Acute paraplegia after myelography: decompensation of a herniatad thoracic disc.

A 71-year-old patient presented with low back pain and slowly progressive weakness of both legs. Within a few hours after lumbar myelography, paraplegia below level L2 evolved. MR-imaging revealed a discogenic stenosis at level Th10/11. Immediate decompression by costo-transversectomy led to reversal of the neurological deficits.

Functional imaging of the cerebral olfactory system in patients with Parkinson's disease.

BACKGROUND: Olfactory dysfunction is a frequent non-motor symptom in Parkinson's disease (PD) and is considered to be an early manifestation of the disease. OBJECTIVE: To establish the cortical basis of olfactory function in patients with PD. METHOD: Functional magnetic resonance imaging (fMRI) was used to investigate brain activity related to olfactory processing in patients with hyposmic PD at mild to moderate stages of the disease (n = 12, median Hoehn and Yahr stage 2.0) and in healthy, age-matched controls (n = 16) while passively perceiving a positively valenced (rose-like) odorant. RESULTS: In both patients with PD and healthy controls, olfactory stimulation activated brain regions relevant for olfactory processing (ie the amygdaloid complex, lateral orbitofrontal cortex, striatum, thalamus, midbrain and the hippocampal formation). In controls, a bilateral activation of the amygdala and hippocampus was observed, whereas patients with PD involved these structures in the left hemisphere only. Group comparison showed that regions of higher activation in patients with PD were located bilaterally in the inferior frontal gyrus (BA 44/45) and anterior cingulate gyrus (BA 24/32), and the left dorsal and right ventral striatum. CONCLUSIONS: In patients with PD, results obtained under the specific conditions used suggest that neuronal activity in the amygdala and hippocampus is reduced. Assuming an impact on olfactory-related regions early in PD, our findings support the idea that selective impairment of these brain regions contributes to olfactory dysfunction. Furthermore, neuronal activity in components of the dopaminergic, cortico-striatal loops appears to be upregulated, indicating that compensatory processes are involved. This mechanism has not yet been demonstrated during olfactory processing in PD.

Spontaneous intracranial hypotension: case report with subdural hematomas, steroid dependency and clinical improvement after myelography.

OBJECTIVE: In spontaneous intracranial hypotension (SIH), also known as spontaneous hypoliquorrhea, an abnormally low intracranial pressure leads to posture-dependent headaches similar to those observed after lumbar puncture. Although its etiology is not yet fully understood, it is now diagnosed more often as clinical awareness increases and the availability of MRI becomes more widespread. CLINICAL PRESENTATION: We report the case of a 42-year-old patient with SIH who developed bilateral subdural hematomas (SDH) and symptomatic diencephalic herniation requiring surgical evacuation. Remarkably, he also developed partial pituitary insufficiency. THERAPY: After SDH was evacuated twice without success, his symptoms resolved rapidly after a diagnostic myelography. CONCLUSION: Besides the orthostatic headache, the possible clinical manifestations are numerous. Serious complications and situations may occur that need to be recognized and treated. In addition to presentation of the case the literature to date is reviewed and discussed.

Microvascular decompression in trigeminal neuralgia with no vascular compression.

BACKGROUND: Microvascular decompression (MVD) is a well-known surgical procedure with one of the best long-term results in the therapy of trigeminal neuralgia. But the exact pathophysiology of this disease has not yet been elucidated. Cases with undetectable vascular compression who are cured after MVD make this dilemma clear. Autopsy studies have also shown vascular compression in asymptomatic cases. METHODS: Five of 40 cases with TN treated with MVD in our clinic had no visible vascular compression. Diagnosis was made with MRI and MRA. RESULTS: Surprisingly all of these 5 patients were cured with MVD. Two of them needed only one operation to become pain free and 3 a second operation. CONCLUSION: We think that the therapeutic effect of MVD is due to minimal trauma of the nerve. It seems that MVD is a good alternative strategy with low complication rates in comparison to ablative procedures.

Dynamics of serum procalcitonin in patients after major neurosurgery.

