Mutation analysis of CCM1, CCM2 and CCM3 genes in a cohort of Italian patients with cerebral cavernous malformation

Cerebral cavernous malformations (CCMs) are vascular lesions of the CNS characterized by abnormally enlarged capillary cavities. CCMs can occur as sporadic or familial autosomal dominant form. Familial cases are associated with mutations in CCM1[K-Rev interaction trapped 1 (KRIT1)], CCM2 (MGC4607) and CCM3 (PDCD10) genes. In this study, a three-gene mutation screening was performed by direct exon sequencing, in a cohort of 95 Italian patients either sporadic or familial, as well as on their at-risk relatives. Sixteen mutations in 16 unrelated CCM patients were identified,nine mutations are novel: c.413T > C; c.601C > T; c.846 + 2T > G; c.1254delA; c.1255-4delGTA; c.1682-1683 delTA in CCM1; c.48A > G; c.82-83dupAG in CCM2; and c.395 + 1G > A in CCM3 genes [corrected].The samples, negative to direct exon sequencing, were investigated by MLPA to search for intragenic deletions or duplications. One deletion in CCM1 exon 18 was detected in a sporadic patient. Among familial cases 67% had a mutation in CCM1, 5.5% in CCM2, and 5.5% in CCM3, whereas in the remaining 22% no mutations were detected, suggesting the existence of either undetectable mutations or other CCM genes. This study represents the first extensive research program for a comprehensive molecular screening of the three known genes in an Italian cohort of CCM patients and their at-risk relatives.

Survival of high grade glioma patients depends on their age at diagnosis

BACKGROUND

Although the prognosis for malignant gliomas is normally dismal, it's not infrequent in neurooncologist's experience to find cases with unusually prolonged survival. In order to understand what factors influence survival of high grade glioma patients, a cohort of 196 high (III-IV) grade glioma patients was investigated for possible association between (1) survival and age at diagnosis; (2) survival and micronuclei in tumor tissue; (3) survival and gender; (4) micronuclei in tumor tissue and age at diagnosis.

RESULTS

Patients diagnosed at an older age (>64 years) had a significantly higher hazard as compared to younger patients (<or=64 years), indicating that older patients survived shorter. On the contrary, no association was found between survival and micronuclei or gender.

METHODS

Survival analysis was performed by the Cox' proportional hazards regression model.

CONCLUSIONS

Age at diagnosis, together with other established prognostic factors such as histologic characteristics, extent of surgery and Karnofsky Performance Score may to a certain extent predict survival of high grade glioma patients.

Overexpression of stromal cell-derived factor 1 and its receptor CXCR4 induces autocrine/paracrine cell proliferation in human pituitary adenomas

PURPOSE

Hypothalamic or locally produced growth factors and cytokines control pituitary development, functioning, and cell division. We evaluated the expression of the chemokine stromal cell-derived factor 1 (SDF1) and its receptor CXCR4 in human pituitary adenomas and normal pituitary tissues and their role in cell proliferation.

EXPERIMENTAL DESIGN

The expression of SDF1 and CXCR4 in 65 human pituitary adenomas and 4 human normal pituitaries was determined by reverse transcription-PCR, immunohistochemistry, and confocal immunofluorescence. The proliferative effect of SDF1 was evaluated in eight fibroblast-free human pituitary adenoma cell cultures.

RESULTS

CXCR4 mRNA was expressed in 92% of growth hormone (GH)-secreting pituitary adenomas (GHoma) and 81% of nonfunctioning pituitary adenomas (NFPA), whereas SDF1 was identified in 63% and 78% of GHomas and NFPAs, respectively. Immunostaining for CXCR4 and SDF1 showed a strong homogenous labeling in all tumoral cells in both GHomas and NFPAs. In normal tissues, CXCR4 and SDF1 were expressed only in a subset of anterior pituitary cells, with a lower expression of SDF1 compared with its cognate receptor. CXCR4 and SDF1 were not confined to a specific cell population in the anterior pituitary but colocalized with discrete subpopulations of GH-, prolactin-, and adrenocorticorticotropic hormone-secreting cells. Conversely, most of the SDF1-containing cells expressed CXCR4. In six of eight pituitary adenoma primary cultures, SDF1 induced a statistically significant increase in DNA synthesis that was prevented by the treatment with the CXCR4 antagonist AMD3100 or somatostatin.

