Examining patient and professional perspectives in the UK for gene therapy in haemophilia.

INTRODUCTION: With the development of gene therapy for people with haemophilia (PWH), it is important to understand how people impacted by haemophilia (PIH) and clinicians prioritise haemophilia treatment attributes to support informed treatment decisions. OBJECTIVE: To examine the treatment attribute preferences of PIH and clinical experts in the United Kingdom (UK) and to develop a profile of gene therapy characteristics fit for use in future discrete choice experiments (DCEs). METHODS: Semi-structured interviews were conducted with PIH (n = 14) and clinical experts (n = 6) who ranked pre-defined treatment attributes by importance. Framework analysis was conducted to identify key themes and treatment attributes; points were allocated based on the rankings. Synthesis of results by a multidisciplinary group informed development of a profile of gene therapy characteristics for use in future research. RESULTS: Key themes identified by PIH and clinical experts included patient relevant features and the importance of 'informed decision making'. The six top-ranked treatment attributes were 'effect on factor level' (79 points), 'uncertainty regarding long-term risks' (57 points), 'impact on daily life' (41 points), 'frequency of monitoring' (33 points), 'impact on ability to participate in physical activity' (29 points), and 'uncertainty regarding long-term benefits' (28 points). The final treatment characteristics were categorised as therapeutic option, treatment effectiveness, safety concerns, impact on self-management and quality of life (role limitations). CONCLUSION: We identified several gene therapy characteristics important to PIH and clinicians in the UK. These characteristics will be used in a future DCE to further investigate patient preferences for gene therapy.

Differential chemokine alteration in the variants of primary progressive aphasia-a role for neuroinflammation.

BACKGROUND: The primary progressive aphasias (PPA) represent a group of usually sporadic neurodegenerative disorders with three main variants: the nonfluent or agrammatic variant (nfvPPA), the semantic variant (svPPA), and the logopenic variant (lvPPA). They are usually associated with a specific underlying pathology: nfvPPA with a primary tauopathy, svPPA with a TDP-43 proteinopathy, and lvPPA with underlying Alzheimer's disease (AD). Little is known about their cause or pathophysiology, but prior studies in both AD and svPPA have suggested a role for neuroinflammation. In this study, we set out to investigate the role of chemokines across the PPA spectrum, with a primary focus on central changes in cerebrospinal fluid (CSF) METHODS: Thirty-six participants with sporadic PPA (11 svPPA, 13 nfvPPA, and 12 lvPPA) as well as 19 healthy controls were recruited to the study and donated CSF and plasma samples. All patients with lvPPA had a tau/Aß42 biomarker profile consistent with AD, whilst this was normal in the other PPA groups and controls. We assessed twenty chemokines in CSF and plasma using Proximity Extension Assay technology: CCL2 (MCP-1), CCL3 (MIP-1a), CCL4 (MIP-1ß), CCL7 (MCP-3), CCL8 (MCP-2), CCL11 (eotaxin), CCL13 (MCP-4), CCL19, CCL20, CCL23, CCL25, CCL28, CX3CL1 (fractalkine), CXCL1, CXCL5, CXCL6, CXCL8 (IL-8), CXCL9, CXCL10, and CXCL11. RESULTS: In CSF, CCL19 and CXCL6 were decreased in both svPPA and nfvPPA compared with controls whilst CXCL5 was decreased in the nfvPPA group with a borderline significant decrease in the svPPA group. In contrast, CCL2, CCL3 and CX3CL1 were increased in lvPPA compared with controls and nfvPPA (and greater than svPPA for CX3CL1). CXCL1 was also increased in lvPPA compared with nfvPPA but not the other groups. CX3CL1 was significantly correlated with CSF total tau concentrations in the controls and each of the PPA groups. Fewer significant differences were seen between groups in plasma, although in general, results were in the opposite direction to CSF, i.e. decreased in lvPPA compared with controls (CCL3 and CCL19), and increased in svPPA (CCL8) and nfvPPA (CCL13). CONCLUSION: Differential alteration of chemokines across the PPA variants is seen in both CSF and plasma. Importantly, these results suggest a role for neuroinflammation in these poorly understood sporadic disorders, and therefore also a potential future therapeutic target.

Microglial burden, activation and dystrophy patterns in frontotemporal lobar degeneration.

