Anatomical and Radiological Analysis of Structures of Petrous Part of the Temporal Bone and Their Impact on Area of Anterior Petrosectomy.

BACKGROUND: Anterior petrosectomy (AP) is a commonly recognized approach for accessing tumors located in the petrous apex region. The essence of AP lies in drilling the petrous part of the temporal bone within the Kawase quadrangle. In our study, we conducted radiological and anatomical analyses of the structures within the petrous portion of the temporal bone, evaluating their impact on the surgical field during AP. METHODS: We conducted an analysis of 15 anatomical specimens and 20 3D reconstructions based on computed tomography scans of the middle ear. The analyzed structures included the impression of the trigeminal nerve, the groove of the greater petrosal nerve, the arcuate eminence, and the angle between eminentia arcuata and grove for greater petrosal nerve. RESULTS: The mean surface area measured by radiological methods does not deviate significantly from the mean surface area measured by anatomical methods 276.265mm2 (interquartile range: 217.603-309.188) versus 233.21mm2 (interquartile range: 210.923-255.453) P = 0.051. We established a threshold 195,99mm2 for radiological determination of the surface area at which another approach should be considered. Additionally, we have developed corrections for specific radiological factors to enable a better assessment of anatomical conditions. CONCLUSIONS: Our results indicate that preoperative assessment of anatomical conditions based on 3D reconstructions of computed tomography of the middle ear can be a valuable tool in preoperative planning of surgery on tumors in the petroclival region using the AP. Further studies involving a larger sample size are necessary to validate the findings of our study.

Calcifying pseudoneoplasm of the foramen magnum--Case report and review of the literature.

We present a case of a 29-year-old male with a calcifying pseudoneoplasm of the neuraxis (CAPNON) located in the region of the foramen magnum, treated successfully by complete resection. After a 2-year follow-up the patient remains recurrence free. Clinical and histopathological characterization of CAPNON is provided with special emphasis on the intraoperative and neuroradiological features of the lesion.

Supratentorial neurenteric cyst--a case report.

Supratentorial neurenteric cyst is a rare congenital lesion. We report here a case of a 33-year-old female who presented with seizures. A multicystic lesion in the left premotor cortex with moderate contrast enhancement was demonstrated with MRI. Microscopically, the lesion showed small cystic structures filled with a proteinaceous fluid. The wall of the cysts was lined with a single layer of ciliated columnar or cuboidal epithelium on a basement membrane. Glandular structures resembling gastrointestinal glands were also present. The cells of the cyst lining and glandular structures revealed strongly positive immunoreactions for epithelial markers (cytokeratin and epithelial membrane antigen).

Rearrangement of motor centers and its relationship to the neurological status of low-grade glioma examined on pre- and postoperative fMRI.

OBJECTIVE: Well-developed compensatory mechanisms, based on the phenomenon of brain plasticity, exist in patients with neuroepithelial tumors, especially with highly differentiated gliomas (WHO grade II). We studied phenomenon of rearrangement of sensorimotor cortex using functional magnetic resonance imaging (fMRI), and verified relationship between observed changes and results of neurological and neuropsychological assessment. METHODS: Study group included 20 patients with WHO grade II gliomas located within motor or sensory cortex. fMRI examination, as well as clinical, neurological (Karnofsky performance score [KPS] and Lovett's scale [Lo]), and neuropsychological assessment (Digit Coding Symbol Test and Digit Span Test) were performed pre-operatively and 3 months post-surgery. RESULTS: There were no significant differences in pre- and postoperative performance status of patients. Although statistically insignificant, an increase in frequency of activation of primary and secondary cortical motor centers was observed postoperatively (p>0.05). Prior to surgery, motor centers were characterized by lower values of t-statistics than in postoperative period (p>0.05). In contrast, values of parameters describing the size of examined centers, i.e. mean number of clusters, were lower, but not statistically significant on postoperative examination (p>0.05). Compared to individuals without motor deficit, patients with preoperative Lo3/Lo4 paralysis showed significantly higher mean values of t-statistics in the accessory motor area on postoperative examination (p<0.05). CONCLUSIONS: The processes of motor cortex rearrangement seemed to be associated with the pre- and postoperative neurological and neuropsychological status of patients. After contralateral primary motor cortex, accessory motor area was the second most frequently activated center, both pre- and postoperatively.

Functional rearrangement of the primary and secondary motor cortex in patients with primary tumors of the central nervous system located in the region of the central sulcus depending on the histopathological type and the size of tumor: Examination by means of functional magnetic resonance imaging.

