Soluble TREM2 Concentrations in the Cerebrospinal Fluid Correlate with the Severity of Neurofibrillary Degeneration, Cognitive Impairment, and Inflammasome Activation in Alzheimer's Disease.

BACKGROUND: Individuals with specific TREM2 gene variants that encode for a Triggering Receptor Expressed on Myeloid cells 2 have a higher prevalence of Alzheimer's disease (AD). By interacting with amyloid and apolipoproteins, the TREM2 receptor regulates the number of myeloid cells, phagocytosis, and the inflammatory response. Higher TREM2 expression has been suggested to protect against AD. However, it is extremely difficult to comprehend TREM2 signaling in the context of AD. Previous results are variable and show distinct effects on diverse pathological changes in AD, differences between soluble and membrane isoform signaling, and inconsistency between animal models and humans. In addition, the relationship between TREM2 and inflammasome activation pathways is not yet entirely understood. OBJECTIVE: This study aimed to determine the relationship between soluble TREM2 (sTREM2) levels in cerebrospinal fluid (CSF) and plasma samples and other indicators of AD pathology. METHODS: Using the Enzyme-Linked Immunosorbent Assay (ELISA), we analyzed 98 samples of AD plasma, 35 samples of plasma from individuals with mild cognitive impairment (MCI), and 11 samples of plasma from healthy controls (HC), as well as 155 samples of AD CSF, 90 samples of MCI CSF, and 50 samples of HC CSF. RESULTS: CSF sTREM2 levels were significantly correlated with neurofibrillary degeneration, cognitive decline, and inflammasome activity in AD patients. In contrast to plasma sTREM2, CSF sTREM2 levels in the AD group were higher than those in the MCI and HC groups. Moreover, concentrations of sTREM2 in CSF were substantially higher in the MCI group than in the HC group, indicating that CSF sTREM2 levels could be used not only to distinguish between HC and AD patients but also as a biomarker to detect earlier changes in the MCI stage. CONCLUSIONS: The results indicate CSF sTREM2 levels reliably predict neurofibrillary degeneration, cognitive decline, and inflammasome activation, and also have a high diagnostic potential for distinguishing diseased from healthy individuals. To add sTREM2 to the list of required AD biomarkers, future studies will need to include a larger number of patients and utilize a standardized methodology.

The attitude and knowledge of medical students regarding dementia.

OBJECTIVE: Due to the growing number of older people with dementia (PWD) worldwide, there is an urgent need to improve undergraduate medical education on dementia and skills of future health professionals to provide the best quality care for PWD. The study aimed to determine attitudes and knowledge regarding dementia among medical students. METHODS: This cross-sectional, survey-based study included 231 final-year medical students who completed the paper-and-pencil questionnaire with seven categories of questions including two dementia knowledge tests. RESULTS: Students have relatively neutral attitudes towards working with PWD and a rather poor theoretical knowledge in the dementia knowledge exam. Students showed the best theoretical knowledge about the symptoms of Alzheimer's disease, while their knowledge was poor in the field of differential diagnoses, epidemiology, and pathogenesis of Alzheimer's disease. One in 11 sixth-year medical students has never had contact with a person with dementia. The opinion of most students was that they should have spent more time with PWD during their medical education and that there are too few classes in the field of dementia at the School of Medicine. The dementia knowledge test with 23 Multiple-Choice Questions showed a higher internal consistency compared to the Alzheimer's Disease Knowledge Scale. CONCLUSION: There is an urgent need to increase the interest and improve attitudes and knowledge towards dementia for all future health care professionals from the earliest student days to provide the best care for PWD.

Dementia care in the Danube Region. A multi-national expert survey.