BACKGROUND: Microglial dysfunction is implicated in frontotemporal lobar degeneration (FTLD). Although studies have reported excessive microglial activation or senescence (dystrophy) in Alzheimer's disease (AD), few have explored this in FTLD. We examined regional patterns of microglial burden, activation and dystrophy in sporadic and genetic FTLD, sporadic AD and controls. METHODS: Immunohistochemistry was performed in frontal and temporal grey and white matter from 50 pathologically confirmed FTLD cases (31 sporadic, 19 genetic: 20 FTLD-tau, 26 FTLD-TDP, four FTLD-FUS), five AD cases and five controls, using markers to detect phagocytic (CD68-positive) and antigen-presenting (CR3/43-positive) microglia, and microglia in general (Iba1-positive). Microglial burden and activation (morphology) were assessed quantitatively for each microglial phenotype. Iba1-positive microglia were assessed semi-quantitatively for dystrophy severity and qualitatively for rod-shaped and hypertrophic morphology. Microglia were compared in each region between FTLD, AD and controls, and between different pathological subtypes of FTLD, including its main subtypes (FTLD-tau, FTLD-TDP, FTLD-FUS), and subtypes of FTLD-tau, FTLD-TDP and genetic FTLD. Microglia were also compared between grey and white matter within each lobe for each group. RESULTS: There was a higher burden of phagocytic and antigen-presenting microglia in FTLD and AD cases than controls, but activation was often not increased. Burden was generally higher in white matter than grey matter, but activation was greater in grey matter. However, microglia varied regionally according to FTLD subtype and disease mechanism. Dystrophy was more severe in FTLD and AD than controls, and more severe in white than grey matter, but this also varied regionally and was particularly extensive in FTLD due to progranulin (GRN) mutations. Presence of rod-shaped and hypertrophic microglia also varied by FTLD subtype. CONCLUSIONS: This study demonstrates regionally variable microglial involvement in FTLD and links this to underlying disease mechanisms. This supports investigation of microglial dysfunction in disease models and consideration of anti-senescence therapies in clinical trials.

Plasma glial fibrillary acidic protein is raised in progranulin-associated frontotemporal dementia.

BACKGROUND: There are few validated fluid biomarkers in frontotemporal dementia (FTD). Glial fibrillary acidic protein (GFAP) is a measure of astrogliosis, a known pathological process of FTD, but has yet to be explored as potential biomarker. METHODS: Plasma GFAP and neurofilament light chain (NfL) concentration were measured in 469 individuals enrolled in the Genetic FTD Initiative: 114 C9orf72 expansion carriers (74 presymptomatic, 40 symptomatic), 119 GRN mutation carriers (88 presymptomatic, 31 symptomatic), 53 MAPT mutation carriers (34 presymptomatic, 19 symptomatic) and 183 non-carrier controls. Biomarker measures were compared between groups using linear regression models adjusted for age and sex with family membership included as random effect. Participants underwent standardised clinical assessments including the Mini-Mental State Examination (MMSE), Frontotemporal Lobar Degeneration-Clinical Dementia Rating scale and MRI. Spearman's correlation coefficient was used to investigate the relationship of plasma GFAP to clinical and imaging measures. RESULTS: Plasma GFAP concentration was significantly increased in symptomatic GRN mutation carriers (adjusted mean difference from controls 192.3 pg/mL, 95% CI 126.5 to 445.6), but not in those with C9orf72 expansions (9.0, -61.3 to 54.6), MAPT mutations (12.7, -33.3 to 90.4) or the presymptomatic groups. GFAP concentration was significantly positively correlated with age in both controls and the majority of the disease groups, as well as with NfL concentration. In the presymptomatic period, higher GFAP concentrations were correlated with a lower cognitive score (MMSE) and lower brain volume, while in the symptomatic period, higher concentrations were associated with faster rates of atrophy in the temporal lobe. CONCLUSIONS: Raised GFAP concentrations appear to be unique to GRN-related FTD, with levels potentially increasing just prior to symptom onset, suggesting that GFAP may be an important marker of proximity to onset, and helpful for forthcoming therapeutic prevention trials.

Cerebrospinal Fluid YKL-40 and Chitotriosidase Levels in Frontotemporal Dementia Vary by Clinical, Genetic and Pathological Subtype.

