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Brain Sciences Feb 2022Dementia is a neurodegenerative disease that leads to the development of cognitive deficits, such as aphasia, apraxia, and agnosia. It is currently considered one of the...
Dementia is a neurodegenerative disease that leads to the development of cognitive deficits, such as aphasia, apraxia, and agnosia. It is currently considered one of the most significant major medical problems worldwide, primarily affecting the elderly. This condition gradually impairs the patient's cognition, eventually leading to the inability to perform everyday tasks without assistance. Since dementia is an incurable disease, early detection plays an important role in delaying its progression. Because of this, tools and methods have been developed to help accurately diagnose patients in their early stages. State-of-the-art methods have shown that the use of syntactic-type linguistic features provides a sensitive and noninvasive tool for detecting dementia in its early stages. However, these methods lack relevant semantic information. In this work, we propose a novel methodology, based on the semantic features approach, by using sentence embeddings computed by Siamese BERT networks (SBERT), along with support vector machine (SVM), K-nearest neighbors (KNN), random forest, and an artificial neural network (ANN) as classifiers. Our methodology extracted 17 features that provide demographic, lexical, syntactic, and semantic information from 550 oral production samples of elderly controls and people with Alzheimer's disease, provided by the DementiaBank Pitt Corpus database. To quantify the relevance of the extracted features for the dementia classification task, we calculated the mutual information score, which demonstrates a dependence between our features and the MMSE score. The experimental classification performance metrics, such as the accuracy, precision, recall, and F1 score (77, 80, 80, and 80%, respectively), validate that our methodology performs better than syntax-based methods and the BERT approach when only the linguistic features are used.
PubMed: 35204032
DOI: 10.3390/brainsci12020270 -
Brain Sciences Oct 2021Stroke is the leading cause of cortical deafness (CD), the most severe form of central hearing impairment. CD remains poorly characterized and perhaps underdiagnosed. We... (Review)
Review
BACKGROUND
Stroke is the leading cause of cortical deafness (CD), the most severe form of central hearing impairment. CD remains poorly characterized and perhaps underdiagnosed. We perform a systematic review to describe the clinical and radiological features of stroke-associated CD.
METHODS
PubMed and the Web of Science databases were used to identify relevant publications up to 30 June 2021 using the MeSH terms: "deafness" and "stroke", or "hearing loss" and "stroke" or "auditory agnosia" and "stroke".
RESULTS
We found 46 cases, caused by bilateral lesions within the central auditory pathway, mostly located within or surrounding the superior temporal lobe gyri and/or the Heschl's gyri (30/81%). In five (13.51%) patients, CD was caused by the subcortical hemispheric and in two (0.05%) in brainstem lesions. Sensorineural hearing loss was universal. Occasionally, a misdiagnosis by peripheral or psychiatric disorders occurred. A few (20%) had clinical improvement, with a regained oral conversation or evolution to pure word deafness (36.6%). A persistent inability of oral communication occurred in 43.3%. A full recovery of conversation was restricted to patients with subcortical lesions.
CONCLUSIONS
Stroke-associated CD is rare, severe and results from combinations of cortical and subcortical lesions within the central auditory pathway. The recovery of functional hearing occurs, essentially, when caused by subcortical lesions.
PubMed: 34827382
DOI: 10.3390/brainsci11111383 -
NeuroImage Jul 2021Lesions to posterior temporo-parietal brain regions are associated with deficits in perception of global, hierarchical shapes, but also with impairments in the...
Lesions to posterior temporo-parietal brain regions are associated with deficits in perception of global, hierarchical shapes, but also with impairments in the processing of objects presented under demanding viewing conditions. Evidence from neuroimaging studies and lesion patterns observed in patients with simultanagnosia and agnosia for object orientation suggest similar brain regions to be involved in perception of global shapes and processing of objects in atypical ('non-canonical') orientation. In a localizer experiment, we identified individual temporo-parietal brain areas involved in global shape perception and found significantly higher BOLD signals during the processing of non-canonical compared to canonical objects. In a multivariate approach, we demonstrated that posterior temporo-parietal brain areas show distinct voxel patterns for non-canonical and canonical objects and that voxel patterns of global shapes are more similar to those of objects in non-canonical compared to canonical viewing conditions. These results suggest that temporo-parietal brain areas are not only involved in global shape perception but might serve a more general mechanism of complex object perception. Our results challenge a strict attribution of object processing to the ventral visual stream by suggesting specific dorsal contributions in more demanding viewing conditions.
