Safety and Accuracy of Ultrasound-guided Burr Hole Brain Abscess Aspiration.

BACKGROUND: Ultrasound-guided burr hole biopsies or catheter placements are quick and safe procedures. The use of these procedures for treatment of brain abscesses has been reported, but larger series are missing. The aim of our study was to evaluate the accuracy and safety of the methods. PATIENTS: Twenty-five brain abscess aspirations in 17 patients were analyzed. Fourteen procedures were performed to evacuate abscesses in eloquent regions; another 3 were located deeply in the cerebellar hemispheres. RESULTS: In all the procedures, a histopathologic diagnosis could be established. Only one transient deterioration of a hemiparesis occurred; other operative complications were not observed. Six patients needed more than one operation due to a relapse of the abscess. Two out of three cerebellar abscesses could be cured with one aspiration. Thirteen patients had an excellent outcome, and 2 remained severely disabled. One patient died from cerebritis and another from a neoplasm. In every procedure, a proper visualization of the abscess and monitoring of the penetration and aspiration could easily be performed. CONCLUSION: Ultrasound-guided burr hole aspiration is minimally invasive, quick, and has a very low complication rate. It offers the advantage to adapt to intraoperatively changing anatomy. The rate of recurrence is not lower than in other treatment modalities.

Symptomatic Intracranial Hemorrhage after Dural Tear in Spinal Surgery-A Series of 10 Cases and Review of the Literature.

OBJECTIVE: Intracranial hemorrhage (IH) after spinal surgery is a rare but potentially life-threatening complication. Knowledge of predisposing factors and typical clinical signs is essential for early recognition, helping to prevent an unfavorable outcome. METHODS: A retrospective analysis was performed of patients with IH after spinal surgery treated in our institution between 2012 and 2018. The literature dealing with IH complicating spinal surgery was reviewed. RESULTS: Our investigation found 10 patients with IH (6 female and 4 male). To the best of our knowledge, this is the largest series reported so far. The assumable incidence of IH after spinal surgery in our population was 0.0657%. Durotomy was noticed in 6 patients, all of whom were treated according to a local standard protocol. In 4 patients, the dural tear was occult. Hemorrhage occurred mostly in the cerebellar compartment. Eight of 10 patients had long-standing arterial hypertension, which seems to be a risk factor (hazard ratio, 1.58). Five patients were treated conservatively, whereas 3 required a cerebrospinal fluid (CSF) diversion procedure. In 2 patients, revision surgery with duraplasty was necessary. Seven patients were discharged with little to no neurologic symptoms, and 3 had significant deterioration. One patient died because of brainstem herniation. Review of the literature identified 54 articles with 72 patients with IH complicating spinal surgery. CONCLUSIONS: Patients with intraoperative CSF loss should be kept under close supervision postoperatively. After opening of the dura, a watertight closure should be attempted. The use of subfascial suction drainage in cases of a dural tear as well as preexistent arterial hypertension seems to be a risk factor for the development of IH. Intracranial bleeding must be considered in every patient with unexplained neurologic deterioration after spinal surgery and should be ruled out by cranial imaging. To ensure early recognition and prevent an unfavorable outcome, a high index of suspicion is required, especially in revision spinal surgery. The treatment is specific to the extent and location of the IH, thus dictating the outcome. In most patients, conservative treatment led to a good outcome. CSF diversion measures may be necessary in patients with compression or obstruction of the fourth ventricle. Large hematomas with mass effect may require decompressive surgery.

Polyether Ether Ketone Cranioplasties Are Permeable to Diagnostic Ultrasound.

It is a common assumption that the human skull and solid skull implants are impermeable to diagnostic ultrasound. We demonstrated in 2 patients that frontoparietal polyetheretherketone cranioplasties allowed useful imaging of intracranial parenchymal and vascular structures with higher ultrasound frequencies than the 2 MHz used for the temporal bone window. This knowledge about additional imaging properties may be helpful in emergency situations and for vascular monitoring. The decision for a polyether ether ketone cranioplasty may contribute to patient safety.

