High-grade intramedullary astrocytomas: 30 years’ experience at the Neurosurgery Department of the University of Rome “Sapienza”

J Neurosurg Spine 12:144–153, 2010. (DOI: 10.3171/2009.6.SPINE08910)

The goal in this study was to review a series of patients who underwent surgical removal of intramedul- lary high-grade gliomas, focusing on the functional outcome, recurrence rates, and technical problems continually debated in neurosurgical practice.

Methods. Between December 1976 and December 2006, 22 patients underwent removal of intramedullary high- grade gliomas. Lesions were located in the cervical spinal cord in 12 patients, and in the thoracic cord in 10.

Results. Histological examinations showed 10 Grade III astrocytomas and 12 glioblastomas. Only 2 of the 22 high-grade astrocytomas could be completely removed. The clinical postoperative status worsened in 14 patients (63.6%), was unchanged in 7 patients (31.8%), and there was 1 case of intraoperative death (4.5%). None of the 22 patients showed improvement in their neurological status postoperatively. In this series, excluding the 1 intraopera- tive death, all patients died of progression of the malignancy.

Conclusions. Surgical treatment did not ameliorate the postoperative neurological status; instead, in the majority of cases, it prompted a worsening of the deficit. Radiotherapy and chemotherapy have a little influence on the length of survival. In this series, multimodality treatment of intramedullary high-grade astrocytomas has been shown to increase length of survival without improving the neurological status.

Cognitive and motor improvement after retesting in normal-pressure hydrocephalus: a real change or merely a learning effect?

J Neurosurg 112: 399–409, 2010. (DOI: 10.3171/2009.4.JNS081664)

Object. The test-retest method is commonly used in the management of patients with normal-pressure hydrocephalus (NPH). One of the most widely used techniques in the diagnosis of this condition is evaluation of the
patient’s response to CSF evacuation by lumbar puncture (a so-called tap test or spinal tap). However, interpretation of improved results in subsequent evaluations is controversial because higher scores could reflect a real change in specific abilities or could be simply the result of a learning effect.
Methods. To determine the effect of testing-retesting in patients with NPH, the authors analyzed changes documented on 5 neuropsychological tests (the Toulouse-Pieron, Trail Making Test A, Grooved Pegboard, Word Fluency, and Bingley Memory tests) and several motor ability scales (motor performance test, length of step, and walking speed tests) in a series of 32 patients with NPH who underwent the same battery on 4 consecutive days. The same tests were also applied in 30 healthy volunteers. In both groups, the authors used the generalized least-squares regression method with random effects to test for learning effects. To evaluate possible differences in response depending on the degree of cognitive impairment at baseline, the results were adjusted by using the Mini-Mental State Examination scores of patients and controls when these scores were significant in the model.
Results. In patients with NPH there were no statistically significant differences in any of the neuropsychological
or motor tests performed over the 4 consecutive days, except in the results of the Toulouse-Pieron test, which
were significantly improved on Day 3. In contrast, healthy volunteers had statistically significant improvement in the results of the Toulouse-Pieron test, Trail Making Test A, and Grooved Pegboard test but not in the remaining neuropsychological tests. Patients in the healthy volunteer group also exhibited statistically significant improvement in the motor performance test but not in step length or walking speed.
Conclusions. No learning effect was found in patients with NPH on any of the neuropsychological or motor tests. Clinical improvement after retesting in these patients reflects real changes, and this strategy can therefore be used in both the diagnosis and evaluation of surgical outcomes.

Supracerebellar Infratentorial Approach to Cavernous Malformations of the Brainstem: Surgical Variants and Clinical Experience With 45 Patients

Neurosurgery 66:389-399, 2010. DOI: 10.1227/01.NEU.0000363702.67016.5D

OBJECTIVE: The supracerebellar infratentorial (SCIT) approach can be performed at the midline (median variant), lateral to the midline (paramedian variant), or at the level of the angle formed by the transverse and sigmoid sinuses (extreme lateral variant). We analyzed our experience with SCIT approaches for the surgical treatment of cavernous malformations of the brainstem (CMBs).

METHODS: Demographic, clinical, radiologic, and surgical data from 45 patients (20 males and 25 females; mean age, 36.2 years) with CMBs surgically removed through SCIT approaches were reviewed retrospectively. Anatomic information was explored using cadaver head dissection.