Classical markers of infection cannot differentiate reliably between inflammation and infection after neurosurgery. This study investigated the dynamics of serum procalcitonin (PCT) in patients following major neurosurgery. PCT concentrations remained < 0.2 ng/mL during the post-operative course. In contrast, leukocyte and neutrophil counts, as well as C-reactive protein (CRP) levels, increased significantly post-operatively (leukocytes, range 7.1-23.7 x 10(9)/L, p < 0.001; neutrophils, range 70.8-94.5%, p < 0.001; CRP, median 14 mg/L, range 3-95 mg/L, p < 0.001). Analysis of PCT levels using assays with improved sensitivity may be useful in the diagnosis of neurosurgical patients with post-operative fever of unknown origin.

Demographics and prevalent risk factors of chronic subdural haematoma: results of a large single-center cohort study.

Chronic subdural haematoma (CSDH) is a typical disease in elderly patients and encountered frequently in neurosurgical practice. With an increasing number of elderly people in the general population, there is a need to investigate risk factors (age, falls, anticoagulant or antithrombotic therapy) which could be pertinent to the development of this disease. We reviewed 354 patients undergoing surgery for CSDH over a period of 7 years (1996-2002), the occurrence being equally distributed over these years. CSDH occurred more often in elderly (> or = 65 years) than in younger people (69 vs 31%), and in men than in women (64 vs 36%). Falls were reported in 77% of patients. There was a trend towards a higher risk of falls in the elderly. Antithrombotic or anticoagulant therapy was present in 41% of patients, 32% of them having had falls. Overall postoperative mortality was 0% and overall recurrence rate 13.6%. CSDH in the elderly population, especially in men, is frequently associated with falls and anticoagulation or antithrombotic therapy. The indication for these medications, especially in elderly patients at risk for falls, should be carefully evaluated and controlled.

Clinical outcome of standard extracranial-intracranial bypass surgery in patients with symptomatic atherosclerotic occlusion of the internal carotid artery.

OBJECTIVE: In this retrospective study we wanted to determine the role of cerebral revascularization in patients with symptomatic occlusive cerebrovascular disease. Special emphasis was put on subsequent cerebrovascular events, benefit in neurological functioning and bypass patency, as evaluated during the follow-up period. METHODS: A total of 73 superficial temporal artery to the middle cerebral artery bypasses were performed on 67 patients from 1986-2000. All patients exhibited a symptomatic occlusion of the internal carotid artery verified by angiography. All patients in our group were refractory to medical treatment. 65 patients (69 bypasses) with a mean age of 61 years (range: 38-79 years) were followed up over an average time of 44 months (range: 1.5-150 months). RESULTS: The peri-operative morbidity rate was 3% with no mortality. 55 patients (85%) had no further cerebrovascular events after surgery, and only 7 (11%) patients experienced another cerebrovascular event. 57 (88%) patients showed an improvement of symptoms after surgery and only 1 patient fared worse during the follow-up period due to a stroke he suffered two years after bypass surgery. 90% of all bypasses remained patent during the follow-up. CONCLUSIONS: Although bypass surgery for occlusive cerebrovascular disease is still controversial, our retrospective study suggests both an improvement of symptoms and signs and a risk-reduction for future cerebrovascular events after surgery.

Local injection of the 90Y-labelled peptidic vector DOTATOC to control gliomas of WHO grades II and III: an extended pilot study.

We have previously presented preliminary observations on targeting somatostatin receptor-positive malignant gliomas of all grades by local injection of the radiolabelled peptidic vector 90Y-DOTATOC. We now report on our more thorough clinical experience with this novel compound, focussing on low-grade and anaplastic gliomas. Small peptidic vectors have the potential to target invisible infiltrative disease within normal surrounding brain tissue, thereby opening a window of opportunity for early intervention. Five progressive gliomas of WHO grades II and III and five extensively debulked low-grade gliomas were treated with varying fractions of 90Y-DOTATOC. The vectors were locally injected into the resection cavity or into solid tumour. The activity per single injection ranged from 555 to 1,875 MBq, and the cumulative activity from 555 to 7,030 MBq, according to tumour volumes and eloquence of the affected brain area, yielding dose estimates from 76+/-15 to 312+/-62 Gy. Response was assessed by the clinical status, by steroid dependence and, every 4-6 months, by magnetic resonance imaging and fluorine-18 fluorodeoxyglucose positron emission tomography. In the five progressive gliomas, lasting responses were obtained for at least 13-45 months without the need for steroids. Radiopeptide brachytherapy had been the only modality applied to counter tumour progression. Interestingly, we observed the slow transformation of a solid, primarily inoperable anaplastic astrocytoma into a resectable multi-cystic lesion 2 years after radiopeptide brachytherapy. Based on these observations, we also assessed the feasibility of local radiotherapy following extensive debulking, which was well tolerated. Targeted beta-particle irradiation based on diffusible small peptidic vectors appears to be a promising modality for the treatment of malignant gliomas.