BACKGROUND: Dementia is a particularly severe societal challenge in several countries of the Danube Region due to higher-than-average increment in population longevity, disproportionate increase of the old-age dependency ratio, and selective outward migration of health care professionals. A survey was conducted among dementia experts to obtain a deeper understanding of the dementia care structures and services in this geographical area, and to identify the educational needs of health care professionals, and the availability of assistive technology. SUBJECTS AND METHODS: A standardized questionnaire was sent out to 15 leading dementia experts/clinicians in 10 Danube Region countries inquiring about professional groups involved in dementia care, availability and reimbursement of services, inclusion of dementia in professional education and training, acceptability of Internet-based education, and availability of assistive technology. The authors are the survey respondents. RESULTS: The majority of individuals with dementia receive care in the community rather than in institutions. The roles of medical specialties are disparate. General practitioners usually identify dementia symptoms while specialists contribute most to clinical diagnosis and treatment. Health care professionals, particularly those who work closely with patients and carers, have limited access to dementia-specific education and training. The greatest need for dementia-specific education is seen for general practitioners and nurses. An Internet-based education and skill-building program is considered to be equivalent to traditional face-to-face but offer advantages in terms of convenience of access. Assistive technology is available in countries of the Danube Region but is significantly underused. CONCLUSION: Dementia care in the Danube Region can be improved by an educational and skill-building program for health care professionals who work in the frontline of dementia care. Such a program should also attempt to enhance interdisciplinary and intersectorial collaboration, to intensify the interaction between primary care and specialists, and to promote the implementation of assistive technology.

Integration of complementary biomarkers in patients with first episode psychosis: research protocol of a prospective follow up study.

In this project, we recruited a sample of 150 patients with first episode of psychosis with schizophrenia features (FEP) and 100 healthy controls. We assessed the differences between these two groups, as well as the changes between the acute phase of illness and subsequent remission among patients over 18-month longitudinal follow-up. The assessments were divided into four work packages (WP): WP1- psychopathological status, neurocognitive functioning and emotional recognition; WP2- stress response measured by saliva cortisol during a stress paradigm; cerebral blood perfusion in the resting state (with single photon emission computed tomography (SPECT) and during activation paradigm (with Transcranial Ultrasonography Doppler (TCD); WP3-post mortem analysis in histologically prepared human cortical tissue of post mortem samples of subjects with schizophrenia in the region that synaptic alteration was suggested by WP1 and WP2; WP4- pharmacogenetic analysis (single gene polymorphisms and genome wide association study (GWAS). We expect that the analysis of these data will identify a set of markers that differentiate healthy controls from patients with FEP, and serve as an additional diagnostic tool in the first episode of psychosis, and prediction tool which can be then used to help tailoring individualized treatment options. In this paper, we describe the project protocol including aims and methods and provide a brief description of planned post mortem studies and pharmacogenetic analysis.

Significantly lower right middle cerebral artery blood flow velocity in the first episode of psychosis during neurocognitive testing.

BACKGROUND: Changes in cerebral hemodynamics have been reported in schizophrenia and proposed as underlying the cognitive deficits seen in patients. The objective of our study was to compare changes of the cerebral blood flow velocity (BFV) during neurocognitive tasks between the patients with the first episode of psychosis and healthy controls. SUBJECTS AND METHODS: We recruited 46 patients with the first episode of psychosis (FEP), admitted to the University Hospital Centre Zagreb during 2016-2017 and 41 control subjects. Transcranial Doppler ultrasonography monitoring of BFV in both middle cerebral arteries was recorded during 25-minute long neurocognitive assessment with Phonemic Verbal Fluency test, Trial Making Test B and Stroop test. Between every consecutive test resting periods were recorded. RESULTS: After the adjustment for age, sex and education by quantile regression, patients with FEP had significantly lower BFV in middle cerebral arteries during the 3rd (Δ-15, Δ%-28% p=0.023) and 4th task (Δ-15, Δ%-28% p=0.031) of the Stroop test and the 1st task of Foot tapping test (Δ -16, Δ% -30% p=0.034). We observed significantly lower changes of right middle cerebral artery BFV in FEP between two consecutive tests in all four tasks of the Phonemic verbal fluency test, 1st and 2nd task of the Stroop test and Trail making test, and the1st task of Foot tapping test; and of the left artery between first three tasks of the Phonemic verbal fluency test, the last one of the Phonemic verbal fluency test and all first three tasks of the Stroop test. CONCLUSIONS: Decreased middle BFV during the execution of particular neurocognitive tasks in patients with FEP, compared to control subjects might indicate impaired hemodynamic function in the prefrontal/parietal brain areas, and possibly provide an explanation of some of the observed neurocognitive deficits in patients with the first episode of psychosis.