RESULTS: Twenty-three lesions were in the midbrain, 3 were at the midbrain and extended to the thalamus, 9 were at the pontomesencephalic junction, and 10 were in the upper pons. All patients presented with hemorrhage. The median variant was used in 13 patients, the paramedian variant in 9, and the extreme lateral variant in 23. Intraoperatively, all CMBs were associated with a developmental venous anomaly. At last follow-up, 88% of the patients were the same or better. After a mean follow-up of 20 months, their mean Glasgow Outcome Scale score was 4.1.

CONCLUSION: SCIT approaches provide excellent exposure to CMBs located at the posterior incisural space, not only in the midline but also in the posterolateral surface of the upper pons and midbrain. Careful preoperative planning and neuronavigational assistance are needed to determine the best angle of attack and trajectory for SCIT approaches. Refined microsurgical techniques are paramount to achieve safe surgical removal of CMBs with good outcomes.

Long-term back pain after a single-level discectomy for radiculopathy: incidence and health care cost analysis

J Neurosurg Spine 12:178–182, 2010.(DOI: 10.3171/2009.9.SPINE09410)

Object. The most common spinal procedure performed in the US is lumbar discectomy for disc herniation. Long- term disc degeneration and height loss occur in many patients after lumbar discectomy. The incidence of mechanical back pain following discectomy varies widely in the literature, and its associated health care costs are unknown. The authors set out to determine the incidence of and the health care costs associated with mechanical back pain attributed to segmental degeneration or instability at the level of a prior discectomy performed at their institution.

Methods. The authors retrospectively reviewed the data for 111 patients who underwent primary, single-level lumbar hemilaminotomy and discectomy for radiculopathy. All diagnostic modalities, conservative therapies, and operative treatments used for the management of postdiscectomy back pain were recorded. Institutional billing and accounting records were reviewed to determine the billed costs of all diagnostic and therapeutic measures.

Results. At a mean follow-up of 37.3 months after primary discectomy, 75 patients (68%) experienced minimal to no back pain, 26 (23%) had moderate back pain requiring conservative treatment only, and 10 (9%) suffered severe back pain that required a subsequent fusion surgery at the site of the primary discectomy. The mean cost per patient for conservative treatment alone was $4696. The mean cost per patient for operative treatment was $42,554. The esti- mated cost of treatment for mechanical back pain associated with postoperative same-level degeneration or instability was $493,383 per 100 cases of first-time, single-level lumbar discectomy ($4934 per primary discectomy).

Conclusions. Postoperative mechanical back pain associated with same-level degeneration is not uncommon in patients undergoing single-level lumbar discectomy and is associated with substantial health care costs.

Economic impact of improving outcomes of lumbar discectomy

The Spine Journal 10 (2010) 108–116.doi:10.1016/j.spinee.2009.08.453

BACKGROUND: Lumbar discectomy is usually a successful operation with a relatively low cost. Potential adjunctive procedures, such as repairing the anulus fibrosus or nucleus replacements, necessitate a cost-benefit analysis.

PURPOSE: This economic analysis was performed to understand the potential value of advanced implantable technologies designed to improve outcomes after discectomy.

STUDY DESIGN/SETTING: Using an insurance claims–based database, the economics of lessthan- favorable outcomes after lumbar discectomy were studied. Estimates of improved clinical outcomes because of adjunctive surgical procedural items were modeled.

PATIENT SAMPLE: Using Current Procedural Terminology (CPT-4) codes and International Classification of Diseases, Clinical Modification procedure codes (ICD-9 CM), all lumbar discectomy patients were identified in a 6-month period from a large, 2002, commercially available claims-based data set representing 3.1 million insured lives.

OUTCOME MEASURES: Not applicable.

METHODS: Longitudinal data analysis from 3 years (2002–2004) of the database was performed for evidence of claims after the insured’s discectomy (up to 18 months post) as a utilization estimate of surgical and medical treatment resultant of less-than-favorable outcomes. Incidence and cost of secondary operations, medical management, and complications were determined. Using these inputs, an economic model was generated to estimate the effect of improvement in discectomy outcomes.

