Pulsatile tympanic membrane displacement is associated with cognitive score in healthy subjects

To test the hypothesis that pulsing of intracranial pressure has an association with cognition, we measured cognitive score and pulsing of the tympanic membrane in 290 healthy subjects. This hypothesis was formed on the assumptions that large intracranial pressure pulses impair cognitive performance and tympanic membrane pulses reflect intracranial pressure pulses. 290 healthy subjects, aged 20-80 years, completed the Montreal Cognitive Assessment Test. Spontaneous tympanic membrane displacement during a heart cycle was measured from both ears in the sitting and supine position. We applied multiple linear regression, correcting for age, heart rate, and height, to test for an association between cognitive score and spontaneous tympanic membrane displacement. Significance was set at P < 0.0125 (Bonferroni correction.) A significant association was seen in the left supine position (p = 0.0076.) The association was not significant in the right ear supine (p = 0.28) or in either ear while sitting. Sub-domains of the cognitive assessment revealed that executive function, language and memory have been primarily responsible for this association. In conclusion, we have found that spontaneous pulses of the tympanic membrane are associated with cognitive performance and believe this reflects an association between cognitive performance and intracranial pressure pulses.

Degeneration of basal and limbic networks is a core feature of behavioural variant frontotemporal dementia

The behavioural variant of frontotemporal dementia is a clinical syndrome characterized by changes in behaviour, cognition and functional ability. Although atrophy in frontal and temporal regions would appear to be a defining feature, neuroimaging studies have identified volumetric differences distributed across large parts of the cortex, giving rise to a classification into distinct neuroanatomical subtypes. Here, we extended these neuroimaging studies to examine how distributed patterns of cortical atrophy map onto brain network hubs. We used baseline structural magnetic resonance imaging data collected from 213 behavioural variant of frontotemporal dementia patients meeting consensus diagnostic criteria and having definite evidence of frontal and/or temporal lobe atrophy from a global clinical trial conducted in 70 sites in Canada, United States of America, Australia, Asia and Europe. These were compared with data from 244 healthy elderly subjects from a well-characterized cohort study. We have used statistical methods of hierarchical agglomerative clustering of 68 regional cortical and subcortical volumes (34 in each hemisphere) to determine the reproducibility of previously described neuroanatomical subtypes in a global study. We have also attempted to link the structural findings to clinical features defined systematically using well-validated clinical scales (Addenbrooke’s Cognitive Examination Revised, the Mini-Mental Status Examination, the Frontotemporal Dementia Rating Scale and the Functional Assessment Questionnaire) and subscales derived from them. Whilst we can confirm that the subtypes are robust, they have limited value in explaining the clinical heterogeneity of the syndrome. We have found that a common pattern of degeneration affecting a small number of subcortical, limbic and frontal nodes within highly connected networks (most previously identified as rich club members or functional binding nodes) is shared by all the anatomical subtypes. Degeneration in these core regions is correlated with cognitive and functional impairment, but less so with behavioural impairment. These findings suggest that degeneration in highly connected basal, limbic and frontal networks is a core feature of the behavioural variant of frontotemporal dementia phenotype irrespective of neuroanatomical and clinical heterogeneity, and may underly the impairment of integration in cognition, function and behaviour responsible for the loss of insight that characterizes the syndrome.

The impact of smoking cessation on multiple sclerosis disease progression

The negative impact of smoking in multiple sclerosis is well established; however, there is much less evidence as to whether smoking cessation is beneficial to progression in multiple sclerosis.

Adults with multiple sclerosis registered on the United Kingdom Multiple Sclerosis Register (2011–20) formed this retrospective and prospective cohort study. Primary outcomes were changes in three patient-reported outcomes: normalized Multiple Sclerosis Physical Impact Scale (MSIS-29-Phys), normalized Multiple Sclerosis Walking Scale (MSWS-12) and the Hospital Anxiety and Depression Scale (HADS). Time to event outcomes were clinically significant increases in the patient-reported outcomes.

The study included 7983 participants; 4130 (51.7%) of these had ever smoked, of whom 1315 (16.5%) were current smokers and 2815/4130 (68.2%) were former smokers. For all patient-reported outcomes, current smokers at the time of completing their first questionnaire had higher patient-reported outcomes scores indicating higher disability compared to those who had never smoked (∼10 points difference in MSIS-29-Phys and MSWS-12; 1.5–1.8 points for HADS-Anxiety and HADS-Depression). There was no improvement in patient-reported outcomes scores with increasing time since quitting in former smokers.

Nine hundred and twenty-three participants formed the prospective parallel group, which demonstrated that MSIS-29-Phys [median (IQR) 5.03 (3.71, 6.34)], MSWS-12 [median (IQR) 5.28 (3.62, 6.94)] and HADS-Depression [median (IQR) 0.71 (0.47, 0.96)] scores worsened over a period of 4 years, whereas HADS-Anxiety remained stable. Smoking status was significant at Year 4; current smokers had higher MSIS-29-Phys and HADS-Anxiety scores [median (IQR) 3.05 (0.22, 5.88) and 1.14 (0.52, 1.76), respectively] while former smokers had a lower MSIS-29-Phys score of −2.91 (−5.03, −0.79).

A total of 4642 participants comprised the time to event analysis. Still smoking was associated with a shorter time to worsening event in all patient-reported outcomes (MSIS-29-Phys: n = 4436, P = 0.0013; MSWS-12: n = 3902, P = 0.0061; HADS-Anxiety: n = 4511, P = 0.0017; HADS-Depression: n = 4511, P < 0.0001). Worsening in motor disability (MSIS-29-Phys and MSWS-12) was independent of baseline HADS-Anxiety and HADS-Depression scores. There was no statistically significant difference in the rate of worsening between never and former smokers.

When smokers quit, there is a slowing in the rate of motor disability deterioration so that it matches the rate of motor decline in those who have never smoked. This suggests that smoking cessation is beneficial for people with multiple sclerosis.

