Neurosurgical Issues Research Articles

Convection-Enhanced Delivery: Neurosurgical Issues

Because primary brain tumors treated with surgery, radiation therapy, and chemotherapy have a poor prognosis, this has led investigators to develop new innovative therapies such as targeted toxins. These large molecules do not cross the blood brain barrier and must be delivered into the brain by a technique known as convection-enhanced delivery (CED). When administering these agents, there are a number of pharmacokinetic considerations that must be considered that will directly affect the volume of distribution of the drug being administered and ultimately the therapeutic effect of the agent. A number of different catheter types have been used to perform CED with a hollow fiber design offering several advantages over other variations. Specific parameters have been developed to optimize the placement of the drug delivery catheters in order to enhance drug distribution in the brain. Considerable effort has been expended to identify a reliable way to image the distribution of targeted toxins administered by CED using a combination of magnetic resonance imaging and single photon emission computed tomography. Unfortunately many infusions performed in tumor patients are unsuccessful due to ventricular/subarachnoid leak or pooling of the drug in necrotic tumor tissue. To date, no targeted toxin clinical trial has demonstrated statistically significant clinical results leading to the universal acceptance of this treatment. Other agents such as standard chemotherapy or liposomal preparations have been delivered by CED. Non-neoplastic neurological diseases are being considered for treatment by CED and treating different locations of the brain other that the cerebral hemispheres are under investigation.

Postoperative assessment of the patient after transsphenoidal pituitary surgery

While most transsphenoidal pituitary surgery is accomplished without complication, monitoring is required postoperatively for a set of disorders that are specific to this surgery. Postoperative assessments are tailored to the early and later postoperative periods. In the early period, which spans the first few weeks after surgery, both monitoring of anterior and posterior pituitary function and managing neurosurgical issues are the focus of care. Potential disruption of pituitary-adrenal function is covered with perioperative glucocorticoids. Various strategies exist for ensuring the integrity of this axis, but typically this is done by measuring a morning cortisol on the 2nd or 3rd postoperative days. Patients with levels <10 microg/l should continue therapy with reassessment in the later postoperative period. Monitoring for water imbalances, which are due to deficiency or excess of ADH (DI or SIADH, respectively), is accomplished by continuous accounting of fluid intake, urine output and specific gravities coupled with daily serum electrolyte measurements. DI is characterized by excess volumes of inappropriately dilute urine, which can lead to hypernatremia. Most patients maintain adequate fluid intake and euvolemia, but desmopressin therapy is required for some. SIADH, which peaks in incidence on 7th postoperative day, presents with hyponatremia that can be severe and symptomatic. Management consists of fluid restriction. Neurosurgical monitoring is primarily for disturbances in vision or neurological function, and although uncommon, for CSF leak and infections such as meningitis. In the later postoperative period, the adrenal, thyroid and gonadal axes are assessed. New persistent hypopituitarism is rare when transsphenoidal surgery is performed by an experienced surgeon. Various strategies are available for assessing each axis and for providing replacement therapy in patients with deficiencies. Long term monitoring with assessments of visual, neurological and pituitary function coupled with pituitary imaging is necessary for all patients who have undergone surgery, irrespective of the hormone status of their tumors.

Familial neurological disorders

ic revolution. The increase in genetic information is occurring at an exponential rate. This new knowledge is leading to major advances in the understanding of disease; in areas of research ranging from inherited abnormalities to the genetics of cancer, we are gaining insight that is leading to new treatment paradigms. Most inherited diseases affecting the central nervous system have been defined by the gene alterations involved. Although many of these genetic diseases have no neurosurgical issues, neurosurgeons do need to be familiar with those syndromes that lead to neurosurgically treatable disease. In addition, neurosurgeons may become involved in the treatment of some of these diseases as the physicians delivering genetic therapy to the brain. This issue of Neurosurgical Focus is devoted to inherited diseases. Review articles covering some of the more common disorders, such as neurofibromatosis and tuberous sclerosis, are included. Both the genetic alterations leading to the syndrome and the molecular events responsible for the abnormalities seen are described. In addition, articles about rare disorders such as Cowden disease are presented. The association of Lhermitte::Duclos syndrome with this disease is of great importance, because of the widespread organ involvement in patients with Cowden disease. Given the complexity of brain development, the finding that there is a genetic basis to malformations that occur during cortical development is not surprising. Included here is an excellent review of the cortical dysplasias and what is known about the genetic alterations leading to these abnormalities. Neurosurg Focus 20 (1):Intro, 2006