CONCLUSIONS

CXCR4 and SDF1 are overexpressed in human pituitary adenomas and CXCR4 activation may contribute to pituitary cell proliferation and, possibly, to adenoma development in humans.

CXC receptor and chemokine expression in human meningioma: SDF1/CXCR4 signaling activates ERK1/2 and stimulates meningioma cell proliferation

Recent evidence indicates that cancer cells express chemokine (CK) receptors and that their signaling is crucial for tumor proliferation, migration, and angiogenesis. The profiles of expression of CXC CK receptors (CXCR1-5) and their main ligands (growth-related oncogene, GRO1-2-3/CXCL1-2-3; interleukin 8, IL-8/CXCL8; monokine-induced gamma-interferon MIG/CXCL9; gamma-interferon-inducible-protein-10, IP-10/CXCL10; stromal cell-derived factor-1, SDF1/CXCL12; B-cell activating CK-1, BCA-1/CXCL13) were analyzed by reverse transcription polymerase chain reaction (RT-PCR) in surgical samples of human meningiomas. All the five receptors displayed high percentages of positive cases: 92% CXCR1, 89% CXCR2, 83% CXCR3, 78% CXCR4, and 94% CXCR5. Conversely, their ligands showed a lower pattern of expression: 40% IL-8, 42% GRO1-3, 42% IP-10, 28% MIG, 53% SDF1, and 3% BCA-1. SDF1/CXCR4 interaction plays a pivotal role in cancer proliferation. Thus, the signaling mechanisms activated by the exclusive binding between SDF1 and CXCR4 was investigated in 12 primary cultures from meningioma tissues. CXCR4 was functionally coupled as demonstrated by the significant increase of DNA synthesis in meningioma cells in response to SDF1, measured by [3H]-thymidine uptake. In three primary cultures, the SDF1-dependent mitogenic activity was associated with a marked phosphorylation of extracellular signal-regulated kinase (ERK1/2) as evaluated by Western blots. PD98059 (a MEK inhibitor) significantly reduced ERK1/2 activation, thus linking the SDF1/CXCR4 pathway to meningioma cell proliferation via ERK1/2 signal transduction. We demonstrate, for the first time in human meningiomas, the simultaneous expression of CXCR1-5 and their CKs and the mitogenic activity of SDF1/CXCR4, suggesting a pivotal role of these receptor-ligand pairs in meningeal tumors.

Significance of cyclin D1 expression in meningiomas: A preliminary study

Forty-four evaluable patients with intracranial meningiomas were assessed for the expression of the cell-cycle regulator cyclin D1 and of proteins involved in proliferation and apoptosis such as PCNA, MIB-1, p53 and bcl-2. Analyses were carried out by western blot and immunohistochemistry after immediate processing of fresh tumor specimens. By western blot, expression of cyclin D1 significantly correlated with p53 (p=0.02) and with proliferative activity, as assessed by PCNA expression (p=0.0009). By immunohistochemistry, a significant relationship between cyclin D1 and the proliferation marker MIB-1 was confirmed (p=0.05), whereas significance with bcl-2 expression was not found (p=0.01). Moreover, although the association with tumor grade appeared of borderline statistical significance (p=0.07), all the grade II/III meningiomas showed increased expression of cyclin D1 and high proliferative activity. In conclusion, data from this preliminary study seem to suggest a potential value of the combined expression of cyclin D1 and proliferation indicators in defining subgroups of meningiomas with a more aggressive biological behavior.

CXCR4 and SDF1 expression in human meningiomas: a proliferative role in tumoral meningothelial cells in vitro