BACKGROUND: The aim of this study was to analyze the reorganization of the centers of the motor cortex in patients with primary neuroepithelial tumors of the central nervous system (CNS) located in the region of the central sulcus in relation to the histopathological type and the size of tumor, as determined by means of functional magnetic resonance imaging (fMRI). MATERIAL/METHODS: The fMRI was performed prior to the surgical treatment of patients with tumors located in the region of the central sulcus (WHO stage I and II, n=15; WHO stage III and IV, n=25). The analysis included a record of the activity in the areas of the primary motor cortex (M1) and the secondary motor cortex: the premotor cortex (PMA) and the accessory motor area (SMA). The results were correlated with the histopathological type of the tumor and its size expressed in cm(3). RESULTS: The frequency of activation of the motor center was higher in the group of patients who had less aggressive tumors, such as low-grade glioma (LGG), as well as in tumors of lower volume, and this was true both for the hemisphere where the tumor was located and in the contralateral one. Mean values of t-statistics of activation intensity, mean numbers of activated clusters, and their ranges were lower in all analyzed motor areas of LGG tumors. The values of t-statistics and activation areas were higher in the case of small tumors located in ipsilateral centers, and in large tumors located in contralateral centers, aside from the SMA area where the values of t-statistics were equal for both groups. The contralateral SMA area was characterized by the highest stability of all examined centers of secondary motor cortex. No significant association (p>0.05) was observed between the absolute value of the mean registered activity (t-statistics) and the size of examined areas (number of clusters) when the groups were stratified with regards to the analyzed parameters. CONCLUSIONS: The presence of a neoplastic lesion, its histopathological type and finally its size modulate the functional reorganization of the motor centers as suggested by the differences in the frequency of the neural center activation in the analyzed groups. Processes of functional rearrangement are more pronounced and more precisely defined in patients with less aggressive and/or smaller tumors. The contralateral accessory area is the most frequently activated center in all analyzed groups irrespective of the grade and size of the tumor.

A blood pool contrast aided T1 functional MRI in patients with brain tumors--a preliminary study.

INTRODUCTION: The aim of our study was to determine the possibility of using a new functional technique: a T1-dependent sequence with administration of blood pool contrast agent (BPCA), in patients with brain tumors before and after surgical treatment. We also aimed to compare our results with those obtained using the fMRI technique, based on Blood Oxygenation Level-Dependent (BOLD) contrast. METHODS: For each of our 14 oncologic patients (four before and ten after neurosurgical intervention), we obtained: a T1-3D GRE sequence (TR = 2.6 ms/TE = 1.1 ms/FA = 10°) after intravenous administration of BPCA (0.03 mmol/kg), as well as a T2*EPI sequence (TR = 3 s/TE = 50 ms/FA = 90°). Movement and/or tactile block type paradigms were carried out during both functional runs. SPM5 software was used for analysis. RESULTS: For both functional techniques, maximum activations were localized in the same areas. There were no significant differences observed in the t values calculated for activations located in the primary motor cortex between groups of pre- and post-intervention patients (in the same functional technique). The mean values for T2* EPI examinations were 10.84 and 9.36, respectively. The mean t values for the T1 technique were lower, especially for the post-intervention patients (5.83 and 3.9, respectively). CONCLUSIONS: The T1 technique can be used to detect functional areas in patients with brain tumors, pre-, and post-surgical intervention. This technique enables the evaluation of cortical centers that suffer from susceptibility artifacts when using the T2* BOLD technique. Activations found using both techniques have the same localization, with lower values for the T1 technique.

Low grade malignant peripheral nerve sheath tumor with mesenchymal differentiation: a case report.

Malignant peripheral nerve sheath tumor (MPNST) is an uncommon neoplasm. Rarely, MPNST may display focal mesenchymal differentiation and this is more frequently encountered in high than low grade lesions. Here we present an example of a low grade MPNST with osteoid, cartilaginous and probably smooth muscle components occurring in the subtemporal fossa of a 26-year-old male patient with no associated neurofibromatosis type 1. The tumor exhibited diffuse S-100 protein expression, whereas immunostainings for epithelial membrane antigen and smooth muscle actin were positive in a portion of neoplastic cells.

Glioblastoma multiforme and meningioma in the same patient - a case report.