The value of intraoperative ultrasonography during the resection of relapsed irradiated malignant gliomas in the brain.

PURPOSE: The aim of this study was to investigate whether intraoperative ultrasonography (IOUS) helped the surgeon navigate towards the tumor as seen in preoperative magnetic resonance imaging and whether IOUS was able to distinguish between tumor margins and the surrounding tissue. METHODS: Twenty-five patients suffering from high-grade gliomas who were previously treated by surgery and radiotherapy were included. Intraoperatively, two histopathologic samples were obtained a sample of unequivocal tumor tissue (according to anatomical landmarks and the surgeon's visual and tactile impressions) and a small tissue sample obtained using a navigated needle when the surgeon decided to stop the resection. This specimen was considered to be a boundary specimen, where no tumor tissue was apparent. The decision to take the second sample was not influenced by IOUS. The effect of IOUS was analyzed semi-quantitatively. RESULTS: All 25 samples of unequivocal tumor tissue were histopathologically classified as tumor tissue and were hyperechoic on IOUS. Of the boundary specimens, eight were hypoechoic. Only one harbored tumor tissue (P=0.150). Seventeen boundaries were moderately hyperechoic, and these samples contained all possible histological results (i.e., tumor, infiltration, or no tumor). CONCLUSION: During surgery performed on relapsed, irradiated, high-grade gliomas, IOUS provided a reliable method of navigating towards the core of the tumor. At borders, it did not reliably distinguish between remnants or tumor-free tissue, but hypoechoic areas seldom contained tumor tissue.

Real-time ultrasound monitoring during intracranial needle biopsies: operative results and detection of complications in 100 cases.

OBJECTIVE: Intraoperative ultrasound displays dynamic processes intraoperatively. Performing burr-hole biopsies under a real-time visual control is an interesting option for the neurosurgeon. However, the percentage of conclusive diagnoses obtained by this technique and the rate of complications must be evaluated in a larger series. METHODS: One hundred consecutive intracranial biopsies were analyzed. Through a burr hole, the lesion was localized by ultrasonography, and the planned needle trajectory was superimposed onto the image. Intracranial vessels were imaged by Doppler flow signals. Biopsies were taken in a mean depth of 41 mm (maximal 65 mm) from different parts of each tumor. RESULTS: Thirty-six lesions involved the corpus callosum, 16 lesions were located deeply within the white matter, five in the internal capsule, and one in the upper brainstem. There were three cerebellar and 17 temporal lesions. Ten tumors did not exceed a diameter of 15 mm in any plane. The mean time interval from skin incision to the end of suturing was 45 minutes, and the mean time from the surgeons entering the operating theater to leaving the theater was 63 minutes. In 95% of the lesions, a diagnosis could be established. Transient neurologic deficits occurred in five patients, which were permanent in three. In 42 patients without postoperative neurological symptoms, postoperative computed tomography scans were obtained within 24 hours; a visible hemorrhage occurred in eight (19%), six of which were seen intraoperatively. CONCLUSION: When intraoperative ultrasound-navigated biopsies were used they obtained a similar percentage of conclusive diagnoses as stereotactic biopsies. The complication rate is comparable as well. Emerging intracranial complications such as hemorrhages can be observed. However, their incidence cannot be decreased.

Irrigation can cause prolonged intracranial pressure elevations during endoscopic treatment of intraventricular haematomas.