Concentration-Dependent Activity of Hydromethylthionine on Clinical Decline and Brain Atrophy in a Randomized Controlled Trial in Behavioral Variant Frontotemporal Dementia

BACKGROUND

Hydromethylthionine is a potent inhibitor of pathological aggregation of tau and TDP-43 proteins.

OBJECTIVE

To compare hydromethylthionine treatment effects at two doses and to determine how drug exposure is related to treatment response in bvFTD.

METHODS

We undertook a 52-week Phase III study in 220 bvFTD patients randomized to compare hydromethylthionine at 200 mg/day and 8 mg/day (intended as a control). The principal outcomes were change on the Addenbrookes Cognitive Examination - Revised (ACE-R), the Functional Activities Questionnaire (FAQ), and whole brain volume. Secondary outcomes included Modified Clinical Global Impression of Change (Modified-CGIC). A population pharmacokinetic exposure-response analysis was undertaken in 175 of the patients with available blood samples and outcome data using a discriminatory plasma assay for the parent drug.

RESULTS

There were no significant differences between the two doses as randomized. There were steep concentration-response relationships for plasma levels in the range 0.3-0.6 ng/ml at the 8 mg/day dose on clinical and MRI outcomes. There were significant exposure-dependent differences at 8 mg/day for FAQ, Modified-CGIC, and whole brain atrophy comparing patients with plasma levels greater than 0.346 ng/ml with having minimal drug exposure. The exposure-response is biphasic with worse outcomes at the high concentrations produced by 200 mg/day.

CONCLUSIONS

Hydromethylthionine has a similar concentration-response profile for effects on clinical decline and brain atrophy at the 8 mg/day dose in bvFTD as recently reported in AD. Treatment responses in bvFTD are predicted to be maximal at doses in the range 20-60 mg/day. A confirmatory placebo-controlled trial is now planned.

Clinical nurse specialist's role in young-onset dementia care

Post-diagnostic care in young-onset dementia (YoD) varies, from something that is occasionally structured, to improvised, to frequently non-existent depending on geographic region. In a few regions in England, a nurse designated to helping families may exist. This study aimed to describe this seldom-observed nursing role and its content. It used an investigative qualitative case study design based on the analysis of two YoD clinical nurse specialists (CNSs) describing the work they did in providing post-diagnostic care to YoD service users. The CNSs address various areas affected by mid-life dementia, including patients' mental health, caregiver stress and families' psycho-social problems. They use various approaches in delivering care, including making home visits, acting as a personal contact for service users and liaising with other health and social care services. Desirable attributes of a CNS service include service users having access to the same CNS throughout their care, receiving timely care and experiencing longer-term support and reassurance. In the post-diagnostic period, service user needs are often more psycho-social than medical, and the CNS role can complement and add value to clinical appointments. The role allows service users to be managed in the community, to receive information, guidance and advice and can prevent and de-escalate problems.

Clearance of interstitial fluid (ISF) and CSF (CLIC) group-part of Vascular Professional Interest Area (PIA): Cerebrovascular disease and the failure of elimination of Amyloid-β from the brain and retina with age and Alzheimer's disease-Opportunities for Therapy

Two of the key functions of arteries in the brain are (1) the well-recognized supply of blood via the vascular lumen and (2) the emerging role for the arterial walls as routes for the elimination of interstitial fluid (ISF) and soluble metabolites, such as amyloid beta (Aβ), from the brain and retina. As the brain and retina possess no conventional lymphatic vessels, fluid drainage toward peripheral lymph nodes is mediated via transport along basement membranes in the walls of capillaries and arteries that form the intramural peri-arterial drainage (IPAD) system. IPAD tends to fail as arteries age but the mechanisms underlying the failure are unclear. In some people this is reflected in the accumulation of Aβ plaques in the brain in Alzheimer's disease (AD) and deposition of Aβ within artery walls as cerebral amyloid angiopathy (CAA). Knowledge of the dynamics of IPAD and why it fails with age is essential for establishing diagnostic tests for the early stages of the disease and for devising therapies that promote the clearance of Aβ in the prevention and treatment of AD and CAA. This editorial is intended to introduce the rationale that has led to the establishment of the Clearance of Interstitial Fluid (ISF) and CSF (CLIC) group, within the Vascular Professional Interest Area of the Alzheimer's Association International Society to Advance Alzheimer's Research and Treatment.

UK neurology response to the COVID-19 crisis

COVID-19 has led to seismic changes in neurological practice in a matter of weeks. The Association of British Neurologists has supported neurology specialists and patients during this rapid reorganisation and its attendant challenges. We have written guidance on structured service transformation, considering the need to sustain long term care while responding to acute developments; we have recognised that staff experience differs and that this, as well as individual risk factors should be considered when redeployment occurs. Appreciating that there may be understandable anxiety when facing a working routine outside normal practice, we have signposted ethical and psychological support for individuals. We have also focused on our patients: we have facilitated a national alert system to register all neurological COVID cases, coordinating research efforts on this new disease; finally we have defined how to identify the most vulnerable patients under our care. When this initial wave of the pandemic subsides, we will have planned for return to the new 'norm', ready to embrace innovation where appropriate, aiming to minimise fall-out in our chronic disease population, and potentially having enhanced and modernised our services.