RESULTS: Of the 494 patients who had a discectomy within a 6-month period, 137 (28%) had subsequent claims that suggested the outcome was less than favorable within 18 months. Patients whose insurance claims included codes for a second operation (n552 patients with 56 operations; 11%) and patients being medically/nonsurgically managed (n585, 17%) were studied. Average reimbursed charges incurred (2006 dollars) of repeated discectomy (80% of cases) was $6,907 and for arthrodesis (20% of cases) was $24,375. Average additional medical treatment cost to diagnose or manage poor outcome requiring another surgery was $3,365. Procedure-related complications within 40 days of surgery were evident in 15% of the group; with additional average cost to manage of $3,939.

CONCLUSIONS: Substantial cost associated with poor discectomy outcomes is often overlooked or underappreciated. Surgical technologies that can improve outcomes of discectomy by 50% to 70% thus improving patient quality of life can be overall cost-neutral between $971 and $1,655 additionally per patient.

Hospital Costs Associated With Shunt Infections in Patients Receiving Antibiotic-Impregnated Shunt Catheters Versus Standard Shunt Catheters

Neurosurgery 66:284-289, 2010 DOI: 10.1227/01.NEU.0000363405.12584.4D

BACKGROUND:The average hospital cost for shunt infection treatment is $50 000, making it the most financially costly implant-related infection in the United States. We set out to determine whether introduction of antibiotic-impregnated shunts (AISs) in our practice has decreased the incidence of shunt infection or decreased infection-related hospital costs at our institution.

METHODS: Clinical and hospital billing records of pediatric patients undergoing cerebrospinal fluid (CSF) shunt insertion at a single institution from April 2001 to December 2006 were retrospectively reviewed. Eighteen months before October 2002, all CSF shunts included standard, non-AIS catheters. During the 4 years after October 2002, all CSF shunts included AIS catheters. Patients were followed at least 18 months after surgery.

RESULTS: A total of 406 pediatric patients underwent 608 shunt placement procedures (400 AISs, 208 non-AISs). Of patients with non-AIS catheters, 25 (12%) experienced shunt infection, whereas only 13 patients (3.2%) with AIS catheters experienced shunt infection during follow-up (P < .001). The total hospital cost to treat 25 non-AIS shunt infections over the first 18 months was $1,234,928. The total hospital cost to treat 13 AIS shunt infections over the past 4 years was $606,328. The mean hospital cost per shunt infection was similar for infected AIS and non-AIS catheters ($46 640 vs. $49 397). However, the infection- related hospital cost per 100 patients shunted was markedly lower in the AIS cohort than in the non-AIS cohort ($151 582 vs. $593 715).

DISCUSSION: The introduction of AIS catheters in our institutional practice reduced the incidence of shunt infection and resulted in significant hospital cost savings. AIS systems are efficient and cost-effective instruments to prevent perioperative colonization of CSF shunt components.

Meningiomas in the elderly, the surgical benefit and a new scoring system

Acta Neurochir (2010) 152:87–97 DOI 10.1007/s00701-009-0552-6

Objective The purpose of the study was to define and identify prognostic indicators within an elderly population of patients suffering from intracranial meningiomas. The clinical presentation of the patient with meningioma is diverse, manifesting as a different clinical entity in the elderly patient compared to a similar type of tumor in a young patient.

Methods Two hundred fifty patients aged over 65 years admitted to RAMBAM Medical Center with meningiomas from 1995–2005 were characterized. We report the present- ing symptoms, chronic illnesses, perioperative and long- term follow-up results for a 5-year period.

Results Based on univariate and multivariate analysis, significant prognostic indicators were identified and were implemented into a new geriatric scoring system (GSS) including tumor size and location, peritumoral edema, neurological deficits, Karnofsky score (Clancey J Neurosci Nurs 27:220, 1995; Crooks et al. J Gerontol 46:M139– M144, 1991), and associated diabetes, hypertension or lung disease. Seven outcome parameters were retrospectively tested using the scoring system, namely mortality, Barthel Index score (Mahoney and Barthel Md State Med J 14:61–65, 1965), Karnofsky score and consciousness expressed by the Glasgow Coma Scale score (Jennett and Bond Lancet 1:480–484, 1975) 5 years after surgery, as well as recurrence within and beyond 12 months. Age proved to inversely correlate with outcome. Morbidity and mortality were significantly lower in women. The extent of surgical resection (Simpson J Neurol Neurosurg Psychiatry 20:22–39, 1957) had no influence on function- al outcome, although radical resection was associated with significantly lower mortality. Generally, a GSS score higher than 14 was associated with a significantly more favorable outcome.

