Combined assessment of progressive apraxia of speech brain microstructure by diffusion tensor imaging tractography and multishell neurite orientation dispersion and density imaging.

BACKGROUND: Progressive apraxia of speech (PAOS) is characterized by difficulties with motor speech programming and planning. PAOS targets gray matter (GM) and white matter (WM) microstructure that can be assessed using diffusion tensor imaging (DTI) and multishell applications, such as neurite orientation dispersion and density imaging (NODDI). In this study, we aimed to apply DTI and NODDI to add further insight into PAOS tissue microstructure. METHODS: Twenty-two PAOS patients and 26 age- and sex-matched controls, recruited by the Neurodegenerative Research Group (NRG) at Mayo Clinic, underwent diffusion MRI on 3T MRI. Brain maps of fractional anisotropy (FA) and mean diffusivity (MD) from DTI and intracellular volume fraction (ICVF) and isotropic volume fraction (IsoVF) from NODDI were generated. Global WM and GM, and specific WM tracts were identified using tractography and lobar GM regions. RESULTS: Global WM differences between PAOS and controls were greatest for ICVF, and global GM differences were greatest for MD and IsoVF. Abnormalities in key WM tracts involved in PAOS, including the body of the corpus callosum and frontal aslant tract, were identified with FA, MD, and ICVF, with excellent differentiation of PAOS from controls (area under the receiver operating characteristic curves >.90). MD and ICVF identified abnormalities in arcuate fasciculus, thalamic radiations, and corticostriatal tracts. Significant correlations were identified between an index of articulatory errors and DTI and NODDI metrics from the arcuate fasciculus, frontal aslant tract, and inferior longitudinal fasciculus. CONCLUSIONS: DTI and NODDI represent different aspects of brain tissue microstructure, increasing the number of potential biomarkers for PAOS.

Cross-Sectional and Longitudinal Assessment of Behavior in Primary Progressive Apraxia of Speech and Agrammatic Aphasia.

INTRODUCTION: Progressive agrammatic aphasia (PAA) can be associated with abnormal behaviors; however, it is unknown whether behaviors occur and/or are different in patients with primary progressive apraxia of speech (PPAOS). We aimed to compare baseline and longitudinal behavioral symptomatology between PPAOS, patients with PAA, and patients with both apraxia of speech and PAA (AOS-PAA). METHODS: We recruited 89 patients for this study, 40 with PPAOS, 11 with PAA, and 38 with AOS-PAA. Behavioral disturbances were evaluated using the frontal behavior inventory (FBI) which was also split into negative behaviors and disinhibition, and the 20-item behavioral assessment scale (20-BAS). Data analysis was performed using linear regression and linear mixed models. RESULTS: Of the 89 patients in the study, 54% were women and the mean age at onset was 68 years. All patients, regardless of diagnosis, endorsed at least one symptom on the FBI at baseline, most frequently verbal apraxia (100%), logopenia (95.6%), irritability (55.9%), and apathy (42.6%). On the 20-BAS, 47.6% of the patients endorsed at least one symptom, most commonly "crying more easily" (19.5%) and personality change (18.3%). PPAOS was the least behaviorally affected group, with differences between PPAOS and AOS-PAA mainly driven by negative behaviors as opposed to disinhibition for PPAOS and PAA. The behavioral metrics showed average sensitivity and specificity to distinguish between groups. Behavioral disturbances worsened over time although rate of behavioral change across groups was similar. CONCLUSION: Behavioral disturbances are more common and severe in patients with agrammatic aphasia with or without AOS compared to patients with isolated apraxia of speech.

Quantitative assessment of grammar in amyloid-negative logopenic aphasia.

