS: With a 0-degree endoscope, only the number directly opposite the site of entry was visualized. With increasing angles, additional numbers were visualized. The 70-degree endoscope allowed 4 of 8 numbers to be visualized. Using the multidirectional endoscope, all 8 numbers were visualized. The multidirectional endoscope was more accurate in identifying markers compared to standard endoscopy (p = 0.031). The mean endoscopy times using the multidirectional endoscope and standard endoscopy were 143 and 117 seconds, respectively (p = 0.243). The best performance was obtained when the flat projection map was read (p < 0.01). Using the endoscope prototype, an average of 30.8 (96%) tumors was identified on the brain model. CONCLUSION: The EndActive endoscope is a rigid endoscope that provides complete visualization of a 3D space by controlling an adjustable viewing direction. In our study, the multidirectional endoscope provided superior visualization compared to standard endoscopy.

Humans↗
PubMed2005

Gunshot wounds to the head: gang- and non-gang-related injuries and outcomes.

PRIMARY OBJECTIVE: This study examined the differences between gang and non-gang-related incidents of penetrative missile injuries in terms of demographics, motivation, intra-cranial pathology, transit time, injury time and clinical outcome. RESEARCH DESIGN: Retrospective and prospective chart review. METHODS AND PROCEDURES: Between 1985-1992, 349 patients with penetrating missile injuries to the brain presenting to LAC-USC were studied. EXPERIMENTAL INTERVENTIONS: Inclusion criteria were implemented to keep the cohort as homogenous as possible. Patients excluded were those with multiple gunshot wounds, non-penetrating gunshot wounds to the head, systemic injuries and cases in which the motivation for the incident was unknown. MAIN OUTCOMES AND RESULTS: Gang-related shooting slightly out-numbered non-gang-related incidents. Demographic analysis showed both a male and Hispanic predominance for both gang- and non-gang-related victims and significant differences in gender, race and age. Occipital entrance sites were more common in the gang-related vs temporal entrance sites in the non-gang-related. Mean transit time to the emergency department for gang-related shootings was less than non-gang-related shootings (24.4 vs 27.8 minutes). Most shooting incidents took place between 6pm and 3am. No difference between survival and outcome was noted between gang and non-gang victims. CONCLUSIONS: Significant differences were found between gang- and non-gang-related shooting victims in terms of demographics, entrance site and transit time. No difference was found between injury time, survival and outcome between gang and non-gang populations.

Adolescent↗
PubMed2004

Abducens length and vulnerability?

BACKGROUND: Several sources have attributed the vulnerability of the abducens nerve to its long intracranial course. However, other anatomic factors likely contribute to the apparent vulnerability of the abducens nerve to mass lesions and trauma. METHODS: The authors performed a two-part anatomic study of the abducens nerve. In the first part of the study, they compared the length of the abducens with another cranial nerve, the trochlear, at the autopsy of 26 pediatric patients. In the second part of the study, the authors used an endoscopic exposure of these two cranial nerves in a preserved human cadaver head. RESULTS: The abducens nerve was consistently approximately one-third the length of the trochlear nerve at all ages that they studied. The endoscopic views revealed the structural and vascular relationships of the abducens nerve in situ. CONCLUSIONS: The authors conclude from these findings and the literature that abducens nerve vulnerability results from factors other than its intracranial length.

Abducens Nerve↗
PubMed2004

Wheeze detection: recordings vs. assessment of physician and parent.