Variably protease-sensitive prionopathy mimicking frontotemporal dementia

Sporadic prion diseases are fatal neurodegenerative disorders characterized clinically by rapidly progressive dementia and myoclonus. Variably protease‐sensitive prionopathy (VPSPr) is a recently identified sporadic human prion disorder that may present with a lengthy atypical clinical history. Here, we describe a case of VPSPr in a patient with a long history of suspected frontotemporal dementia (FTD). A 61‐year‐old man presented with speech difficulties, including naming objects and constructing multipart sentences, while there was no difficulty in comprehension. Movement abnormalities included slightly jerky pursuit, minor dysmetria of saccades and brisk reflexes. There was no family history of dementia. Later he developed swallowing difficulties and the possibility of FTD with motor neuron disease was suspected. He died at the age of 71 and his brain was donated to the London Neurodegenerative Diseases Brain Bank. The brain (1004 g) showed mild to moderate atrophy, predominantly in the frontal lobe. Histology revealed moderate spongiform microvacuolation mostly affecting the frontal and parietal cortices, but also present focally in the basal ganglia and the cerebellum. Only mild Alzheimer pathology was found by extensive immunohistochemistry, in keeping with BrainNet Europe stage II. Trans‐activation response DNA‐binding protein 43 kDa and α‐synuclein immunostains were negative. Immunostaining for prion protein (PrP) showed granular/synaptic positivity in a patchy distribution, mainly within the deeper cortex, and also revealed microplaques in the cerebellum and basal ganglia. Western blotting confirmed a low molecular weight protease‐resistant PrP band with a faint ladder‐like pattern in the absence of types 1 and 2 isoforms. These features are diagnostic of VPSPr. VPSPr can mimic various neurodegenerative conditions; diagnosis requires both PrP immunohistochemistry and Western blotting. The presence of patchy spongiform change in the absence of other neurodegenerative pathology should raise suspicion of VPSPr, even in elderly patients with a lengthy clinical history.

Imaging Care Requirements: Use of Functional Neuroimaging to Predict Dementia Caregiver Burden

Background

Dementia caregivers frequently report high stress, with increased burden associated with worse outcomes for both patients and caregivers. Although many studies relate clinical phenotypes to burden, the relationship between imaging pathology and burden, irrespective of diagnosis, is unknown. This study investigated the relationship between caregiver burden and patient regional cerebral blood flow in dementia.

Methods

Seventy-sev en patients with cognitive impairment undergoing brain perfusion single-photon emission computed tomography imaging in normal clinical care and their caregivers were recruited. Caregiver burden was ranked from “little” to “severe” using the Zarit Burden Interview and perfusion values extracted from the patient images for predefined regions of interest. The associations between burden score and regional function on imaging were tested.

Results

Burden score was significantly higher for caregivers of patients with abnormal perfusion compared to those with normal perfusion in the left and right frontal, right parietal, and right temporal lobes. No difference in burden was found in the left parietal or temporal groups. Correlations showed that a higher caregiver burden was associated with lower patient perfusion scores in the same regions.

Conclusion

Caregiver burden is strongly related to the extent of frontal or right-predominant parietal or temporal lobe dysfunction. Regional abnormality on perfusion imaging can be used to facilitate identification of individuals who are likely to create a high burden on caregivers.

Understanding important issues in young-onset dementia care: the perspective of healthcare professionals

AIM

Psychosocial research on the lived experiences of young-onset dementia patients and caregivers has identified salient issues about their care, however, views on care from the perspective of young-onset dementia healthcare professionals is less well known. The aim of this study was to investigate and identify important issues in young-onset dementia care provision from a healthcare provider perspective.

METHODS

The design was an exploratory qualitative interview study. In-depth semistructured interviews were conducted with healthcare professionals with clinical expertise in young-onset dementia drawn from medicine, nursing and allied health. Thematic analysis was applied to interview transcripts to identify themes representing important underlying issues in care across the dementia clinical pathway (i.e., prediagnosis, diagnosis and postdiagnosis).

RESULTS

In prediagnosis, it is important for healthcare professionals to recognize symptoms as organic and degenerative and more than psychological, and to refer patients to an appropriate clinical facility for assessment. During diagnosis, it may be challenging to determine dementia, and methods are employed to manage diagnostic uncertainty. Following diagnosis, optimizing routine clinical care is important and can include the provision of practical informational guidance, empathic concern and psychoeducational support. Meeting service-user requirements in the community is an important aspect of care, and may be facilitated by the involvement of clinical nurse specialists.

CONCLUSION

The findings are presented as a paradigm for holistic young-onset dementia care. The paradigm offers a framework for contemplating and evaluating the criteria and quality of young-onset dementia care.

Measuring younger onset dementia: A comprehensive literature search of the quantitative psychosocial research

BACKGROUND

Research is beginning to demonstrate the unique psychosocial effects of young onset dementia. Theorising remains at an early stage and there has been little discussion about measurement and methodological issues. Our aim was to conduct a comprehensive literature search of the young onset dementia psychosocial research, and to identify the domains of experience measured with patients and caregivers.

METHOD

We conducted a search of five electronic databases (Medline, CINAHL, PsycINFO, Embase, the Cochrane Library) using equivalent database controlled vocabulary terms. We supplemented this search by using free text searches within electronic databases, searching reference sections of salient papers, and using online search engines. We defined psychosocial as referring to patient and caregiver psychological, behavioural, and social functioning in the context of living with young onset dementia.

RESULTS

We identified 72 published articles, 49 quantitative and 23 qualitative. The quantitative articles form the focus of the present review. We identified 10 domains of patient experience measured and 14 domains of caregiver experience. The patient domains measured most often were behaviour, cognition, functioning, and severity, and reflected a focus on symptoms and clinical features. Quality of Life (QoL) was the patient domain measured least often. The caregiver domains measured most often were mental health and burden, and reflected a focus on psychological well-being and coping.

CONCLUSION

The scope of measurement is broader in caregivers than patients. QoL although under-researched may be a useful domain to measure in future research. Risk factors, measurement and methodological issues are discussed.

Lobar atrophy in frontotemporal dementia: diagnostic and prognostic implications

We review the practical importance of lobar atrophy in frontotemporal dementia (FTD), for diagnosis and prognosis. We discuss specific patterns of frontotemporal atrophy that denote clinical and pathological subtypes of FTD (e.g. semantic dementia). We also discuss the unsatisfactory clinical experience of interpreting MRI scans in individual FTD cases, especially the behavioural presentations (without aphasic or motor impairments). This issue is explored by examining the FTD phenocopy concept. Lobar atrophy emerges as a key observation in defining behavioural FTD patients whose symptoms are likely to progress. In a situation where objective clinical data are few, we highlight the importance of applying caution before diagnosing FTD is the absence of visible brain atrophy.

