Autoimmune Encephalitis with Antibodies Against A-Amino-3hydroxy-5-Methyl-4-Isoxazolepropionic Acid Receptor and γ-Aminobutyric Acid-Beta Receptor: Case Report.

Introduction: Limbic encephalitis is a rapidly progressing disease that presents with seizures, psychiatric symptoms, and recent memory loss. Detection of more than one autoantibody is a rare condition in this disease where an underlying autoantibody is frequently detected. Although different autoantibodies have been reported in the literature, no case has been reported regarding the association of anti-γ-aminobutyric acid-beta-receptor (anti-GABABR) and anti-α-amino-3 hydroxy-5-methyl-4-isoxazolepropionic acid (anti-AMPAR). Case: In this presentation, a 46-year-old female patient with subacute development of short-term memory loss and behavioral symptoms will be described. Anti-GABABR and anti-AMPAR were positive in the anti-neuronal antibody panel sent from the cerebrospinal fluid and serum. Small cell lung cancer was detected as a result of malignancy screening tests. The patient's complaints and autoantibody positivity regressed after immunotherapy. Conclusion: In this case report, a case with coexistence of anti-GABABR and anti-AMPAR antibodies, which has not been previously reported in the literature, is described. As more cases with the coexistence of these two antibodies are detected, knowledge on clinical aspect, laboratory and treatment will increase.

Anticholinergic Burden, Polypharmacy, and Cognition in Parkinson's Disease Patients with Mild Cognitive Impairment: A Cross-Sectional Observational Study.

INTRODUCTION: Anticholinergic burden may be an important risk factor for the cognitive impairment. Especially in polypharmacy, even drugs with low anticholinergic effects may contribute to a significant anticholinergic burden. The drugs with anticholinergic effects are used in treatment of motor and nonmotor symptoms of Parkinson's disease (PD). Therefore, it is important to screen for polypharmacy and anticholinergic burden in PD patients with mild cognitive impairment (MCI). METHODS: This cross-sectional study was conducted with 58 patients with PD. PD-MCI was diagnosed according to MDS Level 2 Comprehensive Assessment. Cognitive performance (attention - working memory, executive functions, language, memory, and visuospatial functions) of patients was evaluated. The anticholinergic burden was scored by Anticholinergic Cognitive Burden (ACB) Scale, Anticholinergic Risk Scale (ARS), and Anticholinergic Drug Scale (ADS). RESULTS: There was no significant difference in anticholinergic burden between PD-MCI and PD-normal cognition. A significant concordance was observed between ACB, ARS, and ADS scores (p < 0.001; Kendall's W = 0.653). While the variable predicting anticholinergic burden was the total number of drugs for ACB and ADS scales, it was the number of antiparkinson drugs for ARS scale. CONCLUSION: Patients with PD are at high risk for polypharmacy and anticholinergic burden. Anticholinergic burden should be considered in the selection of drugs, especially for comorbidities in patients with PD. No significant correlation was found between the cognition and anticholinergic burden in patients with PD-MCI. Although the risk scores of antiparkinson and other drugs were different among the 3 scales, significant concordance was observed between scales.

Cerebellar ataxia, neuropathy and vestibular areflexia syndrome (canvas): an important cause of late-onset ataxia with unique clinical features.

