Should we resect peri-lesional hemosiderin deposits when performing lesionectomy in patients with cavernoma-related epilepsy (CRE)?

In this review, the authors perform a database search and summarize and discuss all eligible studies that provide (subgroup) analysis of the postoperative seizure outcome of patients with cavernoma-related epilepsy undergoing sole lesionectomy or lesionectomy including the hemosiderin rim. Based on the currently available data, the authors conclude that if surgical treatment of cavernoma-related epilepsy is performed, the peri-lesional hemosiderin should be resected. However, cases of eloquent or multiple localization or widespread hemosiderin deposit in which a complete resection is challenging should undergo a specific preoperative work-up.

Simultaneous bedside assessment of global cerebral blood flow and effective cerebral perfusion pressure in patients with intracranial hypertension.

BACKGROUND: We examined a bedside technique transcerebral double-indicator dilution (TCID) for global cerebral blood flow (CBF) as well as the concept of effective cerebral perfusion pressure (CPP(eff)) during different treatment options for intracranial hypertension, and compared global CBF and CPP(eff) with simultaneously obtained conventional parameters. METHODS: Twenty-six patients developing intracranial hypertension in the course of traumatic brain injury or subarachnoid hemorrhage were prospectively analyzed using a combined assessment during elevated ventilation (n = 15) or osmotherapy (hypertonic saline or mannitol). For calculation of global CBF, injections of ice-cold indocyanine green boluses were performed and temperature and dye concentration changes were monitored in the thoracic aorta and the jugular bulb. CBF was then calculated according to the mean transit time principle. Estimation of CCP, the arterial pressure at which cerebral blood flow becomes zero, was performed by synchronized registration of corresponding values of blood flow velocity in the middle cerebral artery and arterial pressure and extrapolation to zero-flow velocity. CPP(eff) was calculated as mean arterial pressure minus critical closing pressure (CPP(eff) = MAP(c) - CCP). RESULTS: Elevated ventilation causes a decrease in both ICP (P < 0.001) and CBF (P < 0.001). While CPP(conv) increased (P < 0.001), CPP(eff) decreased during this observation (P = 0.002). Administration of osmotherapeutic agents resulted in a decrease of ICP (P < 0.001) and a temporary increase of CBF (P = 0.052). CPP(conv) and CPP(eff) showed no striking difference under osmotherapy. CONCLUSION: TCID allows repeated measurements of global CBF at the bedside. Elevated ventilation lowered and osmotherapy temporarily raised global CBF. In situations of increased vasotonus, CPP(eff) is a better indicator of blood flow changes than conventional CPP.

Human memory formation is accompanied by rhinal-hippocampal coupling and decoupling.

In humans, distinct processes within the hippocampus and rhinal cortex support declarative memory formation. But do these medial temporal lobe (MTL) substructures directly cooperate in encoding new memories? Phase synchronization of gamma-band electroencephalogram (EEG) oscillations (around 40 Hz) is a general mechanism of transiently connecting neural assemblies. We recorded depth-EEG from within the MTL of epilepsy patients performing a memorization task. Successful as opposed to unsuccessful memory formation was accompanied by an initial elevation of rhinal-hippocampal gamma synchronization followed by a later desynchronization, suggesting that effective declarative memory formation is accompanied by a direct and temporarily limited cooperation between both MTL substructures.

Sensory gating in the human hippocampal and rhinal regions.

OBJECTIVE: The objective of this work was to ascertain if sensory gating can be demonstrated within the human medial temporal lobe. METHODS: Eight patients with intractable epilepsy with depth electrodes implanted in the medial temporal lobe for pre-surgery evaluation underwent evoked response recording to auditory paired-stimuli (S1-S2). Each of the eight subjects had a diagnosis of left medial temporal lobe epilepsy (MTLE). RESULTS: Data from the non-focal right hippocampi revealed a large negative response on S1 (starting at about 190 ms and lasting for approximately 300 ms from stimulus onset). Rhinal region recordings revealed a positive response (starting at about 240 ms with a rapid incline, followed by a long-lasting decline). A significant attenuation of both responses to S2 stimuli was observed. CONCLUSIONS: Data are suggestive of an involvement of the human medial temporal lobe in the processing of simple auditory information which occurs in a time frame later than the neocortical auditory evoked components. The exact role of these anatomical structures in the sensory gating process remains to be defined. SIGNIFICANCE: This study provides the first evidence of an activation of the rhinal cortex after simple auditory stimulation and provides new evidence that the activation of the medial temporal lobe structures occurs at a later stage than that of the neocortex.