Movement disorder emergencies in childhood

The literature on paediatric acute-onset movement disorders is scattered. In a prospective cohort of 52 children (21 male; age range 2mo-15y), the commonest were chorea, dystonia, tremor, myoclonus, and Parkinsonism in descending order of frequency. In this series of mainly previously well children with cryptogenic acute movement disorders, three groups were recognised: (1) Psychogenic disorders (n = 12), typically >10 years of age, more likely to be female and to have tremor and myoclonus (2) Inflammatory or autoimmune disorders (n = 22), including N-methyl-d-aspartate receptor encephalitis, opsoclonus-myoclonus, Sydenham chorea, systemic lupus erythematosus, acute necrotizing encephalopathy (which may be autosomal dominant), and other encephalitides and (3) Non-inflammatory disorders (n = 18), including drug-induced movement disorder, post-pump chorea, metabolic, e.g. glutaric aciduria, and vascular disease, e.g. moyamoya. Other important non-inflammatory movement disorders, typically seen in symptomatic children with underlying aetiologies such as trauma, severe cerebral palsy, epileptic encephalopathy, Down syndrome and Rett syndrome, include dystonic posturing secondary to gastro-oesophageal reflux (Sandifer syndrome) and Paroxysmal Autonomic Instability with Dystonia (PAID) or autonomic 'storming'. Status dystonicus may present in children with known extrapyramidal disorders, such as cerebral palsy or during changes in management e.g. introduction or withdrawal of neuroleptic drugs or failure of intrathecal baclofen infusion; the main risk in terms of mortality is renal failure from rhabdomyolysis. Although the evidence base is weak, as many of the inflammatory/autoimmune conditions are treatable with steroids, immunoglobulin, plasmapheresis, or cyclophosphamide, it is important to make an early diagnosis where possible. Outcome in survivors is variable. Using illustrative case histories, this review draws attention to the practical difficulties in diagnosis and management of this important group of patients.

Sensitivity of revised diagnostic criteria for the behavioural variant of frontotemporal dementia

Based on the recent literature and collective experience, an international consortium developed revised guidelines for the diagnosis of behavioural variant frontotemporal dementia. The validation process retrospectively reviewed clinical records and compared the sensitivity of proposed and earlier criteria in a multi-site sample of patients with pathologically verified frontotemporal lobar degeneration. According to the revised criteria, 'possible' behavioural variant frontotemporal dementia requires three of six clinically discriminating features (disinhibition, apathy/inertia, loss of sympathy/empathy, perseverative/compulsive behaviours, hyperorality and dysexecutive neuropsychological profile). 'Probable' behavioural variant frontotemporal dementia adds functional disability and characteristic neuroimaging, while behavioural variant frontotemporal dementia 'with definite frontotemporal lobar degeneration' requires histopathological confirmation or a pathogenic mutation. Sixteen brain banks contributed cases meeting histopathological criteria for frontotemporal lobar degeneration and a clinical diagnosis of behavioural variant frontotemporal dementia, Alzheimer's disease, dementia with Lewy bodies or vascular dementia at presentation. Cases with predominant primary progressive aphasia or extra-pyramidal syndromes were excluded. In these autopsy-confirmed cases, an experienced neurologist or psychiatrist ascertained clinical features necessary for making a diagnosis according to previous and proposed criteria at presentation. Of 137 cases where features were available for both proposed and previously established criteria, 118 (86%) met 'possible' criteria, and 104 (76%) met criteria for 'probable' behavioural variant frontotemporal dementia. In contrast, 72 cases (53%) met previously established criteria for the syndrome (P < 0.001 for comparison with 'possible' and 'probable' criteria). Patients who failed to meet revised criteria were significantly older and most had atypical presentations with marked memory impairment. In conclusion, the revised criteria for behavioural variant frontotemporal dementia improve diagnostic accuracy compared with previously established criteria in a sample with known frontotemporal lobar degeneration. Greater sensitivity of the proposed criteria may reflect the optimized diagnostic features, less restrictive exclusion features and a flexible structure that accommodates different initial clinical presentations. Future studies will be needed to establish the reliability and specificity of these revised diagnostic guidelines.

Sensitivity of revised diagnostic criteria for the behavioural variant of frontotemporal dementia

Based on the recent literature and collective experience, an international consortium developed revised guidelines for the diagnosis of behavioural variant frontotemporal dementia. The validation process retrospectively reviewed clinical records and compared the sensitivity of proposed and earlier criteria in a multi-site sample of patients with pathologically verified frontotemporal lobar degeneration. According to the revised criteria, 'possible' behavioural variant frontotemporal dementia requires three of six clinically discriminating features (disinhibition, apathy/inertia, loss of sympathy/empathy, perseverative/compulsive behaviours, hyperorality and dysexecutive neuropsychological profile). 'Probable' behavioural variant frontotemporal dementia adds functional disability and characteristic neuroimaging, while behavioural variant frontotemporal dementia 'with definite frontotemporal lobar degeneration' requires histopathological confirmation or a pathogenic mutation. Sixteen brain banks contributed cases meeting histopathological criteria for frontotemporal lobar degeneration and a clinical diagnosis of behavioural variant frontotemporal dementia, Alzheimer's disease, dementia with Lewy bodies or vascular dementia at presentation. Cases with predominant primary progressive aphasia or extra-pyramidal syndromes were excluded. In these autopsy-confirmed cases, an experienced neurologist or psychiatrist ascertained clinical features necessary for making a diagnosis according to previous and proposed criteria at presentation. Of 137 cases where features were available for both proposed and previously established criteria, 118 (86%) met 'possible' criteria, and 104 (76%) met criteria for 'probable' behavioural variant frontotemporal dementia. In contrast, 72 cases (53%) met previously established criteria for the syndrome (P < 0.001 for comparison with 'possible' and 'probable' criteria). Patients who failed to meet revised criteria were significantly older and most had atypical presentations with marked memory impairment. In conclusion, the revised criteria for behavioural variant frontotemporal dementia improve diagnostic accuracy compared with previously established criteria in a sample with known frontotemporal lobar degeneration. Greater sensitivity of the proposed criteria may reflect the optimized diagnostic features, less restrictive exclusion features and a flexible structure that accommodates different initial clinical presentations. Future studies will be needed to establish the reliability and specificity of these revised diagnostic guidelines.

