A non-aggressive, highly efficient, enzymatic method for dissociation of human brain-tumors and brain-tissues to viable single-cells.

BACKGROUND: Conducting research on the molecular biology, immunology, and physiology of brain tumors (BTs) and primary brain tissues requires the use of viably dissociated single cells. Inadequate methods for tissue dissociation generate considerable loss in the quantity of single cells produced and in the produced cells' viability. Improper dissociation may also demote the quality of data attained in functional and molecular assays due to the presence of large quantities cellular debris containing immune-activatory danger associated molecular patterns, and due to the increased quantities of degraded proteins and RNA. RESULTS: Over 40 resected BTs and non-tumorous brain tissue samples were dissociated into single cells by mechanical dissociation or by mechanical and enzymatic dissociation. The quality of dissociation was compared for all frequently used dissociation enzymes (collagenase, DNase, hyaluronidase, papain, dispase) and for neutral protease (NP) from Clostridium histolyticum. Single-cell-dissociated cell mixtures were evaluated for cellular viability and for the cell-mixture dissociation quality. Dissociation quality was graded by the quantity of subcellular debris, non-dissociated cell clumps, and DNA released from dead cells. Of all enzymes or enzyme combinations examined, NP (an enzyme previously not evaluated on brain tissues) produced dissociated cell mixtures with the highest mean cellular viability: 93 % in gliomas, 85 % in brain metastases, and 89 % in non-tumorous brain tissue. NP also produced cell mixtures with significantly less cellular debris than other enzymes tested. Dissociation using NP was non-aggressive over time-no changes in cell viability or dissociation quality were found when comparing 2-h dissociation at 37 °C to overnight dissociation at ambient temperature. CONCLUSIONS: The use of NP allows for the most effective dissociation of viable single cells from human BTs or brain tissue. Its non-aggressive dissociative capacity may enable ambient-temperature shipping of tumor pieces in multi-center clinical trials, meanwhile being dissociated. As clinical grade NP is commercially available it can be easily integrated into cell-therapy clinical trials in neuro-oncology. The high quality viable cells produced may enable investigators to conduct more consistent research by avoiding the experimental artifacts associated with the presence dead cells or cellular debris.

Sensitivity and specificity of seizure-onset zone estimation by ictal magnetoencephalography.

PURPOSE: Ictal video-electroencephalography (EEG) is commonly used to establish ictal onset-zone location. Recently software development has enabled systematic studies of ictal magnetoencephalography (MEG). In this article, we evaluate the ability of ictal MEG signals to localize the seizure-onset zone. METHODS: Twenty-six patients underwent ictal MEG and epilepsy surgery. Prediction of seizure-onset zone by ictal and interictal MEG was retrospectively compared with ictal-onset area found by intracranial EEG in 12 patients. The specificity and sensitivity of the prediction were calculated at hemisphere-lobe (HL) and at hemisphere-lobe-surface (HLS) levels. KEY FINDINGS: The sensitivity of ictal MEG source localization was 0.958 on HL and 0.706 on HLS levels, and its specificity was 0.900 on HL and 0.731 on HLS levels. The interictal MEG dipole cluster, defined as >10 dipoles on one lobar surface, had sensitivity of 0.400 and specificity of 0.769. Ictal MEG was equally sensitive and specific on dorsolateral and nondorsolateral neocortical surfaces up to a depth of 4 cm from the scalp. SIGNIFICANCE: Sources of ictal-onset MEG signals and interictal dipole clusters are essentially equally specific in estimation of the ictal-onset zone on lobar surface resolution, but ictal MEG is more sensitive. On the lobe resolution, ictal MEG estimates ictal-onset zone with high sensitivity and specificity.

Epilepsy surgery in children compared to adults.