[The trend sport snowblading and its risks]. / Der Trendsport Snowblading und seine Risiken.

The study analysed the results of an examination of 3557 skiing, snowboarding and snowblading injuries treated at the Department of Trauma Surgery at the Klinikum Garmisch-Partenkirchen in winter seasons 99/00 through 02/03. In this study group, a total of 70 injuries occurred while snowblading. These injuries are compared to the remaining injuries resulting from skiing, carving or snowboarding accidents. This study intends to contribute to the tracking and recording of injuries occurring during snowblading, a sport that is popular but not yet well-addressed in medical literature. The results show that snowblading injuries are similar to those of skiing, but different from those attributable to snowboarding, particularly with regard to the affected parts of the body and injury patterns. Acrobatic jumps increase significantly the risk of fractures of the lower extremities. However, ruptures of ligaments, especially of the ACL, are seen more rarely in snowblading than in carving or conventional skiing. Distorsions, on the other hand, are observed significantly more often among snowbladers when compared with carvers and snowboarders. Release bindings for snowblades could reduce the risk of injuries.

Limbic encephalitis not associated with neoplasm as a cause of temporal lobe epilepsy.

OBJECTIVE: To describe four patients with temporal lobe epilepsy with limbic encephalitis unrelated to neoplasm. METHODS: The authors performed a retrospective evaluation of patient data obtained during presurgical evaluation, with additional CSF analyses, serum analyses, and histopathologic investigations. RESULTS: The patients shared the following clinical features: onset of the disease in young adulthood with subacute onset or exacerbation of frequent intractable temporal lobe seizures, verbal and visual memory deficits, and affective abnormalities. MRI showed variably extended areas of increased T2 signal in limbic structures and adjacent areas. In the histopathologic investigation, chronic inflammation was observed without evidence of a viral origin. There was no evidence of an underlying malignancy. CONCLUSIONS: Nonparaneoplastic limbic encephalitis should be included in the differential diagnosis of adult patients with temporal lobe epilepsy.

Expression of the 100-kDa neurotensin receptor sortilin during mouse embryonal development.

Recently, sortilin a non G-protein-coupled receptor has been identified as the 100-kDa neurotensin receptor. In this paper we describe the expression of its gene during mouse embryonal development. We show that the nervous system is the main location of sortilin gene expression and that with ongoing development the forebrain exhibits the highest accumulation of transcripts.

Hippocampal function and visual object processing in temporal lobe epilepsy.

Limbic event-related potentials related to verbal but not to visual recognition memory have been found to be attenuated within the epileptic hippocampus of patients with temporal lobe epilepsy (TLE). To identify hippocampal contributions to visual processing and memory we recorded intracranial ERPs directly from within the epileptic and the non-epileptic hippocampus in 12 patients with unilateral TLE during a visual object decision and naming task. While the non-epileptic hippocampus differentiated reliably between real and nonsense objects, this effect was completely eliminated within the epileptic mesial temporal lobe. This finding suggests that the hippocampus proper contributes to the semantic processing of visual objects and may help to explain visual memory deficits in TLE.

SorCS1, a member of the novel sorting receptor family, is localized in somata and dendrites of neurons throughout the murine brain.

The expression of the sorCS1 protein in the central nervous system of adult mice was studied by immunohistochemistry. A detailed mapping revealed a distribution of sorCS1 immunoreactivity in a widespread population of neurons throughout the brain. Two different types of cellular localization were observed. Many neurons exhibited a punctate cytoplasmic staining which extended into the dendrites, in other neurons sorCS1 immunoreactivity was associated with the plasma membrane. This suggests variable functions for sorCS1 in the neurons of the brain.