BACKGROUND: Parental and professional agreement as to the presence of wheezing in infants and preschool children has been shown to be poor. Agreement on the absence or presence of physical signs on chest examination in these populations is far from perfect, even among experienced physicians. OBJECTIVES: We sought to compare the assessment of a parent, nurse, and physician with the "gold standard" of acoustic analysis for the presence of wheezing in infants and preschool children attending a hospital clinic. SETTING AND SUBJECTS: Urban district general hospital in North London, England. Wheezy children under 6 years old attending a "walk-in" emergency pediatric ambulatory care unit. RESULTS: Comparisions were completed on 31 children (age range 4-62 months). The severity of wheeze was independently evaluated by a parent, nurse, and experienced pediatrician, and these were compared with breath sounds recorded and analyzed by acoustic techniques for the presence and severity of wheezing. In only 10 of 31 (32%) children did the parent and the physician agree on the wheeze severity score. In 13 infants, the parent scored higher than the doctor and in 8 the parent scored lower. In 16 (52%) of the children, there was complete agreement as to the severity of wheezing by the nurse and the physician. In 24 of the 31 children (77%), the acoustic wheeze score agreed with the physician wheeze score; in 6 children the acoustic score was lower and in 1 it was higher. CONCLUSIONS: The physician was able reliably to judge the severity of wheeze measured objectively, whereas nurses and parents were not. This study has important implications for the interpretation of parental questionnaire studies of asthma prevalence and severity.

Acoustics↗
PubMed2001

Clinical manifestations in a cohort of 41 Rothmund-Thomson syndrome patients.

Rothmund-Thomson syndrome (RTS) is a rare autosomal recessive genodermatosis characterized by a poikilodermatous rash starting in infancy, small stature, skeletal abnormalities, juvenile cataracts, and predisposition to specific cancers. We have identified a contemporary cohort of 41 patients to better define the clinical profile, diagnostic criteria, and management of patients with RTS. Patients with the diagnosis of RTS were ascertained by referrals from dermatology, ophthalmology, genetics, and oncology or from direct contact with the patient's family. Medical information was obtained from interviews with physicians, patients, and their parents and a review of medical records. The age range at ascertainment was 9 months to 42 years (28 males and 13 females; M:F, 2:1). All subjects displayed a characteristic rash. Thirteen subjects had osteosarcoma (OS) (32%), eight had radial defects (20%), seven had gastrointestinal findings (17%), two had cataracts (6%), and one had skin cancer (2%). Twenty-two of 28 patients without OS were less than 15 years old and thus remain at significant risk for this tumor. This case-series study reveals a clinical profile of RTS that includes a higher prevalence of OS and fewer cataracts, compared with historical reports. These differences may reflect either allelic or genetic heterogeneity. This study documents the frequency of clinical anomalies in a contemporary cohort of RTS patients and revises guidelines for diagnosis and management of RTS.

Adolescent↗
PubMed2001

Injuries from falls in the pediatric population: an analysis of 729 cases.

BACKGROUND/PURPOSE: Falls are classified as low or high level for triage purposes. Because triage criteria dictate less urgency for low-level falls, this classification scheme has important implications for pediatric emergency care. METHODS: Retrospective analysis was conducted of 729 (393 low-level and 336 high-level) pediatric patients treated for fall-related trauma (1992 through 1998). Falls were classified as low (<15 feet) or high-level (> or =15 feet). All falls were reported as accidental or unintentional. RESULTS: The overall mortality rate was 1.6% (2.4% for high-level falls compared with 1.0% for low-level falls). All 4 patients who died of a low-level fall had an abnormal head computed tomography (CT) scan and intracranial hypertension. Half of deaths from high-level falls were attributable to intracranial injuries, and half were caused by severe extracranial injuries. Common extracranial injuries were upper extremity fracture (6.2%), lower extremity fracture (5.6%), pulmonary contusion (1.8%), pneumothorax (1.1%), liver laceration (1.1%), bowel injury (1.0%), and splenic injury (2.1%). Orthopedic and thoracic injuries resulted more commonly from high-level falls, whereas abdominal injuries were as likely to occur after a low-level fall. CONCLUSIONS: Intracranial injury accounts for the majority of deaths from falls. Children suffering low-level falls were at similar risk for intracranial and abdominal injuries compared with those who fell from greater heights. Pediatric trauma triage criteria should account for these findings.

Abdominal Injuries↗
PubMed2001

Choroid plexus tumors in children: significance of stromal invasion.