Chemokines participate in cellular processes associated with tumor proliferation, migration, and angiogenesis. We previously demonstrated that stromal cell-derived factor 1 (SDF1) exerts a mitogenic activity in glioblastomas through the activation of its receptor CXCR4. Here we studied the expression of this chemokine in human meningiomas and its possible role in cell proliferation. Reverse transcriptase-PCR analysis for CXCR4 and SDF1 was performed on 55 human meningiomas (47 WHO grade I, 5 WHO II, and 3 WHO III). Immunolabeling for CXCR4 and SDF1 was performed on paraffin-embedded sections of these tumors. [(3)H]Thymidine uptake and Western blot analyses were performed on primary meningeal cell cultures of tumors to evaluate the proliferative activity of human SDF1alpha (hSDF1alpha) in vitro and the involvement of extracellular signal-regulated kinase 1/2 (ERK1/2) activation in this process. CXCR4 mRNA was expressed by 78% of the tumor specimens and SDF1 mRNA by 53%. CXCR4 and SDF1 were often detected in the same tumor tissues and colocalized with epithelial membrane antigen immunostaining. In 9 of 12 primary cultures from meningiomas, hSDF1alpha induced significant cell proliferation that was strongly reduced by the mitogen-activated protein kinase kinase inhibitor PD98059, involving ERK1/2 activation in the proliferative signal of hSDF1alpha. In fact, CXCR4 stimulation led to ERK1/2 phosphorylation/activation. In addition, the hSDF1alpha-induced cell proliferation was significantly correlated with the MIB1 staining index in the corresponding surgical specimen. In conclusion, we found that human meningiomas express CXCR4 and SDF1 and that hSDF1alpha induces proliferation in primary meningioma cell cultures through the activation of ERK1/2.

Expression of Somatostatin Receptor mRNA in Human Meningiomas and their Implication in in vitro Antiproliferative Activity

Somatostatin receptors (SSTRs) have been detected in many normal and malignant tissues. This wide expression has been used for diagnostic, prognostic and therapeutic purposes. Five SSTR subtypes (SSTR 1-5) have been identified whose activation is responsible for the signal transduction through many different intracellular pathways. In the present study the expression of SSTR mRNA was determined by reverse-transcriptase (RT)-PCR in 42 meningiomas. About 88% of the tumors analyzed (37/42) were positive for at least one of the five SSTR subtypes displaying a variable pattern of expression of the different SSTR subtypes. SSTRI and SSTR2 were the most frequently mRNA detected (69% and 79% of the sample analyzed, respectively). The other subtypes were found in the 43%, 33% and 33% of cases for SSTR3, SSTR4 and SSTR5, respectively. In 22, out of 42 patients (52%) three or more SSTRs were detected. The expression of the different SSTR subtypes did not correlate with the expression of bcl-2 (apoptosis-associated protein) and MIB-1 (a proliferation marker), assessed by immunohistochemistry in a series of 34 tumor samples, while a correlation between the expression of SSTR3 and p53 was observed (p = 0.08). To evaluate a possible role of SSTR in the control of human meningioma cell proliferation, seven primary cell cultures obtained from fresh meningioma surgical tissues, were analyzed for their proliferative behavior by MTT assay and for their response to SST by [3H]-thymidine incorporation. In four out of six tumors (in one case no SSTR were detected) the treatment with SST caused a significant inhibition of DNA synthesis induced by the tumor-promoter phorbol myristate acetate. The evidence of the expression of SSTRs, mainly of SSTR2, in this series of specimens we analyzed altogether with in vitro antiproliferative effects of SST may open interesting perspectives for the diagnosis and the therapy of meningiomas.

Identification of a novel KRIT1 mutation in an Italian family with cerebral cavernous malformation by the protein truncation test

Familial cerebral cavernous malformation (CCM) exhibits autosomal dominant inheritance and is characterized by vascular disorders of the brain, which can lead to seizures, focal neurological deficits, hemorrhagic stroke, and migraine. Three CCM loci have been mapped, but the gene for only one locus--KRIT1 coding for Krev-1/rap1 interaction trapped 1 (KRIT1) protein, which is responsible for more than 40% of familial cases--has been identified. To date, a total of 72 mutations have been described, with one founder effect in the Mexican/Hispanic community. We report the case of an Italian family with CCM that has a novel KRIT1 gene mutation leading to a truncated KRIT1 protein. The protein truncation test (PTT) has been used as a rapid method of identifying germline mutations in the KRIT1 gene.

