Strand, Edythe A.

Background and purposeA subset of patients with Alzheimer's disease (AD) present with early and prominent language deficits. It is unclear whether the burden of underlying β‐amyloid pathology is associated with language or general cognitive impairment in these subjects.MethodsThe relationship between cortical β‐amyloid burden on [11C]Pittsburgh compound B (PiB) positron emission tomography (PET) and performance on the Montreal Cognitive Assessment (MoCA), the Wechsler Memory Scale − Third Edition (WMS‐III), the Boston Naming Test (BNT) and the Western Aphasia Battery (WAB) was assessed using regression and correlation analyses in subjects presenting with aphasia who showed β‐amyloid deposition on PiB PET.ResultsThe global PiB ratio was inversely correlated with MoCA (P = 0.02) and the WMS‐III Visual Reproduction (VR) subtest (VR I, P = 0.02; VR II, P = 0.04). However, the correlations between PiB ratio, BNT (P = 0.13), WAB aphasia quotient (P = 0.11) and WAB repetition scores (P = 0.34) were not significant.ConclusionThis study demonstrates that an increased cortical β‐amyloid burden is associated with cognitive impairment, but not language deficits, in AD subjects presenting with aphasia. The results suggest that β‐amyloid deposition could be partly contributing to impaired cognition in such patients whilst language dysfunction may be more influenced by other pathological mechanisms, perhaps downstream pathways of β‐amyloid deposition.

A good clinical understanding of the neurologic substrates of neurologic communicative disorders is important both to diagnosis and treatment. This article briefly reviews neurologic substrates for motor speech disorders (MSD) and how clinicians may identify neurologic signs and symptoms to facilitate differential diagnosis of apraxia of speech (AOS) and the various types of dysarthria. Students and clinicians have numerous resources regarding general neuroanatomy and neurophysiology (e.g. Benarroch, 2006; Kandel, Schwartz, and Jessel, 1991; Nolte, 2002; Snell, 1997) as well as neuroanatomic correlates of speech-language behavior and disorders (Bhatnagar, 2012; Duffy, 2013). Articles on aspects of neuroimaging (Brown, Petersen and Schlaggar, 2003; Shuster, 2003) and neurologic substrates for MSDs (Farinella-Bocian, Strand, and Benarroch, 2007) are also available in previous editions of Perspectives. This article begins with an overview of the differing MSDs. A brief overview of neurologic systems is provided, followed by a more detailed description of the neurologic substrates for MSDs. Examples of clinical observations of speech and non-speech characteristics that can aid the clinician in understanding the underlying neural deficit are provided.

We aimed to determine whether there is an association between teaching and the development of progressive speech and language disorders (SLDs). Occupation was compared between 100 patients with a progressive SLD, 404 patients with Alzheimer’s dementia, and the 2008 US census. In SLDs, the most common occupation was teacher (22%) versus 8% in Alzheimer’s dementia. The odds ratio (OR) of being a teacher in SLDs compared to Alzheimer’s dementia was 3.4 (95% confidence interval [CI] = 1.87-6.17). No differences were observed in the frequency of other occupations. The frequency of teachers was higher in SLDs compared to the US census, OR of 6.9 (95% CI = 4.3-11.1). Farming, forestry, and fishing occupations were more frequent in SLDs compared to the US census. We identified an association between progressive SLDs and the occupation of teaching. Since teaching is a communication demanding occupation, teachers may be more sensitive to the development of speech and language impairments.

Abstract Background Microbleeds have been associated with Alzheimer's disease (AD), although it is unclear whether they occur in atypical presentations of AD, such as the logopenic variant of primary progressive aphasia (lvPPA). We aimed to assess the presence and clinical correlates of microbleeds in lvPPA. Methods Thirteen lvPPA subjects underwent 3T T2*‐weighted and fluid‐attenuated inversion recovery magnetic resonance imaging and Pittsburgh compound B (PiB) positron emission tomography imaging. Microbleeds were identified on manual review and assigned a regional location. Total and regional white matter hyperintensity (WMH) burden was measured. Results Microbleeds were observed in four lvPPA subjects (31%), most commonly in the frontal lobe. Subjects with microbleeds were older, more likely female, and had a greater burden of WMH than those without microbleeds. The regional distribution of microbleeds did not match the regional distribution of WMH. All cases were PiB positive. Conclusions Microbleeds occur in approximately one third of subjects with lvPPA, with older women at the highest risk.

PurposeIn this article, the authors report reliability and validity evidence for the Dynamic Evaluation of Motor Speech Skill (DEMSS), a new test that uses dynamic assessment to aid in the differential diagnosis of childhood apraxia of speech (CAS).MethodParticipants were 81 children between 36 and 79 months of age who were referred to the Mayo Clinic for diagnosis of speech sound disorders. Children were given the DEMSS and a standard speech and language test battery as part of routine evaluations. Subsequently, intrajudge, interjudge, and test–retest reliability were evaluated for a subset of participants. Construct validity was explored for all 81 participants through the use of agglomerative cluster analysis, sensitivity measures, and likelihood ratios.ResultsThe mean percentage of agreement for 171 judgments was 89% for test–retest reliability, 89% for intrajudge reliability, and 91% for interjudge reliability. Agglomerative hierarchical cluster analysis showed that total DEMSS scores largely differentiated clusters of children with CAS vs. mild CAS vs. other speech disorders. Positive and negative likelihood ratios and measures of sensitivity and specificity suggested that the DEMSS does not overdiagnose CAS but sometimes fails to identify children with CAS.ConclusionsThe value of the DEMSS in differential diagnosis of severe speech impairments was supported on the basis of evidence of reliability and validity.

Background and purposePrimary progressive apraxia of speech, a motor speech disorder of planning and programming, is a tauopathy that has overlapping histological features with progressive supranuclear palsy. We aimed to compare, for the first time, atrophy patterns, as well as white matter tract degeneration, between these two syndromes.MethodsSixteen primary progressive apraxia of speech subjects were age‐ and gender‐matched to 16 progressive supranuclear palsy subjects and 20 controls. All subjects were prospectively recruited, underwent neurological and speech evaluations and 3.0‐Tesla magnetic resonance imaging. Grey and white matter atrophy was assessed using voxel‐based morphometry and atlas‐based parcellation, and white matter tract degeneration was assessed using diffusion tensor imaging.ResultsAll progressive supranuclear palsy subjects had typical oculomotor/gait impairments, but none had speech apraxia. Both syndromes showed grey matter loss in supplementary motor area, white matter loss in posterior frontal lobes and degeneration of the body of the corpus callosum. Whilst lateral grey matter loss was focal, involving superior premotor cortex, in primary progressive apraxia of speech, loss was less focal extending into prefrontal cortex in progressive supranuclear palsy. Caudate volume loss and tract degeneration of superior cerebellar peduncles were also observed in progressive supranuclear palsy. Interestingly, area of the midbrain was reduced in both syndromes compared to controls, although this was greater in progressive supranuclear palsy.ConclusionsAlthough neuroanatomical differences were identified between these distinctive clinical syndromes, substantial overlap was also observed, including midbrain atrophy, suggesting these two syndromes may have common pathophysiological underpinnings.