Cerebellar ataxia, neuropathy, vestibular areflexia syndrome (CANVAS) is a late-onset, slowly progressive disorder characterized by cerebellar ataxia, sensory neuropathy and bilateral vestibulopathy. Recently, a biallelic intronic AAGGG repeat expansion, (AAGGG)exp, in the Replication Factor C1 (RFC1) gene was identified as the cause of this disorder. In this study, we describe the phenotypic features of five patients from five different families diagnosed as CANVAS. The mean age at onset was 49.00 ± 9.05 years (between 34 and 56 years) and the most frequent presenting symptom in CANVAS was gait ataxia, followed by sensory disturbances. Persistent coughing was prominent in three patients, and it preceded the onset of ataxia and sensory symptoms in two patients. Parental consanguinity was present in three patients. Two patients showed symptoms or signs suggesting autonomic involvement. Sural nerve biopsy revealed axonal neuropathy in two patients. The mean age at onset was 49.00 ± 9.05 years (between 34 and 56 years) and the most frequent presenting symptom in CANVAS was gait ataxia, followed by sensory disturbances. Persistent coughing was prominent in three patients, and it preceded the onset of ataxia and sensory symptoms in two patients. Parental consanguinity was present in three patients. Two patients showed symptoms or signs suggesting autonomic involvement. Sural nerve biopsy revealed axonal neuropathy in two patients. Our study describes clinical findings, histopathological features and diagnostic clues of CANVAS from Turkey, a country with a high consanguineous marriage rate. Repeat expansion in the RFC1 gene should be considered in all cases with late-onset ataxia, especially when sensory disturbances, vestibular involvement and persistent coughing coexist.

A comprehensive analysis of copy number variation in a Turkish dementia cohort.

BACKGROUND: Copy number variants (CNVs) include deletions or multiplications spanning genomic regions. These regions vary in size and may span genes known to play a role in human diseases. As examples, duplications and triplications of SNCA have been shown to cause forms of Parkinson's disease, while duplications of APP cause early onset Alzheimer's disease (AD). RESULTS: Here, we performed a systematic analysis of CNVs in a Turkish dementia cohort in order to further characterize the genetic causes of dementia in this population. One hundred twenty-four Turkish individuals, either at risk of dementia due to family history, diagnosed with mild cognitive impairment, AD, or frontotemporal dementia, were whole-genome genotyped and CNVs were detected. We integrated family analysis with a comprehensive assessment of potentially disease-associated CNVs in this Turkish dementia cohort. We also utilized both dementia and non-dementia individuals from the UK Biobank in order to further elucidate the potential role of the identified CNVs in neurodegenerative diseases. We report CNVs overlapping the previously implicated genes ZNF804A, SNORA70B, USP34, XPO1, and a locus on chromosome 9 which includes a cluster of olfactory receptors and ABCA1. Additionally, we also describe novel CNVs potentially associated with dementia, overlapping the genes AFG1L, SNX3, VWDE, and BC039545. CONCLUSIONS: Genotyping data from understudied populations can be utilized to identify copy number variation which may contribute to dementia.

Frequency of frontotemporal dementia-related gene variants in Turkey.

Just as its clinical heterogeneity, genetic basis of Frontotemporal dementia (FTD) is also diverse and multiple molecular pathways are thought to be involved in disease pathogenesis. In the present study, FTD- related genes were evaluated in a Turkish cohort of 175 index FTD patients with a gene panel including GRN, MAPT, TARDBP, FUS, CHMP2B and VCP genes. Potential genetic associations were prospected in 16 patients (9.1%); five variants (p.(Gly35Glufs) and p.(Cys253Ter) in GRN; p.(Arg95Cys) in VCP; p.(Met405Val) in TARDBP and p.(Pro636Leu) in MAPT) were classified as pathogenic (P) or likely pathogenic (LP), in four familial and one sporadic patients. Three novel variants in MAPT, CHMP2B and FUS were also identified in familial cases. The most common pathogenic variants were observed in the GRN gene with a frequency of 1.14% (2/175) and this rate was 4.57% (8/175), including variants of uncertain significance (VUS). In this study with the largest cohort of Turkish FTD patients, GRN and MAPT variants were identified as the most common genetic associations; and rare causes like VCP, TARDBP, CHMP2B and FUS variants are recommended to be considered in patients with compatible clinical findings.

TREM2 variants as a possible cause of frontotemporal dementia with distinct neuroimaging features.