Extracellular levels of glucose and lactate measured by quantitative microdialysis in the human brain.

The aim of this study was to use quantitative microdialysis to estimate the true extracellular concentrations of glucose and lactate in minimally disturbed human brain. These values are important as criteria for microdialytical monitoring in critical care patients and for determining therapy. Microdialysis procedures were carried out during tumor operations, the probe being inserted distant from the site of manipulation in minimally disturbed tissue. Two methods were used: 1. The zero net flux method of Lönnroth. 2. The low flow method (10 mm membrane length, flow rate 0.3 microliter min-1, high in vivo recovery). Both methods gave similar values of about 2000 microM for lactate and slightly less for glucose (1700 microM). Glucose levels correspond with those measured by other methods in humans, allowing for the fact that our patients were anesthetised. Extracellular glucose levels were positively correlated with blood glucose values measured before the operation, and with extracellular lactate. Results confirm that extracellular glucose is zero when blood glucose is about 2 mM.

Microdialytical monitoring of uric and ascorbic acids in the brains of patients after severe brain injury and during neurovascular surgery.

OBJECTIVES: Microdialysis has been extensively used to monitor brain metabolism in the extracellular fluid of patients with severe head injury, to detect the onset of secondary ischaemic damage. The aim was to investigate whether concentrations of uric and ascorbic acids were altered in such patients. Both these compounds play a part in free radical metabolism, which is accelerated after ischaemia and brain injury. METHODS: Patients with aneurysm or bypass operations were monitored intraoperatively to assess concentrations in minimally disturbed tissue. Afterwards, 13 patients with severe head trauma were monitored for up to 13 days in the intensive care unit. RESULTS: Intraoperatively, concentrations of both ascorbic and uric acids were significantly higher in the bypass group than in patients with aneurysm, which might be attributed to chronic ischaemic conditions caused by the unilateral occlusion of the carotid artery. In the patients with trauma, mean values of uric acid, varying between 6 microM and 180 microM, did not correlate with type of injury (contusion or diffuse) or duration of monitoring time. Patients who died had significantly higher concentrations of uric acid than those with a good outcome. Ascorbic acid could be detected only intermittently, probably due to technical problems. Concentrations of these two compounds could not be correlated with clinical findings during the course of monitoring. CONCLUSIONS: Although uric and ascorbic acids are influenced by ischaemic conditions-for example, in bypass patients, neither compound is suitable for monitoring for free radical activity after severe head injury. Patients with a bad outcome tended to have higher concentrations of uric acid.

Coagulopathy induced spinal intradural extramedullary haematoma: report of three cases and review of the literature.

In a retrospective review of patients operated for coagulopathy induced spinal intradural-extramedullary haematoma the literature regarding coagulopathy induced spinal haemorrhage is reviewed and the etiology of these rare spinal subdural and subarachnoid haemorrhages is discussed. Spinal intradural haematomas are usually related to trauma or a previous lumbar puncture. A review of the literature revealed only a handful cases of spinal intradural haemorrhages occurring secondary to an underlying haematological disorder or an iatrogenic coagulopathy. Coagulopathy induced spinal haemorrhage should be included in the differential diagnosis of acute paraparesis in patients with co-existent haematological disorders or undergoing anticoagulation therapy. Due to the often mixed subdural and subarachnoid bleeding patterns we have termed this entity spinal intradural-extramedullary haematoma.

