Screening for Fabry Disease by Urinary Globotriaosylceramide Isoforms Measurement in Patients with Left Ventricular Hypertrophy.

BACKGROUND: Left ventricular hypertrophy (LVH) is a frequent echocardiographic feature in Fabry disease (FD) and in severe cases may be confused with hypertrophic cardiomyopathy (HCM) of other origin. The prevalence of FD in patients primarily diagnosed with HCM varies considerably in screening and case finding studies, respectively. In a significant proportion of patients, presenting with only mild or moderate LVH and unspecific clinical signs FD may remain undiagnosed. Urinary Gb3 isoforms have been shown to detect FD in both, women and men. We examined whether this non-invasive method would help to identify new FD cases in a non-selected cohort of patients with various degree of LVH. METHODS AND RESULTS: Consecutive patients older than 18 years with a diastolic interventricular septal wall thickness of ≥12mm determined by echocardiography were included. Referral diagnosis was documented and spot urine was collected. Gb3 was measured by mass spectroscopy. Subjects with an elevated Gb3-24:18 ratio were clinically examined for signs of FD, α-galactosidase-A activity in leukocytes was determined and GLA-mutation-analysis was performed. We examined 2596 patients. In 99 subjects urinary Gb3 isoforms excretion were elevated. In these patients no new cases of FD were identified by extended FD assessment. In two of three patients formerly diagnosed with FD Gb3-24:18 ratio was elevated and would have led to further diagnostic evaluation. CONCLUSION: Measurement of urinary Gb3 isoforms in a non-selected cohort with LVH was unable to identify new cases of FD. False positive results may be prevented by more restricted inclusion criteria and may improve diagnostic accuracy of this method.

Detection of disease-associated α-synuclein in the cerebrospinal fluid: a feasibility study.

With the aim to evaluate the significance and reliability of detecting disease-specific α-synuclein in the cerebrospinal fluid (CSF) we developed an ELISA and bead-assay. We used a commercial antibody (5G4) that does not bind to the physiological monomeric form of α-synuclein, but is highly specific for the disease-associated forms, including high molecular weight fraction of ß-sheet rich oligomers. We applied both tests in CSF from a series of neuropathologically confirmed α-synucleinopathy cases, including Parkinson' disease dementia (PDD) and dementia with Lewy bodies (DLB) (n = 7), as well as Alzheimer' disease (n = 6), and control patients without neurodegenerative pathologies (n = 9). Disease-specific α-synuclein was detectable in the CSF in a subset of patients with α-synuclein pathology in the brain. When combined with the analysis of total α-synuclein, the bead-assay for disease-specific α-synuclein was highly specific for PDD/DLB. Detection of disease-associated αsynuclein combined with the total levels of α-synuclein is a promising tool for the in-vivo diagnosis of α-synucleinopathies, including PDD and LBD.

Multifactorial White Matter Damage in the Acute Phase and Pre-Existing Conditions May Drive Cognitive Dysfunction after SARS-CoV-2 Infection: Neuropathology-Based Evidence.

BACKGROUND: There is an urgent need to better understand the mechanisms underlying acute and long-term neurological symptoms after COVID-19. Neuropathological studies can contribute to a better understanding of some of these mechanisms. METHODS: We conducted a detailed postmortem neuropathological analysis of 32 patients who died due to COVID-19 during 2020 and 2021 in Austria. RESULTS: All cases showed diffuse white matter damage with a diffuse microglial activation of a variable severity, including one case of hemorrhagic leukoencephalopathy. Some cases revealed mild inflammatory changes, including olfactory neuritis (25%), nodular brainstem encephalitis (31%), and cranial nerve neuritis (6%), which were similar to those observed in non-COVID-19 severely ill patients. One previously immunosuppressed patient developed acute herpes simplex encephalitis. Acute vascular pathologies (acute infarcts 22%, vascular thrombosis 12%, diffuse hypoxic-ischemic brain damage 40%) and pre-existing small vessel diseases (34%) were frequent findings. Moreover, silent neurodegenerative pathologies in elderly persons were common (AD neuropathologic changes 32%, age-related neuronal and glial tau pathologies 22%, Lewy bodies 9%, argyrophilic grain disease 12.5%, TDP43 pathology 6%). CONCLUSIONS: Our results support some previous neuropathological findings of apparently multifactorial and most likely indirect brain damage in the context of SARS-CoV-2 infection rather than virus-specific damage, and they are in line with the recent experimental data on SARS-CoV-2-related diffuse white matter damage, microglial activation, and cytokine release.