Differentiation between high- and low-grade astrocytoma using a human recombinant antibody to the extra domain-B of fibronectin

Different fibronectin (FN) isoforms are generated by the alternative splicing of the primary FN transcript. We previously demonstrated that the isoform containing the extra domain B sequence of fibronectin (B-FN), a complete type-III-homology repeat, is a marker of angiogenesis that accumulates around neovasculature only during angiogenic processes. We produced a single-chain human recombinant antibody (scFv), L19, which reacts specifically with B-FN and selectively targets tumor vasculature in vivo. We used this scFv and an antibody against a pan-endothelial marker (Factor VIII) in a double-staining procedure on specimens of low- and high-grade astrocytomas to determine the percentage of B-FN-positive vessels, (denominating the resulting value angiogenic index [AI]). Compared to vascular density and proliferative activity (evaluated using antibodies to Factor VIII and Ki67, respectively), AI correlated better with tumor grade (1.6 +/- 2.6% and 92.0 +/- 8.7% of B-FN-positive vessels in low- and high-grade astrocytomas, respectively) and was a more precise diagnostic tool than either of the two conventional methods. In fact, discriminating analysis using these three parameters showed that only AI accurately classified 100% of the cases studied, compared to 64% and 89% correctly diagnosed by vascular density and of proliferating cells, respectively.

Occurrence of a glioblastoma-associated tenascin-C isoform in cerebral cavernomas and neighboring vessels

OBJECTIVE

Regrowth of cerebral cavernomas after apparently complete excision, de novo occurrence, and evidence of proliferation-related patterns raise the question as to their intrinsic growth potential. A particular isoform (Type III repeat c) of the glycoprotein tenascin-C (TN-C), typically associated with the vessels of anaplastic gliomas, is regarded as a marker of vascular proliferation in lesions growing within brain tissue. This study sought to ascertain whether this isoform is expressed in cerebral cavernomas to gain further insight into the growth potential of these lesions.

METHODS

Sixteen cerebral cavernomas and three fragments of normal brain underwent immunohistochemical examinations via two antibody fragments obtained by phage display technology. Previous characterization demonstrated that the fragment TN-12 recognizes the epidermal growth factor-like repeat, common to all TN-C isoforms. On the contrary, the fragment TN-11 was found to be highly specific for the Type III repeat c isoform.

RESULTS

Accumulation of total TN-C was found in the vascular walls and in the interspaces between the blood cavities of all examined cavernomas. When the antibody fragment TN-11 was used, staining of the subendothelial layers occurred in both the bulk of the cavernomas and vessels of the white matter surrounding the lesions, but staining was absent in the control specimens.

CONCLUSION

The distribution of the Type III repeat c isoform of TN-C, a putative marker of vascular proliferation, within cerebral cavernomas is consistent with the hypothesis of a growth potential of cerebral cavernomas. Enlargement of these lesions might involve recruitment of neighboring vasculature, which is possibly dependent on environmental conditions.

Growth factor supplemented matrigel improves ectopic skeletal muscle formation--a cell therapy approach

Following damage to skeletal muscle, satellite cells become activated, migrate towards the injured area, proliferate, and fuse with each other to form myotubes which finally mature into myofibers. We tested a new approach to muscle regeneration by incorporating myoblasts, with or without the exogenous growth factors bFGF or HGF, into three-dimensional gels of reconstituted basement membrane (matrigel). In vitro, bFGF and HGF induced C2C12 myoblast proliferation and migration and were synergistic when used together. In vivo, C2C12 or primary i28 myoblasts were injected subcutaneously together with matrigel and growth factors in the flanks of nude mice. The inclusion of either bFGF or HGF increased the vascularization of the gels. Gels supplemented with bFGF showed myogenesis accompanied by massive mesenchymal cell recruitment and poor organization of the fascicles. Samples containing HGF showed delayed differentiation with respect to controls or bFGF, with increased myoblast proliferation and a significantly higher numbers of cells in myotubes at later time points. HGF samples showed limited mesenchymal cell infiltration and relatively good organization of fascicles. The use of both bFGF and HGF together showed increased numbers of nuclei in myotubes, but with bFGF-mediated fibroblast recruitment dominating. These studies suggest that an appropriate combination of basement membrane components and growth factors could represent a possible approach to enhance survival dispersion, proliferation, and differentiation of myogenic cells during muscle regeneration and/or myoblast transplantation. This model will help develop cell therapy of muscle diseases and open the future to gene therapy approaches.