Evaluation of cerebrospinal fluid phosphorylated tau231 as a biomarker in the differential diagnosis of Alzheimer's disease and vascular dementia.

BACKGROUND: The diagnosis of either Alzheimer's disease (AD) or vascular dementia (VaD) is still largely based on clinical guidelines and exclusion of other diseases that may lead to dementia. AIMS: In this study, we assessed whether the use of sensitive and specific biomarkers such as phosphorylated tau proteins could contribute to an earlier and more accurate diagnosis of AD and VaD, as well as to their differentiation. MATERIAL AND METHODS: A total of 198 patients, of which 152 had AD, 28 VaD, and 18 were healthy controls (HC), were included in the analyses. We analyzed cerebrospinal fluid (CSF) levels of total tau protein (t-tau), tau protein phosphorylated at threonine 231 (p-tau231), and factor score (FS) determined by combination of p-tau231 and Mini-Mental State Examination (MMSE) in patients with AD and VaD, as well as in HC. We tested the diagnostic accuracy of these biomarkers in the CSF and FS (p-tau231, MMSE) in differentiating AD from VaD and HC. RESULTS: Total tau levels were significantly elevated in subjects with AD compared to HC, as well as in VaD subjects compared to HC. DISCUSSION: p-tau231 levels were significantly higher in patients with ADvsHC as well in patients with VaD vsHC. p-tau231 levels did not distinguish AD from VaD patients. Importantly, FS(p-tau231 and MMSE) showed statistically significant differences in the distribution of subjects with AD and VaD. CONCLUSION: These results indicate that FS (p-tau231 and MMSE) has a strong potential to provide an early distinction between AD and VaD.

Ultrasound and dynamic functional imaging in vascular cognitive impairment and Alzheimer's disease.

BACKGROUND: The vascular contributions to neurodegeneration and neuroinflammation may be assessed by magnetic resonance imaging (MRI) and ultrasonography (US). This review summarises the methodology for these widely available, safe and relatively low cost tools and analyses recent work highlighting their potential utility as biomarkers for differentiating subtypes of cognitive impairment and dementia, tracking disease progression and evaluating response to treatment in various neurocognitive disorders. METHODS: At the 9th International Congress on Vascular Dementia (Ljubljana, Slovenia, October 2015) a writing group of experts was formed to review the evidence on the utility of US and arterial spin labelling (ASL) as neurophysiological markers of normal ageing, vascular cognitive impairment (VCI) and Alzheimer's disease (AD). Original articles, systematic literature reviews, guidelines and expert opinions published until September 2016 were critically analysed to summarise existing evidence, indicate gaps in current knowledge and, when appropriate, suggest standards of use for the most widely used US and ASL applications. RESULTS: Cerebral hypoperfusion has been linked to cognitive decline either as a risk or an aggravating factor. Hypoperfusion as a consequence of microangiopathy, macroangiopathy or cardiac dysfunction can promote or accelerate neurodegeneration, blood-brain barrier disruption and neuroinflammation. US can evaluate the cerebrovascular tree for pathological structure and functional changes contributing to cerebral hypoperfusion. Microvascular pathology and hypoperfusion at the level of capillaries and small arterioles can also be assessed by ASL, an MRI signal. Despite increasing evidence supporting the utility of these methods in detection of microvascular pathology, cerebral hypoperfusion, neurovascular unit dysfunction and, most importantly, disease progression, incomplete standardisation and missing validated cut-off values limit their use in daily routine. CONCLUSIONS: US and ASL are promising tools with excellent temporal resolution, which will have a significant impact on our understanding of the vascular contributions to VCI and AD and may also be relevant for assessing future prevention and therapeutic strategies for these conditions. Our work provides recommendations regarding the use of non-invasive imaging techniques to investigate the functional consequences of vascular burden in dementia.

Hemodynamic monitoring of middle cerebral arteries during cognitive tasks performance.