Conclusion The present results suggest that common experience-based considerations may be optimized and implemented into a simple scoring system that in turn may allow for outcome prediction and evidence-based decision making.


Outcome of 132 Operations in 97 Patients With Chordomas of the Craniocervical Junction and Upper Cervical Spine

Neurosurgery 66:59-65, 2010 DOI: 10.1227/01.NEU.0000362000.35742.3D

OBJECTIVE: To study the outcomes of surgery for chordomas of the craniocervical junction and upper cervical spine as well as complication rates, survival, and associated adverse factors.

METHODS: Retrospective review of patients (1982-2007) at 2 European centers who underwent transoral, transfacial, transmandibular, and anterior cervical approaches for excision of chordomas of the craniocervical junction and cervical spine. The χ2 test and Fisher exact test were used to determine significant adverse factors (P < .05), and log-rank survival analysis was used to compare outcome in different groups.

RESULTS: One hundred thirty-two operations were performed in 97 patients. The most common operations were transoral surgeries and maxillotomies. After surgery, neck pain was the same or better in 98.1% of patients. Of the 18.6% of patients who presented with myelopathy, 27.8% improved, 44.4% remained unchanged, and 27.8% deteriorated. Major complication rates were velopharyngeal incompetence, 3.1%; vertebral artery stroke, 1%; wound infection, 3.1%; dysphagia, 3.1%; failure of fixation, 2.1%; sepsis, 3.1%; meningitis, 3.1%; and cerebrospinal fluid leakage, 6.2%. Five- and 10-year overall survivals were 55% and 36%, respectively. Patients who presented to our units for revision surgery, after prior attempts at resection elsewhere, were associated with a worse survival than patients who underwent de novo surgery.

CONCLUSION: We present, to our knowledge, the largest published series of chordomas at the craniocervical junction. Complication rates for these major operations can be minimized at specialist centers, with careful patient selection and counseling. As complete or as radical an operation as possible should be performed at first presentation; the best chance for the patient is the first chance.

Quality of life in obstructive hydrocephalus: endoscopic third ventriculostomy compared to cerebrospinal fluid shunt

Childs Nerv Syst (2010) 26:75–79.DOI 10.1007/s00381-009-0983-7

In the current literature, there are essentially no comparisons of quality of life (QOL) outcome after endoscopic third ventriculostomy (ETV) and shunt in childhood hydrocephalus. Our objective was to compare QOL in children with obstructive hydrocephalus, treated with either ETVor shunt. Methods A cross-sectional survey was conducted at SickKids, Toronto of children between ages five and 18 years, with obstructive hydrocephalus due to aqueductal obstruction and no other brain abnormalities. Measures of QOL were the Hydrocephalus Outcome Questionnaire and the Health Utilities Index Mark 3. A subset of patients was given the Wechsler Intelligence Scales for Children (WISC-IV). Results A total of 47 of 59 (80%) eligible patients participated (24 had ETV as primary treatment, 23 had shunt as primary treatment), with a mean age of 12.1 years (standard deviation 3.9) at assessment. The ETV group was older at initial surgery (p<0.001) and had larger ventricle size at last follow-up (p= 0.047). In all QOL measures, there were no significant differences between the ETV group and shunt group (all p≥ 0.09). Treatment failure, hydrocephalus complications, and the presence of a functioning ETV at assessment were not associated with QOL differences. Among the 11 children (six ETV, five shunt) who were given the WISC-IV, there were no significant differences between the scores of the ETV group and shunt group (all p≥0.11). Conclusions This is the first study to provide a meaningful comparison of QOL after ETV and shunt in children. These preliminary results suggest that there is no obvious difference in QOL after ETVand shunt.

