Impact of muscle biopsy on the clinical decision-making process in patients with suspected idiopathic inflammatory myopathy.

BACKGROUND: The significance of muscle biopsy as a diagnostic tool in idiopathic inflammatory myopathies (IIM) remains elusive. We aimed to determine the diagnostic weight that has been given to muscle biopsy in patients with suspected IIM, particularly in terms of clinical diagnosis and therapeutic decisions. MATERIAL AND METHODS: In this retrospective multicentric study, we analyzed muscle biopsy results of adult patients with suspected IIM referred to a tertiary center between January 1, 2007, and October 31, 2021. Information regarding referral department, suspected diagnosis, biopsy site, demographic, clinical, laboratory data, and imaging results were extracted. Statistical analyses included the level of agreement between suspected and histological diagnosis and calculation of diagnostic performance (positive and negative predictive values, positive and negative likelihood ratios, sensitivity, and specificity of muscle biopsy in relation to clinical diagnosis and/or treatment initiation). Performance was tested in different strata based on clinical pre-test probability. RESULTS: Among 758 muscle biopsies, IIM was histologically compatible in 357/758 (47.1%) cases. Proportion of IIM was higher if there was a solid clinical pre-test probability (64.3% vs. 42.4% vs. 48% for high, medium and low pre-test probability). Sensitivity and specificity of muscle biopsy were highest (82%) when the diagnosis by the clinician was used as outcome scenario. Negative predictive value was only moderate (between 63% and 80%) and lowest if autoantibodies were positive (35%). CONCLUSION: In patients with clinically suspected IIM, approximately 50% of biopsies revealed features indicative of IIM. Diagnostic performance of muscle biopsy was moderate to high depending on clinical pre-test probability.

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.

Clinico-genetic spectrum of limb-girdle muscular weakness in Austria: A multicentre cohort study.

BACKGROUND AND PURPOSE: Hereditary myopathies with limb-girdle muscular weakness (LGW) are a genetically heterogeneous group of disorders, in which molecular diagnosis remains challenging. Our aim was to present a detailed clinical and genetic characterization of a large cohort of patients with LGW. METHODS: This nationwide cohort study included patients with LGW suspected to be associated with hereditary myopathies. Parameters associated with specific genetic aetiologies were evaluated, and we further assessed how they predicted the detection of causative variants by conducting genetic analyses. RESULTS: Molecular diagnoses were identified in 62.0% (75/121) of the cohort, with a higher proportion of patients diagnosed by next-generation sequencing (NGS) than by single-gene testing (77.3% vs. 22.7% of solved cases). The median (interquartile range) time from onset to genetic diagnosis was 8.9 (3.7-19.9) and 17.8 (7.9-27.8) years for single-gene testing and NGS, respectively. The most common diagnoses were myopathies associated with variants in CAPN3 (n = 9), FKRP (n = 9), ANO5 (n = 8), DYSF (n = 8) and SGCA (n = 5), which together accounted for 32.2% of the cohort. Younger age at disease onset (p = 0.043), >10× elevated creatine kinase activity levels (p = 0.024) and myopathic electromyography findings (p = 0.007) were significantly associated with the detection of causative variants. CONCLUSIONS: Our findings suggest that an earlier use of NGS in patients with LGW is needed to avoid long diagnostic delays. We further present parameters predictive of a molecular diagnosis that may help to select patients for genetic analyses, especially in centres with limited access to sequencing.

Muscle involvement in SARS-CoV-2 infection.

BACKGROUND AND PURPOSE: Since the outbreak of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pandemic, several reports indicated neurological involvement in COVID-19 disease. Muscle involvement has also been reported as evidenced by creatine kinase (CK) elevations and reports of myalgia. METHODS: Creatine kinase, markers of inflammation, pre-existing diseases and statin use were extracted from records of Austrian hospitalised COVID-19 patients. Disease severity was classified as severe in case of intensive care unit (ICU) admission or mortality. COVID-19 patients were additionally compared to an historical group of hospitalised influenza patients. RESULTS: Three hundred fifty-one patients with SARS-CoV-2 and 258 with influenza were included in the final analysis. CK was elevated in 27% of COVID-19 and in 28% of influenza patients. CK was higher in severe COVID-19 as were markers of inflammation. CK correlated significantly with inflammation markers, which had an independent impact on CK when adjusted for demographic variables and disease severity. Compared to influenza patients, COVID-19 patients were older, more frequently male, had more comorbidities, and more frequently had a severe disease course. Nevertheless, influenza patients had higher baseline CK than COVID-19, and 35.7% of intensive care unit (ICU)-admitted patients had CK levels >1,000 U/L compared to only 4.7% of ICU-admitted COVID-19 patients. CONCLUSIONS: HyperCKemia occurs in a similar frequency in COVID-19 and influenza infection. CK levels were lower in COVID-19 than in influenza in mild and severe disease. CK levels strongly correlate with disease severity and markers of inflammation. To date, it remains unclear whether hyperCKemia is due to a virus-triggered inflammatory response or direct muscle toxicity.