BACKGROUND: Irrigation may elevate the intracranial pressure (ICP) during neuroendoscopic procedures. It is unlikely that rinsing the ventricles during routine endoscopic ventriculostomy causes persistent neurological impairment or damage, but procedures such as the endoscopic evacuation of intraventricular haematomas (IVH) are performed in patients who may be prone to elevated ICP. We report a series of such patients in which we measured the ICP intraoperatively. METHOD: The charts and intraoperative ICP recording protocols of 22 patients were analysed for ICP elevations of more than 30 seconds. The measurements were performed remote from the endoscope using intraventricular catheters in 20 cases and epidural probes in 2 cases. These had been placed before the endoscopic operation for the purpose of monitoring unconscious patients or definitively diagnosing hydrocephalus. Thirteen patients suffered from intraventricular haemorrhages. Nine patients had an occlusive hydrocephalus without intraventricular blood. FINDINGS: Intraoperatively, at least one episode of ICP exceeding 30 mmHg was observed in all of the IVH patients and in seven of the remaining patients. Seven out of thirteen patients suffering from IVH exhibited more than one episode with ICP exceeding 50 mmHg, ranging from 35 up to 180 seconds. Three out of nine patients without IVH presented with such episodes, but only one of these patients presented with more than one. CONCLUSIONS: Endoscopic procedures within the cerebral ventricles are considered relatively uncomplicated procedures. However, patients undergoing treatment of IVH may suffer prolonged elevated ICP which may be critical because of their age and co-morbidity.

An ultrasound study of brain tissue biomechanics in patients following craniectomy.

So far, little attention has been paid to the biomechanical aspects of decompressive craniectomy. The brain tissue deformation occurring in these patients is difficult to quantify. Twenty-six patients suffering from a large bone defect after craniectomy were examined in supine position. The third ventricle's axial diameter was measured by transcranial ultrasound. Subsequently, the patient was brought into a sitting position. After 5 minutes, another measurement was taken. This procedure was repeated about 7 days after cranioplasty. The patients were grouped according to "early cranioplasty" (cranioplasty within 40 days after craniectomy, median 30 days) and "late cranioplasty", (cranioplasty more than 40 days, median 80 days). Data of 13 healthy volunteers were used as a reference standard. In the healthy volunteers, the third ventricle was enlarging after reaching the sitting position. The median diameter was 2.35 mm in the lying and 2.9 mm in the sitting position (p > 0.05). In the patients before early cranioplasty, a decrease of the diameter after reaching the sitting position was observed. The mean diameter was 7.0 mm in the lying and 5.9 mm in the sitting position (p > 0.01). This difference was not significant in patients before late cranioplasty (9.7 vs. 9.4 mm). After cranioplasty, the mean diameter was 6.6 and 6.2 mm in the early cranioplasty group and 9.2 mm and 9.4 mm in the late cranioplasty group (lying and sitting position, respectively). This data demonstrate for the first time that unphysiological orthostatic brain tissue deformation occurs in patients after craniectomy.

Candidate genes for sensitivity and resistance of human glioblastoma multiforme cell lines to erlotinib. Laboratory investigation.

OBJECT: The authors have previously reported that erlotinib, an EGFR tyrosine kinase inhibitor, exerts widely variable antiproliferative effects on 9 human glioblastoma multiforme (GBM) cell lines in vitro and in vivo. These effects were independent of EGFR baseline expression levels, raising the possibility that more complex genetic properties form the molecular basis of the erlotinib-sensitive and erlotinib-resistant GBM phenotypes. The aim of the present study was to determine candidate genes for mediating the cellular response of human GBMs to erlotinib. METHODS: Complementary RNA obtained in cell lines selected to represent the sensitive, somewhat responsive, and resistant phenotypes were hybridized to CodeLink Human Whole Genome Bioarrays. RESULTS: Expression analysis of 814 prospectively selected genes involved in major proliferation and apoptosis signaling pathways identified 19 genes whose expression significantly correlated with phenotype. Functional annotation analysis revealed that 2 genes (DUSP4 and STAT1) were significantly associated with sensitivity to erlotinib, and 10 genes (CACNG4, FGFR4, HSPA1B, HSPB1, NFATC1, NTRK1, RAC1, SMO, TCF7L1, and TGFB3) were associated with resistance to erlotinib. Moreover, 5 genes (BDNF, CARD6, FOSL1, HSPA9B, and MYC) involved in antiapoptotic pathways were unexpectedly found to be associated with sensitivity. Gene expressions were confirmed by quantitative polymerase chain reaction. CONCLUSIONS: Based on an analysis of gene expressions in cell lines with sensitive, somewhat responsive, and resistant phenotypes, the authors propose candidate genes for GBM response to erlotinib. The 10 gene candidates for conferring GBM resistance to erlotinib may represent therapeutic targets for enhancing the efficacy of erlotinib against GBMs. Five additional genes warrant further investigation into their role as putative cotargets of erlotinib.

