Liquid Biopsy in Alzheimer's Disease Patients Reveals Epigenetic Changes in the PRLHR Gene.

In recent years, new DNA methylation variants have been reported in genes biologically relevant to Alzheimer's disease (AD) in human brain tissue. However, this AD-specific epigenetic information remains brain-locked and unreachable during patients' lifetimes. In a previous methylome performed in the hippocampus of 26 AD patients and 12 controls, we found higher methylation levels in AD patients in the promoter region of PRLHR, a gene involved in energy balance regulation. Our aim was to further characterize PRLHR's role in AD and to evaluate if the liquid biopsy technique would provide life access to this brain information in a non-invasive way. First, we extended the methylation mapping of PRLHR and validated previous methylome results via bisulfite cloning sequencing. Next, we observed a positive correlation between PRLHR methylation levels and AD-related neuropathological changes and a decreased expression of PRLHR in AD hippocampus. Then, we managed to replicate the hippocampal methylation differences in plasma cfDNA from an additional cohort of 35 AD patients and 35 controls. The isolation of cfDNA from the plasma of AD patients may constitute a source of potential epigenetic biomarkers to aid AD clinical management.

Association of Blood-Based DNA Methylation Markers With Late-Onset Alzheimer Disease: A Potential Diagnostic Approach.

BACKGROUND AND OBJECTIVES: There is an urgent need to identify novel noninvasive biomarkers for Alzheimer disease (AD) diagnosis. Recent advances in blood-based measurements of phosphorylated tau (pTau) species are promising but still insufficient to address clinical needs. Epigenetics has been shown to be helpful to better understand AD pathogenesis. Epigenetic biomarkers have been successfully implemented in other medical disciplines, such as oncology. The objective of this study was to explore the diagnostic accuracy of a blood-based DNA methylation marker panel as a noninvasive tool to identify patients with late-onset Alzheimer compared with age-matched controls. METHODS: A case-control study was performed. Blood DNA methylation levels at 46 cytosine-guanine sites (21 genes selected after a comprehensive literature search) were measured by bisulfite pyrosequencing in patients with "probable AD dementia" following National Institute on Aging and the Alzheimer's Association guidelines (2011) and age-matched and sex-matched controls recruited at Neurology Department-University Hospital of Navarre, Spain, selected by convenience sampling. Plasma pTau181 levels were determined by Simoa technology. Multivariable logistic regression analysis was performed to explore the optimal model to discriminate patients with AD from controls. Furthermore, we performed a stratified analysis by sex. RESULTS: The final study cohort consisted of 80 patients with AD (age: median [interquartile range] 79 [11] years; 58.8% female) and 100 cognitively healthy controls (age 77 [10] years; 58% female). A panel including DNA methylation levels at NXN, ABCA7, and HOXA3 genes and plasma pTau181 significantly improved (area under the receiver operating characteristic curve 0.93, 95% CI 0.89-0.97) the diagnostic performance of a single pTau181-based model, adjusted for age, sex, and APOE ɛ4 genotype. The sensitivity and specificity of this panel were 83.30% and 90.00%, respectively. After sex-stratified analysis, HOXA3 DNA methylation levels showed consistent association with AD. DISCUSSION: These results highlight the potential translational value of blood-based DNA methylation biomarkers for noninvasive diagnosis of AD. REGISTRATION INFORMATION: Research Ethics Committee of the University Hospital of Navarre (PI17/02218).

Neurologic complications in herpes simplex encephalitis: clinical, immunological and genetic studies.