Bulbospinal muscular atrophy (Kennedy disease) responsive to immunoglobulins?

A 61 year old man with facial diplegia, quadruparesis, tongue atrophy/fasciculations, bulbar speech, muscle weakness/wasting, hypotonia, tremor, dysdiadochokinesia, absent tendon reflexes, fasciculations, and gynecomastia, received immunoglobulins for suspected immune-neuropathy with limited benefit. After reconsideration, Kennedy disease was diagnosed upon 44 CAG repeats in AR. In conclusion, immunoglobulins exhibit limited benefit on immune-neuropathy in patients with coexisting KD.

Treatment for paraneoplastic neuropathies.

BACKGROUND: It is not unusual to observe peripheral nervous system involvement in people with tumours outside the nervous system. Any part of the peripheral nervous system can be involved, from sensory and motor neurons to nerve roots and plexuses, from distal trunks to neuromuscular junctions. Pathogenesis also varies from direct infiltration by cancer cells, to treatment toxicity, to metabolic derangement, cachexia, infections and paraneoplastic syndromes.Paraneoplastic neurological syndromes are symptoms or signs resulting from damage to organs or tissues that are remote from the site of the malignancy or its metastases. The pathogenesis is thought to be immune-mediated as a result of a cross-reaction against antigens shared by the tumour and nervous system cells.Paraneoplastic neuropathies are the most frequently reported paraneoplastic syndromes. They are, however, heterogeneous and require several therapeutic approaches. This review was undertaken to systematically assess any data available from randomised controlled trials (RCTs) on the treatment of paraneoplastic syndromes of the peripheral nervous system and not the whole range of paraneoplastic neurological syndromes. OBJECTIVES: To assess the benefits and harms of treatments for paraneoplastic neuropathies. SEARCH METHODS: We searched the Cochrane Neuromuscular Disease Group Specialized Register (14 February 2012), CENTRAL (2012, Issue 1), MEDLINE (January 1966 to February 2012), EMBASE (January 1980 to February 2012) and LILACS (January 1982 to February 2012) for RCTs, quasi-RCTs, historically controlled studies and trials with concurrent controls.We adapted this strategy to search MEDLINE from 1966 and EMBASE from 1980 for comparative cohort studies, case-control studies and case series. SELECTION CRITERIA: We planned to include all RCTs and quasi-RCTs (in which allocation is not random but is intended to be unbiased, for example alternate allocation) of any treatment for paraneoplastic neuropathies. Since we expected there to be few or no included studies, we also planned to assess and summarise observational studies, prospective and retrospective comparative cohort studies, case-control studies and case series that met minimum criteria in the discussion. DATA COLLECTION AND ANALYSIS: Three review authors selected the trials for inclusion. When there was any disagreement we reached an agreement by discussion. Two review authors extracted data independently onto a specially designed data extraction form. We would have collected adverse event data from included studies. MAIN RESULTS: Despite many reports on paraneoplastic neuropathy, we identified no RCT or quasi-RCTs for inclusion in this review. We found only six studies, involving 54 participants, from among the non-randomised evidence that were judged by predefined criteria to be of suitable quality for inclusion in the discussion. These studies were not readily comparable. The treatments focused on tumour treatment and immunomodulation, mainly intravenous immunoglobulin. AUTHORS' CONCLUSIONS: At present there are no RCTs or quasi-RCTs of treatment for paraneoplastic neuropathies on which to base practice. There is only evidence from case series, case reports or expert opinion (class IV evidence) for the effect of immunomodulation (intravenous immunoglobulin, plasma exchange, steroid treatment or chemotherapy) on paraneoplastic neuropathy.  

Myeloid sarcoma in the central nervous system: case report and review of the literature.

Myeloid sarcomas are rare manifestations of mainly myeloblastic leukemia. Their occurrence in the central nervous system is exceptional and current literature is limited to case studies. A case is added herewith and a review was performed to investigate clinical characteristics and treatment options of central nervous system myeloid sarcoma. A 61-year-old female with acute myeloblastic leukemia (FAB M5) and progressive left sided hemiparesis showed a right parieto-occipital epidural lesion mimicking meningioma. Partial resection was performed to reveal a myeloid sarcoma. Reviewing the literature we identified 44 cases with sufficient description of the diagnosis, treatment and follow up to one year. In these patients different treatment regimens were applied. However, when systemic chemotherapy or irradiation was included in the treatment regimen, patients showed the best 1-year survival proportion.

