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Right temporal variant of frontotemporal dementia (rtv-FTD) represents an uncommon and recently described frontotemporal dementia (FTD) entity presenting with symptoms in many ways comparable to those of the frontal or behavioral variant of FTD (bv-FTD). The aims of this study were to explore the timing of cognitive and behavioral symptoms of rtv-FTD, and to compare the distinct cognitive deficits including prosopagnosia and behavioral symptoms of rtv-FTD patients with those observed in bv-FTD patients. We reviewed the records of 105 patients clinically diagnosed with FTD. A total of 7 patients (5 men/2 women) with FTD and marked right temporal atrophy in magnetic resonance imaging (MRI) were detected. Clinical features were compared with those observed in a group of 22 age-matched patients (16 men/6 women) with FTD and predominant frontal lobe atrophy. The main presenting symptoms of rtv-FTD were prosopagnosia, apathy, and episodic memory impairment. In contrast, social awkwardness and compulsive behaviors were dominant in later stages of the disease together with disinhibition and loss of insight with a marked personality change. Although the cognitive and behavioral profiles of patients with right temporal or frontal lobes atrophy present substantial similarities, each subtype has a number of distinct characteristics. It appears that prosopagnosia, obsessive behaviors, and psychotic symptoms are more prominent in rtv-FTD patients.

Objectives: To validate a visual rating scale of frontal atrophy with quantitative imaging and study its association with clinical status, APOE ε4, CSF biomarkers, and cognition.Methods: The AddNeuroMed and ADNI cohorts were combined giving a total of 329 healthy controls, 421 mild cognitive impairment patients, and 286 Alzheimer's disease (AD) patients. Thirty-four patients with frontotemporal dementia (FTD) were also included. Frontal atrophy was assessed with the frontal sub-scale of the global cortical atrophy scale (GCA-F) on T1-weighted images. Automated imaging markers of cortical volume, thickness, and surface area were evaluated. Manual tracing was also performed.Results: The GCA-F scale reliably reflects frontal atrophy, with orbitofrontal, dorsolateral, and motor cortices being the regions contributing most to the GCA-F ratings. GCA-F primarily reflects reductions in cortical volume and thickness, although it was able to detect reductions in surface area too. The scale showed significant associations with clinical status and cognition.Conclusion: The GCA-F scale may have implications for clinical practice as supportive diagnostic tool for disorders demonstrating predominant frontal atrophy such as FTD and the executive presentation of AD. We believe that GCA-F is feasible for use in clinical routine for the radiological assessment of dementia and other disorders.Key Points: • The GCA-F visual rating scale reliably reflects frontal brain atrophy. • Orbitofrontal, dorsolateral, and motor cortices are the most contributing regions. • GCA-F shows significant associations with clinical status and cognition. • GCA-F may be supportive diagnostic tool for disorders demonstrating predominant frontal atrophy. • GCA-F may be feasible for use in radiological routine. [ABSTRACT FROM AUTHOR]

Background Atrophy in the medial temporal lobe, frontal lobe and posterior cortex can be measured with visual rating scales such as the medial temporal atrophy ( MTA), global cortical atrophy - frontal subscale ( GCA-F) and posterior atrophy ( PA) scales, respectively. However, practical cut-offs are urgently needed, especially now that different presentations of Alzheimer's disease ( AD) are included in the revised diagnostic criteria. Aims The aim of this study was to generate a list of practical cut-offs for the MTA, GCA-F and PA scales, for both diagnosis of AD and determining prognosis in mild cognitive impairment ( MCI), and to evaluate the influence of key demographic and clinical factors on these cut-offs. Methods AddNeuroMed and ADNI cohorts were combined giving a total of 1147 participants (322 patients with AD, 480 patients with MCI and 345 control subjects). The MTA, GCA-F and PA scales were applied and a broad range of cut-offs was evaluated. Results The MTA scale showed better diagnostic and predictive performances than the GCA-F and PA scales. Age, apolipoprotein E ( ApoE) ε4 status and age at disease onset influenced all three scales. For the age ranges 45-64, 65-74, 75-84 and 85-94 years, the following cut-offs should be used. MTA: ≥1.5, ≥1.5, ≥2 and ≥2.5; GCA-F, ≥1, ≥1, ≥1 and ≥1; and PA, ≥1, ≥1, ≥1 and ≥1, respectively, with an adjustment for early-onset ApoE ε4 noncarrier AD patients ( MTA: ≥2, ≥2, ≥3 and ≥3; and GCA-F: ≥1, ≥1, ≥2 and ≥2, respectively). Conclusions If successfully validated in clinical settings, the list of practical cut-offs proposed here might be useful in clinical practice. Their use might also (i) promote research on atrophy subtypes, (ii) increase the understanding of different presentations of AD, (iii) improve diagnosis and prognosis and (iv) aid population selection and enrichment for clinical trials. [ABSTRACT FROM AUTHOR]

Right temporal variant of frontotemporal dementia (rtv-FTD) represents an uncommon and recently described frontotemporal dementia (FTD) entity presenting with symptoms in many ways comparable to those of the frontal or behavioral variant of FTD (bv-FTD). The aims of this study were to explore the timing of cognitive and behavioral symptoms of rtv-FTD, and to compare the distinct cognitive deficits including prosopagnosia and behavioral symptoms of rtv-FTD patients with those observed in bv-FTD patients. We reviewed the records of 105 patients clinically diagnosed with FTD. A total of 7 patients (5 men/2 women) with FTD and marked right temporal atrophy in magnetic resonance imaging (MRI) were detected. Clinical features were compared with those observed in a group of 22 age-matched patients (16 men/6 women) with FTD and predominant frontal lobe atrophy. The main presenting symptoms of rtv-FTD were prosopagnosia, apathy, and episodic memory impairment. In contrast, social awkwardness and compulsive behaviors were dominant in later stages of the disease together with disinhibition and loss of insight with a marked personality change. Although the cognitive and behavioral profiles of patients with right temporal or frontal lobes atrophy present substantial similarities, each subtype has a number of distinct characteristics. It appears that prosopagnosia, obsessive behaviors, and psychotic symptoms are more prominent in rtv-FTD patients.

Long-term intake of excessive alcohol causes various forms of brain damage, most of which are now visualized by magnetic resonance imaging (MRI) and proved to be contributing to the early onset of dementia. Bi-frontal atrophy has a unique position among these various forms of damage because of its lobar conformation localized only to the higher cortex, and because the same kind of atrophy is also seen in dyslipidemic patients like hypercholesterolemia. Multiple logistic regression analysis of 3100 subjects with MRI revealed no other significant group for this finding. Morphological features of this type of atrophy and its rate of progression are described in this paper, and computerized image analysis showed that this atrophy seems to depend mainly on the decrease of white matter. However, a common biochemical factor underlying the frontal atrophy in these two groups has not yet been identified. Importantly, dyslipidemic patients also show some type of T2 high white matter changes, which are not seen in ‘pure’ alcoholics. For dyslipidemic patients, this white matter change, which seems to be the degradation of myelin sheath, is another basis for early dementia. Although the author can propose a new concept of ‘dyslipidemic dementia’ due to frontal atrophy and white matter damage, details of its mechanism and its relation to alcoholism are left to future investigations. [ABSTRACT FROM AUTHOR]