-
Brain : a Journal of Neurology Nov 2022Focal anterior temporal lobe degeneration often preferentially affects the left or right hemisphere. While patients with left-predominant anterior temporal lobe atrophy...
Focal anterior temporal lobe degeneration often preferentially affects the left or right hemisphere. While patients with left-predominant anterior temporal lobe atrophy show severe anomia and verbal semantic deficits and meet criteria for semantic variant primary progressive aphasia and semantic dementia, patients with early right anterior temporal lobe atrophy are more difficult to diagnose as their symptoms are less well understood. Focal right anterior temporal lobe atrophy is associated with prominent emotional and behavioural changes, and patients often meet, or go on to meet, criteria for behavioural variant frontotemporal dementia. Uncertainty around early symptoms and absence of an overarching clinico-anatomical framework continue to hinder proper diagnosis and care of patients with right anterior temporal lobe disease. Here, we examine a large, well-characterized, longitudinal cohort of patients with right anterior temporal lobe-predominant degeneration and propose new criteria and nosology. We identified individuals from our database with a clinical diagnosis of behavioural variant frontotemporal dementia or semantic variant primary progressive aphasia and a structural MRI (n = 478). On the basis of neuroimaging criteria, we defined three patient groups: right anterior temporal lobe-predominant atrophy with relative sparing of the frontal lobes (n = 46), frontal-predominant atrophy with relative sparing of the right anterior temporal lobe (n = 79) and left-predominant anterior temporal lobe-predominant atrophy with relative sparing of the frontal lobes (n = 75). We compared the clinical, neuropsychological, genetic and pathological profiles of these groups. In the right anterior temporal lobe-predominant group, the earliest symptoms were loss of empathy (27%), person-specific semantic impairment (23%) and complex compulsions and rigid thought process (18%). On testing, this group exhibited greater impairments in Emotional Theory of Mind, recognition of famous people (from names and faces) and facial affect naming (despite preserved face perception) than the frontal- and left-predominant anterior temporal lobe-predominant groups. The clinical symptoms in the first 3 years of the disease alone were highly sensitive (81%) and specific (84%) differentiating right anterior temporal lobe-predominant from frontal-predominant groups. Frontotemporal lobar degeneration-transactive response DNA binding protein (84%) was the most common pathology of the right anterior temporal lobe-predominant group. Right anterior temporal lobe-predominant degeneration is characterized by early loss of empathy and person-specific knowledge, deficits that are caused by progressive decline in semantic memory for concepts of socioemotional relevance. Guided by our results, we outline new diagnostic criteria and propose the name, 'semantic behavioural variant frontotemporal dementia', which highlights the underlying cognitive mechanism and the predominant symptomatology. These diagnostic criteria will facilitate early identification and care of patients with early, focal right anterior temporal lobe degeneration as well as in vivo prediction of frontotemporal lobar degeneration-transactive response DNA binding protein pathology.
Topics: Humans; Frontotemporal Dementia; Semantics; Frontotemporal Lobar Degeneration; Atrophy; Magnetic Resonance Imaging; Aphasia, Primary Progressive; DNA-Binding Proteins; Neuropsychological Tests
PubMed: 35731122
DOI: 10.1093/brain/awac217 -
Current Neurology and Neuroscience... Oct 2021Color provides important information about the identity of the objects we encounter. After early processing stages in the retinal cones, thalamus, and occipital cortex,... (Review)
Review
PURPOSE OF REVIEW
Color provides important information about the identity of the objects we encounter. After early processing stages in the retinal cones, thalamus, and occipital cortex, retinal signals reach the ventral temporal cortex for high-level color and object processing, which links color perception with top-down expectations and knowledge. In the language-dominant hemisphere, some of these regions communicate with the language systems; by assigning verbal labels to percepts, these circuits speed up stimulus categorization, and permit fast and accurate inter-individual communication. This paper provides a review of color processing deficits, from dysfunction of wavelength discrimination in the retinal photoreceptors to deficits of high-level processing in the ventral temporal cortex.
RECENT FINDINGS
Neuroimaging evidence defined the existence and localization of color-preferring domains in the ventral occipito-temporal cortex. Evidence from the performance of a brain-damaged patient with color anomia but preserved color categorization demonstrated the independence of color categorization from color naming in the adult brain. Evidence from patients with brain damage suggests that high-level color processing may be divided into at least three functional domains: perceptual color experience, color naming, and color knowledge.