BACKGROUND AND PURPOSE: Nasu-Hakola disease (NHD) is a rare, autosomal recessive disorder characterized by skeletal and neurological symptoms. Behavioral symptoms with cognitive impairment may mimic the behavioral variant of frontotemporal dementia (bvFTD) and other early-onset dementias. Our patients were analyzed and the literature was reviewed to delineate neurological and neuroimaging findings suggestive of NHD. METHOD: Fourteen patients carrying a pathogenic mutation in the TREM2 gene were found in our database. Demographic, clinical, laboratory and radiological data were retrieved and analyzed. RESULTS: The presenting clinical picture was behavioral changes with cognitive decline resembling bvFTD in all patients. The mean age was 37.1 ± 4.97 years and the mean duration of the disease was 8.9 ± 3.51 years. Only two patients had typical bone cysts. Seven patients had bilateral calcification of the basal ganglia in computed tomography of the brain. Magnetic resonance imaging of the brain revealed severe atrophy of the corpus callosum, enlargement of the ventricles, atrophy of the caudate nuclei and periventricular white matter changes in all patients. Symmetrical global atrophy of the brain mainly affecting frontoparietal and lateral temporal regions were observed in all cases, and 13 patients had atrophy of the hippocampus. Cerebrospinal fluid examination of 10 patients showed elevated protein levels in six and the presence of oligoclonal bands in four patients. CONCLUSION: A combination of white matter changes, enlarged ventricles, atrophy of the caudate nuclei and thinning of the corpus callosum in magnetic resonance imaging strongly suggests NHD in patients with FTD syndrome. Molecular genetic analysis should be performed in suspected cases, and families should receive genetic counseling.

PHACTR1 genetic variability is not critical in small vessel ischemic disease patients and PcomA recruitment in C57BL/6J mice.

Recently, several genome-wide association studies identified PHACTR1 as key locus for five diverse vascular disorders: coronary artery disease, migraine, fibromuscular dysplasia, cervical artery dissection and hypertension. Although these represent significant risk factors or comorbidities for ischemic stroke, PHACTR1 role in brain small vessel ischemic disease and ischemic stroke most important survival mechanism, such as the recruitment of brain collateral arteries like posterior communicating arteries (PcomAs), remains unknown. Therefore, we applied exome and genome sequencing in a multi-ethnic cohort of 180 early-onset independent familial and apparently sporadic brain small vessel ischemic disease and CADASIL-like Caucasian patients from US, Portugal, Finland, Serbia and Turkey and in 2 C57BL/6J stroke mouse models (bilateral common carotid artery stenosis [BCCAS] and middle cerebral artery occlusion [MCAO]), characterized by different degrees of PcomAs patency. We report 3 very rare coding variants in the small vessel ischemic disease-CADASIL-like cohort (p.Glu198Gln, p.Arg204Gly, p.Val251Leu) and a stop-gain mutation (p.Gln273*) in one MCAO mouse. These coding variants do not cluster in PHACTR1 known pathogenic domains and are not likely to play a critical role in small vessel ischemic disease or brain collateral circulation. We also exclude the possibility that copy number variants (CNVs) or a variant enrichment in Phactr1 may be associated with PcomA recruitment in BCCAS mice or linked to diverse vascular traits (cerebral blood flow pre-surgery, PcomA size, leptomeningeal microcollateral length and junction density during brain hypoperfusion) in C57BL/6J mice, respectively. Genetic variability in PHACTR1 is not likely to be a common susceptibility factor influencing small vessel ischemic disease in patients and PcomA recruitment in C57BL/6J mice. Nonetheless, rare variants in PHACTR1 RPEL domains may influence the stroke outcome and are worth investigating in a larger cohort of small vessel ischemic disease patients, different ischemic stroke subtypes and with functional studies.

Small ubiquitin-related modifier (SUMO) 3 and SUMO4 gene polymorphisms in Parkinson's disease.