Update on protein biomarkers in traumatic brain injury with emphasis on clinical use in adults and pediatrics

Purpose  This review summarizes protein biomarkers in mild and severe traumatic brain injury in adults and children and presents a strategy for conducting rationally designed clinical studies on biomarkers in head trauma.
Methods  We performed an electronic search of the National Library of Medicine’s MEDLINE and Biomedical Library of University of Pennsylvania database in March 2008 using a search heading of traumatic head injury and protein biomarkers. The search was focused especially on protein degradation products (spectrin breakdown product, c-tau, amyloid-β1–42) in the last 10 years, but recent data on “classical” markers (S-100B, neuron-specific enolase, etc.) were also examined.
Results  We identified 85 articles focusing on clinical use of biomarkers; 58 articles were prospective cohort studies with injury and/or outcome assessment.
Conclusions  We conclude that only S-100B in severe traumatic brain injury has consistently demonstrated the ability to predict injury and outcome in adults. The number of studies with protein degradation products is insufficient especially in the pediatric care. Cohort studies with well-defined end points and further neuroproteomic search for biomarkers in mild injury should be triggered. After critically reviewing the study designs, we found that large homogenous patient populations, consistent injury, and outcome measures prospectively determined cutoff values, and a combined use of different predictors should be considered in future studies.
Doi: 10.1007/s00701-009-0463-6

Meningiomas of the ventral foramen magnum and lower clivus: factors influencing surgical morbidity, the extent of tumour resection, and tumour recurrence

Acta Neurochir (2010) 152:79–86 DOI 10.1007/s00701-009-0511-2

Purpose To identify an appropriate surgical approach for meningiomas of the foramen magnum and lower clivus and determine the factors influencing the surgical outcomes. Method The study involved 23 patients with foramen magnum or lower clival meningiomas (8 men, 15 women; average age, 56 years; range, 26–70 years) treated at Keio University Hospital between 1991 and 2008. Their clinical data were retrospectively reviewed with regard to the surgical approaches and outcomes. The average follow-up duration was 42.8 months, the mean tumour size, 25.9 mm (range, 12.0–50.0 mm).

Findings The tumours most commonly originated in the anterolateral rim of the foramen magnum. In 12 cases with lateral compression of the brain stem, the tumours were resected via the suboccipital approach with C1 laminectomy. The transcondylar approach was adopted in 11 cases where the tumour was located on the anterior rim of the foramen magnum. Four patients required epidural drilling of the jugular tubercle. Gross total resection was achieved in 15 cases (62.5%), the resection rate being lowest in cases of tumour extension to the lower clivus. The transient and permanent morbidity rates were 30.4% and 17.4%, respectively. Logistic regression analysis revealed that extension to the lower clivus (noted in 6 of 23 patients) was a statistically significant, independent factor influencing the permanent morbidity rate (p = 0.005).

Conclusions Selecting an appropriate surgical approach considering the tumour location resulted in a good surgical outcome. However, tumour extension to the lower clivus strongly influenced the morbidity and tumour radicality.

Diagnostic Intracranial Pressure Monitoring and Surgical Management in Idiopathic Normal Pressure Hydrocephalus: A 6-Year Review of 214 Patients

Neurosurgery 66:80-91, 2010 DOI: 10.1227/01.NEU.0000363408.69856.B8

OBJECTIVE: To review our experience of managing idiopathic normal pressure hydrocephalus (iNPH) during the 6-year period from 2002 to 2007, when intracranial pressure (ICP) monitoring was part of the diagnostic workup.

METHODS: The review includes all iNPH patients undergoing diagnostic ICP monitoring during the years 2002 to 2007. Clinical grading was done prospectively using a normal pressure hydrocephalus (NPH) grading scale (scores from 3 to 15). The selection of patients for surgery was based on clinical symptoms, enlarged cerebral ventricles, and findings on ICP monitoring. The median follow-up time was 2 years (range, 0.3-6 years). Both static ICP and pulsatile ICP were analyzed.

