A transfacet approach to the lumbar nerve root canal: technical note

BACKGROUND

Intraforaminal and extraforaminal nerve root compressions caused by disk herniation or stenosis are relatively common causes of lumbar radiculopathy. Currently, the two available surgical treatment methods are decompression from the spinal canal or lateral decompression via the Wiltse approach.

OBJECTIVE

To describe a novel transosseous approach to the lumbar nerve root canal.

METHODS

Transfacet foraminotomy was performed in 11 patients with intraforaminal or extraforaminal disk herniation. The outcome was measured using the Patient Satisfaction Index (PSI), need for reoperation, radiographic criteria, and finite element analysis.

RESULTS

We noted that at the time of dismissal, PSI scores of 1 and 3 were reported by 10 and one patients, respectively. At the last follow-up, 10 patients reported a PSI score of 1 or 2. Two patients required reoperation because of recurrent disk herniation. Two patients underwent computed tomography (CT) postoperatively, which showed the transfacet approach. Intriguingly, a second postoperative CT after one month showed that the hole through the facet joint had shrunk significantly.

CONCLUSION

A posterior-anterior transfacet approach for intraforaminal or extraforaminal disk herniations using an ellipsoid facetectomy is safe and allows for fast and comfortable decompression of the nerve root without compromising the long-term strength of the facet joint.

Long-Term Reduction of Sacroiliac Joint Pain With Peripheral Nerve Stimulation

BACKGROUND

We recently demonstrated that 86% of the patients treated with peripheral nerve stimulation (PNS) for therapy-refractory sacroiliac joint (SIJ) pain were satisfied with the result after 1 year of treatment.

OBJECTIVE

To investigate the long-term (up to 4 years) response rate of this novel treatment.

METHODS

Sixteen consecutive patients with therapy-refractory SIJ pain were treated with PNS and followed for 4 years in 3 patients, 3 years in 6 patients, and 2 years in 1 patient. Quality of life, pain, and patient satisfaction were assessed using the Oswestry Disability Index 2.0, Visual Analog Scale (VAS), and International Patient Satisfaction Index.

RESULTS

Patients reported a pain reduction from 8.8 to 1.6 (VAS) at 1 year ( P < .001), and 13 of 14 patients (92.9%) rated the therapy as effective (International Patient Satisfaction Index score ≤ 2). At 2 years, average pain score was 1.9 ( P < .001), and 9 of 10 patients (90.0%) considered the treatment a success. At 3 years, 8 of 9 patients (88.9%) were satisfied with the treatment results, reporting an average VAS of 2.0 ( P < .005). At 4 years, 2 of 3 patients were satisfied with the treatment results.

CONCLUSION

We have shown for the first time that PNS is a successful long-term therapy for SIJ pain.

An Enzyme- and Serum-free Neural Stem Cell Culture Model for EMT Investigation Suited for Drug Discovery

Epithelial to mesenchymal transition (EMT) describes the process of epithelium transdifferentiating into mesenchyme. EMT is a fundamental process during embryonic development that also commonly occurs in glioblastoma, the most frequent malignant brain tumor. EMT has also been observed in multiple carcinomas outside the brain including breast cancer, lung cancer, colon cancer, gastric cancer. EMT is centrally linked to malignancy by promoting migration, invasion and metastasis formation. The mechanisms of EMT induction are not fully understood. Here we describe an in vitro system for standardized isolation of cortical neural stem cells (NSCs) and subsequent EMT-induction. This system provides the flexibility to use either single cells or explant culture. In this system, rat or mouse embryonic forebrain NSCs are cultured in a defined medium, devoid of serum and enzymes. The NSCs expressed Olig2 and Sox10, two transcription factors observed in oligodendrocyte precursor cells (OPCs). Using this system, interactions between FGF-, BMP- and TGFβ-signaling involving Zeb1, Zeb2, and Twist2 were observed where TGFβ-activation significantly enhanced cell migration, suggesting a synergistic BMP-/TGFβ-interaction. The results point to a network of FGF-, BMP- and TGFβ-signaling to be involved in EMT induction and maintenance. This model system is relevant to investigate EMT in vitro. It is cost-efficient and shows high reproducibility. It also allows for the comparison of different compounds with respect to their migration responses (quantitative distance measurement), and high-throughput screening of compounds to inhibit or enhance EMT (qualitative measurement). The model is therefore well suited to test drug libraries for substances affecting EMT.