Objectives: The ubiquitin/proteasome system is one of the main axes of the pathogenesis of Parkinson's disease (PD). Small ubiquitin-related modifier (SUMO) proteins are involved in many biochemical events including regulation of transcriptional activity, modulation of signal transduction pathways, and response to cellular stress indicating a role for SUMO in the ubiquitin/proteasome system.Methods: In this study, our aim was to examine the prevalence of SUMO gene variants and their clinical associations in PD. Fifty-four consecutively recruited PD patients (34 male, 20 female) and 74 age-gender matched healthy controls (37 male, 37 female) were included. SUMO1, 2, 3 and 4 genes were screened by a next generation sequencing method using blood samples of participants. Single nucleotide polymorphisms (SNPs) with a significantly altered prevalence were determined by Bonferroni correction.Results: Two SNPs in the SUMO4 gene (rs237025 and rs237024) and two SNPs in the SUMO3 gene (rs180313 and rs235293) were found to have altered prevalence in PD. Although there was no association among these SNPs and clinical features of the patients, an increased family history of cancer was found in patients with SUMO3 gene variants.Discussion: Several SUMO SNPs were identified for the first time in PD patients suggesting that SUMO is involved in the pathophysiology of the disease. rs237025 has also been associated with diabetes mellitus indicating a pathogenic mechanism for SUMO that is shared with other degenerative disorders.

Amyloid Beta Adsorption Problem with Transfer Plates in Amyloid Beta 1-42 IVD Kits.

Adsorption of CSF Aß1-42 during pre-analytical processing is suggested as an important confounder in testing. The aim of the present study was to assess the effect of polypropylene transfer plates (PTP) in the INNOTEST Aß1-42 IVD-ELISA assay on Aß1-42 levels. CSF samples from 26 individuals with subjective cognitive impairment (SCI) and 25 patients with suspected neurodegenerative disorders were tested using four different lots of kits. Aß1-42 levels in all samples that were loaded onto the PTP were significantly lower than the levels in the same samples that were analyzed without prior loading onto the PTP. We found that the PTP may adsorb Aß1-42 in the range 7 to 69%. The diagnosis in 20% of patients and amyloid burden assessment in 23% of SCI patients had to be modified post hoc due to initial erroneously low amyloid levels. Using a PTP prior to loading the samples onto the INNOTEST Aß1-42 test plate may result in erroneously low Aß1-42 levels.

Patients with Lately Diagnosed Cerebrotendinous Xanthomatosis.

OBJECTIVES: Cerebrotendinous xanthomatosis (CTX) is a rare autosomal recessive inborn lipid storage disorder due to various pathogenic mutations in the CYP27A1 gene. Although the symptoms begin commonly in infancy, CTX diagnosis is often delayed. In this study, we report 7 Turkish CTX patients who had a delayed diagnosis despite early clinical signs and belonged to 6 unrelated families. METHODS: We have retrospectively evaluated clinical, laboratory, imaging, and genetic findings of CTX patients, which were collected from 2 centers specialized in movement disorders: the Department of Neurology, Faculty of Medicine, Istanbul University, and the Department of Neurology, Faculty of Medicine, Mersin University. RESULTS: All patients were diagnosed with CTX after neurological symptom development, and their mean age at diagnosis was 38.7 ± 9.6 years, despite a mean onset age of 12.4 ± 10.6 years. The mean follow-up period was 28 months (range: 3-60 months). The most common initial clinical abnormalities in our cohort were unexplained chronic diarrhea (42%), febrile convulsion (42%), juvenile cataract (85%), childhood depression and autism (14%), parkinsonism (14%), and intellectual disability (100%). The most prominent neurological findings were the pyramidal-cerebellar syndrome (85%) and extrapyramidal signs (42%). All patients were genetically confirmed. Serum cholestanol levels were elevated in all patients and decreased after chenodeoxycholic acid (CDCA) treatment in 6 patients. CONCLUSION: This cohort is the largest CTX case series in Turkey. All cases showed improvement in gastrointestinal symptoms as a response to CDCA treatment and stabilization on neurological symptoms, i.e., no further progression of neurological abnormalities were noted during this treatment. Therefore, early diagnosis and treatment is crucial in preventing clinical deterioration.

Olfactory function and olfactory bulb volume in Wilson's disease.