Is the pathology of corticobasal syndrome predictable in life?

Corticobasal syndrome (CBS) has been associated with a heterogeneous spectrum of pathologies with an increasing number of reports of Alzheimer's type pathology. There is, however, no means of predicting pathology of CBS in vivo at present. We compared the clinical features of patients presenting with CBS who have either pathologic changes of classic corticobasal degeneration (CBD) or Alzheimer's disease (AD) at post-mortem to identify predictors of the specific pathological processes in life. Twelve patients with CBS were followed prospectively; six had AD and six had classic CBD neuropathology. After review of the presenting clinical features, we identified nine potential predictor variables, compared their frequency in the two groups, and performed a discriminant function analysis. Initial episodic memory complaints and poor performance on the combined orientation-memory subtest of the Addenbrooke's Cognitive Examination (ACE) reliably predicted AD pathology while varying combinations of early frontal-lobe type behavioral symptoms, nonfluent language disturbance, orobuccal apraxia, and utilization behavior predicted CBD pathology ante-mortem. CBS is frequently associated with Alzheimer's disease pathology. Early episodic memory impairment versus early behavioral symptomatology appears to best predict AD or CBD pathology in life.

Can progressive and non-progressive behavioural variant frontotemporal dementia be distinguished at presentation?

BACKGROUND

Recent findings suggest that patients with behavioural variant frontotemporal dementia (bv-FTD) differ in their disease progression (progressive vs non-progressive patients). The current study investigates whether the two groups can be discriminated by their clinical features at first presentation.

METHODS

Archival clinical data of the Early Onset Dementia Clinic, Cambridge, UK, were analysed for 71 patients with bv-FTD: 45 progressive and 26 non-progressive cases with more than 3 years of follow-up.

RESULTS

The subgroups were largely indistinguishable on the basis of the presenting clinical features but could be distinguished on general cognitive (Addenbrooke's Cognitive Examination-revised) and selected supportive diagnostic features (distractibility, stereotypic speech, impaired activities of daily living (ADLs) and current depression).

CONCLUSIONS

Progressive and non-progressive patients are difficult to differentiate on the basis of current clinical diagnostic criteria for FTD but a combination of general cognitive, executive dysfunction and impaired ADL measures appear to be the most promising discriminators.

Emotion, social functioning and activities of daily living in frontotemporal dementia

Social functioning in FTD is profoundly affected, and forms the basis for the clinical diagnosis of the behavioural variant of the disease (bv-FTD). In particular, there are deficits in emotional processing, but the inter-relationship of such deficits to other aspects of social functioning remains unclear. We studied patients with bv-FTD (n = 14) and AD (n = 14), and compared their performance on a test of emotion recognition with their scores on two carer-based assessments: the Disability Assessment for Dementia (DAD) of activities in daily living (ADL), and the Cambridge Behavioural Inventory (CBI). The bv-FTD group had significantly greater impairments in ADLs, and had higher scores on the CBI, compared to the AD group. Despite a deficit in emotion recognition, particularly involving negative emotions, in the FTD group relative to AD and controls, performance on this task did not correlate with ADL ratings which instead, correlated highly with carer-rated apathy levels on the CBI. The study highlights the multifactorial nature of social dysfunction in FTD which is important in the management of these patients and in designing effective behavioural and therapeutic interventions. The relationship of emotional processing to other aspects of social cognition in FTD is reviewed.

Combined magnetic resonance imaging and positron emission tomography brain imaging in behavioural variant frontotemporal degeneration: refining the clinical phenotype

In patients with the behavioural variant of frontotemporal dementia, prognosis is often surprisingly good when there is normal structural imaging at presentation. Imaging abnormalities are not, however, mandatory for diagnosis, which in the absence of suitable biomarkers, remains entirely clinical. We aimed to test whether cases with normal structural imaging have hypometabolism suggestive of underlying neurodegeneration, or whether it is likely that such patients are false positive diagnoses of behavioural variant frontotemporal dementia. Patients with this disease (n = 24) and age-matched controls (n = 12) underwent both magnetic resonance imaging (MRI) and quantitative fluorodeoxyglucose-positron emission tomography (FDG-PET) scanning, together with clinical and behavioural assessments. Regions of interest were used to calculate metabolic rate in frontotemporal and control regions. Using a semi-quantitative visual rating scale, patients were divided into MRI-abnormal (n = 15) and MRI-normal groups (n = 9). There was definite frontotemporal hypometabolism in the MRI-abnormal group (particularly in the mesial and orbitofrontal regions) even after accounting for brain volume loss, whereas the MRI-normal group was similar to controls in all regions. In contrast, cognitive and behavioural indices did not separate the two behavioural variant frontotemporal dementia patient groups. The results suggest that the clinical syndrome of the behavioural variant of frontotemporal dementia may not be specific for a neurodegenerative disease, and we hypothesize the existence of a phenocopy. A number of alternative neuropsychiatric and developmental explanations are discussed. We advise caution in diagnosing the illness in patients without imaging abnormalities, and propose that imaging findings are included in criteria for diagnosis.

Sensitivity of current criteria for the diagnosis of behavioral variant frontotemporal dementia

BACKGROUND

Diagnosis of behavioral variant frontotemporal dementia (bvFTD) relies on criteria that are constraining and potentially ambiguous. Some features are open to clinical interpretation and their prevalence unknown. This study investigated the sensitivity of current diagnostic criteria in a large group of patients with bvFTD.

METHODS

Forty-five patients with clear evidence of bvFTD as judged by progressive clinical decline (>3 years) with marked frontal features and significant frontal brain atrophy on brain MRI were included. Thirty-two have died; pathologic confirmation of frontotemporal lobar degeneration was found in all 18 coming to autopsy. We established the prevalence of core and supportive diagnostic features at presentation and with disease progression.