Topics: Adult; Female; Humans; Magnetic Resonance Imaging; Male; Parietal Lobe; Photic Stimulation; Recognition, Psychology; Temporal Lobe; Visual Perception; Young Adult
PubMed: 33757908
DOI: 10.1016/j.neuroimage.2021.117982 -
Cortex; a Journal Devoted To the Study... Feb 2022An 84-year-old man manifested false recognition/misidentification of unfamiliar person after cardiogenic cerebral infarction. He had good visual and hearing acuity, no...
An 84-year-old man manifested false recognition/misidentification of unfamiliar person after cardiogenic cerebral infarction. He had good visual and hearing acuity, no hemianopsia, unilateral spatial neglect and visual object agnosia. However, he was unable to remember faces of his rehabilitation therapists, and repeatedly misidentified other patients' visitors and therapists as his family members and friends, without recognizing his mistakes. General cognitive function was preserved with Hasegawa dementia score-revised (HDS-R) 25/30 (cut-off score 20). In terms of recognition of faces, tasks not requiring recognition of facial identity, such as interpreting facial emotions, and gender and age assessment, were relatively preserved, but recognition of family members and celebrities was severely impaired, and matching unfamiliar faces was slightly impaired. Semantic information of family and friends was retained. Although his symptoms resembled associative prosopagnosia, they differed from general associative prosopagnosia in having phonagnosia. MRI lesions were localized in the frontal and temporal lobes including the right anterior temporal lobe, and not in the right occipital and temporal lobes considered to the lesion site of multimodal people recognition disorders manifesting inability of utilization of visual (face) and auditory (voice) cues for person identification. In addition to the facial cognitive impairment, impaired exploratory (monitoring) function of the frontal lobe on the temporal lobe may also contribute to the false recognition/misidentification of this case.
Topics: Aged, 80 and over; Agnosia; Cerebral Infarction; Cognition; Humans; Male; Prosopagnosia; Temporal Lobe
PubMed: 35051711
DOI: 10.1016/j.cortex.2021.12.005 -
Neuroscience and Biobehavioral Reviews Mar 2024Face-selective regions in the human ventral occipito-temporal cortex (VOTC) have been defined for decades mainly with functional magnetic resonance imaging. This... (Review)
Review
Face-selective regions in the human ventral occipito-temporal cortex (VOTC) have been defined for decades mainly with functional magnetic resonance imaging. This face-selective VOTC network is traditionally divided in a posterior 'core' system thought to subtend face perception, and regions of the anterior temporal lobe as a semantic memory component of an extended general system. In between these two putative systems lies the anterior fusiform gyrus and surrounding sulci, affected by magnetic susceptibility artifacts. Here we suggest that this methodological gap overlaps with and contributes to a conceptual gap between (visual) perception and semantic memory for faces. Filling this gap with intracerebral recordings and direct electrical stimulation reveals robust face-selectivity in the anterior fusiform gyrus and a crucial role of this region, especially in the right hemisphere, in identity recognition for both familiar and unfamiliar faces. Based on these observations, we propose an integrated theoretical framework for human face (identity) recognition according to which face-selective regions in the anterior fusiform gyrus join the dots between posterior and anterior cortical face memories.
Topics: Humans; Prosopagnosia; Temporal Lobe; Facial Recognition; Recognition, Psychology; Magnetic Resonance Imaging; Pattern Recognition, Visual; Brain Mapping; Photic Stimulation
PubMed: 38191080
DOI: 10.1016/j.neubiorev.2024.105535 -
Brain Imaging and Behavior Jun 2022Simultanagnosia is a common symptom of posterior cortical atrophy, and its association with brain structural and functional changes remains unclear. In our study, 18...
Simultanagnosia is a common symptom of posterior cortical atrophy, and its association with brain structural and functional changes remains unclear. In our study, 18 posterior cortical atrophy patients with simultanagnosia, 29 patients with Alzheimer's disease and 20 cognitively normal controls were recruited and subjected to full neuropsychological evaluation, including simultanagnosia tests, and structural and resting-state functional MRI. The gray matter volume was assessed by voxel-based morphometry, while the intrinsic functional connectivity was evaluated using the reduced gray matter volume regions of interest as the seed. In contrast to the patients with Alzheimer's disease, those with posterior cortical atrophy showed the following: (1) markedly lower simultanagnosia test scores, (2) an altered regional gray matter volume of the left middle occipital gyrus and ventral occipital areas, and (3) lowered intrinsic functional connectivity with the left middle occipital gyrus, left lingual gyrus and right middle occipital gyrus separately. Additionally, the gray matter volume of the left middle occipital gyrus and left inferior occipital gyrus were each correlated with simultanagnosia in posterior cortical atrophy patients. The intrinsic functional connectivity of the left middle occipital gyrus with the right superior occipital gyrus and that of the right middle occipital gyrus with the left superior parietal gyrus were also correlated with simultanagnosia in posterior cortical atrophy patients. In summary, this study indicated that simultanagnosia is associated with gray matter reductions and decreased functional connectivity in the left middle occipital gyrus and the left inferior occipital gyrus in patients with posterior cortical atrophy.