The chemokine receptor CXCR7 influences prognosis in human glioma in an IDH1-dependent manner

Aims

The chemokine receptor CXCR7 is found on glioma cells and glioma-associated vessels and dependent upon its localisation on tumour or endothelial cells the CXCR7 receptor can mediate glioma cell invasion and tumour angiogenesis. Its expression predicts survival in several types of cancers.

Methods

We immunohistochemically studied the expression of CXCR7 and its ligand SDF1α in a cohort of 354 human patients with glioma. In an in vivo glioma model, we studied the effect of selective CXCR7 inhibition on mean vascular density.

Results

Here we show that expression of either mutant isocitrate dehydrogenase (IDH) 1 or podoplanin (PDPN), two proteins present in basically non-overlapping glioma populations, predicts the prognostic significance of CXCR7. Specifically, expression of CXCR7 on endothelial cells in IDH1 mutant cases predicted poor outcome. Surprisingly, in PDPN expressing gliomas, one of the marker genes for the recently identified mesenchymal subgroup, expression of CXCR7 predicts diminished prognosis on tumour cells and better prognosis on endothelial cells.

Conclusions

Since CXCR7 is expressed on migrating cells our data suggest that, although ubiquitously present, angiogenesis and invasion are outcome-relevant events in specific glioma subgroups, providing a potentially important tool for targeted therapy assignment.

Technical Note: Treatment of Sacroiliac Joint Pain with Peripheral Nerve Stimulation

INTRODUCTION

Sacroiliac joint (SIJ) pain affects older adults with a prevalence of up to 20% among patients with chronic low back pain. While pain medication, joint blocks and denervation procedures achieve pain relief in most patients, some cases fail to improve. Our goal was to determine the effectiveness of SIJ peripheral nerve stimulation in patients with severe conservative therapy-refractory SIJ pain.

MATERIALS AND METHODS

Here we present 12 patients with severe conservative therapy-refractory pain receiving an SIJ peripheral nerve stimulation. Patient satisfaction, pain, and quality of life were evaluated by means of the International Patient Satisfaction Index (IPSI), visual analog scale (VAS), and Oswestry Disability Index 2.0 (ODI) using standard questionnaires. For stimulation we placed an eight-pole peripheral nerve electrode parallel to the SIJ.

RESULTS

Two weeks postoperatively, our patients reported an average ODI reduction from 57% to 32% and VAS from 9 to 2.1. IPSI was 1.1. After six months, the therapy was rated as effective in seven out of eight patients reporting at that period. The average ODI was low at 34% (p = 0.0006), while the VAS index rose to 3.8 (p < 0.0001) and IPSI to 1.9. Twelve months after stimulation, six out of seven patients considered their treatment a success with an average ODI of 21% (p < 0.0005), VAS 1.7 (p < 0.0001), and IPSI 1.3.

CONCLUSIONS

We conclude that SIJ stimulation is a promising therapeutic strategy in the treatment of intractable SIJ pain. Further studies are required to determine the precise target group and long-term effect of this novel treatment method.

Mutant IDH1 inhibits PI3K/Akt signaling in human glioma

BACKGROUND

Recently, isocitrate dehydrogenase 1 (IDH1) was identified as a major participant in glioma pathogenesis. At present, the enzymatic activity of the protein has been the main topic in investigating its physiological function, but its signaling pathway allocation was unsuccessful. Interestingly, proteins regulated by phosphoinositide 3-kinase (PI3K)/Akt signaling, are among the top downregulated genes in gliomas associated with high percentage of IDH1 and IDH2 mutations. The aim of this study was to investigate a hypothetical relation between IDH1 and PI3K signaling.

