Teaching NeuroImages: Nonfluent variant primary progressive aphasia: A distinctive clinico-anatomical syndrome.
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SUBMITTER: Marshall CR
PROVIDER: S-EPMC5177672 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:BackgroundA subset of patients with the nonfluent variant of primary progressive aphasia (PPA) exhibit concomitant single-word comprehension problems, constituting a 'mixed variant' phenotype. This phenotype is rare and currently not fully characterized. The aim of this study was twofold: to assess the prevalence and nature of single-word comprehension problems in the nonfluent variant and to study multimodal imaging characteristics of atrophy, tau, and amyloid burden associated with this mixed phenotype.MethodsA consecutive memory-clinic recruited series of 20 PPA patients (12 nonfluent, five semantic, and three logopenic variants) were studied on neurolinguistic and neuropsychological domains relative to 64 cognitively intact healthy older control subjects. The neuroimaging battery included high-resolution volumetric magnetic resonance imaging processed with voxel-based morphometry, and positron emission tomography with the tau-tracer [18F]-THK5351 and amyloid-tracer [11C]-Pittsburgh Compound B.ResultsSeven out of 12 subjects who had been classified a priori with nonfluent variant PPA showed deficits on conventional single-word comprehension tasks along with speech apraxia and agrammatism, corresponding to a mixed variant phenotype. These mixed variant cases included three females and four males, with a mean age at onset of 65 years (range 44-77 years). Object knowledge and object recognition were additionally affected, although less severely compared with the semantic variant. The mixed variant was characterized by a distributed atrophy pattern in frontal and temporoparietal regions. A more focal pattern of elevated [18F]-THK5351 binding was present in the supplementary motor area, the left premotor cortex, midbrain, and basal ganglia. This pattern was closely similar to that seen in pure nonfluent variant PPA. At the individual patient level, elevated [18F]-THK5351 binding in the supplementary motor area and premotor cortex was present in six out of seven mixed variant cases and in five and four of these cases, respectively, in the thalamus and midbrain. Amyloid biomarker positivity was present in two out of seven mixed variant cases, compared with none of the five pure nonfluent cases.ConclusionsA substantial proportion of PPA patients with speech apraxia and agrammatism also have single-word comprehension deficits. At the neurobiological level, the mixed variant shows a high degree of similarity with the pure nonfluent variant of PPA.Trial registrationEudraCT, 2014-002976-10 . Registered on 13-01-2015.
| S-EPMC6052568 | biostudies-literature
Project description:ImportanceDespite being characterized as a disorder of language production, nonfluent/agrammatic variant primary progressive aphasia (nfvPPA) is frequently associated with auditory symptoms. However, to our knowledge, peripheral auditory function has not been defined in this condition.ObjectiveTo assess peripheral hearing function in individuals with nfvPPA compared with healthy older individuals and patients with Alzheimer disease (AD).Design, setting, and participantsThis cross-sectional single-center study was conducted at the Dementia Research Centre of University College London between August 2015 and July 2018. A consecutive cohort of patients with nfvPPA and patients with AD were compared with healthy control participants. No participant had substantial otological or cerebrovascular disease; all eligible patients fulfilling diagnostic criteria and able to comply with audiometry were included.Main outcomes and measuresWe measured mean threshold sound levels required to detect pure tones at frequencies of 500, 1000, 2000, 4000, and 6000 Hz in the left and right ears separately; these were used to generate better-ear mean and worse-ear mean composite hearing threshold scores and interaural difference scores for each participant. All analyses were adjusted for participant age.ResultsWe studied 19 patients with nfvPPA (9 female; mean [SD] age, 70.3 [9.0] years), 20 patients with AD (9 female; mean [SD] age, 69.4 [8.1] years) and 34 control participants (15 female; mean [SD] age, 66.7 [6.3] years). The patients with nfvPPA had significantly higher scores than control participants on better-ear mean scores (patients with nfvPPA: mean [SD], 36.3 [9.4] decibels [dB]; control participants: 28.9 [7.3] dB; age-adjusted difference, 5.7 [95% CI, 1.4-10.0] dB; P = .01) and worse-ear mean scores (patients with nfvPPA: 42.2 [11.5] dB; control participants: 31.7 [8.1] dB; age-adjusted difference, 8.5 [95% CI, 3.6-13.4] dB; P = .001). The patients with nfvPPA also had significantly higher better-ear mean scores than patients with AD (patients with AD: mean [SD] 31.1 [7.5] dB; age-adjusted difference, 4.8 [95% CI, 0.0-9.6] dB; P = .048) and worse-ear mean scores (patients with AD: mean [SD], 33.8 [8.2] dB; age-adjusted difference, 7.8 [95% CI, 2.4-13.2] dB; P = .005). The difference scores (worse-ear mean minus better-ear mean) were significantly higher in the patients with nfvPPA (mean [SD], 5.9 [5.2] dB) than control participants (mean [SD], 2.8 [2.2] dB; age-adjusted difference, 2.8 [95% CI, 0.9-4.7] dB; P = .004) and patients with AD (mean [SD], 2.8 [2.1] dB; age-adjusted difference, 3.0 [95% CI, 0.9-5.1] dB; P = .005).Conclusions and relevanceIn this study, patients with nfvPPA performed worse on pure-tone audiometry than healthy older individuals or patients with AD, and the difference was not attributable to age or general disease factors. Cases of nfvPPA were additionally associated with increased functional interaural audiometric asymmetry. These findings suggest conjoint peripheral afferent and more central regulatory auditory dysfunction in individuals with nfvPPA.
| S-EPMC6515576 | biostudies-literature
Project description:The left posterior inferior frontal cortex (IFC) is important for syntactic processing, and has been shown in many functional imaging studies to be differentially recruited for the processing of syntactically complex sentences relative to simpler ones. In the nonfluent variant of primary progressive aphasia (PPA), degeneration of the posterior IFC is associated with expressive and receptive agrammatism; however, the functional status of this region in nonfluent PPA is not well understood. Our objective was to determine whether the atrophic posterior IFC is differentially recruited for the processing of syntactically complex sentences in nonfluent PPA. Using structural and functional magnetic resonance imaging, we quantified tissue volumes and functional responses to a syntactic comprehension task in eight patients with nonfluent PPA, compared to healthy age-matched controls. In controls, the posterior IFC showed more activity for syntactically complex sentences than simpler ones, as expected. In nonfluent PPA patients, the posterior IFC was atrophic and, unlike controls, showed an equivalent level of functional activity for syntactically complex and simpler sentences. This abnormal pattern of functional activity was specific to the posterior IFC: the mid-superior temporal sulcus, another region modulated by syntactic complexity in controls, showed normal modulation by complexity in patients. A more anterior inferior frontal region was recruited by patients, but did not support successful syntactic processing. We conclude that in nonfluent PPA, the posterior IFC is not only structurally damaged, but also functionally abnormal, suggesting a critical role for this region in the breakdown of syntactic processing in this syndrome.
| S-EPMC3024013 | biostudies-other
Project description:Background and purposeTo analyze 18F-THK5351 positron emission tomography (PET) scans of patients with clinically diagnosed nonfluent/agrammatic variant primary progressive aphasia (navPPA).MethodsThirty-one participants, including those with Alzheimer's disease (AD, n=13), navPPA (n=3), and those with normal control (NC, n=15) who completed 3 Tesla magnetic resonance imaging, 18F-THK5351 PET scans, and detailed neuropsychological tests, were included. Voxel-based and region of interest (ROI)-based analyses were performed to evaluate retention of 18F-THK5351 in navPPA patients.ResultsIn ROI-based analysis, patients with navPPA had higher levels of THK retention in the Broca's area, bilateral inferior frontal lobes, bilateral precentral gyri, and bilateral basal ganglia. Patients with navPPA showed higher levels of THK retention in bilateral frontal lobes (mainly left side) compared than NC in voxel-wise analysis.ConclusionsIn our study, THK retention in navPPA patients was mainly distributed at the frontal region which was well correlated with functional-radiological distribution of navPPA. Our results suggest that tau PET imaging could be a supportive tool for diagnosis of navPPA in combination with a clinical history.