We describe a case of a 64-year-old female who presented with concurrent left parietal glioblastoma multiforme and left occipital parasagittal meningioma. Both lesions were excised during the operation. There was no clinical evidence of phacomatosis. Aetiological and clinical aspects of the phenomenon are discussed.

Tumour necrosis factor-induced death of adult human oligodendrocytes is mediated by apoptosis inducing factor.

Tumour necrosis factor (TNF)-induced death of oligodendrocytes, the cell type targeted in multiple sclerosis, is mediated by TNF receptor p55 (TNFR-p55). The ligation of TNFR-p55 induces several signal transduction pathways; however, the precise mechanism involved in human oligodendrocyte (hOL) death is unknown. We defined that TNF-induced death of hOLs is non-caspase dependent, as evidenced by lack of generation of caspases 8, 1 and 3 active subunits; lack of cleavage of caspases 1 and 3 fluorogenic substrates; and lack of hOL death inhibition by the general caspase inhibitor, ZVAD.FMK. Electrophoresis of TNF-exposed hOL DNA revealed large-scale DNA fragmentation characteristic of apoptosis-inducing factor (AIF)-mediated cell death, and co-localization experiments showed that AIF translocation to the nucleus occurred upon exposure to TNF. AIF depletion by an antisense strategy prevented TNF-induced hOL death. These results indicate that TNF-induced death of hOLs is dependent on AIF, information of significance for the design strategies to protect hOLs during immune-mediated demyelination.

[Intraoperative assessment of cognitive and executive functions in patients with brain tumors]. / Sródoperacyjne badanie wybranych funkcji poznawczych i wykonawczych u pacjentów z guzem mózgu.

BACKGROUND AND PURPOSE: The aim of this paper was to evaluate the usefulness of selected methods of intraoperative neuropsychological assessment. In order to investigate the influence of the direct cortical stimulation and tumor resection on the patients' intraoperative performance, we examined selected areas of cerebral cortex involved in cognitive activity in patients undergoing awake craniotomy for brain tumors. MATERIAL AND METHODS: The analyzed group consisted of 21 patients (11 men, 10 women) with tumors located in eloquent areas of the left hemisphere. All patients had intact understanding of speech and relatively minor neurological deficits. We applied both experimental methods as well as certain standardized tests (WAIS-R, AVLT) for the investigation of verbal and nonverbal functions. The tests were performed during direct cortical stimulation and tumor resection, and also before and one week after the operation. RESULTS: Verbal areas were identified in 10 patients, sensorimotor strip in 3, whereas both of them in 3. Even though in 5 out of 21 subjects we were unable to identify the eloquent cortex, there was no difference between pre- and postoperative assessment in these patients. Similarly, there was no statistically significant difference in pre- and postoperative tests among patients with successful cortical mapping. CONCLUSIONS: We showed that the presented methods of intraoperative assessment of cognitive activity were useful and appropriate for the identification of the eloquent areas of the brain.

[Supplementation of cranial defects by an autologous bone flap stored in the abdominal wall]. / Uzupelnianie ubytków kosci pokrywy czaszki autologicznym platem kostnym przechowywanym w powlokach brzucha.

BACKGROUND AND PURPOSE: The aim of this paper is to present an alternative method of cranioplasty with the use of an autologous cranial bone flap stored between primary and restorative surgery in the subcutaneous pocket in the lateral hypogastric region. MATERIAL AND METHODS: Between January 1999 and April 2002, in the Department of Neurosurgery of Medical University of Lódz we performed 36 procedures of the bone flap implantation into the abdominal subcutaneous fat tissue. These procedures followed craniectomy, mainly in cases of acute subdural hematomas and ruptured intracranial aneurysms. RESULTS: After storage, the bone flap was reimplanted in 28 patients. The mean time between operations was 14 days (range 8-53 days). In the cranioplasty group we had only one infection of the bone flap. Among patients excluded from the bone flap restoration we observed one inflammatory complication in the abdominal wall and one subcutaneous hematoma requiring evacuation. CONCLUSIONS: In our opinion, the presented method of the cranial defect's supplementation may be competitive to procedures utilizing synthetic prostheses in the population of patients for whom reimplantation of the bone flap will be expected in 2-3 months after the primary operation. Advantages of the procedure are: the autologous bone graft, the excellent cosmetic effect, low costs of the procedure and low rate of inflammatory complications.

Cortical mapping by functional magnetic resonance imaging in patients with brain tumors.