Pellagra encephalopathy as a differential diagnosis for Creutzfeldt-Jakob disease.

In the present study we evaluated cases referred as suspected Creutzfeldt-Jakob disease (CJD). Five out of 59 without prion disease showed neuropathological features of pellagra encephalopathy with widespread chromatolytic neurons (age range 40-48 years at death; one woman). These patients presented with a progressive neuropsychiatric disorder lasting for 2 to 24 months. Common symptoms included gait disorder, para- or tetraspasticity, extrapyramidal symptoms, incontinence, and myoclonus. Protein 14-3-3 in the cerebrospinal fluid was examined in a single patient and was positive, allowing the clinical classification as probable sporadic CJD. Pellagra encephalopathy may be considered as a differential diagnosis of CJD including detection of protein 14-3-3.

The endocardial binary appearance ('binary sign') is an unreliable marker for echocardiographic detection of Fabry disease in patients with left ventricular hypertrophy.

AIMS: The binary sign, a binary appearance of the left ventricular endocardial border, was suggested to be an echocardiographic hallmark in diagnosing Fabry disease, a hereditary, lysosomal storage disorder. The aim of the present study was to examine the reliability of the binary sign as a screening tool to identify patients with Fabry disease. METHODS AND RESULTS: In total 309 subjects with an interventricular septum (IVS) thickness of ≥12 mm were investigated, of which 14 had a confirmed diagnosis of Fabry disease. Urinary globotriaosylceramide testing was used to rule out Fabry disease in the control group. From all patients echocardiographic images of the apical four-chamber view were analysed offline by a blinded observer. A binary sign was seen in 63 patients (20%), 4 had Fabry disease and 59 belonged to the control group. Although the proportion of binary signs in patients with Fabry disease was higher (29%) compared with the control group (20%) this difference was not statistically significant. The sensitivity and specificity were 28% (95% confidence interval (CI): 12-65%) and 80% (95% CI: 76-85%), respectively. In a logistic regression model adjusted for age, sex and presence of Fabry disease, the occurrence of a binary sign was highly dependent on the IVS thickness (odds ratio: 1.21; 95% CI: 1.1-1.35; P<0.001). CONCLUSION: The endocardial binary appearance is associated with the degree of septal hypertrophy but cannot adequately distinguish between patients with Fabry disease and patients with other causes of left ventricular hypertrophy.

Dopamine-deficiency-enhanced hyperthermia and rhabdomyolysis during a heat wave in a metachromatic leucodystrophy heterozygote with metabolic myopathy.

Whether a dopamine-deficiency syndrome in a Parkinson-syndrome (PS) may occur more easily during a heat wave than during more temperate climate conditions is unknown. We report a case that may suggest this. A 56 yo male with heterozygosity for metachromatic leucodystrophy and a history of metabolic myopathy, PS and diabetes experienced worsening of the PS during a heat wave. His condition further deteriorated upon reduction of ropinirol, resulting in hyperthermia, respiratory insufficiency, rhabdomyolysis, and severe thrombocytopenia. One month later he was alert but tetraplegic and required ventilatory support. Hyper-CK-emia returned to similar levels as before rhabdomyolysis. Reduction of dopamine agonists during a heat wave may induce a dopamine deficiency syndrome with hyperthermia, rhabdomyolysis and thrombocytopenia.

Creutzfeldt-Jakob disease in Austria: an autopsy-controlled study.