PURPOSE: To evaluate the olfactory function and the olfactory bulb (OB) volume changes in Wilson's Disease (WD) patients. METHODS: A prospective, controlled, single-blinded study was planned. 12 patients with WD (Group 1) and 12 healthy subjects (Group 2) were included in the study. Connecticut Chemosensory Clinical Research Center (CCCRC) test was applied to evaluate olfactory functions. OB volumes were measured with a 1.5 T General Electric Signa Excite MRI scanner. RESULTS: There was a significant difference between the CCCRC scores of the two groups (p < 0.05). The difference of the OB volumes of the two groups was insignificant (p > 0.05). CONCLUSIONS: WD patients are likely to experience olfactory dysfunction, so its assessment may be a useful tool to the follow-up care of these patients, although further studies are needed to evaluate correlations in WD evolution.

Wernicke's Encephalopathy due to Non-Alcoholic Gastrointestinal Tract Disease.

INTRODUCTION: Wernicke's encephalopathy (WE) is an underdiagnosed neuropsychiatric disorder especially in non-alcoholic groups that causes morbidity-mortality if diagnosis is delayed. Korsakoff syndrome is a chronic consequence of this condition characterized by persistent memory impairment. In this study we present a series of non-alcoholic patients with WE. The purpose of this study was to analyze the predisposing factors in non-alcoholic patients with WE and emphasize the importance of early diagnosis and treatment with thiamine supplementation. METHODS: The clinical records of 6 cases with WE followed by gastrointestinal tract disease and/or surgery who were admitted to our Medical Faculty between 2012 and 2014 were retrospectively reviewed. RESULTS: The study included 3 men and 3 women in the age range of 24 to 55. All patients had gastrointestinal tract diseases and/or had undergone gastrointestinal surgeries, and were non-alcoholic. Vomiting, weight loss, and parenteral nutrition were the frequent precipitating factors. The classic triad of mental impairment, oculomotor alterations and gait ataxia was present in 4 of the 6 patients. Magnetic Resonance Imaging showed typical signal alterations in the medial thalami, mammillary bodies and the periaqueductal region of patients in various degrees. Clinical improvement was seen in each patient after thiamine supplementation. DISCUSSION: Physicians should be aware of the predisposing factors and symptoms to prevent or optimize the management of this potentially devastating disease. Thiamine supplementation should be considered in patients with gastrointestinal tract diseases or those who have undergone surgery.

Expression changes of genes associated with apoptosis and survival processes in Parkinson's disease.

Parkinson's disease (PD) is a neurodegenerative disorder characterized by progressive degeneration of the dopaminergic neurons in substantia nigra, presumably due to increased apoptosis and oxidative stress. To investigate whether PD-induced survival/apoptosis gene expression changes can serve as prognostic biomarkers of PD, we measured expression levels of phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/Akt pathway factors and additional apoptotic and anti-apoptotic factors in peripheral blood mononuclear cells (PBMC) of PD patients (n=50) and healthy controls (n=50) by real time PCR. Expression levels of apoptotic factors phosphatase and tensin homolog (PTEN) and mitochondrial apoptosis-inducing factor 1 (AIFM1) were significantly decreased, anti-apoptotic factors DJ-1 and Akt-1 were significantly increased and anti-apoptotic Bcl-2 was significantly decreased in PD patients. Expression levels of AIFM1 were significantly correlated with Hoehn-Yahr scores. Moreover, PD patients with postural instability showed significantly reduced expression levels of anti-apoptotic DJ-1, Akt-1 and mTOR than PD patients without postural instability. Expression profiles of brain samples of mice with rotenone-induced PD model and PBMC samples of PD patients showed remarkable resemblance. Our results indicate that the anti-apoptotic PI3K/Akt pathway is over activated in PD, presumably as an effort to compensate for increased neuronal apoptosis and oxidative stress. By contrast, patients with postural instability show reduced anti-apoptotic factor expression suggesting that this compensating mechanism fails in patients with this particular motor symptom. PBMC expression levels of AIFM1 might serve as a biomarker of disability and disease progression in PD.

NMDA receptor encephalitis with cancer of unknown primary origin.