The aim of our study was to establish the effectiveness of the functional MRI (fMRI) technique in comparison with intraoperative cortical stimulation (ICS) in planning cortex-saving neurosurgical interventions. The combination of sensory and motor stimulation during fMRI experiments was used to improve the exactness of central sulcus localization. The study subjects were 30 volunteers and 33 patients with brain tumors in the rolandic area. Detailed topographical relations of activated areas in fMRI and intraoperative techniques were compared. The agreement in the location defined by the two methods for motor centers was found to be 84%; for sensory centers it was 83%. When both kinds of activation are taken into account this agreement increases to 98%. A significant relation was found between fMRI and ICS for the agreement of the distance both for motor and sensory centers (p=0.0021-0.0024). Also a strong dependence was found between the agreement of the location and the agreement of the distance for both kinds of stimulation. The spatial correlation between fMRI and ICS methods for the sensorimotor cortex is very high. fMRI combining functional and structural information is very helpful for preoperative neurosurgical planning. The sensitivity of the fMRI technique in brain mapping increases when using both motor and sensory paradigms in the same patient.

Recurrent cerebral gliomas in MRI and Iodine-123[corrected]-alpha-methyl-tyrosine SPECT: the use of digitally fused images.

BACKGROUND: Early detection and site location of recurrent cerebral glioma helps design optimum therapeutic regimen, which contributes to prolonged survival time of the patients. However, diagnosing the neoplastic growth at the post-resection site is a difficult process. The diagnostic modality to provide the most extensive morphological data is dynamic MR tomography. On the other hand, the tumour-related metabolic changes can be best diagnosed using the PET and SPECT techniques of nuclear medicine that employ radiolabelled amino acid 131 I-alpha-metyl-tyrosine (IMT) as the tracer. Thus, for comprehensive diagnostics of brain tumours, it is most effective to combine both the modalities and evaluate the fused images. The aim of the present study was to verify the usefulness of the calculated algorithm for a digital fusion of RM/SPECT images for the assessment of post-resection site of cerebral gliomas. MATERIAL AND METHODS: The findings of MR and SPECT imaging for 21 patients who had surgery for cerebral glioma were subject to assessment. Diagnosis was based on histopathology results (8 cases of anaplastic astrocytoma and 13 cases of multiform glioblastoma). The site and size of the contrast enhancement areas from MR was compared with the hot focus location from SPECT. RESULTS: The study confirmed the feasibility of digital fusion of images yielded by SPECT and MR. The fused images reflect the non-homogeneity of the post-resection site of cerebral gliomas. Contrast enhancement areas only partially overlapped with the hot foci which, furthermore, were found to be substantially smaller. CONCLUSIONS: The consistency of tumour locations detected with MR and SPECT was higher for tumours of the anaplastic astrocytoma type than for multiform glioblastomas (higher polymorphism of pathological changes).

Richter's syndrome in the brain first manifested as an ischaemic stroke.

Isolated central nervous system involvement in Richter's syndrome (RS) is extremely rare and only 6 such cases have been described, so far. We report a 60-year-old woman with B-cell chronic lymphocytic leukemia (B-CLL) heavily pretreated with cladribine based regimens and rituximab in whom RS in the brain was first manifested as a stroke. Initial cranial computed tomography (CT) revealed a hypodense area in the right parietal lobe showing no contrast enhancement. The follow-up CT done after 2 months showed an irregular, slightly hyperdense tumor surrounded by oedema with mass effect and midline shift. However, cerebrospinal fluid (CSF) examinations revealed no pathological changes. Neurosurgical operation was performed and the diagnosis of diffuse large B-cell lymphoma (DLBCL) has been established on the basis of histological and immunological investigation of the tumor. The pattern of immunoglobulin heavy chain (IgH) gene rearrangement in the patients' bone marrow aspirate and brain tumor was identical and suggested that both tumors originated from the same B-cell progenitors. The patient was then treated with brain irradiation (2000 cGy) and complete remission as assessed by MRI was achieved. Significant neurological improvement was observed and no clinical progression was stated 3 months after radiotherapy.

Assessment of clinical usefulness of 131I alpha-methyl-tyrosine and fused SPECT/MRI imaging for diagnostics of recurrent cerebral gliomas.