BACKGROUND: Definite diagnosis of prion diseases or transmissible spongiform encephalopathies (TSEs) requires neuropathology, usually at autopsy. Epidemiology of human TSEs has relied on definite as well as 'probable' cases in which neuropathological confirmation is lacking, usually because of low autopsy rates in most countries. METHODS: In Austria, an active surveillance program for human prion diseases was established in 1996. Since then, more than 900 referrals were analyzed. Postmortem investigation of brain tissue is mandatory in every suspect case of TSE. Thus, epidemiological data on TSEs from Austria may serve as autopsy-controlled reference for countries with lower autopsy rates. RESULTS: The total number of TSE cases in Austria since 1969 is 206. The average yearly mortality for the active surveillance period from 1996 to 30 June 2006 is 1.39 per million, with the highest rates for Vienna (2.37) compared with other provinces. Eighty-five percent of definite TSEs were classified as sporadic Creutzfeldt-Jakob disease (sCJD). We observed a significant linear increase in the mean age at death of 0.6 years per calendar year. Clinical diagnostic surveillance criteria had a sensitivity and specificity of 82.7 and 80.0% for probable CJD, respectively, and a positive predictive value of 80.5% for probable and 38.9% for 'possible' CJD. Alternative neuropathological diagnoses in suspect cases included Alzheimer's disease with or without Lewy body pathology, vascular encephalopathy, metabolic encephalopathies and viral or limbic encephalitis. CONCLUSION: The steady increase in mortality rates, especially in old age groups, most likely reflects improved case ascertainment due to active surveillance causing higher awareness of the medical community. In comparison with other European countries, it is reassuring to note that the overall death rate of TSEs does not differ from the Austrian autopsy-controlled data, thus confirming the value of clinical surveillance criteria.

Refsum disease due to the splice-site mutation c.135-2A>G before exon 3 of the PHYH gene, diagnosed eight years after detection of retinitis pigmentosa.

OBJECTIVES: If Refsum disease (RD) is not considered as a differential at onset of the initial manifestations the diagnosis of RD remains unrecognized for a long time as in the following case. CASE REPORT: A 55-y old Caucasian female with hyperextensible joints developed progressive visual impairment due to retinitis pigmentosa and sensorimotor polyneuropathy of the lower limbs since age 32 y. Screening for causes of polyneuropathy at age 40 y revealed markedly elevated serum phytanic acid (PA) with a maximum value of 293.6 microg/ml (n:<6 microg/ml) why RD was diagnosed. Since age 48 y slowly progressive hypacusis was noted. RD was caused by the known transition A135G in exon 3 of the PHYH gene. Additionally, the polymorphism T153C in exon 3 of the PHYH gene was detected. Upon strict adherence to the Chelsea diet PA levels slightly decreased since onset of this therapy. CONCLUSION: This case confirms that RD remains unrecognized for a long time if RD is not considered as a differential of retinitis pigmentosa as the initial manifestation of the disease. Early recognition of RD is important since there is the therapeutic option of starting a diet.

Glucocorticoids in the treatment of children with acute lymphoblastic leukemia and hodgkin's disease: a pilot study on the adverse psychological reactions and possible associations with neurobiological, endocrine, and genetic markers.

PURPOSE: We did a controlled study to assess adverse psychological reactions (APR) associated with high-dose glucocorticoid therapy and tried to detect somatic correlates for the observed reactions. PATIENTS AND METHODS: Our study included 37 patients with acute lymphoblastic leukemia (ALL) and 11 patients with Morbus Hodgkin (MH) disease, who were treated with high-dose glucocorticoid therapy, and 26 control patients with other types of malignancies. APRs were assessed with a standardized measure via parent-report. Patients with ALL and MH were further analyzed for signs of neuronal cell death in the cerebrospinal fluid, polymorphisms of the glucocorticoid receptor gene, as well as cortisol, adrenocorticorticotropic hormone, and dehydroepiandrosterone sulfate blood levels. RESULTS: Fifty-four percent of ALL, 36% of MH, and 23% of control patients developed APR in the first few weeks of therapy. Approximately 3.5 months later, the majority of patients with ALL showed no APR, similar to control patients. Patients demonstrating a higher, nonsuppressible secretion of cortisol and/or adrenocorticorticotropic hormone during glucocorticoid therapy were found to be more likely to develop APR. No sign of neuronal cell destruction and no correlation of APR with specific glucocorticoid receptor polymorphisms were found. CONCLUSION: Our results suggest that the development of APR due to glucocorticoid therapy is measurable and correlates with hormonal reaction patterns.