METHODS

The presence of mutant IDH1 and markers for active PI3K/Akt signaling, present as phosphorylated Akt and podoplanin (PDPN), were investigated in a discovery cohort of 354 patients with glioma. In vitro experiments were used to confirm functional links.

RESULTS

This study shows an inverse correlation between mutant IDH1 and markers for active PI3K/Akt signaling. In support of a functional link between these molecules, in vitro expression of mutant IDH1 inhibited Akt phosphorylation in a 2-hydroxyglutarate-dependent manner.

CONCLUSIONS

This study provides patient tumor and in vitro evidence suggesting that mutant IDH1 inhibits PI3K/Akt signaling.

Expression of mutated isocitrate dehydrogenase-1 in gliomas is associated with p53 and EGFR expression

Gliomas are the most common primary brain tumours. Several independent studies have shown that isocitrate dehydrogenase 1 (IDH1) mutation in diffuse gliomas is associated with a more favourable patient outcome. The aim of this study was to evaluate the prognostic relevance of an antibody specifically detecting the R132H point mutation of IDH1 in tissue sections in a large series of human gliomas. Surgical specimens of 220 consecutive patients with infiltrative low and high-grade gliomas were included in this retrospective study. In multivariate analysis, IDH expression did not reach significance (p = 0.122) in regard to prognosis, in contrast to WHO grade and age at time of surgery (p < 0.001, Cox regression). A significant correlation of p53 expression to mutated IDH1 and histological grading and an inverse correlation to truncated EGFR expression were observed (p < 0.001, Mann-Whitney test). In sum, our results indicate that IDHR132H mutation correlates significantly with p53 and inversely with EGFR mutations. Further studies should investigate whether these correlations reflect involvement of these three molecules in a common signalling pathway.

Additive effect on survival of Raf kinase inhibitor protein and signal transducer and activator of transcription 3 in high-grade glioma

BACKGROUND

Animal studies have shown cooperative contribution of the Ras/Raf/MAPK and PI3K/Akt/mTOR signaling pathways in glioblastoma formation. However, this joint action has not yet been confirmed in human studies.

METHODS

The expression of Raf kinase inhibitory protein (RKIP) was examined in 159 patients with high-grade and low-grade gliomas and correlated with previously obtained data on the activation of signal transducer and activator of transcription 3 (STAT3), a downstream effector of the PI3K/Akt/mTOR signaling pathway.

RESULTS

RKIP expression was associated with a longer overall survival in high-grade glioma cases without showing a direct or inverse correlation with tyrosine-705 phosphorylation of STAT3 (pSTAT3). Notably, RKIP-positive and pSTAT3 negative cases demarcate a patients group with exceptionally long survival, exceeding the prognostic impact of each single marker.

CONCLUSIONS

The results of this study indicated that 1) RKIP expression correlates with tumor grade and is a marker for good prognosis in high-grade gliomas; 2) RKIP expression and lack of pSTAT3 have a cumulative prognostic impact; and 3) RKIP and pSTAT3 are likely to operate independently to influence survival. These findings represented the first human evidence of an additive effect of 2 distinct signaling pathways in high-grade glioma, suggesting that simultaneous inhibition of multiple pathways should be considered as a treatment strategy for these patients.