Patients with herpes simplex virus (HSV) encephalitis (HSE) often develop neuronal autoantibody-associated encephalitis (AE) post-infection. Risk factors of AE are unknown. We tested the hypotheses that predisposition for AE post-HSE may be involved, including genetic variants at specific loci, human leucocyte (HLA) haplotypes, or the blood innate immune response against HSV, including type I interferon (IFN) immunity. Patients of all ages with HSE diagnosed between 1 January 2014 and 31 December 2021 were included in one of two cohorts depending on whether the recruitment was at HSE onset (Spanish Cohort A) or by the time of new neurological manifestations (international Cohort B). Patients were assessed for the type of neurological syndromes; HLA haplotypes; blood type I-IFN signature [RNA quantification of 6 or 28 IFN-response genes (IRG)] and toll-like receptor (TLR3)-type I IFN-related gene mutations. Overall, 190 patients (52% male) were recruited, 93 in Cohort A and 97 in Cohort B. Thirty-nine (42%) patients from Cohort A developed neuronal autoantibodies, and 21 (54%) of them developed AE. Three syndromes (choreoathetosis, anti-NMDAR-like encephalitis and behavioural-psychiatric) showed a high (≥95% cases) association with neuronal autoantibodies. Patients who developed AE post-HSE were less likely to carry the allele HLA-A*02 (4/21, 19%) than those who did not develop AE (42/65, 65%, P = 0.0003) or the Spanish general population (2005/4335, 46%, P = 0.0145). Blood IFN signatures using 6 or 28 IRG were positive in 19/21 (91%) and 18/21 (86%) patients at HSE onset, and rapidly decreased during follow-up. At Day 21 after HSE onset, patients who later developed AE had higher median IFN signature compared with those who did not develop AE [median Zs-6-IRG 1.4 (0.6; 2.0) versus 0.2 (-0.4; 0.8), P = 0.03]. However, a very high median Zs-6-IRG (>4) or persistently increased IFN signature associated with uncontrolled viral infection. Whole exome sequencing showed that the percentage of TLR3-IFN-related mutations in patients who developed AE was not different from those who did not develop AE [3/37 (8%) versus 2/57 (4%), P = 0.379]. Multivariate logistic regression showed that a moderate increase of the blood IFN signature at Day 21 (median Zs-6-IRG >1.5 but <4) was the most important predictor of AE post-HSE [odds ratio 34.8, interquartile ratio (1.7-691.9)]. Altogether, these findings show that most AE post-HSE manifest with three distinct syndromes, and HLA-A*02, but not TLR3-IFN-related mutations, confer protection from developing AE. In addition to neuronal autoantibodies, the blood IFN signature in the context of HSE may be potentially useful for the diagnosis and monitoring of HSE complications.

Progressive cognitive impairment and familial spastic paraparesis due to PRESENILIN 1 mutation: anatomoclinical characterization.

INTRODUCTION: Autosomal dominant Alzheimer's disease (ADAD) due to presenilin 1 (PSEN1) mutation can induce atypical neurological symptoms such as movement disorders and epileptic seizures in the context of early-onset progressive cognitive impairment. METHODS: This study includes the anatomoclinical description of three patients of two generations of the same family with movement disorders and progressive cognitive impairment. All were evaluated by trained neurologists, underwent protocolized neuropsychological evaluation, and were assessed by structural (magnetic resonance) and functional (SPECT, PET-18FDG, or PET-18F-Florbetapir) brain imaging tests. A molecular genetic study was performed for all patients, and post-mortem confirmatory anatomopathological evaluation for one of them. RESULTS: The three female patients had an age of onset of symptoms of 38-51 years. All developed progressive multidomain cognitive impairment, paraparesis, and dysarthria, two with ophthalmoparesis and one with untriggered epileptic seizures since early stages. Bilateral cortical fronto-parietal atrophy and global cortical hypoperfusion or posterior bilateral hypometabolism were detected. PET-18F-Florbetapir, when performed, was positive for amyloid cortical deposit. The molecular genetic study confirmed the PSEN1 mutation c.869-2 A>G. Postmortem study of one of them confirmed Alzheimer's disease anatomopathological features with classic cotton wool plaques (CWP), including coexistence of amyloid angiopathy and Lewy body co-pathology. DISCUSSION: The phenotype of ADAD due to PSEN1 mutations is very heterogeneous between and across the same family. Family history assessment should include information not only about cognitive decline, but also about movement disorders and untriggered epileptic seizures. Further studies are needed to identify genetic or epigenetic factors that determine phenotypic diversity in this disease.

Frequency and Characterization of Movement Disorders in Anti-IgLON5 Disease.