Logopenic primary progressive aphasia (lvPPA) typically results from underlying Alzheimer's disease, but subjects have been reported that do not show beta-amyloid (Aß) deposition. These subjects do not differ on neurological and speech-language testing from Aß-positive lvPPA, but they impressionistically show increased grammatical deficits. We performed a quantitative linguistic analysis of grammatical characteristics in Aß-negative lvPPA compared to Aß-positive lvPPA and agrammatic PPA, which is characterized by increased grammatical difficulties. Aß-negative lvPPA used fewer function words and correct verbs but more syntactic and semantic errors compared to Aß-positive lvPPA. These measures did not differ between Aß-negative lvPPA and agPPA. Both lvPPA cohorts showed a higher mean length of utterance, more complex sentences, and fewer nouns than agPPA. Aß-negative lvPPA subjects appear unique and share linguistic features with both agPPA and Aß-positive lvPPA. Quantitative language analysis in lvPPA may be able to distinguish those with and without Aß deposition.

Assessment of Orofacial Strength in Patients with Dysarthria.

Assessment of orofacial weakness is common during the evaluation of patients with suspected dysarthria. This study addressed the validity of clinical assessments of orofacial weakness by comparing clinical (subjective) ratings to instrumental (objective) measures. Forty-four adults referred to a speech pathology clinic for dysarthria evaluation were tested for strength of the tongue during elevation, lateralization, and protrusion, and for the strength of the muscles of the lower face during buccodental and interlabial compression. Subjective assessment of weakness involved rating maximum resistance against a firmly held tongue depressor, using a 5-point scale. Objective assessment involved the Iowa Oral Performance Instrument (IOPI), measured as the maximal pressure generated against an air-filled bulb. A recent adaptation to the IOPI permitted testing of tongue and cheek strength using tasks that are comparable to the subjective tasks. Moderate correlations were found between the objective and subjective evaluations, with the strongest correlations for tongue lateralization. Lower pressure values were associated with higher subjective ratings of weakness for each task, although there was substantial overlap in the data. These results, combined with the notion that examiner bias is inherent to clinical assessment, support the use of instrumentation to improve objectivity and precision of measurement in the clinic.

Oral health of children and adults in Latino migrant and seasonal farmworker families.

Oral health is one of the greatest unmet health needs of immigrant farmworkers. This paper describes use of dental services and current oral health problems of children and parents in farmworker families. Interviews were conducted with 108 women in Latino farmworker families in western North Carolina and southwestern Virginia. Dental care had been received in the past year by 73% of children, 47% of mothers, and 37% of spouses. Children were most likely to have received care on a regular basis, while adults usually received no care or emergency care. In general, children's teeth were in better condition than parents' teeth. Children's receipt of dental care and their teeth condition were predicted by being born in the US. No family member's care was related to acculturation or mother's education, typical predictors of health behavior. Differences among family members suggest that access to services, not lack of education, is the primary barrier facing farmworker families.

Experiences of Latino immigrant families in North Carolina help explain elevated levels of food insecurity and hunger.

Household food insecurity is higher among minority households in the U.S., but few data exist on households of recent minority immigrants, in part because such households are difficult to sample. Four studies of a total of 317 Latino immigrant families were conducted in different regions and during different seasons in North Carolina. A Spanish translation of the 18-item U.S. Food Security Survey Module was used to assess the prevalence of food insecurity and hunger. In 3 of the studies, a total of 76 in-depth interviews were conducted to gather information on immigrants' experiences of food insecurity. Households in the 4 studies classified as food secure ranged from 28.7 to 50.9%, compared with 82.4% in the U.S. in 2004. Food insecurity without hunger ranged from 35.6% to 41.8%, compared with 13.3% in the U.S. The highest rates of hunger reported were 18.8% (moderate hunger) and 16.8% (severe hunger) in an urban sample. Qualitative data indicate that food insecurity has both quantitative and qualitative effects on diet. Immigrants experience adverse psychological effects of food insecurity. They report experiencing a period of adjustment to food insecurity leading to empowerment to resolve the situation. Reactions to food insecurity differ from those reported by others, possibly because immigrants encounter a new and not chronic situation. Overall, these findings suggest that immigrant Latinos experience significant levels of food insecurity that are not addressed by current governmental programs.