STAT3 tyrosine phosphorylation influences survival in glioblastoma

Signal transducer and activator of transcription protein 3 (STAT3) is a regulator of central nervous system (CNS) development and a promising therapeutic target in human cancers. Activation of STAT3 promotes oncogenesis in a variety of tissues, but knowledge of its role in glioblastoma is still limited. Recent results indicate that STAT3 acts as a tumor suppressor or an oncogene depending upon the genetic background of the tumor. Here we immunohistochemically assessed Y705-phosphorylated STAT3 (pY705-STAT3) in formalin-fixed, paraffin-embedded specimens of 111 patients with supratentorial glioblastomas and 25 patients with supratentorial grade III gliomas. We found that glioblastoma patients with high or very high numbers of pY705-STAT3-positive tumor cells had significantly shorter overall survival than those with no or low numbers (P = 0.001, Cox regression). Interestingly the proportion of grade III glioma cases with high or very high numbers of pY705-STAT3-positive tumor cells was similar to that in glioblastoma. Our findings provide evidence that activation of STAT3 by Y705 phosphorylation is linked with clinically more aggressive behavior in glioblastomas, but is most likely not associated with tumor progression of grade III gliomas. In sum, our results suggest that STAT3 inhibition should be considered as a therapeutic approach in malignant gliomas.

The role of parvalbumin and calbindin D28k in experimental scrapie

AIMS

Prion diseases are generally characterized by pronounced neuronal loss. In particular, a subpopulation of inhibitory neurones, characterized by the expression of the calcium-binding protein parvalbumin (PV), is selectively destroyed early in the course of human and experimental prion diseases. By contrast, nerve cells expressing calbindin D28 k (CB), another calcium-binding protein, as well as PV/CB coexpressing Purkinje cells, are well preserved.

METHODS

To evaluate, if PV and CB may directly contribute to neuronal vulnerability or resistance against nerve cell death, respectively, we inoculated PV- and CB-deficient mice, and corresponding controls, with 139A scrapie and compared them with regard to incubation times and histological lesion profiles.

RESULTS

While survival times were slightly but significantly diminished in CB-/-, but not PV-/- mice, scrapie lesion profiles did not differ between knockout mice and controls. There was a highly significant and selective loss of isolectin B(4)-decorated perineuronal nets (which specifically demarcate the extracellular matrix surrounding the 'PV-expressing' subpopulation of cortical interneurones) in scrapie inoculated PV+/+, as well as PV-/- mice. Purkinje cell numbers were not different in CB+/+ and CB-/- mice.

CONCLUSIONS

Our results suggest that PV expression is a surrogate marker for neurones highly vulnerable in prion diseases, but that the death of these neurones is unrelated to PV expression and thus based on a still unknown pathomechanism. Further studies including the inoculation of mice ectopically (over)expressing CB are necessary to determine whether the shortened survival of CB-/- mice is indeed due to a neuroprotective effect of this molecule.

Notch controls proliferation and differentiation of stem cells in a dose-dependent manner

Self-renewal and differentiation of CNS stem cells are regulated by still poorly understood cell-cell interactions. Notch is a well-known cell surface protein that can promote both cell cycle progression and mitotic arrest but the molecular mechanism controlling these opposite effects is unknown. Here we demonstrate that, in CNS stem cells, the level of active Notch1 determines the cellular response. Specifically, low levels of the active form of Notch1 promote proliferation whereas high levels lead to growth arrest. Here we provide the first evidence that Notch effects on proliferation and differentiation are a function of dose, and propose a hypothesis on how oncogenes may also act as tumor suppressors.

Severe, early and selective loss of a subpopulation of GABAergic inhibitory neurons in experimental transmissible spongiform encephalopathies

Little is known about the pathogenetic basis of characteristic symptoms in transmissible spongiform encephalopathies (TSEs) such as myoclonus and characteristic EEG hyperactivity. We investigated the GABAergic system and its subpopulations in mice inoculated with experimental scrapie (ME7, RML, 22A strains) and Creutzfeldt-Jakob disease (CJD; Fujisaki strain), to study damage to inhibitory neurons. Since recent studies have shown electrophysiological changes in prion protein (PrP) knockout mice, we also studied mice lacking or overexpressing the PrP gene. Antibodies against glutamic acid decarboxylase (GAD), parvalbumin (PV), calbindin (CB), and calretinin (CR) were used to stain GABAergic neurons, and isolectin-B4 to stain perineuronal nets around PV+ neurons. In scrapie infected mice, cortical PV+ neurons were severely reduced while CB+ and CR+ neurons were well preserved. In CJD inoculated mice, loss of PV+ neurons was severe and occurred very early after inoculation. PrP-/- and tg20 mice showed normal appearance of PV, CB, CR, GAD+ neurons and their neuropil, and of isolectin-B4+ perineuronal nets. The early, severe and selective loss of cortical PV+ neurons in experimental scrapie and CJD suggest selective loss of PV+ GABAergic neurons as important event during disease development, possibly as one basis of excitatory symptoms in TSEs.