Isolation and characterisation of five neurotoxic and cardiotoxic polypeptides from the sea anemone Anthopleura elegantissima.

Five toxins (APE 1 to APE 5) of the sea anemone species Anthopleura elegantissima (Brandt) have been isolated from a toxic by-product fraction of its concentrated crude watery-methanolic extract, prepared previously for the isolation of a neuropeptide (the head-activator) by Schaller and Bodenmüller (Proc. Natl. Acad. Sci. USA 78 (1981) 7000) from 200kg sea anemones. Toxin purification was performed by desalting of the starting material by dialysis (MWCO 3500) against distilled water, anion exchange chromatography on QAE-Sephadex A25 at pH 8, twice gel filtration on Sephadex G50 m, repeated chromatography on QAE-Sephadex at pH 10 and chromatography on the cation exchanger Fractogel EMD SO(3)(-)-650 M.Final purification of the toxins was achieved by HPLC on MN SP 250/10 Nucleosil 500-5 C(18) PPN and MN SP 250/21 Nucleosil 300-7 C(18). Each toxin was composed of at least two isotoxins of which APE 1-1, APE 1-2, APE 2-1, APE 2-2 and APE 5-3 were isolated in preparative scale. With exception of APE 5-3 the sequences of the isotoxins have been elucidated. They resemble the 47 residue type-I long polypeptide toxins native to Anemonia sulcata (Pennant). All isotoxins paralyse the shore crab (Carcinus maenas) by tetanic contractions after i.m. application. The toxins modify current passing through the fast Na(+) channel in neuroblastoma cells, leading to delayed and incomplete inactivation. APE 1-1, APE 2-1 and APE 5-3 produce a positive inotropic effect in mammalian heart muscle, although they differ in potency. The order of potency is APE 2-1>APE 1-1>APE 5-3 (i.e. threshold concentrations are 1, 10 and 300nM, respectively). In addition, they enhance the spontaneous beating frequency in isolated right atria (guinea pig). The most potent cardiotoxic isotoxin is APE 2-1, its sequence is identical with that of AP-C, a toxin isolated and characterised previously by Norton et al. (Drugs and Foods from the Sea, 1978, University of Oklahoma Press, p. 37-50).LD50 APE 2-1:1 micro g/kg b.w. C. maenas (i.m.). LD50 APE 1-1:10 microg/kg b.w. C. maenas (i. m.). LD50 APE 5-3:50 microg/kg b.w. C. maenas (i.m.).

Microsurgical results for small arteriovenous malformations accessible for radiosurgical or embolization treatment.

OBJECTIVE: A consecutive series of microsurgically treated small arteriovenous malformations (AVMs), up to 3 cm in diameter, which are theoretically ideal candidates for radiosurgery or embolization, is described. We intended to elucidate the safety and efficacy of the microsurgical removal of AVMs, as compared with the results for radiosurgery and embolization reported in the literature. METHODS: Sixty-two patients (32 female and 30 male patients) ranging in age from 7 to 72 years (mean age, 33.3 yr) were included in the series. Of these, 46.8% presented with intracerebral hemorrhage and 24.2% presented with seizures. The 62 patients underwent microsurgical removal of their small (<3 cm) cerebral AVMs by the same surgeon. Twenty-six AVMs (41.9%) were assigned Spetzler-Martin Grade I, 24 (38.7%) were assigned Grade II, and 12 (19.4%) were assigned Grade III. Thirty-three AVMs (53.2%) were located in eloquent brain regions. All patients underwent postoperative control angiography and clinical follow-up after 3 and 6 months. RESULTS: The AVMs were extirpated, as confirmed by angiography, in all except one patient, thereby accounting for a 98.4% success rate per angiographic findings. The rate of immediate new postoperative neurological deficits or worsening of preexisting neurological deficits was 27.4%, and the rate of permanent significant neurological deficits was 3.2% at late follow-up. The rate of permanent significant deficits occurring after the microsurgical removal of small AVMs in eloquent regions was 6.1%. The mortality rate in the reported series was 0%. The surgical morbidity rate was 9.7%. CONCLUSION: Microsurgery for small AVMs is superior to radiosurgery or interventional neuroradiology because of its high rate of efficacy and low rate of permanent morbidity and because immediate cure of the AVMs can be achieved in the vast majority of patients. The place for radiosurgery in the treatment of small AVMs needs to be more sharply defined after careful assessment of relevant cases by an experienced vascular neurosurgeon.