BACKGROUND: Chronic glial dysfunction may contribute to the pathogenesis of frontotemporal dementia (FTD). Cerebrospinal fluid (CSF) levels of glia-derived proteins YKL-40 and chitotriosidase are increased in Alzheimer's disease (AD) but have not been explored in detail across the spectrum of FTD. METHODS: We investigated whether CSF YKL-40 and chitotriosidase levels differed between FTD patients and controls, across different clinical and genetic subtypes of FTD, and between individuals with a clinical FTD syndrome due to AD versus non-AD (frontotemporal lobar degeneration, FTLD) pathology (based on CSF neurodegenerative biomarkers). Eighteen healthy controls and 64 people with FTD (behavioural variant FTD, n = 20; primary progressive aphasia [PPA], n = 44: nfvPPA, n = 16, svPPA, n = 11, lvPPA, n = 14, PPA-NOS, n = 3) were included. 10/64 had familial FTD, with mutations in GRN(n = 3), MAPT(n = 4), or C9orf72 (n = 3). 15/64 had neurodegenerative biomarkers consistent with AD pathology. Levels were measured by immunoassay and compared using multiple linear regressions. We also examined relationships of YKL-40 and chitotriosidase with CSF total tau (T-tau), phosphorylated tau 181 (P-tau) and ß-amyloid 1-42 (Aß42), with each other, and with age and disease du-ration. RESULTS: CSF YKL-40 and chitotriosidase levels were higher in FTD, particularly lvPPA (both) and nfvPPA (YKL-40), compared with controls. GRN mutation carriers had higher levels of both proteins than controls and C9orf72 expansion carriers, and YKL-40 was higher in MAPT mutation carriers than controls. Individuals with underlying AD pathology had higher YKL-40 and chitotriosidase levels than both controls and those with likely FTLD pathology. CSF YKL-40 and chitotriosidase levels were variably associated with levels of T-tau, P-tau and Aß42, and with each other, depending on clinical syndrome and underlying pathology. CSF YKL-40 but not chitotriosidase was associated with age, but not disease duration. CONCLUSION: CSF YKL-40 and chitotriosidase levels are increased in individuals with clinical FTD syndromes, particularly due to AD pathology. In a preliminary analysis of genetic groups, levels of both proteins are found to be highly elevated in FTD due to GRN mutations, while YKL-40 is increased in individuals with MAPT mutations. As glia-derived protein levels generally correlate with T-tau and P-tau levels, they may reflect the glial response to neurodegeneration in FTLD.

Searching for novel cerebrospinal fluid biomarkers of tau pathology in frontotemporal dementia: an elusive quest.

BACKGROUND: Frontotemporal dementia (FTD) is a pathologically heterogeneous neurodegenerative disorder associated usually with tau or TDP-43 pathology, although some phenotypes such as logopenic variant primary progressive aphasia are more commonly associated with Alzheimer's disease pathology. Currently, there are no biomarkers able to diagnose the underlying pathology during life. In this study, we aimed to investigate the potential of novel tau species within cerebrospinal fluid (CSF) as biomarkers for tau pathology in FTD. METHODS: 86 participants were included: 66 with a clinical diagnosis within the FTD spectrum and 20 healthy controls. Immunoassays targeting tau fragments N-123, N-mid-region, N-224 and X-368, as well as a non-phosphorylated form of tau were measured in CSF, along with total-tau (T-tau) and phospho-tau (P-tau(181)). Patients with FTD were grouped based on their Aß42 level into those likely to have underlying Alzheimer's disease (AD) pathology (n=21) and those with likely frontotemporal lobar degeneration (FTLD) pathology (n=45). The FTLD group was then subgrouped based on their underlying clinical and genetic diagnoses into those with likely tau (n=7) or TDP-43 (n=18) pathology. RESULTS: Significantly higher concentrations of tau N-mid-region, tau N-224 and non-phosphorylated tau were seen in both the AD group and FTLD group compared with controls. However, none of the novel tau species showed a significant difference between the AD and FTLD groups, nor between the TDP-43 and tau pathology groups. In a subanalysis, normalising for total-tau, none of the novel tau species provided a higher sensitivity and specificity to distinguish between tau and TDP-43 pathology than P-tau(181)/T-tau, which itself only had a sensitivity of 61.1% and specificity of 85.7% with a cut-off of <0.109. CONCLUSIONS: Despite investigating multiple novel CSF tau fragments, none show promise as an FTD biomarker and so the quest for in vivo markers of FTLD-tau pathology continues.