OBJECTIVE: Anti-IgLON5 disease is a recently described neurological disease that shares features of autoimmunity and neurodegeneration. Abnormal movements appear to be frequent and important but have not been characterized and are under-reported. Here we describe the frequency and types of movement disorders in a series of consecutive patients with this disease. METHODS: In this retrospective, observational study, the presence and phenomenology of movement disorders were assessed with a standardized clinical questionnaire. Available videos were centrally reviewed by three experts in movement disorders. RESULTS: Seventy two patients were included. In 41 (57%) the main reason for initial consultation was difficulty walking along with one or several concurrent movement disorders. At the time of anti-IgLON5 diagnosis, 63 (87%) patients had at least one movement disorder with a median of three per patient. The most frequent abnormal movements were gait and balance disturbances (52 patients, 72%), chorea (24, 33%), bradykinesia (20, 28%), dystonia (19, 26%), abnormal body postures or rigidity (18, 25%), and tremor (15, 21%). Other hyperkinetic movements (myoclonus, akathisia, myorhythmia, myokymia, or abdominal dyskinesias) occurred in 26 (36%) patients. The craniofacial region was one of the most frequently affected by multiple concurrent movement disorders (23 patients, 32%) including dystonia (13), myorhythmia (6), chorea (4) or myokymia (4). Considering any body region, the most frequent combination of multiple movement disorders consisted of gait instability or ataxia associated with craniofacial dyskinesias or generalized chorea observed in 31(43%) of patients. In addition to abnormal movements, 87% of patients had sleep alterations, 74% bulbar dysfunction, and 53% cognitive impairment. Fifty-five (76%) patients were treated with immunotherapy, resulting in important and sustained improvement of the movement disorders in only seven (13%) cases. CONCLUSIONS: Movement disorders are a frequent and leading cause of initial neurological consultation in patients with anti-IgLON5 disease. Although multiple types of abnormal movements can occur, the most prevalent are disorders of gait, generalized chorea, and dystonia and other dyskinesias that frequently affect craniofacial muscles. Overall, anti-IgLON5 disease should be considered in patients with multiple movement disorders, particularly if they occur in association with sleep alterations, bulbar dysfunction, or cognitive impairment.

Microglia-Related Gene Triggering Receptor Expressed in Myeloid Cells 2 (TREM2) Is Upregulated in the Substantia Nigra of Progressive Supranuclear Palsy.

BACKGROUND: The role of the microglia-related gene triggering receptor expressed in myeloid cells 2 (TREM2) in primary tauopathies, such as progressive supranuclear palsy (PSP), still remains unclear. OBJECTIVES: The objective of this study was to profile overall and transcript-specific TREM2 expression levels in the substantia nigra (SN) of PSP patients and controls. METHODS: SN samples from neuropathologically confirmed PSP cases (n = 24) and controls (n = 14) were used to measure TREM2 and TREM2-modulating gene Membrane-spanning 4-domains subfamily A member 4A (MS4A4A) mRNA levels by real-time quantitative polymerase chain reaction. Correlation with hyperphosphorylated tau protein burden was assessed. RESULTS: Overall TREM2 and each of the 3 TREM2 transcripts mRNA levels were significantly increased in the SN of PSP cases versus controls. TREM2 mRNA levels positively correlated with hyperphosphorylated tau burden in SN, specifically in neurons. The MS4A4A gene was also upregulated in PSP patients versus controls. CONCLUSIONS: These results add evidence to the involvement of microglia in the disease process of PSP. These findings support the idea that different tauopathies may share common patterns of deregulation in innate immune molecular pathways. © 2020 International Parkinson and Movement Disorder Society.

Anti-IGLON5 disease: A new case without neuropathologic evidence of brainstem tauopathy.

OBJECTIVE: To describe the neuropathologic features and the molecular data of phosphorylated tau (pTau) in a new case of anti-IgLON5 disease. METHODS: Review of clinical data, postmortem neuropathologic examination. Biochemical analyses of pTau were performed in brain samples from the present case and from a previously described patient with anti-IgLON5 with the characteristic brainstem tauopathy. RESULTS: The patient was a 71-year-old man with a clinical syndrome consisting of sleep disturbance and bulbar symptoms. IgLON5 antibodies of predominant IgG4 subtype were detected in serum and CSF. He carried the HLA DRB1*10:01-DQB1*05:01 haplotype. Despite treatment with IV immunoglobulins, he unexpectedly died during sleep 2 years after disease onset. Histology showed neurofibrillary pathology and ß-amyloid deposits consistent with Alzheimer disease (AD) of intermediate severity. pTau deposits were absent in the brainstem. There were few perivascular CD8+ T-cell infiltrates in the posterior hypothalamus, amygdala, and brainstem with microglial activation. The pTau immunoblot showed a pattern of bands consistent with AD, which was different from that observed in the patient with anti-IgLON5 with brainstem tauopathy who presented a differential band around 56 KDa. CONCLUSION: The absence of pTau deposits in the brainstem of the present patient suggests that the tauopathy of patients with anti-IgLON5 disease may be a late, secondary event. The anti-IgLON5 brainstem tauopathy has a specific molecular signature different from primary tauopathies. pTau deposits restricted to the hippocampus/limbic regions of patients with anti-IgLON5 may represent an age-related comorbidity.