Topics: Alzheimer Disease; Atrophy; Brain; Brain Mapping; Gray Matter; Humans; Magnetic Resonance Imaging
PubMed: 34787788
DOI: 10.1007/s11682-021-00568-8 -
Cortex; a Journal Devoted To the Study... May 2021The organisational principles of the visual ventral stream are still highly debated, particularly the relative association/dissociation between word and face recognition...
The organisational principles of the visual ventral stream are still highly debated, particularly the relative association/dissociation between word and face recognition and the degree of lateralisation of the underlying processes. Reports of dissociations between word and face recognition stem from single case-studies of category selective impairments, and neuroimaging investigations of healthy participants. Despite the historical reliance on single case-studies, more recent group studies have highlighted a greater commonality between word and face recognition. Studying individual patients with rare selective deficits misses (a) important variability between patients, (b) systematic associations between task performance, and (c) patients with mild, severe and/or non-selective impairments; meaning that the full spectrum of deficits is unknown. The Back of the Brain project assessed the range and specificity of visual perceptual impairment in 64 patients with posterior cerebral artery stroke recruited based on lesion localization and not behavioural performance. Word, object, and face processing were measured with comparable tests across different levels of processing to investigate associations and dissociations across domains. We present two complementary analyses of the extensive behavioural battery: (1) a data-driven analysis of the whole patient group, and (2) a single-subject case-series analysis testing for deficits and dissociations in each individual patient. In both analyses, the general organisational principle was of associations between words, objects, and faces even following unilateral lesions. The majority of patients either showed deficits across all domains or in no domain, suggesting a spectrum of visuo-perceptual deficits post stroke. Dissociations were observed, but they were the exception and not the rule: Category-selective impairments were found in only a minority of patients, all of whom showed disproportionate deficits for words. Interestingly, such selective word impairments were found following both left and right hemisphere lesions. This large-scale investigation of posterior cerebral artery stroke patients highlights the bilateral representation of visual perceptual function.
Topics: Brain; Humans; Temporal Lobe
PubMed: 33770511
DOI: 10.1016/j.cortex.2021.01.021 -
Lin Chuang Er Bi Yan Hou Tou Jing Wai... Jun 2021This study aimed to provide better understanding of the otolaryngologic features, combined with ophthalmologic and neurologic characteristics in mitochondrial...
This study aimed to provide better understanding of the otolaryngologic features, combined with ophthalmologic and neurologic characteristics in mitochondrial encephalomyopathy(MEM), and to help ENT and auditory practitioner making correct diagnosis as well. Twenty-eight patients with MEM were enrolled between September 2001 and January 2020. Information about family histories and clinical symptoms was retrospectively analyzed. All patients underwent otorhinolaryngological, ophthalmological and neurological examinations, including: pure-tone audiometry, acoustic immittance(AI), distortion-product otoacoustic emissions(DPOAE), auditory brainstem response(ABR), cochlear micropotential(CM), speech discrimination score(SDS), electroneurography(ENoG), computed tomography(CT) of the temporal bone and cranial magnetic resonance weighted imaging scan(MRI), muscle biopsy and mtDNA gene testing. ENT subjective manifestations were present in 15 cases (53.6%) with sensorineural hearing loss(SNHL), 4(14.3%) with tinnitus, 4(14.3%) with facial weakness, 3(10.7%) with dysphagia, 1(3.6%) with auditory agnosia. Ophthalmological and neurological symptoms included ptosis in 16 cases (57.1%), exercise intolerance in 16(57.1%), optic atrophy in 15(53.6%), muscular atrophy in 6(21.4%), and stroke-like episodes in 5(17.9%). The results of objective examinations were as follows: DPOAE were not elicited in 18(64.3%) cases, ABR abnormalities in 18(64.3%) cases, hearing threshold shift in 15(53.6%) cases, AI normal and CM was not detected in all cases, SDS decreased in 6(21.4%) cases, facial ENoG abnormalities in 4(14.3%) cases, laryngeal ENoG abnormalities in 3(10.7%) cases, EMG abnormalities in 6(21.4%) cases, and ECG abnormalities in 8(28.6%) cases. Temporal CT were normal, but cranial MRI abnormalities were found in 19 cases(67.9%), including central nerve demyelination, white matter hyperintensities, generalized cerebellar and cerebral atrophy, multiple cortical/subcortical infarct-like lesions, basal ganglia calcification. Multisystemic syndromes in MEM can present as a variety of otolaryngological, ophthalmological and neurological abnormalities, such as ptosis, audio-visual disturbance, exercise intolerance and stroke-like episodes etc. SNHL, tinnitus, auditory agnosia, facial weakness and dysphagia were ENT specific manifestations. SNHL in MEM is bilateral symmetrical progressive or of sudden onset since teenage. mtDNA testing may be helpful for adolescent patient whose SNHL was associated with neuromuscular symptoms. Muscle biopsy should be considered when middle-aged patients developed facial weakness and dysphagia. DPOAE and ABR are the optimal objective audiometric tests to monitor the progression of MEM associated with SNHL.