OBJECTIVE: A group of choroid plexus tumors fit the cellular criteria for choroid plexus papilloma (CPP) except for invasion into the adjacent parenchyma, with associated loss of the normal villus architecture at the site of invasion. These tumors retain a benign cellular appearance. In the existing literature, it is unclear whether these tumors are classified as choroid plexus carcinomas or as CPPs. In our experience, although evidence of invasion is present, these tumors tend to exhibit benign behavior. We suggest that stromal invasion of this type remains consistent with a benign clinical course, although surgical results may demonstrate higher morbidity rates, given the invasive nature of the tumors. The failure to classify these tumors as CPPs may explain some of the variability in outcomes reported for various studies. METHODS: To study this question, clinical and histological data for children diagnosed with CPPs (either with or without stromal invasion) between 1985 and 1995 were examined. Only cases with pre- and postoperative magnetic resonance imaging data were included in the series. RESULTS: A total of 12 patients with CPPs were identified, with 4 tumors being notable for stromal invasion. After gross total tumor removal, none of the eight children with CPPs received adjuvant therapy at our institution; all are alive without evidence of tumor recurrence after surgical excision (mean, 108 mo). Of the four patients with stromal invasion, three underwent gross total resection. The one patient who underwent subtotal resection received chemotherapy at another facility. All four of these patients are alive, after a mean of 100 months of follow-up monitoring. CONCLUSION: It is recommended that CPPs with a benign cellular appearance but with evidence of local parenchymal invasion and loss of the normal villus architecture at the site of invasion be classified as CPPs. Patients with these tumors respond to surgical therapy alone, without the need for adjuvant treatment.

Child↗
PubMed2001

Radiosurgical management of benign cavernous sinus tumors: dose profiles and acute complications.

OBJECTIVE: Radiosurgery has emerged as an alternative treatment modality for cranial base tumors in patients deemed not suited for primary surgical extirpation, patients with recurrent or residual tumor after open surgery, or patients who refuse surgical treatment. We review our short-term experience with radiosurgical management of cavernous sinus region tumors with the Leksell gamma knife. METHODS: From August 1994 to February 1999, 69 patients with cavernous sinus lesions were treated in 72 separate treatment sessions. The tumor type distribution was 29 pituitary adenomas, 35 meningiomas, 4 schwannomas, and 1 paraganglioma. The median follow-up was 122 weeks. Lesions were stratified according to a five-level surgical grade. The grade distribution of the tumors was as follows: Grade I, 13; Grade II, 21; Grade III, 19; Grade IV, 12; Grade V, 4. Median tumor volume was 4.7 cm3. The median radiation dose was 15 Gy to the 50% isodose line. Median maximal radiation dose was 30 Gy. RESULTS: Analysis of tumor characteristics and radiation dose to optic nerve and pontine structures revealed a significant correlation between distance and dose. Much lower correlation coefficients were found between tumor volume and dose. One lesion in this series had evidence of transient progression and later regression on follow-up radiographic studies. No other lesions in this series were demonstrated to have exhibited progression. Complications after radiosurgical treatment were uncommon. Two patients had cranial nerve deficits after treatment. One patient with a surgical Grade III pituitary adenoma had VIth cranial nerve palsy 25 months after radiosurgical treatment that spontaneously resolved 10 months later. A patient with a bilateral pituitary adenoma experienced bilateral VIth cranial nerve palsy 3 months after treatment that had not resolved at 35 months after treatment. Six patients with preoperative cranial nerve deficits experienced resolution or improvement of their deficits after treatment. One patient with a prolactin-secreting adenoma experienced normalization of endocrine function with return of menses. CONCLUSION: Radiosurgical treatment represents an important advance in the management of cavernous sinus tumors, with low risk of neurological deficit in comparison with open surgical treatment, even in patients with high surgical grades.

Adolescent↗
PubMed2001

Treating stroke as a medical emergency: a survey of resident physicians' attitudes toward "brain attack" and carotid endarterectomy.