Redox metals and oxidative abnormalities in human prion diseases

Prion diseases are characterized by the accumulation of diffuse and aggregated plaques of protease-resistant prion protein (PrP) in the brains of affected individuals and animals. Whereas prion diseases in animals appear to be almost exclusively transmitted by infection, human prion diseases most often occur sporadically and, to a lesser extent, by inheritance or infection. In the sporadic cases (sporadic Creutzfeld-Jakob disease, sCJD), PrP-containing plaques are infrequent, whereas in transmitted (variant CJD) and inherited (Gerstmann-Straussler-Scheinker Syndrome) cases, plaques are a usual feature. In the current study, representative cases from each of the classes of human prion disease were analyzed for the presence of markers of oxidative damage that have been found in other neurodegenerative diseases. Interestingly, we found that the pattern of deposition of PrP, amyloid-beta, and redox active metals was distinct for the various prion diseases. Whereas 8-hydroxyguanosine has been shown to be increased in sCJD, and inducible NOS is increased in scrapie-infected mice, well-studied markers of oxidative damage that accumulate in the lesions of other neurodegenerative diseases (such as Alzheimer's disease, progressive supranuclear palsy, and Parkinson's disease), such as heme oxygenase-1 and lipid peroxidation, were not found around PrP deposits or in vulnerable neurons. These findings suggest an important distinction in prion-related oxidative stress, indicating that different neurodegenerative pathways are involved in different prion diseases.

Complement activation in human prion disease

The central event in the neuropathological process of prion diseases (PrD) is the accumulation of abnormal prion protein accompanied by severe neuronal loss. Despite the infectious nature of these diseases, no prominent immune response has been detected yet. However, recent studies have shown that complement, a component of the innate immune system, is involved in the early pathogenesis of experimental prion infection. Here we demonstrate, in the diseased human brains, the presence of active compounds of the complement system, like C1q and C3b, in extracellular disease-associated prion protein deposits and the membrane attack complex in neurons. The neuronal localization of the membrane attack complex correlates well with the severity of disease-specific pathology and TUNEL labeling of neurons, irrespective of genotype or molecular phenotype of human prion diseases.

Oxidative damage to nucleic acids in human prion disease

Recently, several studies proposed a physiological role for the cellular prion protein (PrP(c)) in defense against oxidative stress. Since the pathogenesis of prion disease necessarily involves a disturbance of PrP(c) homeostasis, we hypothesized that such diseases would be associated with concomitant disturbances in oxidative balance. In support of such a notion, in this study we show increased oxidative damage to nucleic acids in affected brains of patients with Creutzfeldt-Jakob disease. These data suggest that damage by free radicals is a likely cause for neurodegeneration in human prion disease, and antioxidants are a potential therapy for these disorders. Further, our data support the hypothesis that loss of the anti-oxidant function of PrP(c) plays a key role in the pathogenesis of these disorders.

Marked increase of neuronal prion protein immunoreactivity in Alzheimer's disease and human prion diseases

In neurodegenerative disorders including Alzheimer's disease (AD), free radical damage to lipids, carbohydrates, proteins and DNA has been demonstrated to play a key pathogenetic role. In vitro studies have suggested a function of the cellular prion protein (PrPc) in the defense against oxidative stress. Therefore, we investigated the distribution of PrPc immunoreactivity in hippocampus (sectors CA4-CA1), subiculum (Sub), entorhinal (EC), and temporal cortex (TC) in sections from AD, human transmissible spongiform encephalopathy (TSE) and control brains. Compared to control cases, AD brains revealed an increase in the proportion of PrPc-immunoreactive neurons, which was statistically significant in CA2, Sub, and TC. In TSEs, a statistically significant increase of PrPc-immunoreactive neurons was observed in CA2, CA1, Sub, EC, and TC. In conclusion, our data show a striking up-regulation of PrPc in neurodegeneration and provide additional support for the concept that PrPc may be involved in the defense against oxidative stress.