Amylin as a potential link between type 2 diabetes and alzheimer disease.

OBJECTIVE: Alzheimer disease (AD) is the leading cause of dementia, and although its etiology remains unclear, it seems that type 2 diabetes mellitus (T2DM) and other prediabetic states of insulin resistance could contribute to the appearance of sporadic AD. As such, we have assessed whether tau and ß-amyloid (Aß) deposits might be present in pancreatic tissue of subjects with AD, and whether amylin, an amyloidogenic protein deposited in the pancreas of T2DM patients, might accumulate in the brain of AD patients. METHODS: We studied pancreatic and brain tissue from 48 individuals with no neuropathological alterations and from 87 subjects diagnosed with AD. We examined Aß and tau accumulation in the pancreas as well as that of amylin in the brain. Moreover, we performed proximity ligation assays to ascertain whether tau and/or Aß interact with amylin in either the pancreas or brain of these subjects. RESULTS: Cytoplasmic tau and Aß protein deposits were detected in pancreatic ß cells of subjects with AD as well as in subjects with a normal neuropathological examination but with a history of T2DM and in a small cohort of control subjects without T2DM. Furthermore, we found amylin deposits in the brain of these subjects, providing histological evidence that amylin can interact with Aß and tau in both the pancreas and hippocampus. INTERPRETATION: The presence of both tau and Aß inclusions in pancreatic ß cells, and of amylin deposits in the brain, provides new evidence of a potential overlap in the mechanisms underlying the pathogenesis of T2DM and AD. ANN NEUROL 2019;86:539-551.

PLD3 epigenetic changes in the hippocampus of Alzheimer's disease.

BACKGROUND: Whole-exome sequencing has revealed a rare missense variant in PLD3 gene (rs145999145) to be associated with late onset Alzheimer's disease (AD). Nevertheless, the association remains controversial and little is known about the role of PLD3 in AD. Interestingly, PLD3 encodes a phospholipase that may be involved in amyloid precursor protein (APP) processing. Our aim was to gain insight into the epigenetic mechanisms regulating PLD3 gene expression in the human hippocampus affected by AD. RESULTS: We assessed PLD3 mRNA expression by qPCR and protein levels by Western blot in frozen hippocampal samples from a cohort of neuropathologically confirmed pure AD cases and controls. Next, we profiled DNA methylation at cytosine-phosphate-guanine dinucleotide (CpG) site resolution by pyrosequencing and further validated results by bisulfite cloning sequencing in two promoter regions of the PLD3 gene. A 1.67-fold decrease in PLD3 mRNA levels (p value < 0.001) was observed in the hippocampus of AD cases compared to controls, and a slight decrease was also found by Western blot at protein level. Moreover, PLD3 mRNA levels inversely correlated with the average area of ß-amyloid burden (tau-b = - 0,331; p value < 0.01) in the hippocampus. A differentially methylated region was identified within the alternative promoter of PLD3 gene showing higher DNA methylation levels in the AD hippocampus compared to controls (21.7 ± 4.7% vs. 18.3 ± 4.8%; p value < 0.05). CONCLUSIONS: PLD3 gene is downregulated in the human hippocampus in AD cases compared to controls. Altered epigenetic mechanisms, such as differential DNA methylation within an alternative promoter of PLD3 gene, may be involved in the pathological processes of AD. Moreover, PLD3 mRNA expression inversely correlates with hippocampal ß-amyloid burden, which adds evidence to the hypothesis that PLD3 protein may contribute to AD development by modifying APP processing.

Frequency, symptoms, risk factors, and outcomes of autoimmune encephalitis after herpes simplex encephalitis: a prospective observational study and retrospective analysis.