AIM: The purpose of this study was to compare the frequency of various surgical techniques and surgical outcome between pediatric and adult populations that underwent epilepsy surgery by the same team. METHODS: All patients who underwent epilepsy surgery at the Tel Aviv Medical Center between 1997 and 2006 and had been followed up for >2 years were eligible for this study. The majority (90%) of all epilepsy surgeries carried out in Israel were performed in this institution and by a single neurosurgeon. Only patients that underwent video-EEG monitoring as part of the presurgical evaluation were included in the study. RESULTS: A total of 186 patients (131 adults and 55 children) underwent epilepsy surgery in our institute during the study period, and follow-up was available for 177 patients (95%). While the adults underwent significantly more temporal lobe resections (51 vs. 20%, p < 0.0001), the children had significantly more extra-temporal non-lesional resections (18 vs. 1%, p < 0.0001) and hemispherectomies (5 vs. 1%, p = 0.002). Over one half (54%) of all the patients had a postoperative reduction in seizures of >90%, and 72% had a reduction of >50%, with no group difference in surgical success. Among the lesionectomies, the outcome was better for tumors, especially those in the temporal lobe. Only 1% of the patients had a long-term neurological deficit. CONCLUSIONS: Children comprised 30% of the epilepsy surgical cases during the study period. Children underwent more non-lesional resections and hemispherectomies, while adults underwent more temporal lobe resections. There was no age-related difference in surgical outcome.

Trochlear nerve neuroma manifested with intractable atypical facial pain: case report.

OBJECTIVE AND IMPORTANCE: Trochlear nerve neuromas are extremely rare. Seventeen surgical cases of this pathological condition have been reported in the English literature. The presented case is distinct from previous reports. CLINICAL PRESENTATION: A 26-year-old woman presented with atypical facial pain. The neurological examination results were normal. Magnetic resonance imaging revealed a left parasellar mass. INTERVENTION: A left pterional craniotomy was performed, providing access to the left parasellar area. After incision of the tentorial edge, the tumor was observed to originate from the short segment of the trochlear nerve that runs between the tentorial leaves. The neuroma was totally removed. CONCLUSION: The facial pain resolved immediately after surgery. Although facial dysesthesias have been noted among patients with trochlear nerve neuromas, here the atypical facial pain was the only clinical manifestation. In all previously reported cases, neuromas originated from the cisternal segment of the trochlear nerve (always before the site of nerve entrance into the tentorial leaves) and expanded mainly into the prepontine and interpeduncular cisterns. Subtemporal and suboccipital approaches were used. In this case, the tumor arose from the short segment of the nerve running between the tentorial leaves. The tumor did not extend either into the ambient cistern or into the cavernous sinus but did involve the parasellar area. A pterional approach was appropriate for tumor removal. A trochlear nerve neuroma should be considered as a potential cause of atypical facial pain.

Recombinant coagulation factor VIIa for rapid preoperative correction of warfarin-related coagulopathy in patients with acute subdural hematoma.

BACKGROUND: Intracranial hemorrhage, either spontaneous or traumatic is a well-known and potentially lethal complication of Warfarin treatment. Patients with Warfarin-related intracranial hemorrhage need urgent reversal of anticoagulation that must be especially rapid if surgical intervention is indicated. The traditional treatment with fresh frozen plasma (FFP) and vitamin K often fails to achieve the desired correction of coagulopathy in urgent neurosurgical settings. CASE REPORT: In the present case Recombinant Coagulation Factor VIIa (rFVIIa) was used for preoperative reversal of Warfarin-related coagulopathy. The patient was a fifty two years old man, mechanic valve recipient with Warfarin-induced coagulopathy: International Normalization Ratio (INR) of 6.39, who suffered from acute subdural hematoma and needed urgent neurosurgical intervention. He received a single dose of rFVIIa 120 mg/kg and immediately underwent craniotomy and evacuation of the hematoma. Appropriate hemostasis was achieved during surgery and coagulation test taken two hours after rFVIIa injection revealed INR of 1.25. The INR remained normalized for additional 14 hours. To the best of our knowledge, this is the first report on the use of rFVIIa in the preoperative management of Warfarin-induced intracranial hemorrhage. RESULTS: Recombinant Coagulation Factor VIIa provides rapid correction of coagulation to a level that allows safe neurosurgical intervention without significant delay. This agent is safe and effective; and should be considered for reversal of Warfarin-induced coagulopathy in cases of intracranial hemorrhage, especially when urgent surgical intervention is required.