Clinical value of cerebrospinal fluid neurofilament light chain in semantic dementia.

BACKGROUND: Semantic dementia (SD) is a neurodegenerative disorder characterised by progressive language problems falling within the clinicopathological spectrum of frontotemporal lobar degeneration (FTLD). The development of disease-modifying agents may be facilitated by the relative clinical and pathological homogeneity of SD, but we need robust monitoring biomarkers to measure their efficacy. In different FTLD subtypes, neurofilament light chain (NfL) is a promising marker, therefore we investigated the utility of cerebrospinal fluid (CSF) NfL in SD. METHODS: This large retrospective multicentre study compared cross-sectional CSF NfL levels of 162 patients with SD with 65 controls. CSF NfL levels of patients were correlated with clinical parameters (including survival), neuropsychological test scores and regional grey matter atrophy (including longitudinal data in a subset). RESULTS: CSF NfL levels were significantly higher in patients with SD (median: 2326 pg/mL, IQR: 1628-3593) than in controls (577 (446-766), p<0.001). Higher CSF NfL levels were moderately associated with naming impairment as measured by the Boston Naming Test (rs =-0.32, p=0.002) and with smaller grey matter volume of the parahippocampal gyri (rs =-0.31, p=0.004). However, cross-sectional CSF NfL levels were not associated with progression of grey matter atrophy and did not predict survival. CONCLUSION: CSF NfL is a promising biomarker in the diagnostic process of SD, although it has limited cross-sectional monitoring or prognostic abilities.

Plasma tau is increased in frontotemporal dementia.

BACKGROUND: Frontotemporal dementia (FTD) is a heterogeneous neurodegenerative disorder presenting clinically with personality change (behavioural variant FTD (bvFTD)) or language deficits (primary progressive aphasia (PPA)). About a third of FTD is familial with mutations in GRN, MAPT and C9orf72 being the major genetic causes. Robust biomarkers of the underlying pathology are still lacking in FTD with no markers currently being able to distinguish those with tau and TDP-43 inclusions during life. METHODS: This study used an ultrasensitive single molecule methodology to measure plasma tau concentrations in 176 participants: 71 with bvFTD, 83 with PPA and 22 healthy controls. The patient group included 36 with pathogenic mutations in either MAPT (n=12), GRN (n=9) or C9orf72 (n=15). Group comparisons were performed between clinical and genetic groups and controls using a linear regression model with bias-corrected bootstrap CIs. Correlative analyses were performed to investigate associations with measures of disease severity and progression. RESULTS: Higher plasma tau concentrations were seen in bvFTD (mean 1.96 (SD 1.07) pg/mL) and PPA (2.65 (2.15) pg/mL) compared with controls (1.67 (0.50) pg/mL). Investigating the PPA group further showed significantly higher levels compared with controls in each of the PPA subtypes (non-fluent, semantic and logopenic variants, as well as a fourth group not meeting criteria for one of the three main variants). In the genetic groups, only the MAPT group had significantly increased concentrations (2.62 (1.39) pg/mL) compared with controls. No significant correlations were seen with cross-sectional or longitudinal brain volumes, serum neurofilament light chain concentrations or disease duration. CONCLUSION: Plasma tau levels are increased in FTD in all clinical groups, but in the genetic subtypes only in MAPT mutations, the group of patients who definitively have tau pathology at postmortem. Future studies will be required in pathologically confirmed cohorts to investigate this association further, and whether plasma tau will be helpful in differentiating patients with FTD with tau from those with other pathologies.

Pathological correlates of white matter hyperintensities in a case of progranulin mutation associated frontotemporal dementia.

White matter hyperintensities (WMH) are often seen on MRI brain scans in frontotemporal dementia (FTD) due to progranulin (GRN) mutations, but their pathological correlates are unknown. We examined the histological changes underlying WMH in a patient with GRN mutation associated behavioral variant FTD. In vivo and cadaveric MRI showed progressive, asymmetric frontotemporal and parietal atrophy, and asymmetrical WMH predominantly affecting frontal mid-zones. We first performed segmentation and localization analyses of WMH present on cadaveric MRI FLAIR images, then selected five different brain regions directly matched to differing severities of WMH for histological analysis. We used immunohistochemistry to assess vascular pathology, degree of spongiosis, neuronal and axonal loss, TDP-43, demyelination and astrogliosis, and microglial burden and morphology. Brain regions with significant WMH displayed severe cortical and white matter pathology, and prominent white matter microglial activation and microglial dystrophy, but only mild axonal loss and minimal vascular pathology. Our study suggests that WMH in GRN mutation carriers are not secondary to vascular pathology. Whilst cortical pathology induced axonal degeneration could contribute to white matter damage, individuals with GRN mutations could develop selective white matter vulnerability and myelin loss due to chronic, regional microglial dysfunction arising from GRN haploinsufficiency.

