Amnesia in frontotemporal dementia: shedding light on the Geneva historical data

The UT health Psychological Autopsy Interview Schedule (UTH- PAIS) - Description and reliability of diagnoses and transdiagnostic personality measures

Few studies have used psychological autopsies to evaluate large and diverse populations on transdiagnostically relevant variables such as personality, temperament, and trauma exposure; rather, they tend to focus on specific psychiatric disorders or manner of death. We therefore developed the UT Health Psychological Autopsy Interview Schedule (UTH-PAIS). The measure is described, and our results show that the PAIS diagnoses and dimensions can be reliably assessed. Furthermore, we were able to show that our sample of donated brains overall matches the demographic characteristics of a larger pool of individuals receiving a medical autopsy. In the Discussion we review the strengths and potential limitations of the study and outline in which context the PAIS will prove to be useful.

Frontotemporal lobar degeneration with TAR DNA-binding protein 43 (TDP-43): its journey of more than 100 years

Frontotemporal lobar degeneration (FTLD) with TDP-43-immunoreactive inclusions (FTLD-TDP) is a neurodegenerative disease associated with clinical, genetic, and neuropathological heterogeneity. An association between TDP-43, FTLD and amyotrophic lateral sclerosis (ALS) was first described in 2006. However, a century before immunohistochemistry existed, atypical dementias displaying behavioral, language and/or pyramidal symptoms and showing non-specific FTLD with superficial cortical neuronal loss, gliosis and spongiosis were often confused with Alzheimer's or Pick's disease. Initially this pathology was termed dementia lacking distinctive histopathology (DLDH), but this was later renamed when ubiquitinated inclusions originally found in ALS were also discovered in (DLDH), thus warranting a recategorization as FTLD-U (ubiquitin). Finally, the ubiquitinated protein was identified as TDP-43, which aggregates in cortical, subcortical, limbic and brainstem neurons and glial cells. The topography and morphology of TDP-43 inclusions associate with specific clinical syndromes and genetic mutations which implies different pathomechanisms that are yet to be discovered; hence, the TDP-43 journey has actually just begun. In this review, we describe how FTLD-TDP was established and defined clinically and neuropathologically throughout the past century.

Differential Diagnosis of Behavioral Variant and Semantic Variant of Frontotemporal Dementia Using Visual Rating Scales

BACKGROUND

Frontotemporal dementia (FTD) represents the second most frequent early onset of dementia in people younger than 65 years. The main syndromes encompassed by the term FTD are behavioral variant of Frontotemporal dementia (bvFTD), non-fluent variant primary progressive aphasia (nfvPPA) and semantic variant (SD).

AIMS

To assess the bvFTD and SD, which represent the most common subtypes of FTD, using visual rating scales.

METHODS

Brain MRI exams of 77 patients either with bvFTD (n=43) or SD (n=34) were evaluated. The rating scales used were: Global cortical atrophy (GCA), Fazekas Scale: periventricular (PV) and white matter (WM) changes, Koedam rating scale and visual scales regarding specific cortical regions: dorsofrontal (DF), orbitofrontal (OF), anterior cingulate (AC), basal ganglia (BG), anterior- temporal (AT), insula, lateral-temporal (LT), entorhinal (ERC), perirhinal (PRC), anterior fusiform( AF), anterior hippocampus (AHIP) and posterior hippocampus (PHIP). Both Left (L) and Right (R) hemispheres were evaluated.

RESULTS

R-OF (p=0.059), L-OF (p<0.0005), L-AT (p=0.047) and L-AHIP (p=0.007) have a statistically significant effect on the variable occurrence of SD compared to bvFTD. The indicators with the highest value of the area under the curve (AUC) were R-AC (0.829), L-OF (0.808), L-AC (0.791) and L-AF (0.778). Highest sensitivity was achieved by R-OF (97%) and L-AF (75%). Highest specificity was achieved by L-OF (95%), L-AT (91%) followed by R-AC (84%). Best combination of sensitivity and specificity was achieved by L-AF (74%-79%), L-OF (56%-95%) and R-OF (97%-42%). Best combination of PPV and NPV was achieved by L-OF (90%-73%), LAT (83%-72%) and R-AC (77%-77%).