RESULTS

Only 25/45 patients (56%) showed all five core features necessary for a diagnosis of bvFTD at initial presentation and 33/45 (73%) as their disease progressed. Two core features, emotional blunting and loss of insight, were never observed in 25% and 13% of cases. Executive dysfunction, hyperorality, mental inflexibility, and distractibility were the only supportive features present in >50% of cases at initial presentation. Although not a diagnostic feature, impaired activities of daily living was present in 33/45 patients (73%).

CONCLUSIONS

Strict application of the criteria misses a significant proportion of patients. Many supportive features have low prevalence and are clinically not useful. Revision of the criteria to include level of certainty (definite, probable, possible) dependent on the number of features present and the presence of ancillary information (e.g., brain atrophy, neuropsychological abnormalities, impaired activities of daily living) is encouraged.

Understanding social dysfunction in the behavioural variant of frontotemporal dementia: the role of emotion and sarcasm processing

Social interaction is profoundly affected in the behavioural form of frontotemporal dementia (bvFTD) yet there are few means of objectively assessing this. Diagnosis of bvFTD is based on informant report, however a number of individuals with a clinical profile consistent with the disease have no imaging abnormality and seem to remain stable, with doubt about the presence of underlying neurodegenerative pathology. We aimed to quantify aspects of the behavioural disorder and link it to the underlying level of atrophy in socially relevant brain regions. We tested individuals with either bvFTD (N = 26) or Alzheimer's disease (N = 9) and 16 controls using The Awareness of Social Inference Test (TASIT) to assess their ability to identify emotion and sarcasm in video vignettes. A subset of bvFTD patients (N = 21) and controls (N = 12) were scanned using MRI within 6 months of assessment. There was marked impairment in the ability of bvFTD patients whose scans showed abnormalities to recognize sarcastic, but not sincere statements. Their capacity to interpret negative emotion was also impaired, and this appeared to be a major factor underlying the deficit in sarcasm recognition. Clinically diagnosed bvFTD patients whose scans were normal, Alzheimer's disease patients and controls had no difficulty in appreciating both types of statement. In a multivariate imaging analysis it was shown that the sarcasm (and emotion recognition) deficit was dependent on a circuit involving the lateral orbitofrontal cortex, insula, amygdala and temporal pole, particularly on the right. Performance on a more global test of cognitive function, the Addenbrooke's Cognitive Examination did not have a unique association with these regions. The TASIT is an objective test of social dysfunction in bvFTD which indexes the frontotemporal volume loss in bvFTD patients and provides an objective measure for separating behavioural patients who are likely to decline from those who may remain stable. These results provide additional evidence for the role of the orbitofrontal cortex and related structures in the processing of socially relevant signals, particularly those where negative emotion recognition is important.

Theory of mind in frontotemporal dementia

Patients with frontotemporal dementia (FTD) exhibit marked changes in social and emotional functioning including lack of empathy, disinhibition, altered emotional reactivity, apathy and lack of insight. These changes are believed to be dependent on progressive frontal and temporal lobe degeneration. In this review, we discuss the nature of defective theory of mind and empathy in this group and relate it to regional dysfunction in the orbitofrontal and medial prefrontal cortex, based on evidence from several recent studies. The role of executive ability and co-existing emotional deficits are also considered.

Measuring progression in frontotemporal dementia: implications for therapeutic interventions

BACKGROUND

There is a need for instruments which can measure progression of disease in frontotemporal dementia (FTD), particularly with respect to the assessment of potential therapeutic agents.

METHODS

The Cambridge Early Onset Dementia Clinic database was reviewed for all prospectively enrolled cases of FTD with documented scores on the Mini-Mental State Examination (MMSE) or Addenbrooke's Cognitive Examination (ACE) on at least two occasions. We identified 50 cases fulfilling these criteria: pathologic confirmation was present in 11 of 16 patients who had died, 12 of the remainder had imaging abnormalities on their initial scans, and 22 had structural scans no different from controls. We compared these groups to a cohort with early AD (n = 25) and healthy controls (n = 10).

RESULTS

There was clear cognitive decline (measured by the MMSE and ACE) in patients who had died, and those with documented atrophy on initial MRI scan. In contrast, patients with FTD with normal scans showed no change in cognitive scores over a much longer interval, and serial ACE measurements paralleled those of controls. Power calculations showed that the inclusion of these patients with FTD would significantly increase the number of cases needed in any therapeutic trial.

CONCLUSION

Addenbrooke's Cognitive Examination is a simple monitoring tool which can detect progression of disease in frontotemporal dementia over a 1- to 2-year interval without the need for serial imaging. We estimated that a clinical trial that enrolled subjects with abnormal MR scans would require 135 subjects per group to detect a small effect, and 35 for a medium effect.

Disgust and happiness recognition correlate with anteroventral insula and amygdala volume respectively in preclinical Huntington's disease

Patients with Huntington's disease (HD) can show disproportionate impairments in recognizing facial signals of disgust, but the neural basis of this deficit remains unclear. Functional imaging studies have implicated the anterior insula in the ability to recognize disgust, but have identified other structures as well, including the basal ganglia. In view of variable insula and basal ganglia volume changes in HD, we used voxel-based morphometry to map regional variations in gray matter (GM) volume in participants carrying the mutation for HD, and correlated this with their performance on a test of facial emotion recognition for six basic emotions (disgust, fear, anger, happiness, sadness, surprise). The volume of the anteroventral insula was strongly correlated with performance on the disgust recognition task. The amygdala volume (bilaterally) correlated with the ability to recognize happy facial expressions. There was marked specificity of the regional correlations for the emotion involved. Recognition of other emotion expressions, or more general cognitive or motor performance as measured by a standardized rating scale, did not correlate with regional brain volume in this group. Control participants showed no effect for any measure. The strong linear correlations for disgust and happiness recognition imply direct involvement of the anterior insula in disgust appreciation, and a similar role for the amygdala in recognizing happy facial expressions. The absence of a significant correlation with the basal ganglia suggests a less critical role for these structures in disgust recognition than has previously been suggested. The findings also highlight the role of neurodegenerative diseases combined with statistical imaging techniques in elucidating the brain basis of behavior and cognition.