724 Injury Patterns from Operation Iraqi Freedom Seen at Walter Reed Army Medical Center and National Naval Medical Center

INTRODUCTION: Operation Iraqi Freedom (OIF) started on March 20, 2003. Major offensive campaigns ended May 1, 2003. Since that time, troops have remained in Iraq serving in a wide variety of roles. The purpose of this paper is to present the experience at Walter Reed Army Medical Center (WRAMC) and National Naval Medical Center-Bethesda (NNMC) with patients who were medically evacuated from the theater for neurosurgical issues over the first year of combat. METHODS: A retrospective chart review was performed on all medical evacuations from OIF to WRAMC and NNMC from March 20, 2003, through March 20, 2004. Patients who were medically evacuated for neurosurgical evaluation or consultation were included. RESULTS: There were 2594 patients evacuated to WRAMC/ NNMC during this time period. Two thousand twenty-three (78%) were from OIF. Neurosurgery was either the primary or consulting service for 281 (14%) of these patients. There were 102 cranial injuries (36%) and 150 (53%) spine or spinal cord disorders. The remaining evacuations were composed of a variety of disorders such as peripheral nerve injuries and newly discovered tumors. One hundred four (37%) were battle injuries and 177 (63%) were nonbattle injuries or disease. Of the cranial cases, 54 (53%) were penetrating head injuries, and 48 (47%) were closed-head injuries. Of the spine cases, 134 (89%) were low back pain, neck pain, or radiculopathies. Sixteen of these cases (11%) were penetrating spine/spinal cord injuries or fractures. CONCLUSION: OIF and continued operations in Iraq represent the longest continuous large-scale active military conflict since Vietnam. By reviewing the medical evacuations from the theater, it is possible to determine the role for a military neurosurgeon in times of war. It also provides evidence for further research into body armor and helmets that eliminate vulnerable areas, such as the neck and face, and are practical for use in austere environments.