A remote control for intraoperative ultrasound--is it really necessary?

BACKGROUND: A remote control, which can be used to manipulate the scanner functions remotely from within the sterile field, is designed to save time during IOUS. This study was designed to evaluate whether the time saved by using a remote control should be a decisive factor in buying a special system. METHODS: During 50 intracranial operations, the temporary arrest of the operative procedure caused by the use of ultrasound was measured. In 25 arbitrarily chosen operations, the remote control was draped and used (group 1); in the other group (group 2), it was not used. In addition, we analyzed the use of vascular duplex sonography in 12 of the operations with remote control (group 1a) and 14 of the operations without remote control (group 2a). RESULTS: The average time spent for ultrasound use including draping was 390 seconds in group 1, compared to 388 seconds in group 2 (without remote control). During examinations including duplex sonography, the average time spent for IOUS including draping was 464 seconds for group 1a and 466 seconds for group 2a. CONCLUSION: Based on results, the neurosurgeon does not save much time by using a remote control. The time used for draping the additional remote control is equal to the length of time that is saved. However, the surgeon's frustration in attempting to instruct a layperson to operate the ultrasound keyboard and its impact on the operative procedure cannot be measured.

Lumbar subdural haematoma after temporomesial resection in epilepsy patients--report of two cases and review of the literature.

We present two cases of lumbar subdural haematoma, both occurring after an uneventful temporomesial focus resection in patients suffering from medically intractable epilepsy. Initial symptom was back pain and sciatica 4 days and 13 days postoperatively, but no neurological deficits were observed. The diagnosis was confirmed by MRI. No risk factor could be identified. The pain responded well to conservative treatment and the haematomas resolved without neurological sequelae. A review of the literature reveals that the characteristics of spinal subdural haematoma following craniotomy are very similar. Six out of 12 reported cases occurred in temporal epilepsy surgery. All had a benign course and did not require an operative procedure. Back pain after epilepsy surgery may be caused by an intraspinal haematoma and should be investigated by MRI.

Successful treatment of multiple Pseudallescheria boydii brain abscesses and ventriculitis/ependymitis in a 2-year-old child after a near-drowning episode.

RATIONALE: We report on a cerebral infection by Pseudallescheria boydii in a 21-month-old boy after a near-drowning episode. MRI revealed multiple (> 60) intracerebral abscesses. METHODS: The surgical therapy included CSF drainage and microsurgical resection of one abscess for microbiological diagnosis. Antimycotic therapy included terbinafine and intraventricular caspofungin in addition to voriconazole. RESULTS: Systemic side effects of chemotherapy were not observed. After placement of a ventriculoperitoneal shunt, the boy was transferred to a rehabilitation clinic and improved neurologically. After 20 months, MRI documented a continuing remission of the disease. CONCLUSION: Our case proves that an aggressive treatment should be undertaken and can be successful in CNS pseudallescheriasis.

Blood flow velocities in the basal cerebral vein after head trauma: a prospective study in 82 patients.

