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Fatal secondary increase in serum S-100B protein after severe head injury

Report of three cases

Andreas Raabe and Volker Seifert

✓ The S-100B protein is a small cytosolic protein that is found in astroglial or Schwann cells. It is highly specific for brain tissue and is increasingly being investigated as a diagnostic tool to assess the neurological damage after head injury, stroke, subarachnoid hemorrhage, and cardiopulmonary bypass.

The authors report on three patients with severe head injury with otherwise normal cerebral perfusion pressure, SaO2, PaCO2, and controlled intracranial pressure (ICP), in whom a secondary excessive increase in serum S-100B was observed. In all cases, the S-100B increase was followed by an increase in ICP. All three patients died within 72 hours after the excessive increase in S-100B. These findings indicate that major secondary brain damage may occur at a cellular level without being identified by current neuromonitoring techniques.

In Journal of Neurosurgery Volume 91: Issue 5 (Nov 1999)

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Revisiting the rules for freehand ventriculostomy: a virtual reality analysis

Clemens Raabe, Jens Fichtner, Jürgen Beck, Jan Gralla, and Andreas Raabe

OBJECTIVE

Frontal ventriculostomy is one of the most frequent and standardized procedures in neurosurgery. However, many first and subsequent punctures miss the target, and suboptimal placement or misplacement of the catheter is common. The authors therefore reexamined the landmarks and rules to determine the entry point and trajectory with the best hit rate (HtR).

METHODS

The authors randomly selected CT scans from their institution’s DICOM pool that had been obtained in 50 patients with normal ventricular and skull anatomy and without ventricular puncture. Using a 5 × 5–cm frontal grid with 25 entry points referenced to the bregma, the authors examined trajectories 1) perpendicular to the skull, 2) toward classic facial landmarks in the coronal and sagittal planes, and 3) toward an idealized target in the middle of the ipsilateral anterior horn (ILAH). Three-dimensional virtual reality ventriculostomies were simulated for these entry points; trajectories and the HtRs were recorded, resulting in an investigation of 8000 different virtual procedures.

RESULTS

The best HtR for the ILAH was 86% for an ideal trajectory, 84% for a landmark trajectory, and 83% for a 90° trajectory, but only at specific entry points. The highest HtRs were found for entry points 3 or 4 cm lateral to the midline, but only in combination with a trajectory toward the contralateral canthus; and 1 or 2 cm lateral to the midline, but only paired with a trajectory toward the nasion. The same “pairing” exists for entry points and trajectories in the sagittal plane. For perpendicular (90°) trajectories, the best entry points were at 3–5 cm lateral to the midline and 3 cm anterior to the bregma, or 4 cm lateral to the midline and 2 cm anterior to the bregma.

CONCLUSIONS

Only a few entry points offer a chance of a greater than 80% rate of hitting the ILAH, and then only in combination with a specific trajectory. This “pairing” between entry point and trajectory was found both for landmark targeting and for perpendicular trajectories, with very limited variability. Surprisingly, the ipsilateral medial canthus, a commonly reported landmark, had low HtRs, and should not be recommended as a trajectory target.

In Journal of Neurosurgery Volume 128: Issue 4 (Apr 2018)

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Efficacy of silver-bearing external ventricular drainage catheters: a retrospective analysis

Clinical article

Jens Fichtner, Erdem Güresir, Volker Seifert, and Andreas Raabe

Object

Catheter-related infection of CSF is a potentially life-threatening complication of external ventricular drainage (EVD). When using EVD catheters, contact between the ventricular system and skin surface occurs and CSF infection is possible. The aim of this analysis was to compare the efficacy of silver-bearing EVD catheters for reducing the incidence of infection with standard nonimpregnated EVD catheters in neurosurgical patients with acute hydrocephalus.

Methods

Two hundred thirty-one consecutive patients were retrospectively reviewed. Of these, 164 were enrolled in the final analysis. Six patient charts were incomplete or missing, 15 patients were excluded because of catheter insertion within the previous 30 days, 6 because of a suspected CSF infection before ventriculostomy, 7 because the catheter was removed < 24 hours after insertion, and 33 patients because of the requirement of bilateral ventriculostomy. The control group with standard nonimpregnated EVD catheters consisted of 90 patients. The study group with silver-bearing EVDs consisted of 74 patients. For assessing the primary outcome, the authors recorded all CSF samples and liquor cell counts routinely obtained in sterile fashion. After removal of the catheters, they also reviewed microbiology reports of the removed catheters to assess colonization of the catheter tips.

Results

The occurrence of a positive CSF culture, colonization of the catheter tip, or liquor pleocytosis (white blood cell count > 4/μl) was ~ 2 times less in the study group with silver-bearing EVD catheters than that in the control group (18.9% compared with 33.7%, p = 0.04). Positive CSF cultures alone occurred 2 times less frequently for microorganisms in the study group (2.7% compared with 4.7%, p = 0.55). Silver-bearing catheters were 4 times less likely to become colonized as nonimpregnated EVDs (1.4% compared with 5.8%, p = 0.14). Liquor pleocytosis was half as likely in the study group (17.6% compared with 30.2%, p = 0.06).