OBJECTIVE: A major impetus of the "brain attack" campaign is the early recognition and treatment of acute stroke. Critical to this goal is the education of physicians during their residency training. METHODS: Resident physicians in Los Angeles who were in family practice (18%), internal medicine (51%), emergency medicine (20%), and neurology (11%) and had already completed their first year of training responded to a questionnaire on stroke and the treatment of carotid stenosis. RESULTS: Of the 266 respondents, 76% had heard of the "brain attack" campaign, 22% did not identify dysarthria as a symptom of stroke, and 21% did not identify obtundation as a presentation of stroke. Twenty-eight percent chose not to use tissue plasminogen activator for acute ischemic stroke, and 60% recognized the need to begin treatment within 3 hours. More than 90% of respondents were able to identify correct screening tests for patients with suspected carotid stenosis. However, 56% responded that they would not advocate operating on patients with asymptomatic severe stenosis (>70%) until stenosis reached a critical value (85%). Conversely, 45% would recommend operative treatment for symptomatic patients who had less than 60% stenosis. Sixty-eight percent would refer patients to vascular surgeons, 14% to neurosurgeons, and 17% to both for carotid endarterectomy. CONCLUSION: Recognition of stroke as a medical emergency is improving. However, significant progress can still be made in the recognition of stroke symptoms. Primary care and neurology residents remain skeptical about carotid endarterectomy for asymptomatic patients, whereas there is enthusiasm for treating stroke survivors. Education by members of the surgical community could promote the aggressive treatment of asymptomatic patients to prevent stroke.

Attitude of Health Personnel↗
PubMed2001

A new, pluronic-based, bone hemostatic agent that does not impair osteogenesis.

OBJECTIVE: Intraoperative bone hemostasis can be accomplished using surgical beeswax (bone wax). However, bone wax locally interferes with osteogenesis, and its use is avoided when bone fusion is critical. We describe the use of a Pluronic copolymer blend as a biocompatible, absorbable, hemostatic agent. METHODS: A rat femur defect model and a femur gap nonunion model were used. For each surgical model, 24 rats were divided into three treatment groups, i.e., those receiving bone wax implants, Pluronic (90% Pluronic P85/10% Pluronic F88) implants, or no implants (control group). After 10, 21, or 42 days, animals were killed and femora were removed for radiographic analysis and hematoxylin and eosin staining. RESULTS: In the femur defect model, no differences were observed between the Pluronic-treated and control groups; hematoxylin and eosin staining demonstrated bone formation and osteocytes within the defect. In the femur gap nonunion model, no fusions occurred in any group. Development of an osseous callus at the gap site was observed for the control and Pluronic-treated groups. In both models, rats that received bone wax implants exhibited no osseous growth. CONCLUSION: The Pluronic blend exhibits handling properties similar to those of bone wax, readily achieves hemostasis, and does not inhibit bone regrowth. Pluronic compounds may serve as effective absorbable hemostatic agents for the treatment of bone bleeding in sites where fusion is critical. In addition, this copolymer blend may find use as a vehicle for the short-term release of pharmacological agents, which may further reduce the incidence of infections, reduce inflammation, and improve fusion rates.

Absorbable Implants↗
PubMed2001

Maternal lung adenocarcinoma metastatic to the scalp of a fetus. Case report.

Maternal malignancy metastatic to the fetus is a rare event, with most neoplasms being either melanocytic or hematopoietic in origin. This report is the first known case of a maternal lung adenocarcinoma metastatic to a fetus. At 2 months of age, this male infant developed multiple scalp masses that were locally resected but rapidly recurred. The histology of the scalp lesions and that of a biopsy of the mother's tumor were both adenocarcinoma and were remarkably similar in appearance. In situ hybridization of tumor cells from this male infant found many large nuclei with XX signals indicating that the tumor was of maternal origin. This patient is alive, well and free of malignancy 5 years after a wide local resection of the scalp and skin grafting.

Adenocarcinoma↗
PubMed2001

Vagus nerve stimulation for control of intractable seizures in childhood.

Vagus nerve stimulation (VNS) is gaining increasing popularity and credibility as a treatment option for children with intractable epilepsy. VNS offers several advantages over extant treatments. Its efficacy is maintained during prolonged stimulation, and seizure control actually improves with time. There is no associated cognitive impairment and no adverse drug interactions. Unlike cerebral surgery, VNS is a potentially reversible form of therapy. The computer-controlled characteristic of the device permits complete and involuntary treatment compliance. VNS is safe and well-tolerated. Its side effects are generally transient and mild, and no physiologic perturbations have been reported despite extensive monitoring. Serious adverse events are rare, and no deaths have been attributed to VNS therapy itself or to the technique of surgical insertion. In this article, we discuss the theoretical background behind VNS and review the clinical studies that substantiate its long-term safety, feasibility, tolerability and potential efficacy in children with refractory epilepsy.