Diagnosis of X-linked adrenoleukodystrophy in blood leukocytes.

OBJECTIVES: Our aim was to replace cultured skin fibroblasts in the diagnosis of X-linked adrenoleukodystrophy (X-ALD) by peripheral blood cells. DESIGN AND METHODS: Very long chain fatty acids (VLCFAs) were analyzed in leukocytes from X-ALD patients, heterozygotes, and controls using gas chromatography-mass spectrometry (GC-MS). Immunofluorescence for adrenoleukodystrophy protein (ALDP) was performed in mononuclear blood cell preparations of X-ALD patients known to be ALDP negative in fibroblasts, heterozygote relatives of these patients, and controls. RESULTS: All X-ALD patients were distinguishable from controls by VLCFA analysis in leukocytes. 91.7% of heterozygotes were identified by combined VLCFA analysis in leukocytes and plasma. All patients investigated lacked ALDP immunoreactivity in mononuclear cells, while heterozygotes showed mosaic patterns of positive and negative cells. CONCLUSION: Determination of VLCFAs by GC-MS in combination with ALDP immunofluorescence in peripheral blood cells provides a fast and minimally invasive diagnostic method for X-ALD, which, in contrast to plasma analysis, is independent of alimentary influences. Notably, joint evaluation of leukocytes and plasma considerably improves the identification of heterozygotes.

Endoplasmic reticulum stress features are prominent in Alzheimer disease but not in prion diseases in vivo.

Prion diseases and Alzheimer disease (AD) share a variety of clinical and neuropathologic features (e.g. progressive dementia, accumulation of abnormally folded proteins in diseased tissue, and pronounced neuronal loss) as well as pathogenic mechanisms like generation of oxidative stress molecules and complement activation. Recently, it was suggested that neuronal death in AD may have its origin in the endoplasmic reticulum (ER). Cellular stress conditions can interfere with protein folding and subsequently cause accumulation of unfolded or misfolded proteins in the ER lumen. The ER responds to this by the activation of adaptive pathways, which are termed unfolded protein response (UPR). The UPR transducer PERK, which launches the most immediate response to ER stress (i.e. the transient attenuation of mRNA translation), and the downstream effector of PERK, eIF2alpha, were shown to be activated in AD. We demonstrate that neither in sporadic nor in infectiously acquired or inherited human prion diseases can the activated forms of PERK and eIF2alpha be detected, except when concomitant neurofibrillary pathology is present; whereas the distribution of phosphorylated PERK correlates with abnormally phosphorylated tau in AD. In brains of scrapie-affected mice and mice infected with sporadic or variant Creutzfeldt-Jakob disease, activated PERK is only very faintly expressed. The lack of prominent activation of the PERK-eIF2alpha pathway in prion diseases suggests that, in contrast to AD, ER stress does not play a crucial role in neuronal death in prion disorders.

The prion protein in human neurodegenerative disorders.

We evaluate cellular prion protein (PrP(C)) immunoreactivity (IR) in Alzheimer's, Parkinson's, diffuse Lewy body, and motor neuron diseases (MND), progressive supranuclear palsy, and multiple system atrophy. We use immunohistochemistry for PrP, including five monoclonal antibodies against different epitopes and three different pretreatments, alpha-synuclein, phosphorylated tau, beta-amyloid, and ubiquitin. Disease-specific inclusions are devoid of PrP(C) IR. Using double immunofluorescence and confocal laser microscopy we observe focal overlapping of PrP(C) with tau and with alpha-synuclein in early, but not in fully developed inclusions. However, PrP(C) IR neurons may contain abnormal tau or alpha-synuclein aggregates. Additionally, we observe a loss of PrP(C) IR in anterior horn neurons in MND. Our results suggest that expression of PrP(C) reflects a general response to cellular stress rather than specific co-operation in aggregation of other proteins.