Behavioural variant frontotemporal dementia: not all it seems?

BACKGROUND

The diagnosis of the behavioural variant of frontotemporal dementia (bvFTD) can be challenging. At present there is a paucity of prospective work addressing the specificity of current diagnostic criteria for bvFTD with respect to long-term outcome (i.e., false positives versus true positives).

METHODS

Here we report two individuals who met current clinical criteria for bvFTD and who underwent detailed long-term clinical and neuropsychological follow-up. In addition, both had serial volumetric MRI and functional metabolic (FDG-PET) imaging separated by 5 years.

RESULTS

One case had a slow clinical decline as well as both progressive atrophy and hypometabolism in a frontotemporal distribution, consistent with a neurodegenerative FTD syndrome. However, the second developed neither atrophy nor hypometabolism and remained clinically stable, a decade from symptom onset.

CONCLUSION

We propose that these cases illustrate that while there may be a slow evolution in bvFTD, it is possible that some cases who meet current criteria may not have a neurodegenerative syndrome. If correct, this hypothesis has important implications for the current diagnostic criteria. A potential hierarchy for diagnostic certainty in bvFTD is suggested.

Clinical significance of lobar atrophy in frontotemporal dementia: application of an MRI visual rating scale

BACKGROUND/AIMS

The status of imaging findings in the clinical diagnosis of frontotemporal dementia (FTD) remains uncertain; while they may be supportive of a diagnosis of frontotemporal dementia, they are not mandatory. Our aim was to assess patterns of lobar atrophy in a large sample of clinically defined, prospectively studied, patients using a magnetic resonance image (MRI) rating scale, to (1) determine whether imaging findings warrant a more prominent position in FTD diagnosis and (2) correlate the extent of lobar atrophy with clinical data.

METHODS

We adapted a recently devised post mortem rating scale for FTD to rate lobar atrophy on MRI scans. The areas rated included the frontal cortex and both anterior and posterior temporal regions bilaterally. All available brain scans from all patients seen in the Cambridge Dementia Clinic (n = 258) diagnosed as having FTD, together with controls (n = 20), were used to assess the reliability of the method. A subset of these (n = 121) were used for clinico-anatomic analysis.

RESULTS

The scale proved quick and reliable (intra-, inter-rater k = 0.80, 0.67). MRI scans were abnormal in the majority of patients (75%), with focal atrophy present in 100% of semantic dementia (SD) patients. By contrast, nearly half (47%) of the patients with clinical behavioural variant FTD had scans within the normal range. Behavioural cases with normal scans generally had fewer cognitive deficits and milder functional impairment than those with abnormal scans, yet displayed a clinically indistinguishable behavioural syndrome. They were not, however, simply at an earlier stage of the disease.

CONCLUSIONS

MRI findings should form part of the diagnostic criteria for SD; the absence of atrophy on MRI in many behavioural cases raises the prospect that the behavioural syndrome of FTD is not specific for patients with a neurodegenerative disease.

Activities of daily living in frontotemporal dementia and Alzheimer disease

OBJECTIVE

To evaluate activities of daily living (ADLs) in three clinical variants of frontotemporal dementia and the relationship to cognitive dysfunction.

METHODS

Fifty-nine patients and caregivers participated in this cross-sectional study: behavioral variant frontotemporal dementia (bv-FTD, n = 15), progressive nonfluent aphasia (PNFA, n = 10), semantic dementia (n = 15), and Alzheimer disease (AD, n = 19). Caregivers were interviewed with the Disability Assessment for Dementia (DAD) to provide two outcome measures about ADLs: basic and instrumental ADLs (BADLs, IADL). In addition, patients were rated on the Clinical Dementia Rating Scale (CDR), and performance on cognitive measures (Addenbrooke's Cognitive Examination Revised [ACE-R]) was assessed.

RESULTS

On the DAD, the bv-FTD group was most affected (56% of normal), whereas PNFA and semantic dementia patients were least impaired (83% and 85%); AD was intermediate (76%). The opposite pattern was seen on the ACE-R, where PNFA and semantic dementia groups were most affected, and bv-FTD showed least impairment; AD was again intermediate. Scores on the DAD did not correlate with cognitive measures, CDR, or disease duration. We further analyzed which aspect of ADLs was most affected, and a unique pattern of deficits emerged for the bv-FTD group (initiation affected > planning > execution for BADLs).

CONCLUSION

Frontotemporal dementia has a devastating effect on activities of daily living, which is of considerable importance to caregivers and not captured by bedside cognitive tests.

Frontotemporal dementia

PURPOSE OF REVIEW

The syndromes of frontotemporal lobar degeneration are increasingly recognized as an important cause of early-onset dementia. Diagnostic consensus criteria have now been established for almost a decade, and form the framework for its clinical classification. While these criteria remain useful, a growing body of evidence suggests that revisions may be necessary to improve their validity and applicability.

RECENT FINDINGS

In each individual syndrome, the core features are not uniformly present, and criteria that are currently used to exclude a condition, such as impaired episodic memory, are often present. Imaging, however, may warrant increased diagnostic prominence, particularly for diagnosis in semantic dementia and prognosis in behavioural syndromes. There is clinical and pathological overlap between the syndromes, but the clinical distinction between progressive nonfluent aphasia and semantic dementia is strengthening. Several series have refined our understanding of the correspondence between clinical syndromes and histopathological subtype: strong for tau-negative, ubiquitin-positive forms and more variable for tau-positive forms, yet prospective studies are still rare. The influence of genetic factors varies substantially across the syndromes.

SUMMARY

Further research should aim to integrate detailed clinical, radiological, pathological and genetic information.