Topics: Anomia; Color Perception; Color Vision; Humans; Magnetic Resonance Imaging; Occipital Lobe
PubMed: 34606018
DOI: 10.1007/s11910-021-01137-8 -
Cortex; a Journal Devoted To the Study... Nov 2021
Topics: Anomia; Humans; Neuropsychological Tests
PubMed: 34610869
DOI: 10.1016/j.cortex.2021.09.001 -
Handbook of Clinical Neurology 2022The ventral temporal cortex hosts key regions for the high-level visual processing of object shape and color. These areas represent nodes of large-scale neural circuits... (Review)
Review
The ventral temporal cortex hosts key regions for the high-level visual processing of object shape and color. These areas represent nodes of large-scale neural circuits dedicated to object recognition. In the language-dominant hemisphere, some of these regions communicate with the language systems; by assigning verbal labels to percepts, these circuits speedup stimulus categorization, and permit fast and accurate interindividual communication. By impairing the functioning of these circuits, neurological damage may provoke disabling disorders of the processing of visual objects and of their colors. Brain damage of vascular, degenerative, toxic, or traumatic origin can induce deficits at different levels of visual processing, from the building of shape- or wavelength-invariant percepts, to their connections with semantic knowledge and with the appropriate lexical entry. After an overview of the neuroimaging of domain-preferring regions for object shape and color in the ventral temporal cortex, this chapter reviews evidence from historical and recent cases of acquired visual agnosia and color processing deficits. A recurrent motif emerging from patients' patterns of performance and lesion locations is the existence of caudo-rostral gradients in the ventral occipito-temporal cortex, spanning from more perceptual to more cognitive stages of processing.
Topics: Agnosia; Color; Humans; Language; Temporal Lobe; Visual Perception
PubMed: 35964971
DOI: 10.1016/B978-0-12-823493-8.00022-5 -
Brain and Language Sep 2023We systematically reviewed the literature on neural changes following anomia treatment post-stroke. We conducted electronic searches of CINAHL, Cochrane Trials, Embase,... (Review)
Review
We systematically reviewed the literature on neural changes following anomia treatment post-stroke. We conducted electronic searches of CINAHL, Cochrane Trials, Embase, Ovid MEDLINE, MEDLINE-in-Process and PsycINFO databases; two independent raters assessed all abstracts and full texts. Accepted studies reported original data on adults with post-stroke aphasia, who received behavioural treatment for anomia, and magnetic resonance brain imaging (MRI) pre- and post-treatment. Search results yielded 2481 citations; 33 studies were accepted. Most studies employed functional MRI and the quality of reporting neuroimaging methodology was variable, particularly for pre-processing steps and statistical analyses. The most methodologically robust data were synthesized, focusing on pre- versus post-treatment contrasts. Studies more commonly reported increases (versus decreases) in activation following naming therapy, primarily in the left supramarginal gyrus, and left/bilateral precunei. Our findings highlight the methodological heterogeneity across MRI studies, and the paucity of robust evidence demonstrating direct links between brain and behaviour in anomia rehabilitation.
Topics: Adult; Humans; Anomia; Aphasia; Neuroimaging; Neuronal Plasticity; Stroke
PubMed: 37633250
DOI: 10.1016/j.bandl.2023.105300 -
Otolaryngology--head and Neck Surgery :... Jul 2020There is accumulating anecdotal evidence that anosmia and dysgeusia are associated with the COVID-19 pandemic. To investigate their relationship to SARS-CoV2 infection,... (Review)
Review
There is accumulating anecdotal evidence that anosmia and dysgeusia are associated with the COVID-19 pandemic. To investigate their relationship to SARS-CoV2 infection, the American Academy of Otolaryngology-Head and Neck Surgery developed the COVID-19 Anosmia Reporting Tool for Clinicians for the basis of this pilot study. This tool allows health care providers to confidentially submit cases of anosmia and dysgeusia related to COVID-19. We analyzed the first 237 entries, which revealed that anosmia was noted in 73% of patients prior to COVID-19 diagnosis and was the initial symptom in 26.6%. Some improvement was noted in 27% of patients, with a mean time to improvement of 7.2 days in this group (85% of this group improved within 10 days). Our findings suggest that anomia can be a presenting symptom of COVID-19, consistent with other emerging international reports. Anosmia may be critical in timely identification of individuals infected with SARS-CoV2 who may be unwittingly transmitting the virus.