RESULTS: A total of 214 patients underwent the diagnostic workup, of whom 131 went on to surgery. Although 1 patient died shortly after treatment, 103 of the 130 patients (79%) improved clinically. This improvement lasted throughout the observation period. The static ICP observed during ICP monitoring was a poor predictor of the response to surgery. In contrast, among 109 of 130 patients with increased ICP pulsatility (ie, ICP wave amplitude >4 mm Hg on average and >5 mm Hg in >10% of recording time), 101 (93%) were responders (ie, increase in the NPH score of >2). Correspondingly, only 2 of 21 (10%) without increased ICP pulsatility were responders. Superficial wound infection was the only complication of ICP monitoring and occurred in 4 (2%) patients.

CONCLUSION: Surgical results in iNPH were good with almost 80% of patients improving after treatment. The data indicate that improvement after surgery can be anticipated in 9 of 10 iNPH patients with abnormal ICP pulsatility, but in only 1 of 10 with normal ICP pulsatility. Diagnostic ICP monitoring had a low complication rate

Outcome After Surgical Treatment for Lumbar Spinal Stenosis. The Lumbar Extension Test Is Not a Predictive Factor

Spine 2009;34:E930–E935

Study Design. A prospective clinical study.

Objectives. To investigate the predictive value of the lumbar extension test for outcome after surgical treatment of lumbar spinal stenosis (LSS).

Summary of Background Data. Studies have indicated that aggravation of the symptoms from LSS by extension of the lumbar spine has predictive value for the outcome after decompression. The aim of this study was to investigate this theory in a larger group of patients.

Methods. One hundred forty-six consecutive patients surgically treated for LSS were included in the study. The clinical condition was recorded before surgery and at 3, 6, 12, and 24 months after surgery using 3 different scoring systems: Swiss Spinal Stenosis Questionnaire, Neurogenic Claudication Outcome Score, and Oswestry Disability Index. The group of patients with preoperative aggravation of the symptoms by the lumbar extension test, (positive extension test), was compared with the group of patients without aggravation by the test, (negative extension test).

Results. Before surgery, patients with a positive extension test scored significantly worse on all disability scoring systems than patients with a negative test. However, the extension test itself had no prognostic value for the overall outcome after lumbar decompression. Using regression models with the 2-year Oswestry Disability Index as dependent variable, only before surgery self-reported health and age were found to have prognostic significance.

Conclusion. The lumbar extension test has no predictive value for the outcome after surgical treatment of LSS

The natural history of untreated sporadic vestibular schwannomas: a comprehensive review of hearing outcomes

J Neurosurg 112:163–167, 2010.(DOI: 10.3171/2009.4.JNS08895)

Observation is an important consideration when discussing management options for patients with vestibular schwannoma (VS). Most data regarding clinical outcomes after conservative management come from modestsized series performed at individual centers. The authors performed an analysis of the published literature on the natural history of VSs with respect to hearing outcome. Their objective was to provide a comprehensive and unbiased description of outcomes in patients whose disease was managed conservatively. Methods. The authors identified a total of 34 published studies containing hearing outcome data in patients with VSs < 25 mm in largest diameter who underwent observation management. The effects of initial tumor size and tumor growth rate on hearing function at latest follow-up were analyzed. Data from individual and aggregated cases were extracted from each study. Patients with poorer hearing (American Association of Otolaryngology–Head and Neck Surgery Classes C or D, or Gardner-Robertson Classes III, IV, or V) at the time of presentation were excluded.

Results. A total of 982 patients met the inclusion criteria for this analysis, with a mean initial tumor size of 11.3 ± 0.68 mm. The mean growth rate was 2.9 ± 1.2 mm/year. The length of follow-up for these studies ranged from 26 to 52 months. Patients with preserved hearing at latest follow-up had a statistically larger initial tumor size than those whose hearing declined during the observation period (11.5 ± 2.3 mm vs 9.3 ± 2.7 mm, p < 0.0001), but the 2-mm difference of means was at the limit of imaging resolution and observer reliability. In contrast, patients with lower rates of tumor growth (≤ 2.5 mm/year) had markedly higher rates of hearing preservation (75 vs 32%, p < 0.0001) compared with patients with higher tumor growth rates. Interestingly, the authors’ analysis found no difference in the rate of reported intervention for patients in either group (16 vs 18%, p = not significant).

Conclusions. These data suggest that a growth rate of > 2.5 mm/year is a better predictor of hearing loss than the initial tumor size for patients undergoing observation management of VSs < 25 mm in largest diameter.