Conclusions

Although of limited sample size and thus underpowered for subgroup analysis, this analysis indicates that EVD catheters impregnated with silver nanoparticles and an insoluble silver salt may reduce the risk of catheter-related infections in neurosurgical patients.

In Journal of Neurosurgery Volume 112: Issue 4 (Apr 2010)

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Hypervolemia in Cerebral Vasospasm

Andreas Raabe and Bertil Romner

In Journal of Neurosurgery Volume 104: Issue 6 (Jun 2006)

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Continuous dynamic mapping of the corticospinal tract during surgery of motor eloquent brain tumors: evaluation of a new method

Clinical article

Andreas Raabe, Jürgen Beck, Philippe Schucht, and Kathleen Seidel

Object

The authors developed a new mapping technique to overcome the temporal and spatial limitations of classic subcortical mapping of the corticospinal tract (CST). The feasibility and safety of continuous (0.4–2 Hz) and dynamic (at the site of and synchronized with tissue resection) subcortical motor mapping was evaluated.

Methods

The authors prospectively studied 69 patients who underwent tumor surgery adjacent to the CST (< 1 cm using diffusion tensor imaging and fiber tracking) with simultaneous subcortical monopolar motor mapping (short train, interstimulus interval 4 msec, pulse duration 500 μsec) and a new acoustic motor evoked potential alarm. Continuous (temporal coverage) and dynamic (spatial coverage) mapping was technically realized by integrating the mapping probe at the tip of a new suction device, with the concept that this device will be in contact with the tissue where the resection is performed. Motor function was assessed 1 day after surgery, at discharge, and at 3 months.

Results

All procedures were technically successful. There was a 1:1 correlation of motor thresholds for stimulation sites simultaneously mapped with the new suction mapping device and the classic fingerstick probe (24 patients, 74 stimulation points; r2 = 0.98, p < 0.001). The lowest individual motor thresholds were as follows: > 20 mA, 7 patients; 11–20 mA, 13 patients; 6–10 mA, 8 patients; 4–5 mA, 17 patients; and 1–3 mA, 24 patients. At 3 months, 2 patients (3%) had a persistent postoperative motor deficit, both of which were caused by a vascular injury. No patient had a permanent motor deficit caused by a mechanical injury of the CST.

Conclusions

Continuous dynamic mapping was found to be a feasible and ergonomic technique for localizing the exact site of the CST and distance to the motor fibers. The acoustic feedback and the ability to stimulate the tissue continuously and exactly at the site of tissue removal improves the accuracy of mapping, especially at low (< 5 mA) stimulation intensities. This new technique may increase the safety of motor eloquent tumor surgery.

In Journal of Neurosurgery Volume 120 (2014): Issue 5 (May 2014)

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Editorial: Subarachnoid hemorrhage grading scales

Anthony C. Wang and Roberto C. Heros

In Journal of Neurosurgery Volume 124 (2016): Issue 2 (Feb 2016)

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Letter to the Editor: Electric current application for motor tract mapping

Colette Boëx, Shahan Momjian, and Karl Schaller

In Journal of Neurosurgery Volume 124 (2016): Issue 6 (Jun 2016)

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Fluorescence Angiography

Andreas Raabe and Robert F. Spetzler

In Journal of Neurosurgery Volume 108: Issue 2 (Feb 2008)

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The warning-sign hierarchy between quantitative subcortical motor mapping and continuous motor evoked potential monitoring during resection of supratentorial brain tumors

Clinical article

Kathleen Seidel, Jürgen Beck, Lennart Stieglitz, Philippe Schucht, and Andreas Raabe

Object

Mapping and monitoring are believed to provide an early warning sign to determine when to stop tumor removal to avoid mechanical damage to the corticospinal tract (CST). The objective of this study was to systematically compare subcortical monopolar stimulation thresholds (1–20 mA) with direct cortical stimulation (DCS)–motor evoked potential (MEP) monitoring signal abnormalities and to correlate both with new postoperative motor deficits. The authors sought to define a mapping threshold and DCS-MEP monitoring signal changes indicating a minimal safe distance from the CST.

Methods

A consecutive cohort of 100 patients underwent tumor surgery adjacent to the CST while simultaneous subcortical motor mapping and DCS-MEP monitoring was used. Evaluation was done regarding the lowest subcortical mapping threshold (monopolar stimulation, train of 5 stimuli, interstimulus interval 4.0 msec, pulse duration 500 μsec) and signal changes in DCS-MEPs (same parameters, 4 contact strip electrode). Motor function was assessed 1 day after surgery, at discharge, and at 3 months postoperatively.