Rationale for diagnosing human prion disease.

Human prion diseases (PrD) like Creutzfeldt-Jakob disease (CJD) include sporadic, acquired and familial neurodegenerative disorders. The central events in the neuropathological process of PrDs are severe neuronal loss, spongiform change and accumulation of abnormal prion protein (PrPSc). The latter is a conformational variant of the host-encoded cellular PrP (PrPC), a copper-binding protein. The physiological role of PrPC is debated. Definitive diagnosis of PrD is based on post mortem demonstration of PrPSc by immunohistochemistry or Western blot. Mutations in the PrP gene (PRNP), the polymorphic site at codon 129, and the molecular characteristic of protease resistant PrP influence the phenotype. Clinical symptoms, cranial MRI scan, EEG and investigation of 14-3-3 protein in cerebrospinal fluid (CSF) suggest a diagnosis of probable CJD. Variant CJD, related to bovine spongiform encephalopathy, shows a different clinical course, symmetrical high intensity MRI signal in the pulvinar, presence of PrPSc in tonsil biopsy tissue, and a lower sensitivity of CSF 14-3-3 protein compared to sporadic CJD. Future possibilities in diagnosis of PrDs include either the demonstration of PrPSc in body fluids or disease associated changes in laboratory variables or gene expression.

Anderson-Fabry disease in Austria.

Fabry disease is an X-linked inherited inborn error of glycosphingolipid catabolism. The deficiency of alpha-galactosidase A leads to the deposition of glycosphingolipids primarily in lysosomes of blood vessel cells. In classically affected hemizygotes clinical manifestations include pain in the extremities, vessel ectasia (angiokeratoma) in skin and mucous membranes, ophthalmological abnormalities, and hypohidrosis. As disease progresses there is renal, cardiac, cerebral and vascular involvement, with most patients experiencing renal insufficiency, cardiac hypertrophy or stroke. Many female carriers of Fabry disease also have symptoms. Recently available enzyme replacement therapy has the potential to control or even reverse disease progression. The present analysis reports on five Austrian families with Fabry disease, cared for by nephrologists in June 2002. Furthermore we discuss potential indications for enzyme replacement therapy in patients maintained on renal replacement therapy.

[Diagnosis of paraneoplastic neurological syndromes]. / Paraneoplasztikus neurológiai kórképek diagnosztikája.

INTRODUCTION: Paraneoplastic neurological syndromes are rare non-metastatic manifestations of malignancy. They are differentiated from side effects of tumor therapy, tumor-associated coagulopathy, infections, metabolic, and nutritional disorders. In the majority of cases neurological symptoms precede diagnosis of associated malignancy. Detection of anti-neuronal antibodies suggests a paraneoplastic mechanism. OBJECTIVES: To summarize syndromes, diagnostic steps, and currently available diagnostic possibilities. METHODS AND RESULTS: Serum and/or cerebrospinal fluid is analysed using indirect immunfluorescence and Western blotting. The pattern of immunoreactivity suggests the type of antibody. Anti-Hu antibody immunolabels predominantly nuclei, and less the cytoplasm of central and peripheral nervous system neurons. Anti-Yo shows cytoplasmic immunoreactivity primarily of cerebellar Purkinje cells, while anti-Ri is somewhat similar to anti-Hu except that peripheral nervous tissue lacks immunoreactivity. Examination of non-neural tissue allows exclusion of nuclear immunostaining caused by other antinuclear antibodies. Western blot examination specifies the anti-neuronal antibody. CONCLUSIONS: 1. Paraneoplastic neurological syndromes may occur without defined malignancy. 2. Clinical diagnosis is supported by immunofluorescent/Western blot/ELISA detection of antibodies. 3. Knowledge of antibody may suggest the origin of malignancy. 4. Tumor and immunomodulatory therapy may be considered, however, prognosis is different in distinct tumors and syndromes.