Topics: Betacoronavirus; COVID-19; Coronavirus Infections; Global Health; Humans; Incidence; Olfaction Disorders; Otolaryngology; Pandemics; Pneumonia, Viral; SARS-CoV-2; Smell
PubMed: 32340555
DOI: 10.1177/0194599820922992 -
Medical Sciences (Basel, Switzerland) Nov 2023Frontotemporal dementia (FTD) is a neurodegenerative disorder characterized by progressive impairments in behavior, executive function, and language, primarily affecting... (Review)
Review
Frontotemporal dementia (FTD) is a neurodegenerative disorder characterized by progressive impairments in behavior, executive function, and language, primarily affecting individuals under the age of 65. This disorder is associated with expressive and receptive anomia, word comprehension deficits, and behavioral symptoms such as apathy, loss of empathy, and disinhibition, all of which closely correlate with functional impairment in daily activities. Despite substantial efforts, research on occupational therapy (OT) interventions has yet to demonstrate clear benefits in managing the disease. The aim of this study is to investigate OT interventions and assess their efficacy, with a specific focus on individuals suffering from FTD. We systematically conducted searches on two databases, namely Medline and Science Direct, spanning a ten-year period from 2003 to 2023, in accordance with the PRISMA guidelines. Eleven studies met the inclusion criteria. OT interventions targeted both patients and caregivers and yielded significant positive improvements in their lives. A key focus of these interventions was to teach acceptable alternatives to the behaviors exhibited by FTD patients, as these behaviors are strongly influenced by the disease itself. OT contributes positively to enhancing the quality of life of FTD patients and alleviating the caregiving burden experienced by those providing long-term care to these patients.
Topics: Humans; Frontotemporal Dementia; Occupational Therapy; Quality of Life; Pick Disease of the Brain; Caregivers
PubMed: 37987326
DOI: 10.3390/medsci11040071 -
American Journal of Speech-language... Jan 2022Repetition priming has been suggested as a method for targeting implicit processes in anomia treatment. Prior studies have used masked priming for this purpose. This...
PURPOSE
Repetition priming has been suggested as a method for targeting implicit processes in anomia treatment. Prior studies have used masked priming for this purpose. This study extends that work with visible primes, a more clinically feasible approach.
METHOD
This study used a single-subject design across three participants with aphasia. Treatment involved repeated exposure to identity primes (trained condition) or sham primes (untrained condition) paired with pictures. Analyses assessed acquisition effects for trained items and untrained items that were seen during the training period, generalization to untrained items that had not been seen, and generalization to broader language skills, immediately and 3 months post-treatment.
RESULTS
All participants improved in naming trained items immediately after treatment, with greater improvements for trained than for untrained items. All participants maintained some degree of improvement on trained items 3 months post-treatment, although the degree differed across participants. Inconsistent generalization occurred to unexposed items. Improvements were noted in some areas of broader language ability, although these varied.
CONCLUSIONS
These data suggest a repetition priming treatment paradigm may increase naming accuracy for individuals with anomia and may benefit other aspects of language. Participant factors may have influenced response to treatment. Directions for future investigation are discussed.
Topics: Anomia; Aphasia; Humans; Language Therapy; Repetition Priming; Semantics
PubMed: 34029115
DOI: 10.1044/2021_AJSLP-20-00278 -
The Neuroscientist : a Review Journal... Jun 2020Color provides valuable information about the environment, yet the exact mechanisms explaining how colors appear to us remain poorly understood. Retinal signals are... (Review)
Review
Color provides valuable information about the environment, yet the exact mechanisms explaining how colors appear to us remain poorly understood. Retinal signals are processed in the visual cortex through high-level mechanisms that link color perception with top-down expectations and knowledge. Here, we review the neuroimaging evidence about color processing in the brain, and how it is affected by acquired brain lesions in humans. Evidence from patients with brain-damage suggests that high-level color processing may be divided into at least three modules: perceptual color experience, color naming, and color knowledge. These modules appear to be functionally independent but richly interconnected, and serve as cortical relays linking sensory and semantic information, with the final goal of directing object-related behavior. We argue that the relations between colors and their objects are key mechanisms to understand high-level color processing.
Topics: Agnosia; Anomia; Cerebral Cortex; Color Perception; Color Vision Defects; Humans; Visual Pathways
PubMed: 31691627
DOI: 10.1177/1073858419882621