The clinical spectrum of sporadic and familial forms of frontotemporal dementia.

The term frontotemporal dementia (FTD) describes a clinically, genetically and pathologically diverse group of neurodegenerative disorders. Symptoms of FTD can present in individuals in their 20s through to their 90s, but the mean age at onset is in the sixth decade. The most common presentation is with a change in personality and impaired social conduct (behavioural variant FTD). Less frequently patients present with language problems (primary progressive aphasia). Both of these groups of patients can develop motor features consistent with either motor neuron disease (usually the amyotrophic lateral sclerosis variant) or parkinsonism (most commonly a progressive supranuclear palsy or corticobasal syndrome). In about a third of cases FTD is familial, with mutations in the progranulin, microtubule-associated protein tau and chromosome 9 open reading frame 72 genes being the major causes. Mutations in a number of other genes including TANK-binding kinase 1 are rare causes of familial FTD. This review aims to clarify the often confusing terminology of FTD, and outline the various clinical features and diagnostic criteria of sporadic and familial FTD syndromes. It will also discuss the current major challenges in FTD research and clinical practice, and potential areas for future research. This review clarifies the terminology of frontotemporal dementia (FTD) and summarizes the various clinical features and most recent diagnostic criteria of sporadic and familial FTD syndromes. It also discusses the current major challenges in FTD research and clinical practice, and highlights potential areas for future research.

Compulsive versifying after treatment of transient epileptic amnesia.

Compulsive production of verse is an unusual form of hypergraphia that has been reported mainly in patients with right temporal lobe seizures. We present a patient with transient epileptic amnesia and a left temporal seizure focus, who developed isolated compulsive versifying, producing multiple rhyming poems, following seizure cessation induced by lamotrigine. Functional neuroimaging studies in the healthy brain implicate left frontotemporal areas in generating novel verbal output and rhyme, while dysregulation of neocortical and limbic regions occurs in temporal lobe epilepsy. This case complements previous observations of emergence of altered behavior with reduced seizure frequency in patients with temporal lobe epilepsy. Such cases suggest that reduced seizure frequency has the potential not only to stabilize or improve memory function, but also to trigger complex, specific behavioral alterations.

The C9ORF72 expansion mutation: gene structure, phenotypic and diagnostic issues.

The discovery of the C9ORF72 hexanucleotide repeat expansion in 2011 and the immediate realisation of a remarkably high prevalence in both familial and sporadic frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis (ALS) triggered an explosion of interest in studies aiming to define the associated clinical and investigation phenotypes and attempts to develop technologies to measure more accurately the size of the repeat region. This article reviews progress in these areas over the subsequent 2 years, focussing on issues directly relevant to the practising physician. First, we summarise findings from studies regarding the global prevalence of the expansion, not only in FTLD and ALS cases, but also in other neurological diseases and its concurrence with other genetic mutations associated with FTLD and ALS. Second, we discuss the variability in normal repeat number in cases and controls and the theories regarding the relevance of intermediate and pathological repeat number for disease risk and clinical phenotype. Third, we discuss the usefulness of various features within the FTLD and ALS clinical phenotype in aiding differentiation between cases with and without the C9ORF72 expansion. Fourth, we review clinical investigations used to identify cases with the expansion, including neuroimaging and cerebrospinal fluid markers, and describe the mechanisms and limitations of the various diagnostic laboratory techniques used to quantify repeat number in cases and controls. Finally, we discuss the issues surrounding accurate clinical and technological diagnosis of patients with FTLD and/or ALS associated with the C9ORF72 expansion, and outline areas for future research that might aid better diagnosis and genetic counselling of patients with seemingly sporadic or familial FTLD or ALS and their relatives.

CSF glial markers are elevated in a subset of patients with genetic frontotemporal dementia.