AIM: The aim of this study was to obtain temporal pattern and hemispheric dominance of blood flow velocity (BFV) changes and to assess suitability of different cognitive tasks for monitoring of BFV changes in the middle cerebral arteries (MCA). METHODS: BFV were recorded simultaneously in MCA during performance of phonemic verbal fluency test (pVFT), Trail Making Tests A and B (TMTA and TMTB) and Stroop tests in 14 healthy, right-handed volunteers aged 20-26 years. RESULTS: A significant increase of BFV in both MCA was obtained during performance of all cognitive tasks. Statistically significant lateralization was found during performance of Stroop test with incongruent stimuli, while TMTB was found to have the best activation potential for MCA. CONCLUSION: Our findings specify TMTB as the most suitable cognitive test for monitoring of BFV in MCA.

Blood flow velocity changes in anterior cerebral arteries during cognitive tasks performance.

OBJECTIVE: Transcranial Doppler sonography (TCD) enables monitoring of blood flow velocities (BFVs) in basal cerebral arteries during different cognitive tasks performance with great temporal resolution. So far, BFVs changes during mental activity were monitored primarily in middle cerebral arteries (MCAs) and little is known about these changes in anterior cerebral arteries (ACAs). AIM: To determine the effect of different cognitive tasks performance on BFV changes and hemispheric dominance in ACAs and to assess the most suitable activation test for monitoring of BFV changes in ACAs. METHODS: Fourteen right-handed, healthy subjects aged 20-26 were included in the study. BFVs in both ACAs were recorded simultaneously during performance of cognitive tasks designed to activate frontal lobes: phonemic verbal fluency test (pVFT), Stroop tests and Trail Making Tests (TMTs). RESULTS: A statistically significant BFV increase was recorded in both ACAs during performance of all cognitive tasks. Statistically significant right ACA dominance was found during performance of pVFT and TMTB. The most significant BFV increase was obtained during performance of TMTB. CONCLUSION: Our result addressed cognitive tests with great activation potential for monitoring of ACAs that might be used in distinguishing of healthy individuals and patients with neurovascular or neurodegenerative diseases.

The frontal assessment battery in the differential diagnosis of dementia.

AIM: The Frontal Assessment Battery (FAB) has been used in different clinical settings as a valuable quick bedside test for executive dysfunction. The aim of the study was to evaluate clinical utility of the FAB for differential diagnosis of Alzheimer disease (AD), subcortical vascular cognitive impairment (scVCI), and frontotemporal lobar degeneration (FTLD). METHODS: Scores of the total FAB test and subtests were compared between consecutive series of 37 patients with AD, 31 patients with scVCI, 13 patients with FTLD, and 29 cognitively healthy individuals. RESULTS: There was no statistically significant difference in the total FAB scores among the groups of patients with dementia. When comparing subtest scores, patients with FTLD had significantly lower scores on the lexical fluency subtest compared to the patients with AD (P<.001) or scVCI (P<.001); patients with scVCI had significantly lower scores on the motor series subtest compared to patients with FTLD (P=.02) and AD (P=.035) and on conflicting instructions subtest compared to patients with AD (P=.033). CONCLUSION: Some FAB subtests might enhance diagnostic accuracy taking into account clinical history and other tests of executive function.

The reliability and validity of the mini-mental state examination in the elderly Croatian population.

AIM: The aim of this study was standardization and validation of the Mini-Mental State Examination (MMSE) in the general Croatian aging population. METHODS: Three-hundred and forty-four participants underwent the MMSE test, 217 cognitively healthy subjects without neurological and psychiatric disorders and 127 patients with mild cognitive impairment (MCI) or dementia. RESULTS: The optimal cutoff point for screening of the general Croatian population (cognitively healthy vs. MCI and dementia) is 26/27; in the Croatian population aged ≥65 years, the cutoff point is 24/25, whereas for screening of highly educated persons (≥14 years of education) aged ≥65 years a higher cutoff point should be used (26/27). CONCLUSIONS: MMSE results when standardized and validated in a certain population might better contribute to recognition of the individuals at risk that should be directed to dementia outpatient clinics.

Systemic thrombolytic therapy in acute ischemic stroke--new experiences in spreading network of stroke units in Croatia.