Abcd2 is a strong modifier of the metabolic impairments in peritoneal macrophages of ABCD1-deficient mice.

The inherited peroxisomal disorder X-linked adrenoleukodystrophy (X-ALD), associated with neurodegeneration and inflammatory cerebral demyelination, is caused by mutations in the ABCD1 gene encoding the peroxisomal ATP-binding cassette (ABC) transporter ABCD1 (ALDP). ABCD1 transports CoA-esters of very long-chain fatty acids (VLCFA) into peroxisomes for degradation by ß-oxidation; thus, ABCD1 deficiency results in VLCFA accumulation. The closest homologue, ABCD2 (ALDRP), when overexpressed, compensates for ABCD1 deficiency in X-ALD fibroblasts and in Abcd1-deficient mice. Microglia/macrophages have emerged as important players in the progression of neuroinflammation. Human monocytes, lacking significant expression of ABCD2, display severely impaired VLCFA metabolism in X-ALD. Here, we used thioglycollate-elicited primary mouse peritoneal macrophages (MPMΦ) from Abcd1 and Abcd2 single- and double-deficient mice to establish how these mutations affect VLCFA metabolism. By quantitative RT-PCR, Abcd2 mRNA was about half as abundant as Abcd1 mRNA in wild-type and similarly abundant in Abcd1-deficient MPMΦ. VLCFA (C26∶0) accumulated about twofold in Abcd1-deficient MPMΦ compared with wild-type controls, as measured by gas chromatography-mass spectrometry. In Abcd2-deficient macrophages VLCFA levels were normal. However, upon Abcd1/Abcd2 double-deficiency, VLCFA accumulation was markedly increased (sixfold) compared with Abcd1-deficient MPMΦ. Elovl1 mRNA, encoding the rate-limiting enzyme for elongation of VLCFA, was equally abundant across all genotypes. Peroxisomal ß-oxidation of C26∶0 amounted to 62% of wild-type activity in Abcd1-deficient MPMΦ and was significantly more impaired (29% residual activity) upon Abcd1/Abcd2 double-deficiency. Single Abcd2 deficiency did not significantly compromise ß-oxidation of C26∶0. Thus, the striking accumulation of VLCFA in double-deficient MPMΦ compared with single Abcd1 deficiency was due to the loss of ABCD2-mediated, compensatory transport of VLCFA into peroxisomes. We propose that moderate endogenous expression of Abcd2 in Abcd1-deficient murine macrophages prevents the severe metabolic phenotype observed in human X-ALD monocytes, which lack appreciable expression of ABCD2. This supports upregulation of ABCD2 as a therapeutic concept in X-ALD.

Epilepsy in adult X-linked adrenoleucodystrophy due to the deletion c.1415-1416delAG in exon 5 of the ABCD1-gene.

Seizures in cerebral X-linked adrenoleucodystrophy (X-ALD) more frequently occur in the early-onset compared to the late-onset form. Here we describe an adult in whom X-ALD deteriorated after head trauma and who developed epilepsy with progression of X-ALD. In a 50 year-old Caucasian male, cerebral X-ALD was diagnosed upon progressive gait disturbance, intellectual decline, elevated very-long chain fatty acids in the serum or leucocytes, cerebral MRI, showing extensive, symmetric, homogenous demyelination in the parieto-occipital areas, the splenium corporis callosum, the thalamus, the crura cerebri, the brain stem, and the pedunculi cerebelli, and the deletion c.1415-1416delAG in the ABCD1-gene. After a head trauma the phenotype deteriorated to mutism, dysphagia, and severe spastic quadruparesis. At an age of 50 years the patient experienced his first, self-limiting, tonic-clonic seizure during an infection, which is why valproic acid was started. Recurrence of seizures after discharge required repeated adaptation of the valproic acid-dosage. Adult X-ALD may be associated with late-onset seizures, which respond favourably to valproic acid. Since any type of seizure episode in adult-onset cerebral X-ALD is usually followed by neurological decline, prophylactic treatment with antiepileptic drugs should be considered not only in early-onset but also in adult-onset epilepsy in X-ALD.