BACKGROUND: Neuroinflammation has been shown to be an important pathophysiological disease mechanism in frontotemporal dementia (FTD). This includes activation of microglia, a process that can be measured in life through assaying different glia-derived biomarkers in cerebrospinal fluid. However, only a few studies so far have taken place in FTD, and even fewer focusing on the genetic forms of FTD. METHODS: We investigated the cerebrospinal fluid concentrations of TREM2, YKL-40 and chitotriosidase using immunoassays in 183 participants from the Genetic FTD Initiative (GENFI) study: 49 C9orf72 (36 presymptomatic, 13 symptomatic), 49 GRN (37 presymptomatic, 12 symptomatic) and 23 MAPT (16 presymptomatic, 7 symptomatic) mutation carriers and 62 mutation-negative controls. Concentrations were compared between groups using a linear regression model adjusting for age and sex, with 95% bias-corrected bootstrapped confidence intervals. Concentrations in each group were correlated with the Mini-Mental State Examination (MMSE) score using non-parametric partial correlations adjusting for age. Age-adjusted z-scores were also created for the concentration of markers in each participant, investigating how many had a value above the 95th percentile of controls. RESULTS: Only chitotriosidase in symptomatic GRN mutation carriers had a concentration significantly higher than controls. No group had higher TREM2 or YKL-40 concentrations than controls after adjusting for age and sex. There was a significant negative correlation of chitotriosidase concentration with MMSE in presymptomatic GRN mutation carriers. In the symptomatic groups, for TREM2 31% of C9orf72, 25% of GRN, and 14% of MAPT mutation carriers had a concentration above the 95th percentile of controls. For YKL-40 this was 8% C9orf72, 8% GRN and 0% MAPT mutation carriers, whilst for chitotriosidase it was 23% C9orf72, 50% GRN, and 29% MAPT mutation carriers. CONCLUSIONS: Although chitotriosidase concentrations in GRN mutation carriers were the only significantly raised glia-derived biomarker as a group, a subset of mutation carriers in all three groups, particularly for chitotriosidase and TREM2, had elevated concentrations. Further work is required to understand the variability in concentrations and the extent of neuroinflammation across the genetic forms of FTD. However, the current findings suggest limited utility of these measures in forthcoming trials.

Idiopathic intracranial hypertension presenting as iron deficiency anemia: a case report.

BACKGROUND: The presentation of idiopathic intracranial hypertension (IIH) in association with iron deficiency anemia (IDA) is rare. CASE PRESENTATION: This case report depicts the unusual case of a 31-year-old woman of mixed Jamaican and English heritage with IIH who presented initially as IDA in the context of menorrhagia. Subsequent ophthalmic review, lumbar puncture, cerebrospinal fluid analysis and neuroimaging studies revealed severe bilateral optic disc swelling and raised intracranial pressure in keeping with IIH. Prompt treatment of IDA with blood transfusion and orally administered iron supplements, in addition to medical treatment for IIH, contributed to significant improvement of symptoms and prevented long-term visual deficits. CONCLUSION: The possibility of IDA, albeit rare, should always be considered and investigated appropriately in all patients with IIH, as the treatment of the anemia alone may be sight-saving.

Variable clinical phenotype in TBK1 mutations: case report of a novel mutation causing primary progressive aphasia and review of the literature.

TANK-binding kinase 1 (TBK1) mutations are a recently discovered cause of disorders in the frontotemporal dementia (FTD)-amyotrophic lateral sclerosis (ALS) spectrum. We describe a novel L683∗ mutation, predicted to cause a truncated protein and therefore be pathogenic, in a patient presenting with nonfluent variant primary progressive aphasia at the age of 65 years. Her disease progressed over the following years, leading to her being mute and wheelchair bound seven years into her illness. Brain imaging showed asymmetrical left-sided predominant atrophy affecting the frontal, insular, and temporal cortices as well as the striatum in particular. Review of the literature found 60 different nonsense, frameshift, deletion, or splice site mutations, including the newly described mutation, with data on clinical diagnosis available in 110 people: 58% of the cases presented with an ALS syndrome, 16% with an FTD-ALS overlap, 19% with a cognitive presentation (including behavioral variant FTD and primary progressive aphasia) and 4% with atypical parkinsonism. Age at onset (AAO) data were available in 75 people: mean (standard deviation) AAO was 57.5 (10.3) in those with ALS, which was significantly younger than those with a cognitive presentation (AAO = 65.1 (10.5), p = 0.008), or atypical parkinsonism (AAO = 68.3 (8.7), p = 0.021), with a trend compared with the FTD-ALS group (AAO = 61.9 (7.0), p=0.065); there was no significant difference in AAO between the other groups. In conclusion, clinical syndromes across the whole FTD-ALS-atypical parkinsonism spectrum have been reported in conjunction with mutations in TBK1. It is therefore important to include TBK1 on future gene panels for each of these disorders and to suspect such mutations particularly when there are multiple different phenotypes in the same family.