BACKGROUND AND PURPOSE: The authors' aim was to evaluate the time course of the basal vein's (BVR) mean flow velocity (VBVR) in patients after traumatic brain injury and its relation to intracranial pressure (ICP), cerebral perfusion pressure (CPP), and the clinical outcome. METHODS: In 82 head-injured patients (13 women and 69 men, median age = 31 years, Glasgow Coma Score = 15 to 3), daily measurement of the basal cerebral vein's and the middle cerebral artery's (MCA) flow velocities and pulsatilities was performed during each patient's entire stay in the intensive care unit. No angle correction was performed. A computerized sonography system (SD 800, Philips, Irvine, CA) with a 2.0-MHz to 2.5-MHz transducer was used for all measurements. The Glasgow Outcome Score (GOS) was evaluated after 6 months. RESULTS: During the study period, VBVR values on the side of trauma were higher in the patients with favorable outcomes (GOS = 4 and 5) compared to patients with unfavorable outcomes (GOS = 2 and 3). This was statistically significant on days 4, 6, 7, and 11 and was not observed in the mean flow velocity of the MCA (VMCA). VBVR values among the good-outcome group tended to exceed the normal mean flow velocity (9.1 cm/s), whereas the unfavorable-outcome group was below this level. A correlation between venous flow velocity or pulsatility and ICP or CPP was not observed. CONCLUSIONS: Repetitive Doppler examination of the basal cerebral veins may add new aspects to the monitoring of head-injured patients.

Endothelin-converting enzyme activity in human cerebral circulation.

OBJECTIVE: An increased level of endothelin (ET)-1 seems to be involved in the development of augmented cerebrovascular resistance in different pathological conditions, most notably vasospasm after subarachnoid hemorrhage. Therefore, interfering with the ET synthesis or ET receptor blockade may be a promising approach in the treatment of cerebral vasospasm after subarachnoid hemorrhage. Although the receptors mediating the effects of ET-1 human cerebrovasculature are well characterized, data concerning the functionally relevant ET-converting enzyme (ECE) activity are scarce. METHODS: ECE activity was determined in organ bath studies by the use of intraoperatively harvested human pial arteries. The level of ECE activity was analyzed by comparing the shift in the concentration effect curves obtained for ET-1 and its precursor, big ET-1. In addition, the presence of ECE-1alpha immunoreactivity was studied in human cerebral tissue. RESULTS: ECE-1alpha immunoreactivity was found, although not consistently, in human cerebral arteries and was restricted to the endothelium. In isolated pial arterial segments, ET-1 and big ET-1 induced concentration-related contractions with mean pD(2) values of 9.25 +/- 0.34 and 7.13 +/- 0.17, respectively, yielding a 123-fold shift of big ET-1 versus mature ET-1. Preincubation with phosphoramidon (10(-4) mol/L) resulted in a small yet significant inhibition of the contraction induced by big ET-1. CONCLUSION: The results of our study indicate the presence of functional ECE activity and ECE-1alpha immunoreactivity in human cerebral arteries. Furthermore, the data suggest the presence of ECE-like activity that differs from that of ECE-1alpha.

Trigeminal evoked potentials and sensory deficits in atypical facial pain--a comparison with results in trigeminal neuralgia.

Trigeminal evoked potentials (TEPs) and sensory deficits in eighty-three patients admitted for first surgical treatment of facial pain were retrospectively analysed. Thirty-seven patients suffered from trigeminal neuralgia (TN), 10 from symptomatic TN (sTN), and 36 from atypical facial pain (AFP). Eighteen percent of the TN patients reported sensory deficits on the pain side, but 35% had delayed ipsilateral N13 waves. Of the sTN patients, 60% had either sensory deficits or a pathological corneal reflex and 62.5% a pathological N13. Of the AFP patients, 61% complained of sensory deficits, but only 31% had a pathological N13. The percentage of pathological P19 waves was slightly lower (20%, 50%, and 11%, respectively), but showed a similar trend. Normal TEPs were found even in the presence of a sensory deficit (reported only in the AFP group). These findings may add weight to the hypothesis of underlying psychiatric disorders in AFP.