Topics: Adolescent; Audiometry, Pure-Tone; Evoked Potentials, Auditory, Brain Stem; Hearing Loss, Sensorineural; Humans; Middle Aged; Mitochondrial Encephalomyopathies; Neurology; Ophthalmology; Otoacoustic Emissions, Spontaneous; Otolaryngology; Retrospective Studies
PubMed: 34304513
DOI: 10.13201/j.issn.2096-7993.2021.06.010 -
European Neurology 2020Anosognosia and hemineglect are among the most startling neurological phenomena identified during the 20th century. Though both are associated with right hemisphere...
Anosognosia and hemineglect are among the most startling neurological phenomena identified during the 20th century. Though both are associated with right hemisphere cerebral dysfunction, notably stroke, each disorder had its own distinct literature. Anosognosia, as coined by Babinski in 1914, describes patients who seem to have no idea of their paralysis, despite general cognitive preservation. Certain patients seem more than unaware, with apparent resistance to awareness. More extreme, and qualitatively distinct, is denial of hemiplegia. Various interpretations of pathogenesis are still deliberated. As accounts of its captivating manifestations grew, anosognosia was established as a prominent symbol of neurological and psychic disturbance accompanying (right-hemisphere) stroke. Although reports of specific neglect-related symptomatology appeared earlier, not until nearly 2 decades after anosognosia's inaugural definition was neglect formally defined by Brain, paving a path spanning some years, to depict a class of disorder with heterogeneous variants. Disordered awareness of body and extrapersonal space with right parietal lesions, and other symptom variations, were gathered under the canopy of neglect. Viewed as a disorder of corporeal awareness, explanatory interpretations involve mechanisms of extinction and perceptual processing, disturbance of spatial attention, and others. Odd alterations involving apparent concern, attitudes, or belief characterize many right hemisphere conditions. Anosognosia and neglect are re-examined, from the perspective of unawareness, the nature of belief, and its baffling distortions. Conceptual parallels between these 2 distinct disorders emerge, as the major role of the right hemisphere in mental representation of self is highlighted by its most fascinating syndromes of altered awareness.
Topics: Agnosia; History, 19th Century; History, 20th Century; Humans; Neurology; Perceptual Disorders
PubMed: 32927461
DOI: 10.1159/000510397 -
Brain Sciences Dec 2021The aim of this article is to discuss the logic and assumptions behind the concept of neural reuse, to explore its biological advantages and to discuss the implications... (Review)
Review
The aim of this article is to discuss the logic and assumptions behind the concept of neural reuse, to explore its biological advantages and to discuss the implications for the cognition of a brain that reuses existing circuits and resources. We first address the requirements that must be fulfilled for neural reuse to be a biologically plausible mechanism. Neural reuse theories generally take a developmental approach and model the brain as a dynamic system composed of highly flexible neural networks. They often argue against domain-specificity and for a distributed, embodied representation of knowledge, which sets them apart from modular theories of mental processes. We provide an example of reuse by proposing how a phylogenetically more modern mental capacity (mental rotation) may appear through the reuse and recombination of existing resources from an older capacity (motor planning). We conclude by putting arguments into context regarding functional modularity, embodied representation, and the current ontology of mental processes.
PubMed: 34942954
DOI: 10.3390/brainsci11121652