Stereotactic puncture and lysis of spontaneous intracerebral hemorrhage using recombinant tissue-plasminogen activator.

We have tested a treatment protocol for intracerebral hemorrhage (ICH), consisting of stereotactic insertion of a catheter into the clot, hematoma lysis by the injection of a fibrinolytic agent, recombinant tissue-plasminogen activator (rt-PA), and closed system drainage of the liquefied clot. Fourteen patients underwent computed tomographically guided stereotactic hematoma puncture and silicone tube insertion within 72 hours of intracerebral hemorrhage. The majority (nine patients) suffered from ganglionic ICH, and the size of the hematoma ranged between 3 x 3 x 4 cm and 7 x 7 x 4 cm (mean, 5.2 x 4 x 3.6 cm). All patients had major neurological deficits with or without an impaired level of consciousness, but without signs of transtentorial herniation. The initial, then daily, dose (in milligrams) of rt-PA administered via the silicone tube equalled the maximal diameter (in centimeters) of the original and remaining clot as measured initially, then daily, by computed tomographic scan. The number of rt-PA injections was four in one patient, three in eight patients, two in four patients, and one in one patient, and the total dose of rt-PA required ranged from 5 to 16 mg (mean, 9.9 mg). After rt-PA injection, the tubing was clamped for 2 hours and then opened to drain spontaneously through a closed system against 0 cm of pressure. At follow-up 6.6 months (mean) after treatment (ranging from 3 to 13 months) and according to the Glasgow outcome score, one patient was Grade V, four were Grade IV, five were Grade III, two were Grade II, and two had died.(ABSTRACT TRUNCATED AT 250 WORDS)

Transconjunctival approach to a large cavernoma of the orbit.

Orbital tumors, particularly those within the retrobulbar space, are sometimes approached by neurosurgeons as well as by ophthalmic and by maxillofacial surgeons. There are numerous descriptions for the operative techniques applied in this area. Most lesions are attacked extracranially via a lateral orbitotomy or transcranially, with or without resection of the sphenoid bone or the orbital rim. Less traumatic approaches in patients harboring a tumor in this functionally and cosmetically important region, therefore, are desirable. We describe a microneurosurgical transconjunctival approach to a large retrobulbar cavernoma in a 59-year-old man. This technique has led to a very satisfactory result, and the operation can be performed without transient section of extraocular muscles in sections.

Emergency ventriculostomy-experience with a new screw device: technical note.

Emergency situations, such as acute hydrocephalus or ventricular hemorrhage, require immediate and reliable treatment by ventriculostomy. The method used has to be standardized, applicable in a fast manner, and associated with only minimum risk of infection. We present a recently developed set for external ventriculostomy, which meets the above-standing requirements, and which consists of a screw with self-biting thread, a metal cannula, and a special screwdriver. Ventriculostomy can be performed easily within 2 minutes, and the system can be fixed rigidly to the skull of the patient for a period of up to several weeks. Exchange of the cannula is possible within 1 minute. The system has been used in 90 cases so far, with a rate of possible infection of 1.1%.

Is there a benefit of preoperative meningioma embolization?