BACKGROUND: Herpes simplex encephalitis can trigger autoimmune encephalitis that leads to neurological worsening. We aimed to assess the frequency, symptoms, risk factors, and outcomes of this complication. METHODS: We did a prospective observational study and retrospective analysis. In the prospective observational part of this study, we included patients with herpes simplex encephalitis diagnosed by neurologists, paediatricians, or infectious disease specialists in 19 secondary and tertiary Spanish centres (Cohort A). Outpatient follow-up was at 2, 6, and 12 months from onset of herpes simplex encephalitis. We studied another group of patients retrospectively, when they developed autoimmune encephalitis after herpes simplex encephalitis (Cohort B). We compared demographics and clinical features of patients who developed autoimmune encephalitis with those who did not, and in patients who developed autoimmune encephalitis we compared these features by age group (patients ≤4 years compared with patients >4 years). We also used multivariable binary logistic regression models to assess risk factors for autoimmune encephalitis after herpes simplex encephalitis. FINDINGS: Between Jan 1, 2014, and Oct 31, 2017, 54 patients with herpes simplex encephalitis were recruited to Cohort A, and 51 were included in the analysis (median age 50 years [IQR 5-68]). At onset of herpes simplex encephalitis, none of the 51 patients had antibodies to neuronal antigens; during follow-up, 14 (27%) patients developed autoimmune encephalitis and all 14 (100%) had neuronal antibodies (nine [64%] had NMDA receptor [NMDAR] antibodies and five [36%] had other antibodies) at or before onset of symptoms. The other 37 patients did not develop autoimmune encephalitis, although 11 (30%) developed antibodies (n=3 to NMDAR, n=8 to unknown antigens; p<0·001). Antibody detection within 3 weeks of herpes simplex encephalitis was a risk factor for autoimmune encephalitis (odds ratio [OR] 11·5, 95% CI 2·7-48·8; p<0·001). Between Oct 7, 2011, and Oct 31, 2017, there were 48 patients in Cohort B with new-onset or worsening neurological symptoms not caused by herpes simplex virus reactivation (median age 8·8 years [IQR 1·1-44·2]; n=27 male); 44 (92%) patients had antibody-confirmed autoimmune encephalitis (34 had NMDAR antibodies and ten had other antibodies). In both cohorts (n=58 patients with antibody-confirmed autoimmune encephalitis), patients older than 4 years frequently presented with psychosis (18 [58%] of 31; younger children not assessable). Compared with patients older than 4 years, patients aged 4 years or younger (n=27) were more likely to have shorter intervals between onset of herpes simplex encephalitis and onset of autoimmune encephalitis (median 26 days [IQR 24-32] vs 43 days [25-54]; p=0·0073), choreoathetosis (27 [100%] of 27 vs 0 of 31; p<0·001), decreased level of consciousness (26 [96%] of 27 vs seven [23%] of 31; p<0·001), NMDAR antibodies (24 [89%] of 27 vs 19 [61%] of 31; p=0·033), and worse outcome at 1 year (median modified Rankin Scale 4 [IQR 4-4] vs 2 [2-3]; p<0·0010; seizures 12 [63%] of 19 vs three [13%] of 23; p=0·001). INTERPRETATION: The results of our prospective study show that autoimmune encephalitis occurred in 27% of patients with herpes simplex encephalitis. It was associated with development of neuronal antibodies and usually presented within 2 months after treatment of herpes simplex encephalitis; the symptoms were age-dependent, and the neurological outcome was worse in young children. Prompt diagnosis is important because patients, primarily those older than 4 years, can respond to immunotherapy. FUNDING: Mutua Madrileña Foundation, Fondation de l'Université de Lausanne et Centre Hospitalier Universitaire Vaudois, Instituto Carlos III, CIBERER, National Institutes of Health, Generalitat de Catalunya, Fundació CELLEX.

CRTC1 gene is differentially methylated in the human hippocampus in Alzheimer's disease.

BACKGROUND: CRTC1 (CREB regulated transcription coactivator 1) gene plays a role in synaptic plasticity, learning and long-term memory formation in the hippocampus. Recently, CRTC1 has been shown to be downregulated in Alzheimer's disease (AD). Nevertheless, the mechanisms underlying CRTC1 dysregulation in AD remain unclear. METHODS: To understand better the epigenetic mechanisms regulating CRTC1 expression that may be altered in AD, we profiled DNA methylation at CpG site resolution by bisulfite cloning sequencing in two promoter regions (referred to as Prom1 and Prom2) of the CRTC1 gene in human hippocampus from controls and AD cases. Next, we correlated DNA methylation levels with AD-related pathology, i.e., ß-amyloid and phosphorylated-tau (p-tau) burden and also measured CRTC1 mRNA levels by RT-qPCR. RESULTS: Methylation levels were lower in AD cases as compared to controls within both promoter regions (Prom1: 0.95% vs. 5%, p-value < 0.01 and Prom2: 2.80% vs. 17.80%, p-value < 0.001). Interestingly, CRTC1 methylation levels inversely correlated with AD-related neuropathological changes, particularly with p-tau deposition (rSpearman = -0.903, p < 0.001). Moreover, a 1.54-fold decrease in CRTC1 mRNA levels was observed in hippocampus of AD cases compared to controls (p < 0.05) supporting the notion that CRTC1 is downregulated in the AD hippocampus. CONCLUSIONS: DNA methylation levels within two distinct promoter regions of the CRTC1 gene were decreased in human hippocampus affected by AD compared with controls and methylation within Prom1 showed a strong inverse correlation with p-tau deposition. Further studies are guaranteed to elucidate the precise role that CRTC1 methylation plays in AD pathophysiology.