17beta-Estradiol reduces cortical lesion size in the glutamate excitotoxicity model by enhancing extracellular lactate: a new neuroprotective pathway.

Estrogens play an important role in neuronal function and in protecting neurones in the cerebral cortex against pathological conditions. An in vivo model of glutamate excitotoxicity in which glutamate is applied to the cortex of rats through a microdialysis probe has been used to investigate the neuroprotective processes initiated by 17beta-estradiol. Rats were pre-treated with 17beta-estradiol (i.v.) before local application of 100 mM glutamate into the cortex through a microdialysis probe. Pre-treatment with 17beta-estradiol significantly reduced the size of the glutamate-induced cortical lesion. In the cortical microdialysates collected from the probe, a peak of lactate was observed immediately after glutamate application. After 17beta-estradiol pre-treatment this peak of lactate was significantly higher with estradiol than without 120 min after glutamate application, reaching 700% basal level at the end of measurement. The level of extracellular glucose was markedly decreased with and without 17beta-estradiol pre-treatment. Local blockage of neuronal lactate transporters with alpha-cyano-4-hydroxycinnamate (4-CIN) completely abolished the neuroprotective effect of 17beta-estradiol and induced a larger cortical lesion. An accumulation of extracellular lactate was observed after inhibition of the lactate transporters suggesting that transport of lactate into neurones is necessary for the neuroprotective effect of 17beta-estradiol. The anti-estrogen tamoxifen also abolished the neuroprotective effect of 17beta-estradiol on the lesion size and inhibited the production of lactate. These results suggest a new neuroprotective mechanism of 17beta-estradiol by activating glutamate-stimulated lactate production, which is estrogen receptor-dependent.

Quantitative real-time PCR does not show selective targeting of p14(ARF) but concomitant inactivation of both p16(INK4A) and p14(ARF) in 105 human primary gliomas.

In many human cancers, the INK4A locus is frequently mutated by homozygous deletions. By alternative splicing this locus encodes two non-related tumor suppressor genes, p16(INK4A) and p14(ARF) (p19(ARF) in mice), which regulate cell cycle and cell survival in the retinoblastoma protein (pRb) and p53 pathways, respectively. In mice, the role of p16(INK4A) as the critical tumor suppressor gene at the INK4A locus was challenged when it was found that p19(ARF) only knock-out mice developed tumors, including gliomas. We have analysed the genetic status of the INK4A locus in 105 primary gliomas using both microsatellite mapping (MSM) and quantitative real-time PCR (QRT-PCR). Comparison of the results of the two methods revealed agreement in 67% of the tumors examined. In discordant cases, fluorescence in situ hybridization (FISH) analysis was always found to support QRT-PCR classification. Direct assessment of p14(ARF) exon 1beta, p16(INK4A) exon 1alpha and exon 2 by QRT-PCR revealed 43 (41%) homozygous and eight (7%) hemizygous deletions at the INK4A locus. In 49 (47%) gliomas, both alleles were retained. In addition, QRT-PCR, but not MSM, detected hyperploidy in five (5%) tumors. Deletion of p14(ARF) was always associated with co-deletion of p16(INK4A) and increased in frequency upon progression from low to high grade gliomas. Shorter survival was associated with homozygous deletions of INK4A in the subgroup of glioblastoma patients older than 50 years of age (P=0.025, Anova test single factor, alpha=0.05).

Intramedullary spinal cord tumours: a clinical outcome and radiological follow-up study.

PRINCIPLES: Intramedullary spinal cord tumours are rare. The long-term results depend on their varying natural histories and the surgical approach. Less extensive tumour resection avoids greater postoperative neurological impairment without a negative impact on postoperative outcome. METHODS: Twenty-seven patients who underwent a total of 34 surgical interventions (including 7 reoperations) were clinically and radiologically reinvestigated. Histology revealed 19 glial, 4 nonglial and 4 miscellaneous tumours. RESULTS: Postoperative long-term clinical follow-up (mean 62 months postoperatively) in 25 patients revealed functional improvement in 2 cases, stable conditions in 17 and deterioration in 6. Although there was residual tumour on MRI in 19 of the 22 patients reexamined, stable radiological studies were seen in 15 cases. Despite the high percentage of partial resections or biopsies, good long-term clinical results were found in 19 patients (70%). CONCLUSION: The long-term outcome depends on tumour biology and the type of surgery. For low-grade astrocytomas we propose partial resection without incurring the risk of major postoperative neurological deficits, with semi-annual and, after 5 years, annual follow-up. Despite the fact that ependymomas are amenable to complete surgical resection, this was achieved in only one of six cases in this series. Postoperative MRI follow-up of intramedullary tumours must be protracted, as most of these tumours are slow-growing. An increase in the extent and intensity of contrast enhancement of the tumours was defined as tumour recurrence or progressive tumour growth.