Progression in Frontotemporal Dementia

OBJECTIVE

To assess the clinical course and prognosis in patients with behavioral-variant frontotemporal dementia (FTD) lacking evidence of brain atrophy on magnetic resonance imaging (MRI).

DESIGN

Patients were enrolled into this prospective cohort study over a period of 15 years; cognitive status, duration of symptoms, and behavioral indexes were recorded. Brain MRIs were rated using a standardized scale.

SETTING

Regional early-onset dementia clinic.

PARTICIPANTS

Thirty-one participants diagnosed clinically with behavioral-variant FTD. Intervention Rating of MRIs.

MAIN OUTCOME MEASURES

Death or institutionalization after a minimum of 3 years' follow-up indicated poor prognosis, while the ability to live independently was regarded as a good prognosis for the purpose of survival (Kaplan-Meier) and discriminant function analysis.

RESULTS

Patients with normal or borderline MRI findings (n = 15) showed significantly longer survival to institutionalization or death than those (n = 16) with definite frontotemporal atrophy (mean +/- SE, 9.3 +/- 1.7 years vs 3.0 +/- 0.7 years; P<.01). Using groups defined by 3-year outcome (good or bad prognosis), cerebral atrophy predicted poor outcome while age, symptom duration, cognitive performance, behavioral impairment, and overall disability at baseline did not.

CONCLUSIONS

Patients with FTD with normal MRI results follow a more benign course than cases with atrophy at presentation. The substrate of the behavioral symptoms in such cases may differ from the neurodegenerative pathological features typically associated with FTD.

The relationship between affective decision-making and theory of mind in the frontal variant of fronto-temporal dementia

Structural brain imaging and neuropsychological data implicate the orbital aspects of prefrontal cortex in the developing neuropathology of fvFTD. Damage to this region is associated with deficient performance on laboratory tasks assessing theory of mind (ToM) and affective decision-making (DM), but the relationship between these two capacities in patients with prefrontal cortex dysfunction is unclear. We studied a group of patients with early/mild fvFTD (n=20) and a group of matched normal controls (n=10) on the Iowa gambling task (IGT) of affective decision-making, and the "reading the mind in the eyes" (MIE) and "faux pas" (FP) tests of ToM. The fvFTD group was impaired in both ToM tasks and the IGT. While performance measures from the two ToM tasks were significantly correlated, they were not associated with IGT performance. This suggests that whilst similar prefrontal circuitry is implicated in ToM and DM tasks, these cognitive domains may be independent. In clinical settings, the IGT may be useful as a complementary tool to the frontal test battery for patients with early/mild fvFTD. Deficits in decision-making and ToM observed in this study have distinct but additive effects upon the development of social behaviour in patients with prefrontal dysfunction.

Social reasoning, emotion and empathy in frontotemporal dementia

INTRODUCTION

Social cognition is crucial for human interaction, and is markedly impaired in the frontal variant of frontotemporal dementia (fvFTD). The relationship of various aspects of social functioning, however, remains controversial in this group.

METHODS

Patients with fvFTD (n = 18), and matched controls (n = 13), were tested using tasks designed to assess their Theory of Mind (ToM), moral reasoning, emotion recognition and executive function. Caregivers documented changes in empathy compared to premorbid functioning.

RESULTS

We found marked impairments in the abilities of fvFTD patients, relative to controls, in ability to mentalise (ToM), which was evident on a cartoon test, but not on a story-based ToM task. Knowledge of social rules was intact, but moral reasoning was defective, and was due, in part, to an inability to rate the seriousness of moral and conventional transgressions appropriately. Executive function was impaired in this group, and compromised aspects of moral reasoning, but ToM performance was independent of this. Emotion recognition was globally impaired in fvFTD, but was particularly so for anger and disgust which may partly explain the difficulty these patients have with identifying social violations. Empathy, as rated by carers, was also shown to be abnormal.

CONCLUSION

It appears that social reasoning is disrupted in a number of ways in fvFTD, and the findings provide a basis for the understanding and further study of abnormal behaviour in this disease. The results are discussed in light of neuroimaging findings in studies of social cognition and the locus of pathology in fvFTD.

Progression of structural neuropathology in preclinical Huntington's disease: a tensor based morphometry study

BACKGROUND AND OBJECTIVES

Regional cerebral atrophy occurs in carriers of the Huntington's disease (HD) gene mutation before clinical diagnosis is possible. The current inability to reliably measure progression of pathology in this preclinical phase impedes development of therapies to delay clinical onset. We hypothesised that longitudinal statistical imaging would detect progression of structural pathology in preclinical carriers of the HD gene mutation, in the absence of measurable clinical change.

METHODS

Thirty subjects (17 preclinical mutation positive, 13 mutation negative) underwent serial clinical and magnetic resonance imaging (MRI) assessments over an interval of 2 years. Statistically significant changes in regional grey and white matter volume on MRI were analysed using tensor based morphometry (TBM). This technique derives a voxel-wise estimation of regional tissue volume change from the deformation field required to warp a subject's early to late T1 images.

RESULTS

Over 2 years, there was progressive regional grey matter atrophy in mutation-positive relative to negative subjects, without significant clinical progression of disease. Significant grey matter volume loss was limited to bilateral putamen and globus pallidus externa (GPe), left caudate nucleus, and left ventral midbrain in the region of the substantia nigra.

CONCLUSIONS

While these results are consistent with previous cross sectional pathologic and morphometric studies, significant progression of atrophy in HD before the onset of significant clinical decline is now demonstrable with longitudinal statistical imaging. Such measures could be used to assess the efficacy of potential disease modifying drugs in slowing the progression of pathology before confirmed clinical onset of HD.

Movement disorder emergencies

Movement disorders may present acutely, and failure to recognize and exclude important differential diagnoses can result in significant morbidity or mortality. Unfortunately, much of the literature pertaining to this topic is scattered and not easily accessible. This review aims to address this deficit. Movement disorder emergencies are discussed according to their most likely mode of presentation. Diagnostic considerations and early management principles are reviewed, along with appropriate pathophysiology where relevant.