The angiogenesis marker ED-B+ fibronectin isoform in intracranial meningiomas

Fibronectins (FNs), adhesive glycoproteins mainly expressed in the extracellular matrix, are polymorphic molecules whose various isoforms are dependent on alternative splicing patterns. The isoform containing the ED-B sequence and occurring in foetal and neoplastic tissues (oncofoetal or B+FN) has been previously recognized as a marker for angiogenesis. The distribution of this isoform was analyzed in a consecutive series of 134 surgically obtained intracranial meningiomas, using specific monoclonal antibodies. Oncofoetal FN was found to be widely distributed in the vessels of anaplastic meningiomas, with its expression being restricted in the vasculature of the typical subtypes. and absent in the neighbouring cerebral tissue. The ubiquitous vascular expression of B+FN in meningiomatous malignancies might provide a potential target for the in vivo delivery of angiosuppressive agents.

Identification of a glioblastoma-associated tenascin-C isoform by a high affinity recombinant antibody

Tenascin-C exists in several polymorphic isoforms due to alternative splicing of nine fibronectin-like type III repeats. Large Tenascin-C isoforms are present in almost all normal adult tissues but are upregulated in fetal, regenerating, and neoplastic tissues. Here, we report a human antibody fragment, TN11, derived from a phage library with high affinity for the spliced repeat C and demonstrate that this repeat is undetectable in normal adult tissues, barely detectable or undetectable in breast, lung and gastric carcinomas, meningioma, and low grade astrocytoma, but extremely abundant in high grade astrocytoma (grade III and glioblastoma), especially around vascular structures and proliferating cells. The antibody appears to have potential for development of a therapeutic agent for patients with high grade astrocytoma.

Tumor targeting potential of the monoclonal antibody BC-1 against oncofetal fibronectin in nude mice bearing human tumor implants

BACKGROUND

The immunoglobulin G1 (IgG1) monoclonal antibody (MoAb) BC-1 detects human oncofetal fibronectin, which has extremely restricted distribution in normal adult tissues and is highly expressed in fetal and tumor tissues.

METHODS

We studied the biodistribution of 125I-labeled MoAb BC-1 in nude mice bearing subcutaneous human tumor implants of U87MG high-grade astrocytoma and SKMel28 melanoma. 125I-BC-1 was injected either intraperitoneally (i.p.) or intravenously (i.v.), and biodistribution was measured up to 144 hours after injection. In animals bearing SKMel28 implants, tumor targeting was also evaluated by in vivo imaging of the whole mouse by using a dedicated device based on transmitted light excitation after i.v. injection of MoAb BC-1 conjugated with the infrared fluorophore, CY7-bis(N-hydroxy-succinimido)-ester.

RESULTS

125I-BC-1 showed favorable uptake in the human tumor implants, reaching a maximum of 5.27 +/- 0.48% ID/g in the U87MG astrocytoma (72 hours after i.p. injection). The highest uptake in the SKMel28 melanoma implants was 3.49 +/- 0.25% ID/g (24 hours after i.v. injection). Microautoradiography of tumor specimens obtained after administration of 125I-BC-1 clearly showed radioactivity uptake within the two tumors replicating the same pattern of distribution as that of the oncofetal fibronectin shown by immunohistochemistry with MoAb BC-1. Nonspecific uptake of 125I-BC-1 in the bone marrow and skeletal muscle was much lower than in the tumors. In vivo imaging with the fluorophore-labeled MoAb clearly visualized the tumor implants 72-120 hours after i.v. injection.

CONCLUSIONS

The experimental results obtained in this study demonstrate the favorable tumor targeting potential in vivo of the radiolabeled MoAb BC-1, a useful marker of neo angiogenesis induced by cancer.

A pilot pharmacokinetic and immunoscintigraphic study with the technetium-99m-labeled monoclonal antibody BC-1 directed against oncofetal fibronectin in patients with brain tumors

BACKGROUND

Preliminary experiments in an animal model have shown the favorable tumor targeting potential in vivo of radiolabeled BC-1, an immunoglobulin (Ig)G1 monoclonal antibody (MoAb) that recognizes the human fibronectin isoform (B+) containing the ED-B oncofetal domain. This antigen has extremely restricted distribution in normal adult tissues. Instead, it is highly expressed in fetal and tumor tissues, especially in high grade astrocytomas and malignant gliomas of the brain, in which the process of neoangiogenesis linked to tumor growth is particularly important.