Adolescent↗
PubMed2001

Kwashiorkor in the United States: fad diets, perceived and true milk allergy, and nutritional ignorance.

BACKGROUND: Kwashiorkor is the edematous form of protein-energy malnutrition. It is associated with extreme poverty in developing countries and with chronic malabsorptive conditions such as cystic fibrosis in developed countries. Rare cases of kwashiorkor in affluent countries unrelated to chronic illness have been reported. We present 12 cases of kwashiorkor unrelated to chronic illness seen over 9 years by pediatric dermatologists throughout the United States, and discuss common causative themes in this easily preventable condition. OBSERVATIONS: Twelve children were diagnosed as having kwashiorkor in 7 tertiary referral centers throughout the United States. The diagnoses were based on the characteristic rash and the overall clinical presentation. The rash consisted of an erosive, crusting, desquamating dermatitis sometimes with classic "pasted-on" scale-the so-called flaky paint sign. Most cases were due to nutritional ignorance, perceived milk intolerance, or food faddism. Half of the cases were the result of a deliberate deviation to a protein-deficient diet because of a perceived intolerance of formula or milk. Financial and social stresses were a factor in only 2 cases, and in both cases social chaos was more of a factor than an absolute lack of financial resources. Misleading dietary histories and the presence of edema masking growth failure obscured the clinical picture in some cases. CONCLUSIONS: Physicians should consider the diagnosis of kwashiorkor in children with perceived milk allergies resulting in frequent dietary manipulations, in children following fad or unorthodox diets, or in children living in homes with significant social chaos. The presence of edema and "flaky paint" dermatitis should prompt a careful dietary investigation.

Diet Fads↗
PubMed2000

Outcome prediction following penetrating craniocerebral injury in a civilian population: aggressive surgical management in patients with admission Glasgow Coma Scale scores of 6 to 15.

In an attempt to assess admission Glasgow Coma Scale (GCS) scores and other radiographic variables after penetrating craniocerebral injury in relationship to outcome, the author evaluated a series of 294 patients with penetrating injuries who presented with a GCS score of 6 to 15 over a 6-year period. Entrance criteria required a replicable neurological examination that was not altered by the presence of hypotension, drugs/toxins, or systemic injury. All patients underwent surgical intervention and aggressive perioperative management, including resuscitative protocols, in the neurosurgical intensive care unit. The author previously devised prospective models of outcome remained unchanged in this series. The variables most predictive of death include admission GCS score and subarachnoid hemorrhage in one model and admission GCS score and pupillary changes in a second when pupillary response was definitive at admission (p < or = 0.00005). Other important variables related to morbidity include admission GCS, bihemispheric injury when associated with intraventricular hemorrhage, and diffuse fragmentation (p < or = 0.001). In this study a significant relationship between operative intervention and survival (p < or = 0.01) was found in patients with an admission GCS scores of 6 to 8. No significant relationships between operative intervention and survival were found in patients with admission GCS scores of 9 to 12 and 13 to 15. A significant relationship between operative intervention and morbidity (p < or = 0.01) was also demonstrated in patients with an admission GCS score of 12 to 15. No significant relationships between operative intervention and morbidity were found in patients with an admission GCS score of 6 to 8 and 9 to 12.

Adolescent↗
PubMed2000

Analysis of pediatric head injury from falls.