A single lung transplant in a patient with fabry disease: causality or far-fetched? A case report.

Introduction. Fabry disease is a rare X-linked lysosomal storage disorder, characterized by an α-galactosidase A deficiency resulting in globotriaosylceramide storage within cells. Subsequently, various organ systems are involved, clinically the most important are kidneys, the heart, and the peripheral and central nervous systems. Although obstructive lung disease is a common pathological finding in Fabry disease, pulmonary involvement is a clinically disregarded feature. Case Presentation. We report a patient with a diagnosis of chronic obstructive pulmonary disease (COPD) who received a single lung transplant in 2007. Later, a kidney biopsy revealed the diagnosis of Fabry disease, which was confirmed by enzymatic and genetic testing. Ultrastructural changes in a native lung biopsy were consistent with the diagnosis. Although the association of a lung transplant and Fabry disease appears far-fetched on first sight, respiratory impairment cannot be denied in Fabry disease. Conclusion. With this case presentation, we would like to stimulate discussion about rare differential diagnoses hidden beneath widespread disease and that a correct diagnosis is the base of an optimal treatment strategy for each patient. Overall, the patient might have benefited from specific enzyme replacement therapy, especially in view of the chronic kidney disease.

Rapidly progressive dementia with thalamic degeneration and peculiar cortical prion protein immunoreactivity, but absence of proteinase K resistant PrP: a new disease entity?

BACKGROUND: Human prion diseases are a group of rare fatal neurodegenerative conditions with well-developed clinical and neuropathological diagnostic criteria. Recent observations have expanded the spectrum of prion diseases beyond the classically recognized forms. RESULTS: In the present study we report six patients with a novel, apparently sporadic disease characterised by thalamic degeneration and rapidly progressive dementia (duration of illness 2-12 months; age at death: 55-81 years). Light and electron microscopic immunostaining for the prion protein (PrP) revealed a peculiar intraneuritic distribution in neocortical regions. Proteinase K resistant PrP (PrPres) was undetectable by Western blotting in frontal cortex from the three cases with frozen tissue, even after enrichment for PrPres by centrifugation or by phosphotungstic acid precipitation. Conformation-dependent immunoassay analysis using a range of PK digestion conditions (and no PK digestion) produced only very limited evidence of meaningful D-N (denatured/native) values, indicative of the presence of disease-associated PrP (PrPSc) in these cases, when the results were compared with appropriate negative control groups. CONCLUSIONS: Our observation expands the spectrum of conditions associated with rapidly progressive dementia and may have implications for the understanding of the pathogenesis of prion diseases.

Deterioration of anti-Yo-associated paraneoplastic cerebellar degeneration.

OBJECTIVES: Usually, the course of paraneoplastic cerebellar degeneration(PCD) is stable or progresses only slowly. Sudden marked progression after several years, as in the following case, has not been reported. CASE REPORT: After a 57 year old female had developed diplopia, cerebellar signs, upper-limb weakness, and bilateral stocking-type hypoesthesia, and Yo-antibodies were positive, PCD and sensory polyneuropathy were diagnosed. Upon further diagnostic work-up ovarian cancer FIGO-IIC was detected and treated with ovarectomy, hysterectomy, omentectomy, and chemotherapy. Within the following years she experienced several relapses and developed multifocal metastasis requiring surgery, various chemotherapies, thermocoagulations, and radiotherapy. During the first years, PCD showed only minor progression. After 5 years, however, asymmetric ataxia and dysarthria acutely deteriorated such that she became severely handicapped and dependent on the help of others. Several cycles of immunoglobulines were ineffective and she died at age 64 years in a severely disabled state without recovery of the PCD. CONCLUSIONS: PCD, which usually progresses only slowly, can acutely deteriorate without recovery.