Autoimmune post-herpes simplex encephalitis of adults and teenagers.

OBJECTIVE: To report 14 patients with immune-mediated relapsing symptoms post-herpes simplex encephalitis (HSE) and to compare the clinical and immunologic features of the teenage and adult group with those of young children. METHODS: Prospective observational study of patients diagnosed between June 2013 and February 2015. Immunologic techniques have been reported previously. RESULTS: Among the teenage and adult group (8 patients, median age 40 years, range 13-69; 5 male), 3 had an acute symptom presentation suggesting a viral relapse, and 5 a presentation contiguous with HSE suggesting a recrudescence of previous deficits. Seven patients developed severe psychiatric/behavioral symptoms disrupting all social interactions, and one refractory status epilepticus. Blepharospasm occurred in one patient. Five patients had CSF antibodies against NMDA receptor (NMDAR) and 3 against unknown neuronal cell surface proteins. In 5/6 patients, the brain MRI showed new areas of contrast enhancement that decreased after immunotherapy and clinical improvement. Immunotherapy was useful in 7/7 patients, sometimes with impressive recoveries, returning to their baseline HSE residual deficits. Compared with the 6 younger children (median age 13 months, range 6-20, all with NMDAR antibodies), the teenagers and adults were less likely to develop choreoathetosis (0/8 vs 6/6, p < 0.01) and decreased level of consciousness (2/8 vs 6/6, p < 0.01) and had longer delays in diagnosis and treatment (interval relapse/antibody testing 85 days, range 17-296, vs 4 days, range 0-33, p = 0.037). CONCLUSION: In teenagers and adults, the immune-mediated relapsing syndrome post-HSE is different from that known in young children as choreoathetosis post-HSE and is underrecognized. Prompt diagnosis is important because immunotherapy can be highly effective.

Parkinson's Disease Case Ascertainment in the EPIC Cohort: The NeuroEPIC4PD Study.

BACKGROUND/AIMS: Large epidemiological prospective studies represent an important opportunity for investigating risk factors for rare diseases such as Parkinson's disease (PD). Here we describe the procedures we used for ascertaining PD cases in the EPIC (European Prospective Investigation into Cancer and Nutrition) study. METHODS: The following three-phase procedure was used: (1) elaboration of a NeuroEPIC4PD template for clinical data collection, (2) identification of all potential PD cases via record linkage and (3) validation of the diagnosis through clinical record revision, in a population of 220,494 subjects recruited in 7 European countries. All cases were labelled with the NeuroEPIC4PD diagnoses of 'definite', 'very likely', 'probable', or 'possible' PD. RESULTS: A total of 881 PD cases were identified, with over 2,741,780 person-years of follow-up (199 definite, 275 very likely, 146 probable, and 261 possible). Of these, 734 were incident cases. The mean age at diagnosis was 67.9 years (SD 9.2) and 458 patients (52.0%) were men. Bradykinesia was the most frequent presenting motor sign (76.5%). Tremor-dominant and akinetic rigid forms of PD were the most common types of PD. A total of 289 patients (32.8%) were dead at the time of the last follow-up. CONCLUSIONS: This exercise proved that it is feasible to ascertain PD in large population-based cohort studies and offers a potential framework to be replicated in similar studies.

[Stroke and Takotsubo syndrome: a reciprocal relationship]. / Ictus y síndrome de takotsubo: una relación recíproca.