PURPOSE: N-methyl-D-aspartate receptor (NMDAR) encephalitis may present as a paraneoplastic syndrome in young women and is often associated with ovarian teratoma. METHODS: We report 2 male cases of NMDAR encephalitis presenting with metastatic cancer of unknown primary origin. RESULTS: Both patients showed cognitive dysfunction as well as other neurological symptoms, slow waves on EEG, and NMDAR antibodies in sera and CSF. Symptoms were effectively treated by pulse steroid and intravenous immunoglobulin treatment. The patients developed metastatic small cell neuroendocrine carcinoma of the parotid gland and inguinal metastatic squamous cell cancer shortly after their neurological episodes. Follow-up PET studies showed small cell lung cancer in the first patient while no primary origin could be found in the second patient. CONLUSIONS: Our cases imply that NMDAR encephalitis may present with metastatic cancers that display slow progression rates and occur after encephalitis attacks.

The interleukin 1 alpha, interleukin 1 beta, interleukin 6 and alpha-2-macroglobulin serum levels in patients with early or late onset Alzheimer's disease, mild cognitive impairment or Parkinson's disease.

Alzheimer's disease (EOAD, LOAD), mild cognitive impairment (MCI), Parkinson's disease (PD) and healthy controls were included to determine the serum interleukin-1s (IL-1α, IL-1ß), IL-6 and alpha-2-macroglobulin (α2M) levels using ELISA. IL-6 might be a significant contributor to the inflammatory response in LOAD. The MCI data indicate that IL-1s, α2M and BDNF are somehow related, and this relationship might allow MCI patients to be more similar to the healthy controls. A correlation analysis of multiple biomarkers in different neurodegenerative disorders might be more useful than determining the levels of a single cytokine in a single disorder.

The distinct genetic pattern of ALS in Turkey and novel mutations.

The frequency of amyotrophic lateral sclerosis (ALS) mutations has been extensively investigated in several populations; however, a systematic analysis in Turkish cases has not been reported so far. In this study, we screened 477 ALS patients for mutations, including 116 familial ALS patients from 82 families and 361 sporadic ALS (sALS) cases. Patients were genotyped for C9orf72 (18.3%), SOD1 (12.2%), FUS (5%), TARDBP (3.7%), and UBQLN2 (2.4%) gene mutations, which together account for approximately 40% of familial ALS in Turkey. No SOD1 mutations were detected in sALS patients; however, C9orf72 (3.1%) and UBQLN2 (0.6%) explained 3.7% of sALS in the population. Exome sequencing revealed mutations in OPTN, SPG11, DJ1, PLEKHG5, SYNE1, TRPM7, and SQSTM1 genes, many of them novel. The spectrum of mutations reflect both the distinct genetic background and the heterogeneous nature of the Turkish ALS population.

BDNF, TNFα, HSP90, CFH, and IL-10 serum levels in patients with early or late onset Alzheimer's disease or mild cognitive impairment.

Identifying early-detection biomarkers have become an increasingly important approach in the treatment and prevention of Alzheimer's disease (AD). In this study, we investigated the potential of brain-derived neurotrophic factor (BDNF), complement factor H (CFH), tumor necrosis factor-α (TNFα), interleukin 10 (IL-10), and heat shock protein 90 (Hsp90) as serum biomarkers for AD in a cohort of the Turkish population because they have been suggested to be associated with AD. Serum BDNF, CFH, TNFα, IL-10, and Hsp90 levels in three groups of patients, early-onset AD (EOAD; age of onset < 65; n = 22), late-onset AD (LOAD; age of onset > 65; n = 54), and mild cognitive impairment (MCI) (n = 30), were compared with age-matched healthy controls (age < 65, n = 18 and age > 65; n = 32) using ELISA. The serum BDNF levels significantly decreased and TNFα levels significantly increased in the EOAD and LOAD groups compared to the age-matched healthy controls. There was a correlation between serum TNFα and IL-10 levels in the LOAD and healthy control groups. Serum CFH levels in the LOAD and MCI patients were significantly decreased compared with controls. Serum Hsp90 levels in the EOAD, LOAD, and MCI patients were significantly decreased compared with controls. The protein misfolding, the inflammatory response, and decreased neurotrophic factor synthesis are all suggested to be related to AD type brain pathology, and our results indicate these alterations might be traced from serum samples. For accurate early diagnosis of AD, it is important to determine a profile of alterations in multiple biomarkers in large-scale population studies.