CONCLUSION

Visual rating scales can be a practical diagnostic tool in the characterization of patterns of atrophy in FTLD and may be used as an alternative to highly technical methods of quantification.

So Close Yet So Far: Executive Contribution to Memory Processing in Behavioral Variant Frontotemporal Dementia

BACKGROUND

Memory impairment in behavioral variant frontotemporal dementia (bvFTD) is traditionally considered to be mild and attributed to prefrontal cortex dysfunction. Recent studies, however, indicated that some patients can present with a memory impairment of the hippocampal type, showing storage and consolidation deficits in addition to the more executive/prefrontal related encoding and strategic difficulties.

OBJECTIVE

This study aimed to study the relationship between executive functions (EF) and memory processes in bvFTD via a data-driven approach.

METHOD

Participants consisted of 71 bvFTD (among which 60.6% had a lumbar puncture showing non-Alzheimer biomarker profile) and 60 controls (among which 45% had amyloid imaging showing a normal profile). EF were assessed by the Frontal Assessment Battery, semantic/lexical verbal fluency tests, and forward/backward digit spans. Patients were split into amnestic (n = 33) and non-amnestic (n = 38) subgroups based on normative data (total recall score) from the Free and Cued Selective Reminding Test (FCSRT). Relationships between FCSRT subscores and EF measures were explored through hierarchical clustering analysis, partial correlation analysis with an EF component, and automated linear modeling.

RESULTS

Convergent findings across the statistical approaches show that, overall, memory performance was independent from EF in bvFTD whereas the relationship was stronger in controls. Indeed, in bvFTD, memory performance did not cluster with EF, was not correlated with the EF component, and was only partially (4% - 12.7%) predicted by EF.

DISCUSSION

These findings show that executive dysfunctions cannot solely explain the memory deficits occurring in bvFTD. Indeed, some patients present with a genuine amnesia affecting storage and consolidation abilities, which are independent from executive dysfunctions. On the clinical level, this study highlights the importance of revising the neuropsychological diagnosis criteria for bvFTD.

Neuropsychiatric Symptoms in a Cohort of Patients with Frontotemporal Dementia: Our Experience

INTRODUCTION

About 20-50% of relatively young onset dementia belongs to frontotemporal type. Most of these patients are diagnosed as psychiatric illness as their memory and instrumental activities of daily living remain unaltered till late and most of these patients do not qualify for dementia by the Diagnostic and Statistical Manual of Mental Disorders-IV criteria. In this study, we analyzed the behavioral symptoms in our patients with radiologically and neuropsychologically proven as probable behavioral variant of frontotemporal dementia (FTD).

PATIENTS AND METHODS

Twenty patients qualifying the International Consensus Criteria were included and evaluated using National Institute of Mental Health and Neurosciences neuropsychological battery in addition to all mandatory dementia workup.

RESULTS

The mean age was 53.9 ± 9.9 years and the mean duration of illness was 2 ± 1.3 years. Sixty percent of them were <60 years. There were 9 males and 11 females. Most common heralding symptom noticed in 85% of the patients was irritability and aggression as against apathy in 100% in western studies. Memory impairment was found in only 11.1% as against 25% in western studies. Disinhibition, eating problems, stereotyped behavior, delusions, and paranoia were comparable between the study population and literature.

DISCUSSION AND CONCLUSION

There are minor variations in the neuropsychological manifestations in our patients compared to western population. Agitation and aggression are more and memory impairment is very less making the diagnosis of FTD possible only if there is a high degree of suspicion. These symptoms are less amenable for pharmacotherapy and therefore, there is a need to explore the benefits of nonpharmacological treatment options such as yoga and meditation.