Results

The lowest individual motor thresholds (MTs) were as follows (MT in mA, number of patients): > 20 mA, n = 12; 11–20 mA, n = 13; 6–10 mA, n = 20; 4–5 mA, n = 30; and 1–3 mA, n = 25. Direct cortical stimulation showed stable signals in 70 patients, unspecific changes in 18, irreversible alterations in 8, and irreversible loss in 4 patients. At 3 months, 5 patients had a postoperative new or worsened motor deficit (lowest mapping MT 20 mA, 13 mA, 6 mA, 3 mA, and 1 mA). In all 5 patients DCS-MEP monitoring alterations were documented (2 sudden irreversible threshold increases and 3 sudden irreversible MEP losses). Of these 5 patients, 2 had vascular ischemic lesions (MT 20 mA, 13 mA) and 3 had mechanical CST damage (MT 1 mA, 3 mA, and 6 mA; in the latter 2 cases the resection continued after mapping and severe DCS-MEP alterations occurred thereafter). In 80% of patients with a mapping MT of 1–3 mA and in 75% of patients with a mapping MT of 1 mA, DCS-MEPs were stable or showed unspecific reversible changes, and none had a permanent motor worsening at 3 months. In contrast, 25% of patients with irreversible DCS-MEP changes and 75% of patients with irreversible DCS-MEP loss had permanent motor deficits.

Conclusions

Mapping should primarily guide tumor resection adjacent to the CST. DCS-MEP is a useful predictor of deficits, but its value as a warning sign is limited because signal alterations were reversible in only approximately 60% of the present cases and irreversibility is a post hoc definition. The true safe mapping MT is lower than previously thought. The authors postulate a mapping MT of 1 mA or less where irreversible DCS-MEP changes and motor deficits regularly occur. Therefore, they recommend stopping tumor resection at an MT of 2 mA at the latest. The limited spatial and temporal coverage of contemporary mapping may increase error and may contribute to false, higher MTs.

In Journal of Neurosurgery Volume 118 (2013): Issue 2 (Feb 2013)

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Bleeding risk of cerebral cavernous malformations in patients on β-blocker medication: a cohort study

Johannes Goldberg, Christian Jaeggi, Daniel Schoeni, Pasquale Mordasini, Andreas Raabe, and David Bervini

OBJECTIVE

Cerebral cavernous malformations (CCMs) are frequently diagnosed vascular malformations of the brain. Although most CCMs are asymptomatic, some can be responsible for intracerebral hemorrhage or seizures. In selected cases, microsurgical resection is the preferred treatment option. Treatment with the unselective β-blocker propranolol has been presumed to stabilize and eventually lead to CCM size regression in a limited number of published case series; however, the underlying mechanism and evidence for this effect remain unclear. The aim of this study was to investigate the risk for CCM-related hemorrhage in patients on long-term β-blocker medication.

METHODS

A single-center database containing data on patients harboring CCMs was retrospectively interrogated for a time period of 35 years. The database included information about hemorrhage and antihypertensive medication. Descriptive and survival analyses were performed, focusing on the risk of hemorrhage at presentation and during follow-up (first or subsequent hemorrhage) in patients on long-term β-blocker medication versus those who were not. Follow-up was censored at the first occurrence of new hemorrhage, surgery, or the last clinical review. For purposes of this analysis, the β-blocker group was divided into the following main subgroups: any β-blocker, β1-selective β-blocker, and any unselective β-blocker.

RESULTS

Of 542 CCMs among 408 patients, 81 (14.9%) were under treatment with any β-blocker; 65 (12%) received β1-selective β-blocker, and 16 (3%) received any unselective β-blocker. One hundred thirty-six (25.1%) CCMs presented with hemorrhage at diagnosis. None of the β-blocker groups was associated with a lower risk of hemorrhage at the time of diagnosis in a univariate descriptive analysis (any β-blocker: p = 0.64, β1-selective: p = 0.93, any unselective β-blocker: p = 0.25). Four hundred ninety-six CCMs were followed up after diagnosis and included in the survival analysis, for a total of 1800 lesion-years. Follow-up hemorrhage occurred in 36 (7.3%) CCMs. Neither univariate descriptive nor univariate Cox proportional-hazards regression analysis showed a decreased risk for follow-up hemorrhage under treatment with β-blocker medication (any β-blocker: p = 0.70, HR 1.19, 95% CI 0.49–2.90; β1-selective: p = 0.78, HR 1.15, 95% CI 0.44–3.00; any unselective β-blocker: p = 0.76, HR 1.37, 95% CI 0.19–10.08). Multivariate Cox proportional-hazards regression analysis including brainstem location, hemorrhage at diagnosis, age, and any β-blocker treatment showed no reduced risk for follow-up hemorrhage under any β-blocker treatment (p = 0.53, HR 1.36, 95% CI 0.52–3.56).

CONCLUSIONS

In this retrospective cohort study, β-blocker medication does not seem to be associated with a decreased risk of CCM-related hemorrhage at presentation or during follow-up.

In Journal of Neurosurgery Volume 130: Issue 6 (Jun 2019)