A four lumen screwing device for multiparametric brain monitoring.

We describe multiparametric monitoring in severe head trauma using a new screwing device. Our aim was to create a screw which would make the implantation of the probes and thus multiparametric monitoring easier. The new screw allows us to implant 3 probes (microdialysis, Paratrend and an intracranial pressure device) through one burr hole. The screw has four channels, the fourth being for ventricular drainage. We monitored 13 patients with severe head trauma (GCS = 3-8) for up to 7 days. Brain tissue pO2, pCO2, pH, and temperature were measured on-line with the Paratrend 7 machine. The microdialytic parameters glucose, lactate, pyruvate and glutamate were determined semi on-line with a CMA 600 enzymatic analyser. There were no complications in any of the patients that could be ascribed to the screw.

The PTEN lipid phosphatase domain is not required to inhibit invasion of glioma cells.

The tumor suppressor PTEN negatively controls the phosphoinositide 3-kinase pathway for cell survival by dephosphorylating the phospholipid substrates phosphatidylinositol 3,4-bisphosphate and phosphatidylinositol 3,4,5-trisphosphate. PTEN has been proposed to dephosphorylate focal adhesion kinase and is implicated in the regulation of cell spreading and motility. We analyzed the role of PTEN in invasion using the two highly infiltrative glioma cell lines U87MG (which lacks functional PTEN) and LN229 (wild-type PTEN). After constitutive overexpression of wild-type and phosphatase-deficient (C124S) PTEN, we found significant inhibition of invasion (50-70%) independent of the PTEN status of the cell and of the catalytic core domain of PTEN. Although wild-type but not mutant (C124S) PTEN decreased PKB/Akt phosphorylation and induced a stellate morphology in U87MG cells, an accompanying reduction of focal adhesion kinase phosphorylation was not seen. We conclude that phosphatase-independent domains of PTEN markedly reduced the invasive potential of glioma cells, defining a structural role for PTEN that regulates cell motility distinct of the PKB/Akt pathway.

Treatment of syringomyelia after posttraumatic paraparesis or tetraparesis.

This retrospective study of 12 patients with syringomyelia related to spinal cord trauma with paraplegia or tetraplegia and secondary progressive neurologic deficits was conducted to evaluate various surgical treatments. Judging by the results of postoperative neuroradiologic examinations, 75% had incomplete reduction of the spinal fracture at the time of initial surgery. The secondary neurologic deterioration occurred within a delay of 146 +/- 16 months and included ascending sensory deficits in 92%, deafferentation pain in 83%, and increased motor weakness in 33%. There was a positive correlation between the severity of symptoms, incomplete reduction of spinal fracture, and the degree of arachnoid scarring in preoperative neuroradiologic examinations. Syringoperitoneal shunting was performed in 83% of patients, and laminectomy with arachnoid lysis and dural grafting were performed in 17%. Pain was improved in 75%, sensory deficits in 25%, and motor weakness in 8%. During the follow-up period of 44 +/- 25 months, 30% of patients with syringoperitoneal shunting required repeated operation for obstruction or infection, whereas the syringomyelia remained collapsed in the two patients with laminectomy with arachnoid lysis and dural grafting, but this did not require additional surgery. In conclusion, laminectomy with arachnoid lysis and dural grafting seems to be a promising alternative treatment for patients with secondary neurologic deterioration after traumatic paraplegia or tetraplegia. Syringoperitoneal shunting may be reserved for patients without severe arachnoid scarring.