BACKGROUND: Early detection and diagnostic differentiation of neoplastic tissue from necrotic changes and scars following the treatment of cerebral gliomas is essential for determining further therapy and prognosis. The primary technique used for the diagnostics of recurrent neoplastic growth is the magnetic resonance imaging (MRI), which in some cases, however, does not allow one to identify the character of cerebral lesions. Recently, MRI has been supplemented with single-photon emission computed tomography (SPECT) or positron emission tomography (PET) employing radiolabelled amino acids. e.g. tyrosine or methionine. The aim of the project was to assess the diagnostic potential of SPECT when iodine-131 alpha-methyl tyrosine (IMT), a Polish make of radiopharmaceutical (OBRI--POLATOM, Otwock-Rwierk, Poland), was applied. The use of 131I as a substitute for the more costly, imported iodine-123 has been justified in view of the nature and significance of the diagnostic problem on the one hand, and the possibility of 131-iodine application on a larger scale in CEE countries, on the other. MATERIAL AND METHODS: MRI and SPECT were performed in 24 patients with a history of surgical treatment and radiotherapy of cerebral glioma (WHO grade II/IV). A SPECT was carried out 15 min after an i.v. injection of 74-111 MBq IMT. The tomograms were evaluated visually and in quantitative terms. The fused SPET/MR images were also analyzed. The obtained results were verified against histopathological findings, control MRI examinations and the clinical course of disease within 7-28 months of monitoring. RESULTS: In 19 patients, an increased IMT uptake indicative of a recurrent tumour was found, and the presence of the tumour was confirmed. In five patients no hot spots were detected which would indicate the neoplastic growth and verification did not provide any evidence for relapse. CONCLUSIONS: The examination employing iodine-131 IMT made it possible to confirm or exclude tumour recurrence in all the subjects, also in the cases when the CT/MR images were inconclusive. The MRI/SPECT fusion made it possible to more accurately identify the location of tumour recurrence as well as determine the area for spectroscopic MR analysis, for stereotactic biopsy and radiotherapy.

[Awake craniotomy and brain mapping for eloquent cortex in patients with supratentorial tumors: a preliminary report]. / Sródoperacyjne wybudzanie i mapowanie elokwentnych okolic mózgu u pacjentów z guzami nadnamiotowymi--doniesienie wstepne.

Malignant brain tumours are incurable at present. Since none of the hitherto used treatment methods allows to significantly extend these patients' survival time, the basic aim is to improve their quality of life. Intraoperative brain mapping seems to be an approach enabling to minimize the risk of irreversible damages to functionally important structures of the brain. In the Department of Neurosurgery of the Medical University of Lódz awake craniotomy with stimulation of eloquent cortex was attempted from May 1999 to July 2000 in 13 patients aged 16 to 77 years. In two patients the attempt of intraoperative awakening was unsuccessful. In 8 out of the 11 awakened patients intraoperative brain mapping had a significant effect on the course of surgery (i.e. on the resection magnitude and "safe corridor"). Out of six patients with tumors situated in the neighbourhood of motor cortex--one developed a severe and permanent paresis of the upper limb. On the grounds of the literature and the authors' own experience an algorithm of awake craniotomy and intraoperative brain mapping was worked out.

TNF-induced death of adult human oligodendrocytes is mediated by c-jun NH2-terminal kinase-3.

Tumour necrosis factor (TNF) induces death of oligodendrocytes, the putative cell target in multiple sclerosis. We defined that the intracellular transduction pathway involved in TNF-induced death of human adult oligodendrocytes (hOLs) is dependent on c-jun NH(2)-terminal kinase (JNK) activation, but not the other mitogen-activated protein kinase (MAPK), p38. JNK activation, measured by c-jun phosphorylation and induction of the phosphorylated form of JNK, was enhanced, prolonged and correlated with cell death in hOLs exposed to TNF. Comparative autoradiographic analysis revealed that JNK-3, but not JNK-1 or JNK-2, is responsible for prolonged JNK activation in TNF exposed hOLs. Expression of a dominant-negative mutant of JNK upstream kinase, MKK4/SEK1, inhibited apoptosis induced by TNF, whereas expression of a constitutive active mutant of MEKK1, an upstream kinase to JNK, accelerates TNF-induced apoptosis. JNK activation occurred prior to changes of mitochondrial membrane potential in hOLs exposed to TNF. These results demonstrate that TNF-induced death in adult hOLs depends on prolonged JNK-3 activation, and that this apoptosis requires the mitochondrial dysfunction that occurs after JNK activation. This is the first evidence that a JNK-3 isoform is involved in oligodendrocyte death and might have significant importance in designing new molecules to protect hOLs demise in multiple sclerosis.