Serotonergic nuclei of the raphe are not affected in human ageing

Sleep disorders increase with ageing. The serotonergic system has been linked with sleep regulation. In fatal familial insomnia, a prion disease with insomnia as one major clinical feature, we recently observed a disturbance in the serotonergic system as likely substrate of typical symptoms. Using immunohistochemistry for the serotonin synthesizing enzyme, tryptophan hydroxylase, we investigated the serotonergic median raphe nuclei (dorsal raphe nucleus, superior central nucleus, and raphe obscurus nucleus) in brains of an older (n = 12; age range 62-84 years) and a younger group (n = 10; age range 5-29 years). We found no significant difference between age groups in the percentage of neurons able to synthesize serotonin. Other changes might relate to sleep disturbances in the elderly.

Alteration of the serotonergic nervous system in fatal familial insomnia

Fatal familial insomnia (FFI) is a unique hereditary prion disease with characteristic disturbances of sleep. We studied the serotonergic system in 8 FFI-affected subjects by immunohistochemistry for the serotonin-synthesizing enzyme, tryptophan hydroxylase (TH). Quantification of neurons in median raphe nuclei showed no total neuronal loss in FFI but a substantial increase of TH+ neurons (approximately 62%) in FFI subjects compared with controls. Our data indicate an alteration of the serotonergic system that might represent the functional substrate of some typical symptoms of FFI.

Evidence for oxidative stress in experimental prion disease

Oxidative stress has been shown to be important in several neurodegenerative disorders. Previous in vitro studies have already demonstrated the ability of a prion protein fragment to induce oxidative stress in cultured cells. By immunohistochemistry for nitrotyrosine (NT) and heme oxygenase-1 as markers for oxidative stress, we found widespread neuronal labeling for NT in scrapie-infected mouse brains, in agreement with peroxynitrite mediated neuronal degeneration. Damage by free radicals is a likely cause for neurodegeneration in prion disease, and antioxidants are a potential therapy of these disorders.

Selective neuronal vulnerability in human prion diseases. Fatal familial insomnia differs from other types of prion diseases

Human transmissible spongiform encephalopathies (TSEs) or prion diseases are neurodegenerative disorders of infectious, inherited or sporadic origin and include Creutzfeldt-Jakob disease (CJD), Gerstmann-Sträussler-Scheinker disease (GSS), kuru and fatal familial insomnia (FFI). Clinicopathologic features of FFI differ markedly from other human TSEs. Previous studies demonstrated selective neuronal vulnerability of parvalbumin positive (PV+) GABAergic inhibitory interneurons in sporadic CJD and experimental TSEs. In this report we show uniform severe loss of PV+ neurons also in other TSEs such as GSS, kuru, new variant and familial CJD. In contrast, these neurons are mostly well preserved, or only moderately reduced, in FFI. Only PV+ neurons surrounded by isolectin-B4 positive perineuronal nets were severely affected in TSEs, suggesting a factor residing in this type of extracellular matrix around PV+ neurons as modulator for the selective neuronal vulnerability.