OBJECTIVE: To evaluate the effect of preoperative embolization of meningiomas on surgery and outcomes. METHODS: In a prospective study, 60 consecutive patients with intracranial meningiomas who were treated in two neurosurgical centers were included. In Center A, embolization was performed for none of the patients (n = 30). In Center B, 30 consecutive patients with embolized meningiomas were treated. Preoperatively, tumor size and location, neurological status, and Barthel scale score were recorded. In Center B, the extent of tumor devascularization was evaluated using angiography and postembolization magnetic resonance imaging. Intraoperatively, blood loss, the numbers of blood units transfused, and the observations of the neurosurgeon concerning hemostasis, tumor consistency, and intratumoral necrosis were recorded. Postoperatively, the neurological status and duration of hospitalization were recorded. Six months after surgery, the outcomes were assessed using the Barthel scale and neurological examinations. RESULTS: The mean tumor sizes were 22.9 cc in Center A and 29.6 cc in Center B (P > 0.1). The mean blood losses did not differ significantly (646 ml in Center A versus 636 ml in Center B; P > 0.5). However, for a subgroup of patients with subtotal devascularization (>90% of the tumor) on postembolization magnetic resonance imaging scans in Center B, blood loss was less, compared with the entire group in Center A (P < 0.05). The observations of the neurosurgeon regarding hemostasis, tumor consistency, and intratumoral necrosis did not differ significantly. There were no surgery-related deaths in either center. The rates of surgical morbidity, with permanent neurological worsening, were 20% (n = 6) in Center A and 16% (n = 5) in Center B. There was one permanent neurological deficit (3%) caused by embolization. CONCLUSION: In this preliminary study, only complete embolization had an effect on blood loss. The value of preoperative embolization for all meningiomas must be reconsidered, especially in view of the high costs and risks of embolization.

Is stagnating flow in former feeding arteries an indication of cerebral hypoperfusion after resection of arteriovenous malformations?

OBJECT: The authors' goal in this study was to challenge the proposed mechanism of the occlusive hyperemia theory, in which it is asserted that stagnating flow in the former feeding arteries of cerebral arteriovenous malformations (AVMs) leads to parenchymal hypoperfusion or ischemia, from which postoperative edema and hemorrhage originate. METHODS: Cortical oxygen saturation (SaO2) was measured in 52 patients by using microspectrophotometry in areas adjacent to AVMs before and after resection. The appearance of the former feeding arteries was categorized as normal (Group A); moderately stagnating (Group B); and excessively stagnating (Group C) on postoperative angiographic fast-film series. Patients and SaO2 values were pooled accordingly and compared using analysis of variance and Duncan tests (p < 0.05). Angiographic stagnation times in former feeding arteries were correlated in a linear regression/correlation analysis with SaO2 data (p < 0.05). All values are given as the mean +/- standard deviation. The average median postoperative SaO2 in Group C (15 patients) was significantly higher than in Groups B (17 patients) and A (20 patients) (Group C, 75.2 +/- 8.5; Group B, 67.5 +/- 10.8; Group A, 67.1 +/- 12 %SaO2), as was the average postoperative increase in SaO2 (Group C. 25.9 +/- 14.9; Group B, 14.6 +/- 14; Group A, 11.1 +/- 14 %SaO2). Angiographically confirmed stagnation times were also significantly longer in Group C than in Group B (Group C, 5.6 +/- 2.5; Group B, 1.3 +/- 0.6 seconds). A significant correlation/regression analysis showed a clear trend toward higher postoperative SaO2 levels with increasing stagnation time. CONCLUSIONS: Stagnating flow in former feeding arteries does not cause cortical ischemia, but its presence on angiographic studies is usually indicative of hyperperfusion in the surrounding brain tissue after AVM resection. In the context of the pathophysiology of AVMs extrapolations made from angiographically visible shunt flow to blood flow in the surrounding brain tissue must be regarded with caution.

Percutaneous ventriculostomy--evolution of a device.

The technique applied for external ventriculostomy should allow simple, fast, stable and clean performance of this procedure. The stepwise development of a metallic ventriculostomy kit should help overcome shortcomings of traditional methods of external ventriculostomy such as catheter obstruction and propensity for infection. A rigid ventriculostomy set for precoronary puncture was developed, consisting of a screw with selfbiting conical thread and a cannula with distal holes for CSF drainage. The rate of infection was < 2% in nonseptic patients with a mean duration of the ventriculostomy of 11 days (maximum: 2 months). Hemorrhage occurred in 1% of patients. Problems were secondary wound healing after prolonged periods with ventriculostomy in place and rapid CSF-infection in cases of loosened screws which were not instantly removed. Ventriculostomy can be performed bedside within 5 min and clotted cannulas can be exchanged via the indwelling screw. The system can be resterilized and the titanium device is MRI-compatible. The method tested compares favorably with conventional techniques of external ventriculostomy. Use of the system requires continuous education of the personnel involved in order to avoid complications such as hemorrhage and loosening of the screw.