INTRODUCTION: Takotsubo syndrome is a transient stress cardiomyopathy associated with a distinctive left ventricular contraction pattern. It has been described as a cardioembolic source or as a consequence of stroke. Two patients are reported that illustrate the reciprocal relationship between Takotsubo syndrome and stroke and the physiopathological mechanisms implicated are analyzed. CASE REPORTS: Two women aged 70 and 78 years respectively are described. The first one was admitted with electro-cardiogram ST-segment elevation, slight troponin elevation and stroke symptoms. Ecocardiography and cardiac magnetic resonance findings were consistent with Takotsubo syndrome that was the probable source of cardioembolic stroke. The second patient suffered a Takotsubo syndrome 72 hours after a brain infarction involving the insular cortex that was considered the trigger of Takotsubo syndrome. CONCLUSIONS: Takotsubo syndrome and stroke may have a reciprocal etiological relationship that is suggested by the temporal profile between the two processes. Cardiac magnetic resonance may aid in the establishment of the diagnosis of Takotsubo syndrome.

Ictus y síndrome de takotsubo: una relación recíproca / Stroke and Takotsubo syndrome: a reciprocal relationship

Introducción. El síndrome de takotsubo es una miocardiopatía aguda de estrés reversible que se caracteriza de forma habitual por la presencia de anomalías segmentarias y circunferenciales de la porción anteroapical del ventrículo izquierdo. Se ha descrito tanto como causa como consecuencia de un ictus isquémico. Presentamos dos casos clínicos que ilustran esta relación recíproca entre ictus y síndrome de takotsubo, y analizamos los mecanismos fisiopatológicos implicados. Casos clínicos. Se describen dos mujeres de 70 y 78 años. La primera ingresa por un ictus con alteraciones electrocardiográficas y una elevación leve de enzimas cardíacas. Tanto el ecocardiograma como la resonancia magnética cardíaca apuntaron al diagnóstico de síndrome de takotsubo, que fue el probable desencadenante de un embolismo cerebral. La segunda paciente ingresa por un ictus, y a las 72 horas del ingreso presenta un síndrome de takotsubo, que se consideró consecuencia del infarto cerebral que afectaba a la ínsula. Conclusión. El síndrome de takotsubo puede tener una doble relación con el ictus isquémico, y es el curso temporal entre ambos procesos lo que puede determinar el tipo de relación etiológica. Destaca el papel que desempeña la resonancia magnética cardíaca en el diagnóstico de esta entidad (AU)

Introduction. Takotsubo syndrome is a transient stress cardiomyopathy associated with a distinctive left ventricular contraction pattern. It has been described as a cardioembolic source or as a consequence of stroke. Two patients are reported that illustrate the reciprocal relationship between Takotsubo syndrome and stroke and the physiopathological mechanisms implicated are analyzed. Case reports. Two women aged 70 and 78 years respectively are described. The first one was admitted with electrocardiogram ST-segment elevation, slight troponin elevation and stroke symptoms. Ecocardiography and cardiac magnetic resonance findings were consistent with Takotsubo syndrome that was the probable source of cardioembolic stroke. The second patient suffered a Takotsubo syndrome 72 hours after a brain infarction involving the insular cortex that was considered the trigger of Takotsubo syndrome. Conclusions. Takotsubo syndrome and stroke may have a reciprocal etiological relationship that is suggested by the temporal profile between the two processes. Cardiac magnetic resonance may aid in the establishment of the diagnosis of Takotsubo syndrome (AU)

Myasthenia gravis: sleep quality, quality of life, and disease severity.

INTRODUCTION: There is much research on quality of life in myasthenia gravis (MG), and its relationship to disease severity is well-established. However, evidence regarding sleep disturbance in MG is inconclusive. METHODS: To evaluate sleep and quality of life among clinically stable MG patients, 54 subjects were investigated by means of the Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS) and 15-Item-Quality-Of-Life Instrument for MG (MG-QOL15). RESULTS: A pathological PSQI score, which was observed in 59% of patients, was increased in subjects with active disease compared with patients in clinical remission [odds ratio = 4.3; confidence interval 95% (1.0-17.6); P = 0.04]. We found a relationship between PSQI and MG-QOL15 scores in patients with clinically active disease (r = 0.62; P < 0.001). CONCLUSIONS: Our study highlights the high prevalence of sleep disturbance among MG patients. Disease severity may be considered to be a MG-specific risk factor for patient-reported sleep disturbance. The MG-QOL15 and PSQI should be used to estimate the impact of the disease on sleep and quality of life.

Increased dopaminergic cells and protein aggregates in the olfactory bulb of patients with neurodegenerative disorders.