Distribution of parvalbumin-immunoreactive neurons in brain correlates with hippocampal and temporal cortical pathology in Creutzfeldt-Jakob disease

There is a distinctive pattern of hippocampal involvement in Creutzfeldt-Jakob disease (CJD) and evidence for selective vulnerability of GABAergic neurons in experimental and human prion disease. We studied hippocampus and temporal cortex from human CJD and control autopsy brains and surgical cryptogenic temporal lobe epilepsy specimens for distribution and density of parvalbumin (PV) and calbindin-D28K (Cal) -positive neurons that are subpopulations of GABAergic neurons. Pathology was evaluated semiquantitatively in 8 regions in 23 CJD brains for severity of spongiform change, astrogliosis and pathological prion protein deposition. In CJD, pathology was severe in pre-parasubiculum and temporal cortex, and little or absent in CA1-4; PV+ neurons were severely reduced or absent in all cases, whereas Cal+ neurons were largely preserved. In controls, the density of PV+ neurons was highest in pre-parasubiculum and temporal cortex, and lowest in CA1-4. In cTLE, loss of PV+ neurons was seen only in CA1-4. The diffuse and severe loss of PV+ neurons in CJD, and the topographical correlation of tissue lesioning in CJD with density of PV+ neurons in controls suggest selective vulnerability and early loss of this subset of inhibitory neurons in CJD. This might relate to characteristic CJD symptoms such as myoclonus and the distinctive EEG pattern.

[Creutzfeldt-Jakob disease in Austria]

Between 1969 and 30th June 1996, Creutzfeldt-Jakob disease (CJD) was definitively diagnosed in 88 Austrian patients by autopsy and/or biopsy. The number of diagnosed cases has steadily increased in recent years (average incidence in 1969-1985: 0.18 per million; 1986-1994: 0.67 per million; 1995: 1.25 per million; estimate for 1996: 1.7 per million). The percentage of patients older than 70 years increased until 1989 and has decreased slightly since then. One patient received a lyophilised dura transplant 11 years before death. Another patient gave a history of intramuscular injections of bovine RNA (Regeneresen) extracted from various organs including brain administered over a ten-year period. One female patient had familial CJD with a glutamate-->lysine mutation at codon 200 of the prion protein (PrP) gene PRNP. The ages at death are distributed symmetrically around the median of 64 years. Two female patients died at the unusually young ages of 27 and 30 years. Median duration of disease was 4.5 months; 77% of the patients died within 6 months after onset of the disease. Retrospectively, 83% of the patients fulfilled the clinical criteria of probable or possible CJD. Neuropathologically, each patient showed accumulation of immunocytochemically detectable pathological PrP in the central nervous system. No patient had the neuropathological profile of the new CJD variant recently described in the U.K. The recent rise in diagnosed CJD in Austria probably reflects increased awareness and recognition rather than a real increase. Since bovine spongiform encephalopathy (BSE) has not been observed in Austria, our data argue against an association between the rise of incidence of CJD and BSE.

Creutzfeldt-Jakob disease in Austria

Between 1969 and 30 September 1995, 79 Austrian patients had Creutzfeldt-Jakob disease (CJD) diagnosed neuropathologically by necropsy or biopsy. The annual incidence has significantly increased in recent years (average 0.18 per million in 1969-85, and 0.67 per million in 1986-94; estimate for 1995: 1.5 per million). Also, the percentage of patients with CJD over 70 years at death increased significantly until 1989 but is since in decline. There is no regional clustering, familial occurrence, or recognised iatrogenic risk. One patient had a 10 year history of intramuscular injection of purified bovine RNA preparation (Regeneresen) from various organs including the brian. The ages at death are symmetrically distributed around the median of 64 years. The median duration of disease is four months. Most patients (76%) died within six months of onset. Retrospectively, 86% of patients fulfilled clinical criteria of probable or possible CJD. Neuropathology showed the classic triad of spongiform change, astrogliosis, and neuronal loss in most cases. Two cases did not show unequivocal tissue alterations, but anti-PrP immunocytochemistry detected PrP deposits also in these cases. It is concluded that the recent rise in incidence of CJD in Austria most likely reflects increased awareness and diagnosis of CJD rather than a real increase. As bovine spongiform encephalopathy (BSE) has not been reported in Austria, the data do not support a link between a rise in incidence of sporadic CJD and BSE.