Novel compound heterozygous mutation in TREM2 found in a Turkish frontotemporal dementia-like family.

Triggering receptor expressed on myeloid cells 2 (TREM2) homozygous mutations cause Nasu-Hakola disease, an early-onset recessive form of dementia preceded by bone cysts and fractures. The same type of mutations has recently been shown to cause frontotemporal dementia (FTD) without the presence of any bone phenotype. Here, we further confirm the association of TREM2 mutations with FTD-like phenotypes by reporting the first compound heterozygous mutation in a Turkish family.

Silent neurological involvement in biopsy-defined coeliac patients.

Coeliac disease (CD) is an autoimmune disease of small intestine associated with sensitivity to gluten. The clinical manifestations are often of gastrointestinal nature, although the disease may be present asymptomatically as well. It is a chronic disease and in the absence of overt neurological involvement, extended gluten exposure may give rise to silent or subtle morphological and white-matter changes in central nervous system. The present study investigates such changes using brain volumetry and the assessment of white-matter tissue in CD patients without neurological symptoms. Seventeen CD patients without any neurological involvement were included in the study and went under neurological evaluation and anatomical MRI. Individual gray- and white-matter, and subcortical structure volumes were acquired for using automated volumetric analyses. The observed white-matter hyperintensities (WMH) evaluated using Age-Related White-Matter Changes scale. Findings show a bilateral decrease in cortical gray-matter and caudate nuclei volumes in CD compared to controls. Negative correlations were found between the duration of the disease and the volumes of the affected regions. Cerebellum was seemingly unaffected. In addition, significantly higher proportion of WMH was found in CD patients, specifically in bilateral frontal and occipitoparietal cortices. We observed a significant gray-matter and caudate nucleus atrophy in the CD patients in the absence of marked neurological symptoms. Present findings point out to a need for histopathological investigations potentially focusing on anti-TG2 antibodies, and serial volumetric analyses on the CD-related cortical and subcortical changes.

Using exome sequencing to reveal mutations in TREM2 presenting as a frontotemporal dementia-like syndrome without bone involvement.

OBJECTIVE: To identify new genes and risk factors associated with frontotemporal dementia (FTD). Several genes and loci have been associated with different forms of FTD, but a large number of families with dementia do not harbor mutations in these genes. DESIGN: Whole-exome sequencing and whole-genome genotyping were performed in all patients. Genetic variants obtained from whole-exome sequencing were integrated with the data obtained from whole-genome genotyping. SETTING: Database of the Behavioral Neurology Outpatient Clinic of the Department of Neurology, Istanbul Faculty of Medicine, Istanbul, Turkey. PATIENTS Forty-four Turkish patients with an FTD-like clinical diagnosis were included in the study. Relatives were screened when appropriate. MAIN OUTCOME MEASURE: Mutations in the triggering receptor expressed on myeloid cells 2 gene (TREM2). RESULTS: In 3 probands with FTD-like disease, we identified different homozygous mutations in TREM2 that had previously been associated with polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy (PLOSL). None of these 3 patients had a typical clinical presentation of PLOSL: they presented with behavioral change and subsequent cognitive impairment and motor features but without any bone cysts or bone-associated phenotypes. Imaging showed white matter abnormalities as well as frontal atrophy in all 3 patients. CONCLUSIONS: Our results show that TREM2 is responsible for an unexpectedly high number of dementia cases in our cohort, suggesting that this gene should be taken into account when mutations in other dementia genes are excluded. Even for complex syndromes such as dementia, exome sequencing has proven to be a rapid and cost-effective tool to identify genetic mutations, allowing for the association of clinical phenotypes with unexpected molecular underpinnings.