BACKGROUND: The aims of this paper are: 1) to present the data of systemic thrombolysis for ischemic stroke in five Croatian centers from July 2008 till January 2010; 2) to compare the results between centers and; 3) to compare data with previously published results from 2006 to 2008 period from our center, and with the data from SITS (Safe Implementation of Treatments in Stroke). METHODS: We retrospectively reviewed the medical data of thrombolysed patients in following hospitals: University Hospital Center Zagreb (91 patients), University Hospital Split (25 patients), University Hospital Osijek (22 patients), General Hospital Varazdin (21 patient), and General Hospital Zadar (7 patients). RESULTS: The "time to door" for all centers was 79.71±38.63 min, the "door to needle" period was 64.39±24.18 min. Systolic and diastolic blood pressures at admission were 158.65±27.72 and 90.18±15.03 mm Hg, respectively. Systolic and diastolic blood pressures measured immediately prior to administering rt-PA were 152.19±23.17 and 85.40±15.27 mm Hg, respectively. Initial median NIHSS score was 12, median NIHSS 2h post thrombolysis was 8, and 7th day after rt-PA treatment 4. Intracerebral hemorrhages or secondary hemorrhagic transformations occurred in 21 (12.65%) patients, among which nine were symptomatic. In a 4.5h time window total of 17 patients were thrombolysed. We did not find any differences in outcome between this group and group of patients thrombolysed in the 3h time-window. The group of patients older than 80 years had a worse outcome. CONCLUSIONS: According to our data, treatment with rt-PA is safe, feasible and effective for stroke patients in both university as well as regional hospitals having stroke units established. Organization of stroke units in regional hospitals, as well as systematic education of public health workers and neurologists, leads to the possibility for each patient to reach the nearest stroke unit and gets the thrombolytic therapy in the therapeutic time window.

Systemic thrombolysis with recombinant tissue plasminogen activator in acute ischemic stroke: first Croatian experiences.

In September 2003, recombinant tissue plasminogen activator (rt-PA) for acute treatment of ischemic stroke was finally approved by the Croatian Ministry of Health. For the next 5 years, only three stroke units in the country implemented this therapy in their routine practice until summer 2008, when neurological wards in most Croatian hospitals started to treat acute stroke patients with systemic thrombolysis. We present a 2-year experience of thrombolytic therapy (2006-2008) in the stroke unit of the University Hospital in Zagreb, Croatian largest hospital, serving nearly one-fifth of the citizens of Croatia. Obtained data (vitals at admission and before administration of rt-PA; NIHSS and MRS scores at admission, 2 h and 7th day after rt-PA treatment, "time to door" and "door to needle" intervals, duration of hospital treatment as well as outcomes and complications of our 66 thrombolysed patients) are presented and discussed. We also present our results regarding benefits of this therapy as well as possible reasons for complications noticed.

Skeletal fluorosis causing high cervical myelopathy.

Skeletal fluorosis is endemic in some parts of the world and is the result of life-long ingestion of high amounts of fluoride in drinking water. Its clinical presentation is characterized mostly by bone and dental changes with later ossification of many ligaments and interosseous membranes. We present a rare case of high cervical myelopathy caused by ossification of the posterior longitudinal ligament and ligamentum flavum in a patient from an area endemic for skeletal fluorosis. The clinical presentation of skeletal fluorosis and treatment options are discussed.

Epilepsy due to malformations of cortical development--correlation of clinical, MRI and Tc-99mECD SPECT findings.

Malformations of cortical development (MCD) have been increasingly recognized as an important cause of intractable epilepsy. The aim of our study was to define epileptogenicity of MCDs by correlating MRI, EEG and semiology of epileptic attacks, and to determine the effect of MCD on drug resistant epilepsy. We also intended to reveal the utility of interictal single photo emission computed tomography (SPECT) in verification of MCD lesions and relative prevalence of different MCDs. Based on interictal EEG finding, semiology of the epileptic attacks and brain magnetic resonance imaging (MRI) "electroclinical epileptogenicity" of MCD was defined. Brain MRI revealed cortical dysplasia (CD) in nine patients, polymicrogyria in four patients, lissencephaly and schizencephaly in one patient each. Three patients had a combination of malformations. The localization of SPECT hypoperfusion corresponded to MCD lesion in ten (66.67%) patients. Electroclinically confirmed epileptogenicity of MCD overlapped with MR and interictal SPECT findings in fourteen (93.3%) and nine (60.0%) patients, respectively. Our study results demonstrated the MCD lesions to be highly epileptogenic and a frequent cause of intractability.