| S-EPMC6428011 | biostudies-literature
Project description:ObjectiveTo investigate the cognitive and neural basis for nonfluent speech in progressive nonfluent aphasia (PNFA).BackgroundNonfluent speech is the hallmark feature of PNFA, and this has been attributed to impairments in syntactic processing, motor-speech planning, and executive functioning that also occur in these patients. Patients with PNFA have left inferior frontal atrophy.MethodsA large semi-structured speech sample and neuropsychological measures of language and executive functioning were examined in 16 patients with PNFA, 12 patients with behavioral-variant frontotemporal dementia (bvFTD), and 13 age-matched controls. Speech fluency was quantified as words per minute (WPM) in the semi-structured speech sample. Stepwise linear regression analyses were used to relate WPM to grammatic, motor-speech planning, and executive aspects of patient functioning. These measures were then related to cortical thickness in 8 patients with PNFA and 7 patients with bvFTD using structural MRI.ResultsWPM was significantly reduced in patients with PNFA relative to controls and patients with bvFTD. Regression analyses revealed that only grammatic measures predicted WPM in PNFA, whereas executive measures were the only significant predictor of WPM in bvFTD. Cortical thinning was significant in PNFA relative to controls in left inferior frontal and anterior-superior temporal regions, and a regression analysis related this area to reduced WPM in PNFA. Significant cortical thinning associated with limited grammatic processing also was seen in the left inferior frontal-superior temporal region in PNFA, and this overlapped with the area of frontal-temporal thinning related to reduced WPM.ConclusionNonfluent speech in PNFA may be due in part to difficulty with grammatic processing associated with left inferior frontal and anterior-superior temporal disease.
| S-EPMC2931767 | biostudies-literature
Project description:ObjectiveAlzheimer disease (AD) and frontotemporal lobar degeneration (FTLD) are hypothesized to cause clinically distinct forms of primary progressive aphasia (PPA) that predominantly affect expressive speech. AD is thought to cause logopenic progressive aphasia (LPA), and FTLD may cause progressive nonfluent aphasia (PNFA). We sought to determine the value of clinical characterization, neuropsychological analysis, and MRI atrophy in predicting pathology of LPA and PNFA.MethodsPatients with LPA (n = 19) and patients with PNFA (n = 19) were evaluated with neuropsychological assessments, structural MRI, CSF analysis, and neuropathologic examination.ResultsTwelve of 19 patients with LPA (63%) and 6 of 19 patients with PNFA (32%) had neuropathologic findings or CSF biomarkers consistent with AD. Neuropsychological testing showed that naming was more impaired in patients with AD, and letter-guided fluency was more affected in patients with a non-AD disorder. Voxel-based morphometry analysis revealed that in patients with AD, patients with LPA and PNFA had significant posterior-superior temporal atrophy; in patients with non-AD, patients with LPA had peri-Sylvian atrophy and patients with PNFA had dorsolateral prefrontal and insular atrophy. Receiver operator characteristic curve analysis showed that combining neuropsychological testing with MRI atrophy pattern had 90% specificity for pathology or CSF biomarkers consistent with AD, and combining clinical features with neuropsychological analysis had 100% sensitivity for pathology or CSF biomarkers consistent with AD.ConclusionsNeither PPA phenotyping nor imaging alone is a reliable predictor of pathology. Multimodal predictors, such as combining neuropsychological testing with MRI analysis, can improve noninvasive prediction of underlying pathology in nonfluent forms of PPA.
| S-EPMC2931765 | biostudies-literature
Project description:The pathophysiology of nonfluent primary progressive aphasia (nfvPPA) remains poorly understood. Here, we compared quantitatively speech parameters in patients with nfvPPA versus healthy older individuals under altered auditory feedback, which has been shown to modulate normal speech output. Patients (n=15) and healthy volunteers (n=17) were recorded while reading aloud under delayed auditory feedback [DAF] with latency 0, 50 or 200 ms and under DAF at 200 ms plus 0.5 octave upward pitch shift. DAF in healthy older individuals was associated with reduced speech rate and emergence of speech sound errors, particularly at latency 200 ms. Up to a third of the healthy older group under DAF showed speech slowing and frequency of speech sound errors within the range of the nfvPPA cohort. Our findings suggest that (in addition to any anterior, primary language output disorder) these key features of nfvPPA may reflect distorted speech input signal processing, as simulated by DAF. DAF may constitute a novel candidate pathophysiological model of posterior dorsal cortical language pathway dysfunction in nfvPPA.