METHODS

This study was carried out with five patients who had malignant brain tumors (four gliomas and one malignant angioblastic meningioma). The BC-1 MoAb was labeled with technetium-99m (99mTc) by MDP transchelation. Planar and single photon emission computed tomography (SPECT) imaging was acquired at 4-6 and 20 hours after intravenous injection of about 450 MBq/0.2 mg 99mTc-BC-1 and was compared with the nonspecific indicator of blood-brain barrier disruption, 99mTc-diethylenetriamine pentaacetic acid (DTPA). Plasma pharmacokinetic analysis was based on serial blood sampling. All patients underwent potentially curative surgery at the end of the study.

RESULTS

The plasma clearance curves were biexponential, with average T(1/2) values of 2-4 hours and 28-33 hours, respectively. 99mTc-BC-1 showed very low nonspecific uptake in the bone marrow, liver, and spleen. Planar and SPECT imaging with 99mTc-BC-1 visualized brain tumors in all patients, with a pattern of intratumor distribution that specifically identified areas of peripheral tumor growth more accurately than the nonspecific indicator, 99mTc-DTPA. Tumor uptake of 99mTc-BC-1 was correlated with the expression of the specific oncofetal fibronectin, as shown by immunohistochemistry on surgical samples.

CONCLUSIONS

These results indicate the diagnostic potential of MoAb 99mTc-BC-1 for immunoscintigraphy in cancer patients, at least when neoangiogenesis induced by cancer is particularly important.

Distribution of tenascin in human malignant gliomas is not related to cell proliferation

Images

Third ventricular meningiomas of infancy. A case report

Intraventricular location of meningiomas is impressively higher in childhood and adolescence than in adult patients, respectively 15 to 22% versus 0.2 to 4%. However, location of this tumor within the third ventricle is extremely rare in the pediatric population, since, as far as we know, 17 cases have been reported so far. A case of meningioma of the third ventricle in a 9-year-old boy and its clinical and pathological finding are discussed.

Tenascin distribution in human brain tumours

Using a monoclonal antibody specific for human tenascin (TN), 180 intracranial growths were immunohistochemically studied. In 69 cases of meningioma, neoplastic cells were negative, with some positivity being observed only in the perivascular and the supporting stroma, especially in anaplastic meningiomas. In 57 cases of glioma different degrees of reactivity occurred in both the cellular conglomerates and the stromal components of the tumours. A higher variability in reactivity was observed in anaplastic astrocytomas and glioblastomas. The most constant finding of the study was the staining of the stroma, which was observed in all types of growths, including metastasis, abscess and tuberculoma. The results are consistent with the hypothesis that tenascin is a stromal marker rather than a true marker of malignant tumours. The heterogeneous distribution of TN in anaplastic gliomas may be a factor in the variable response to treatment with radiolabelled anti-TN monoclonal antibodies.

The fibronectin isoform containing the ED-B oncofetal domain: a marker of angiogenesis

Different fibronectin (FN) isoforms are generated by the alternative splicing of 3 regions (ED-A, ED-B and IIICS) of the primary transcript. The FN isoform containing the ED-B sequence, a complete type-III-homology repeat, while having extremely restricted distribution in normal adult tissues, reveals high expression in fetal and tumor tissues. Using the monoclonal antibody (MAb) BC-I, specific for the FN isoform containing the ED-B sequence (B+.FN), we demonstrated here, using immunohistochemical techniques, that while this FN isoform is undetectable in mature vessels, it is highly expressed during angiogenesis both in neoplastic and in normal tissues, as in the case of the functional layer of endometrium during the proliferative phase. B+.FN is thus a marker for the formation of new vessels, and the BC-I MAb may be a useful reagent for evaluating the level of the angiogenetic process in different neoplasms.

Changes in infratentorial blood flow following experimental cerebellar haemorrhage. A preliminary report

The temporal progression of changes in blood flow within the hemispheric cerebellar cortex, following an experimental cerebellar ipsilateral haemorrhage, was investigated in rats by using the hydrogen clearance technique. Stereotactical injection of 50 microliters of fresh autologous blood into the paramedian white matter was found to produce an early drop of cerebellar blood flow, with subsequent rise toward higher values. An increase of the intracranial pressure only occurred at the time of injection of blood. Arterial blood gases, mean arterial blood pressure and blood glucose levels did not exhibit significant changes. Histochemical evaluations of glycogen phosphorylase showed a posthaemorrhagic pattern of enzyme depletion, consistent with the occurrence of an ischaemic damage in both the cerebellum and the brain stem.