When do psychogenic nonepileptic seizures occur on a video/EEG telemetry unit?

To maximize the efficiency of diagnostic video/EEG telemetry, we retrospectively studied the occurrence of clinical events during admission in 254 patients. One hundred fifty-nine patients had psychogenic nonepileptic seizures (PNES) and 95 had epileptic seizures (ES). Twenty-five with PNES and none with ES had an event before or during electrode placement (P<0.0001). In the remaining 229, the initial event occurred within 48 hours of electrode placement in 98.5% patients with PNES and 100.0% of patients with ES. Time to occurrence of initial event did not differ between groups (P=0.69). 17.1% patients with PNES and 51.6% with ES had events between 12 AM and 6 AM (P=0.001). In conclusion, during diagnostic video/EEG telemetry, most patients who experience PNES or ES have diagnostic, typical events within 2 days. Although time to initial event after electrode placement does not differ between diagnoses, events prior to or during placement are most likely PNES and events at night are most likely ES.

Two pathologically confirmed cases of novel mutations in the MAPT gene causing frontotemporal dementia.

MAPT mutations were the first discovered genetic cause of frontotemporal dementia (FTD) in 1998. Since that time, over 60 MAPT mutations have been identified, usually causing behavioral variant FTD and/or parkinsonism clinically. We describe 2 novel MAPT mutations, D252V and G389_I392del, each presenting in a patient with behavioral variant FTD and associated language and cognitive deficits. Neuroimaging revealed asymmetrical left greater than right temporal lobe atrophy in the first case, and bifrontal atrophy in the second case. Disease duration was 8 years and 5 years, respectively. Postmortem examination in both patients revealed a 3-repeat predominant tauopathy, similar in appearance to Pick's disease. These 2 mutations add to the literature on genetic FTD, both presenting with similar clinical and imaging features to previously described cases, and pathologically showing a primary tauopathy similar to a number of other MAPT mutations.

Altered phobic reactions in frontotemporal dementia: A behavioural and neuroanatomical analysis.

INTRODUCTION: Abnormal behavioural and physiological reactivity to emotional stimuli is a hallmark of frontotemporal dementia (FTD), particularly the behavioural variant (bvFTD). As part of this repertoire, altered phobic responses have been reported in some patients with FTD but are poorly characterised. METHODS: We collected data (based on caregiver reports) concerning the prevalence and nature of any behavioural changes related to specific phobias in a cohort of patients representing canonical syndromes of FTD and Alzheimer's disease (AD), relative to healthy older controls. Neuroanatomical correlates of altered phobic reactivity were assessed using voxel-based morphometry. RESULTS: 46 patients with bvFTD, 20 with semantic variant primary progressive aphasia, 25 with non-fluent variant primary progressive aphasia, 29 with AD and 55 healthy age-matched individuals participated. Changes in specific phobia were significantly more prevalent in the combined FTD cohort (15.4% of cases) and in the bvFTD group (17.4%) compared both to healthy controls (3.6%) and patients with AD (3.5%). Attenuation of phobic reactivity was reported for individuals in all participant groups, however new phobias developed only in the FTD cohort. Altered phobic reactivity was significantly associated with relative preservation of grey matter in left posterior middle temporal gyrus, right temporo-occipital junction and right anterior cingulate gyrus, brain regions previously implicated in contextual decoding, salience processing and reward valuation. CONCLUSION: Altered phobic reactivity is a relatively common issue in patients with FTD, particularly bvFTD. This novel paradigm of strong fear experience has broad implications: clinically, for diagnosis and patient well-being; and neurobiologically, for our understanding of the pathophysiology of aversive sensory signal processing in FTD and the neural mechanisms of fear more generally.