| S-EPMC4267508 | biostudies-literature
Project description:Clinical understanding of primary progressive aphasia (PPA) has been established based on English-speaking population. The lack of linguistic diversity in research hinders the diagnosis of PPA in non-English speaking patients. This case report describes the tonal and orthographic deficits of a multilingual native Cantonese-speaking woman with nonfluent/agrammatic variant PPA (nfvPPA) and progressive supranuclear palsy. Our findings suggest that Cantonese-speaking nfvPPA patients exhibit tone production impairments, tone perception deficits at the lexical selection processing, and linguistic dysgraphia errors unique to logographic script writer. These findings suggest that linguistic tailored approaches offer novel and effective tools in identifying non-English speaking PPA individuals.
| S-EPMC9345301 | biostudies-literature
Project description:Despite recent work, the nosology of nonfluent primary progressive aphasia (PPA) remains unresolved.We describe a clinical and neurolinguistic cross-sectional analysis of a cohort of 24 patients with nonfluent PPA. Patients were initially classified based on analysis of spontaneous speech into 4 groups: apraxia of speech (AOS)/agrammatism (10 patients); AOS/no agrammatism (4 patients); no AOS/agrammatism (3 patients); no AOS/no agrammatism (7 patients). These groups were further characterized using a detailed neurolinguistic and neuropsychological battery. Parkinsonism was present in 3/10 patients in the AOS/agrammatism group. All patients in the no AOS/agrammatism group had mutations in the progranulin (GRN) gene, while 5/7 cases in the no AOS/no agrammatism group had CSF findings compatible with Alzheimer disease.The groups without AOS showed more severe neurolinguistic impairments for a given disease stage, and sentence comprehension, speech repetition, and reading were impaired in all groups. Prolonged word-finding pauses and impaired single word comprehension were salient features in the no AOS/agrammatism group. Additional impairments of executive function and praxis were present in both groups with agrammatism, and impaired episodic memory was a feature of the no AOS/no agrammatism group.PPA with AOS is aligned with the syndrome previously designated progressive nonfluent aphasia; agrammatism may emerge as the syndrome evolves, or alternatively, the pure AOS group may be pathophysiologically distinct. PPA without AOS resembles the syndrome designated logopenic/phonologic aphasia; however, there is evidence for a distinct subsyndrome of GRN-associated aphasia. The findings provide a rationale for further longitudinal studies with pathologic correlation.
| S-EPMC2931766 | biostudies-other
Project description:BackgroundApraxia of speech (AOS) is a core feature of nonfluent/agrammatic primary progressive aphasia (naPPA), but its precise characteristics and the prevalence of AOS features in spontaneous speech are debated.ObjectiveTo assess the frequency of features of AOS in the spontaneous, connected speech of individuals with naPPA and to evaluate whether these features are associated with an underlying motor disorder such as corticobasal syndrome or progressive supranuclear palsy.MethodsWe examined features of AOS in 30 patients with naPPA using a picture description task. We compared these patients to 22 individuals with behavioral variant frontotemporal dementia and 30 healthy controls. Each speech sample was evaluated perceptually for lengthened speech segments and quantitatively for speech sound distortions, pauses between and within words, and articulatory groping. We compared subgroups of naPPA with and without at least two features of AOS to assess the possible contribution of a motor impairment to speech production deficits.ResultsnaPPA patients produced both speech sound distortions and other speech sound errors. Speech segmentation was found in 27/30 (90%) of individuals. Distortions were identified in 8/30 (27%) of individuals, and other speech sound errors occurred in 18/30 (60%) of individuals. Frequent articulatory groping was observed in 6/30 (20%) of individuals. Lengthened segments were observed rarely. There were no differences in the frequencies of AOS features among naPPA subgroups as a function of extrapyramidal disease.ConclusionFeatures of AOS occur with varying frequency in the spontaneous speech of individuals with naPPA, independently of an underlying motor disorder.
| S-EPMC10259074 | biostudies-literature