The authors conducted a study to describe the incidence and types of fall-related head injury observed at a pediatric trauma center. We performed a retrospective analysis of all patients under 15 years of age treated for fall-related trauma between 1992 and 1998. Falls were classified as low (< 15 feet) and high level (> or = 15 feet). Seven hundred twenty-nine cases were identified with a mortality rate of 1.7%. A fall of greater than 15 feet (high-level fall) was associated with a higher mortality rate than low-level falls (2.4% compared with 1.0%, respectively). Ninety-eight patients had sustained a calvarial fracture and 93 experienced a basal skull fracture. Twenty-six patients had suffered a cerebral contusion, 25 a subarachnoid hemorrhage, 22 a subdural hematoma, and 12 had an epidural hematoma. Forty-nine patients required surgery for traumatic injuries; of these, 10 underwent craniotomy for evacuation of a blood clot. Height was not predictive of the Glasgow Coma Scale (GCS) score. In all four deaths resulting from a low-level fall there was an admission GCS score of 3, and abnormal findings were demonstrated on computerized tomography scanning. Death from high-level falls was attributable to either intracranial injuries (50%) or severe extracranial injuries (50%). Intracranial injury is the major source of fall-related death in children and, unlike extracranial insults, brain injuries are sustained with equal frequency from low- and high-level falls in this population. The only cause of mortality from low-level falls was intracranial injury. Trauma triage criteria must account for these differences in the pediatric population.

Accidental Falls↗
PubMed2000

Infestations in the pediatric patient.

This article specifically focuses on arthropods that act as ectoparasites to the human host. A cutaneous eruption caused by the larvae of roundworms is briefly discussed.

Child↗
PubMed2000

A randomized controlled evaluation of specialist nurse education following accident and emergency department attendance for acute asthma.

We investigated whether hospital-based specialist asthma nurses improved recognition and self-treatment of asthma episodes by patients followed up after attending accident and emergency departments (A&E) for asthma exacerbations. We carried out a randomized prospective controlled trial of adult asthma self-management, following a hospital outpatient nurse consultation in two outer-London District General Hospitals (secondary care centres). The study included 211 adults, over 18 years old (mean age 40 years) who attended for asthma in two accident and emergency departments over 13 months. One hundred and eight evaluable patients were randomized into the control group who continued with their usual medical treatment and were not offered any intervention during the study period. One hundred and three evaluable patients were randomized into the intervention group. They were offered three 6-weekly outpatient appointments with one of two specialist asthma nurses for a structured asthma consultation, after attendance at the accident and emergency department. Following assessment of their asthma treatment and control, the nurses advised patients, through the use of self-management-plans, how to recognize and manage uncontrolled asthma and when to seek medical assistance. Medication and inhaler device type were altered if necessary The primary outcome was patient reported self-management of asthma exacerbations for 6 months. Secondary outcomes were assessed at baseline, 3 months and 6 months. These included home peak flow and symptom diaries, structured telephone questionnaires and audit of general practitioner records to determine utilization of services (6 months before and after A&E). Data were analysed on an intention to treat basis by multiple and logistic regression. The intervention group increased their use of inhaled topical steroids in 31/61 (51%) vs. 15/70 (21%) attacks in controls (OR 3.91 CI 1.8-8.4, P<0.001) and their use of rescue medication in 54/61 (89%) severe attacks vs. 53/70 (76%) controls (OR 2.88 CI 1.1-7.9, P<0.05). Intervention patients had significantly higher (mean 20.1 l min(-1); CI 0.4-39.7; P<0.05) and less variable PEF and significantly lower and less variable symptom scores 6 months after entry. Thirty-four percent of intervention patients vs. 42% controls had severe attacks (61 and 70 respectively, OR 0.96 CI 0.7-1.4) during the 6 months. Intervention patients had fewer days off work than controls in the first 3 months (NS) but similar days off during the 6-month period. Intervention patients had fewer episodes away from work in the first (0.34 vs. 0.54, P = 0.08) and the second 3 months (0.25 vs. 0.30, NS) than the controls. Over 80% of the patients records were audited by their general practitioners; the active group had less routine consultations with the doctor (P = 0.03) and practice nurse (P = 0.03), less consultations for uncontrolled episodes (P = 0.06) and less hospital visits (NS) than the controls. Hospital-based specialist nurses reduced asthma morbidity by improving patient self-management behaviour in acute attacks leading to reduced symptoms, improved lung function, less time off work and fewer consultations with health professionals.

Acute Disease↗