Olfactory dysfunction is a frequent and early feature of patients with neurodegenerative disorders such as Alzheimer's disease (AD) and Parkinson's disease (PD) and is very uncommon in patients with frontotemporal dementia (FTD). Mechanisms underlying this clinical manifestation are poorly understood but the premature deposition of protein aggregates in the olfactory bulb (OB) of these patients might impair its synaptic organization, thus accounting for the smell deficits. Tau, ß-amyloid and alpha-synuclein deposits were studied in 41 human OBs with histological diagnosis of AD (n = 24), PD (n = 6), FTD (n = 11) and compared with the OB of 15 control subjects. Tau pathology was present in the OB of all patients, irrespective of the histological diagnosis, while ß-amyloid and alpha-synuclein protein deposit were frequently observed in AD and PD, respectively. Using stereological techniques we found an increased number of dopaminergic periglomerular neurons in the OB of AD, PD and FTD patients when compared with age-matched controls. Moreover, volumetric measurements of OBs showed a significant decrease only in AD patients, while the OB volume was similar to control in PD or FTD cases. The increased dopaminergic tone created in the OBs of these patients could reflect a compensatory mechanism created by the early degeneration of other neurotransmitter systems and might contribute to the olfactory dysfunction exhibited by patients with neurodegenerative disorders.

A re-examination of the striatal input from the mediodorsal thalamic nucleus in the rat / Una re-evaluación de la aferencia estriatal procedente del núcleo talámico mediodorsal de la rata

The projection from the mediodorsal thalamic nucleus to the striatum in the rat was studied by placing injections of the retrograde tracer Fluoro-Gold into the caudate putamen and small deposits of biotinylated dextran amine (BDA) into the mediodorsal thalamic nucleus. The relationship of thalamic afferent fibers with the compartmental organization of the striatum was studied by combining (BDA) tracing and enkephalin immunohistochemistry. The medial segment of the mediodorsal thalamic nucleus projects to the nucleus accumbens whereas the lateral segment projects sparsely to the medial regions of the caudate putamen. The caudal pole of the mediodorsal thalamic nucleus was found to project abundantly to ventrolateral regions of the precommissural caudate putamen, reaching areas of strong enkephalin immunoreactivity. The dorsolateral and caudal regions of the striatum did not receive projections from the mediodorsal thalamic nucleus. The present findings demonstrate a topographical organization of the thalamostriatal projections originating in the mediodorsal thalamic nucleus of the rat (AU)

La proyección desde el núcleo talámico mediodorsal al estriado en la rata fue investigada mediante inyecciones del trazador retrógrado fluoro-oro en el putamen caudal y pequeños depósitos de amino dextrano biotinilado (BDA) en el núcleo talámico mediodorsal. La relación entre las fibras talámicas eferentes y la organización compartimental se estudió combinando el trazado con BDA e inmunohistoquímica para encefalina. El segmento medial del núcleo talámico mediodorsal proyecta hacia el núcleo accumbens, mientras que el segmento lateral proyecta escasamente hacia las regiones mediales del putamen caudal. El polo caudal del núcleo talámico mediodorsal se vio que proyecta abundantemente hacia las regiones ventrolaterales del putamen caudal precomisural, alcanzando áreas de fuerte inmunorreactividad para la encefalina. Las regiones dorsolateral y caudal del estriado no recibían proyecciones procedentes del núcleo talámico mediodorsal. Los hallazgos de este estudio apuntan hacia una organización topográfica de las proyecciones talamo-estriatales que se originan en el núcleo talámico mediodorsal de la rata La proyección desde el núcleo talámico mediodorsal al estriado en la rata fue investigada mediante inyecciones del trazador retrógrado fluoro-oro en el putamen caudal y pequeños depósitos de amino dextrano biotinilado (BDA) en el núcleo talámico mediodorsal. La relación entre las fibras talámicas eferentes y la organización compartimental se estudió combinando el trazado con BDA e inmunohistoquímica para encefalina. El segmento medial del núcleo talámico mediodorsal proyecta hacia el núcleo accumbens, mientras que el segmento lateral proyecta escasamente hacia las regiones mediales del putamen caudal. El polo caudal del núcleo talámico mediodorsal se vio que proyecta abundantemente hacia las regiones ventrolaterales del putamen caudal precomisural, alcanzando áreas de fuerte inmunorreactividad para la encefalina. Las regiones dorsolateral y caudal del estriado no recibían proyecciones procedentes del núcleo talámico mediodorsal. Los hallazgos de este estudio apuntan hacia una organización topográfica de las proyecciones talamo-estriatales que se originan en el núcleo talámico mediodorsal de la rata (AU)