The end-of-life hospital setting in patients with glioblastoma.

Despite aggressive treatment, outcome of patients with glioblastoma is poor. Several distinct clinical problems arise in the terminal stage of this disease. The purpose of this study was to evaluate the end-of-life phase in a hospital setting in patients with glioblastoma. Twenty-nine consecutive patients with glioblastoma, who died in our department, were included in this analysis regarding symptoms, medication, diagnostics, and interventional procedures. The patients were comparable with respect to age, gender, and overall survival with data from the literature. Relevant clinical symptoms, medications, diagnostics, well as interventional procedures increased continuously toward end of life. Pain, epileptic seizures, and symptoms of brain edema were the most frequent clinical symptoms. According to this, most patients were on antiepileptic drugs (AED), steroids, and analgesics. In the last phase, symptoms from brain edema, fever, decrease of vigilance, dysphagia, and pneumonia were the prominent clinical features. Our study demonstrates that the end of life in patients with glioblastoma has several periods with different clinical aspects with respect to symptoms and treatment.

Creutzfeldt-Jakob disease and inclusion body myositis: abundant disease-associated prion protein in muscle.

Pathologicalprion protein (PrP(Sc)) is the hallmark of prion diseases affecting primarily the central nervous system. Using immunohistochemistry, paraffin-embedded tissue blot, and Western blot, we demonstrated abundant PrP(Sc) in the muscle of a patient with sporadic Creutzfeldt-Jakob disease and inclusion body myositis. Extraneural PrP(C)-PrP(Sc) conversion in Creutzfeldt-Jakob disease appears to become prominent when PrP(C) is abundantly available as substrate, as in inclusion body myositis muscle.

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.

Nucleus-specific alteration of raphe neurons in human neurodegenerative disorders.

Neurodegenerative diseases share symptoms suggested to be related to the serotonergic system. To evaluate the involvement of serotonergic raphe nuclei, we compared the percentage of neurons synthesizing serotonin in the nucleus centralis superior (NCS), raphe obscurus and pallidus (NROP) in Alzheimer's disease (AD), progressive supranuclear palsy (PSP), Parkinson's disease (PD), multiple system atrophy (MSA), and control brains. We used immunohistochemistry for tryptophan hydroxylase (TpOH), phosphorylated tau, and alpha-synuclein. We observed a significant decrease in the NCS in the NROP in AD, but a significant increase in PSP and MSA. Cytoskeletal pathology was present in the NCS and NROP to a variable degree. We conclude that there is disease- and nucleus-specific alteration of serotonin synthesis in the raphe.

Visualizing central effects of S-adenosyl-L-methionine (SAMe), a natural molecule with antidepressant properties, by pharmaco-EEG mapping.

In a double-blind, placebo-controlled, cross-over study, the central effects of the natural molecule S-adenosyl-L-methionine (SAMe), or ademetionine (ADE), used in low doses as a nutraceutical and in higher doses as a pharmaceutical, were investigated by means of EEG mapping and psychometry. Ten young, normal healthy volunteers of both sexes, with a mean age of 25.2+3.9 yr received, in random order, infusions of 800 mg ADE in 250 ml of isotonic solution, and placebo consisting of 250 ml of isotonic solution administered over 30 min for 7 d, with a wash-out period of 3 wk in between. EEG recordings and psychometric tests were carried out 0, 1, 3 and 6 h after drug administration on days 1 and 7. While there were no significant changes in psychometric findings, multivariate analyses of the EEG results based on MANOVA/Hotelling T 2 tests demonstrated significant encephalotropic effects of ADE compared to placebo. ADE-induced changes were characterized by a decrease in total power, an increase in absolute delta power and a decrease in absolute alpha and beta power, further by an increase in relative delta and beta power and a decrease in relative alpha power, a slowing of the delta/theta centroid, an acceleration of the alpha centroid as well as a slowing of the centroid of the total power spectrum. These changes are typical of classical antidepressants of the thymoleptic type such as imipramine and amitriptyline. Time-efficacy calculations demonstrated a significant central effect of ADE in the first hour after the first infusion, declining slowly until the third hour and thereafter steeply until the sixth hour; a further significant effect was after 1 wk of daily infusions and in the third hour after one superimposed infusion on day 7 of subacute treatment. Our pharmaco-EEG findings suggest both inhibitory and excitatory drug effects at the neurophysiological level, underlying the antidepressant properties well-documented in clinical trials.