Estudio sobre el sistema de guardias en los servicios españoles de neurocirugía

1)To study the alert system (on call duty) in the Spanish neurosurgical departments and main issues of the emergency neurosurgical attention; 2) To establish common sense criteria for a thorough review of the system; 3) To analyse the effects of the current alert system on neurosurgical planning in Spain from the point of view of aging of Spanish neurosurgeons. An interview containing 11 items related to the main aspects of the alert system was developed. The interview was sent to 51 departments. Answer from 42 of them were received. Neurosurgical departments were categorized in two different patterns to analyse the results: 1 st )according to the size of the staff. Three different types were observed:Type A (more than 10 neurosurgeons);Type B (between 6 and 10), and Type C (less than 6). 2 nd ) according to qualification of the personnel receiving the patient in the emergency area:Type I (the patient is received by paramedic personnel);Type II (trainee sends patient to specialist);Type III (training doctor orders diagnostic procedures) and Type IV (neurosurgeon orders diagnostic procedures and decides next actions). Type A departments :This group is formed by 8 departments. Alerts are always mix (at home or in hospital). There are usually 3 neurosurgeons on call (sometimes 4). Staff personnel is on call duty at the hospital 5 days a month plus 5-6 days at home. In 38% of the hospitals, department is type I-II (the patient is initially attended by paramedic personnel, not responsible for diagnostic or treatment). Surgical emergencies account for 0.54 a day as a rule and 12.75 patients require neurosurgeon's attention every day. In 75% of the hospital the neurosurgeon must also read neuroimaging procedures and suture scalps in 37%. Next day, neurosurgeon on call is off duty almost routinely. Type B :it was formed by 21 services. Alert are always mix (at home or in hospital). There are usually two neurosurgeons on call. Staff personnel are on call 4-5 days a month at the hospital and 5-6 days at home. The patient is initially attended by a doctor starting diagnosis in 85% of the cases (types III and IV).They operate 0.52 times a day,attending 6.19 patients/day as a mean. Neurosurgeon must read neuroimaging procedures in 57%. They do not repair scalps (except for a 5%) and personnel is off duty next day routinely. Type C :Nine (9) departments were grouped under this lining. Staff is always on call at home. There is usually only one neurosurgeon (sometimes two). Staff perform 10-12 alerts at home along the month. In 4 of the departments they must duplicate the number of days as far as there are two of them on-call. Patients are attended initially as type III-IV in 100% of the cases (doctor asks for diagnostic tools and decides therapy in 78%). Neurosurgeon on-call receives 4-5 phone-calls a day. Surgical emergencies account for 0.34 a day and 1.84 patients a day are attended directly by them. They never suture scalps. They seldom are off-duty next day. Aging of the Spanish neurosurgeons (389 interviewed). Most important issues are: 152 neurosurgeons will be 55 yo between 2003 and 2008, so they can ask for leaving on-call duties. 121 neurosurgeons will be 65 yo between 2009 and 2013. 1 st ) Alert system, mostly in bigger departments, is disproportioned and does not to fit to reality. 2 nd ) Emergency is worse organized in bigger hospitals. Besides, neurosurgeon on-call is not properly consulted. 3 rd ) Almost routinely neurosurgeons are offduty the day after alert in hospital. 4 th ) 152 neurosurgeons are necessary in the next five years to maintain the current system, which is obviously unviable. 5 th ) Most of the finishing trainees (residents) should tolerate "on-call contracts"in bigger departments to sustain the actual system. 6 th )For future planning, Neurosurgical National Committee must offer 20 training places a year to fill jubilees to happen from 2009 on. Finally we believe that the current alert system cannot be maintained any more, so Health Administratt system cannot be maintained any more, so Health Administrations must develop a profound reform. In this sense, the role that Local Neurosurgical Societies must play is essential.

Neuroscience education of undergraduate medical students. Part I: role of neurosurgeons as educators.

Economic, demographic, and political pressures have mandated that medical schools increase the number of primary care physicians. The goal of this study was to determine the nature of the average medical student's exposure to neurosurgical issues. Surveys were sent to every neurosurgical program director in the United States and to the dean of every medical school in North America, querying the extent of neurosurgical involvement in medical student education. Specifically, the respondents were asked how medical students were educated about the management of low-back pain and radiculopathy, carotid artery disease, head and spine trauma, and headache. Survey results were obtained from 65 (67%) of 97 neurosurgery program directors and from 57 (40%) of 143 medical school deans. Only one program in North America reported having a required neurosurgical rotation for all medical students, and just over 50% (29 of 57 deans and 34 of 65 program directors) reported that neurosurgery was an option in a required neuroscience or surgical subspecialty course. Neurosurgeons were not listed among the top three sources for medical student education in the topics of low-back pain and radiculopathy or carotid artery disease. Neurosurgeons were the most frequently cited source of education regarding head and spinal injuries, despite the fact that the majority of medical schools do not have any required medical student exposure to neurosurgery. With rare exceptions, neurosurgeons are not significantly involved in the education of medical students concerning the management of common neurosurgical issues. As a result, most emerging primary care physicians are taught about these issues by other specialists or not at all. The implications of this situation are discussed.

Neurosurgical issues

Neurosurgical issues