Physiological steal around AVMs of the brain is not equivalent to cortical ischemia.

To challenge the concept of steal rendering the surrounding cortex ischemic, we examined patterns of nutritive capillary flow in the vicinity of AVMs. With a spectrophotometer (EMPHO, BGT) capillary O2 saturation (O2 satn.) was intraoperatively scanned around AVMs in n = 44 patients and in n = 42 controls. 130,000 O2 satn. values before AVM resection were calculated as medians, ratio of critical values (< 25% O2 satn.), coefficients of variance and compared via ANOVA (p < 0.05). n = 40 AVM patients had no postoperative complication (group A), while in n = 4 cases a hyperperfusion syndrome occurred (group B). Physiological variables were comparable among groups A, B and C (controls). Medians (A: 52.9+/-16.3, B: 44.2+/-17.1, C: 51.9+/-11.5% O2 satn.) and the ratio of critical values (A: 6.5+/-5.1, B: 14.7+/-11.1, C: 7.1+/-4.9 O2 satn.) were identical in groups A and C, but significantly different in group B, indicating exhausted compensation. Decreased flow heterogeneity in group A (A: 20.2+/-12.7, B: 27.9+/-12.4, C: 26.8+/-10.9 O2 satn.) kept median cortical perfusion identical to group C. These results confirm recent findings, that cerebrovascular adaption by capillary recruitment keeps CBF at normal levels in the majority of cases and that chronic noninfarctional cerebral hypoperfusion is eventually the equivalent of steal around AVMs. Only around AVMs predisposed to hemodynamic derangement some areas of local low flow anoxia may exist.

Spondylodiscitis after lumbar discectomy. Incidence and a proposal for prophylaxis.

STUDY DESIGN: An analysis of the incidence of spondylodiscitis after lumbar disc surgery in 1642 patients. In 508 patients no prophylactic antibiotics were given. In 1134 patients a collagenous sponge containing gentamicin was placed in the cleared disc space. OBJECTIVES: To report the incidence of postoperative spondylodiscitis in cases in which no antibiotic prophylaxis was used, and to define the value of a collagenous sponge containing gentamicin in preventing disc space infections. SUMMARY OF BACKGROUND DATA: Spondylodiscitis is considered to be a rare complication of lumbar disc surgery. The retrospective design of most studies and the rare use of magnetic resonance imaging for early radiologic diagnosis suggest that the reported incidence rates may be underestimates. Postoperative spondylodiscitis is the result of intraoperative contamination and, theoretically, could be prevented by treating these patients with prophylactic antibiotics. METHODS: In 1642 patients, 1712 discectomies were performed. In 508 of these patients no prophylactic antibiotics were given; in 1134 of these patients a collagenous sponge containing gentamicin was placed in the cleared disc space. Clinical reexamination and, in cases of unsatisfactory results, laboratory and radiologic investigations were performed 4-8 weeks after surgery. RESULTS: In nineteen of the 508 patients who were not treated with antibiotic prophylaxis (3.7%) a postoperative spondylodiscitis developed, whereas none of the 1134 patients who received antibiotic prophylaxis became symptomatic (P < 0.00001). CONCLUSION: In the current study, a 3.7% incidence of postoperative spondylodiscitis was found in the absence of prophylactic antibiotics. Gentamicin-containing collagenous sponges placed in the cleared disc space were effective in preventing postoperative spondylodiscitis.

[Intravenous DSA following kidney transplantation]. / Intravenöse DSA nach Nierentransplantation.

Intravenous DSA is a simple angiographic technique in the follow-up of patients with renal transplants. It is of value in the post-operative anuric phase, for investigating renal function which is deteriorating and for demonstrating, or excluding, stenosis of the renal artery at the anastomosis during the development of hypertension. Changes in the peripheral arteries are not usually demonstrable. Reduced opacification of the parenchyma is observed during rejection and if there has been damage to the transplant, but is not seen if the transplant is functioning normally.