Biomedical subjects

Bruce L Miller

Publications and source records attributed to Bruce L Miller.

78 records · Page 5Linked to original sources

PubMedDate not supplied

Referral patterns for syndromes associated with frontotemporal lobar degeneration.

We compared demographics of subjects diagnosed with frontotemporal degeneration (FTD) at a group of 5 clinics specializing in this non-Alzheimer dementia against those subjects diagnosed at standard Alzheimer disease centers, to determine any differences in referral patterns between such clinics. Of the two major phenotypes of FTD, behavior and language, the latter more frequently presented to the specialty clinics (46% of FTD diagnoses versus 19%, P < 0.001). Mean age at onset for the behavioral presentation phenotype was one year younger at the specialty clinics (P < 0.01). Mean age at onset for the language phenotype was 3 years older (P < 0.001) than for the behavioral phenotype at standard centers but did not differ between the two evaluating groups. Cases with FTD referred to all of the dementia evaluation sites in this study did not differ significantly from those previously reported in the literature. Clinics specializing in FTD recruit more language presentation cases. There were statistical but not clinically significant differences in ages at onset.

Academic Medical Centers↗

PubMedDate not supplied

Clinical features of frontotemporal dementia.

What was once called Pick's disease has three major anatomic variants. With all three, frontotemporal brain is selectively injured whereas posterior cortical regions are spared. These three clinical patterns include a bifrontal, slightly asymmetric subtype with more involvement of the right frontotemporal region called frontotemporal dementia or the frontal variant of FTD (fvFTD), a temporal-predominant subtype called the temporal variant of FTD or semantic dementia (SD), and a left frontal-predominant subtype called progressive nonfluent aphasia (PNFA). The three anatomic groups help to classify distinctive clinical syndromes with unique features. Careful study of these subtypes of frontotemporal dementia, using combinations of new quantitative neuroimaging, behavioral and physiological measures are yielding important information about the functioning of the brain's frontal and temporal regions. As we come to better understand the biologic basis for the three FTD clinical syndromes, new classification schemas may emerge, but our current clinical criteria serve as a strong guide to the diagnosis and separation of FTD from Alzheimer disease and other dementias.

Diagnosis, Differential↗

PubMedDate not supplied

Effects of Alzheimer disease on fronto-parietal brain N-acetyl aspartate and myo-inositol using magnetic resonance spectroscopic imaging.

Previous magnetic resonance (MR) spectroscopy studies of Alzheimer disease (AD) reporting reduced N-acetyl aspartate (NAA) and increased myo-Inositol (mI) used single voxel techniques, which have limited ability to assess the regional distribution of the metabolite abnormalities. The objective of this study was to determine the regional distribution of NAA and mI alterations in AD by using MR spectroscopic imaging. Fourteen patients with AD and 22 cognitively normal elderly were studied using structural MR imaging and MR spectroscopic imaging. Changes of NAA, mI, and various metabolite ratios were measured in frontal and parietal lobe gray matter (GM) and white matter. This study found: (1) when compared with cognitively normal subjects, AD patients had increased mI and mI/creatine (Cr) ratios primarily in parietal lobe GM, whereas frontal lobe GM and white matter were spared; (2) in the same region where mI was increased, AD patients had also decreased NAA and NAA/Cr ratios, replicating previous findings; (3) however, increased mI or mI/Cr ratios did not correlate with decreased NAA or NAA/Cr ratios; and (4) using mI/Cr and NAA/Cr together improved sensitivity and specificity to AD from control as compared with NAA/Cr alone. In conclusion, decreased NAA and increased mI in AD are primarily localized in parietal lobe GM regions. However, the NAA and mI changes are not correlated with each other, suggesting that they represent different processes that might help staging of AD.

Aged↗

PubMedDate not supplied

Patterns of cerebral atrophy in primary progressive aphasia.

The authors illustrate the spectrum of clinical and imaging patterns in primary progressive aphasia (PPA), a syndrome of slowly progressive speech and language impairment occurring with neurodegenerative disease. Although PPA presents with relatively isolated impairment in language, many patients progress to global cognitive or behavioral dysfunction. The syndrome may be associated with frontotemporal dementia (FTD)- or Alzheimer disease (AD)-type changes. Authors describe the clinical presentation in three cases of PPA and analyze the pattern of cerebral atrophy in each case with voxel-based morphometry. Two patients presented with nonfluent progressive aphasia. Subtle differences in the clinical features were suggestive of FTD in one case and AD in the other. Neuroimaging revealed a predominance of frontal atrophy in the first case and temporo-parietal atrophy in the second. The third case presented with the syndrome of semantic dementia and showed the typical behavioral problems associated with FTD and a pattern of left-greater-than-right temporal atrophy. Different clinical syndromes in PPA are associated with different patterns of atrophy. In the future, combined analysis of imaging and clinical characteristics may allow more accurate etiologic diagnosis.

Aged↗

PubMedDate not supplied

Neuropsychological and functional measures of severity in Alzheimer disease, frontotemporal dementia, and semantic dementia.

Many studies attempting to compare the clinical features in different dementia syndromes have attempted to control for overall disease severity using neuropsychological or functional measures. However, these measures may not give equivalent estimates of disease severity. We examined a functional measure of severity (Clinical Dementia Rating scale [CDR] scores) in patients with Alzheimer disease (AD, n = 23), frontotemporal dementia (FTD, n = 24), and semantic dementia (SD, n = 25) who were matched for age and Mini-Mental State Examination (a neuropsychological measure of severity). Total CDR scores were significantly worse in the FTD group compared with both AD and SD patients, whose total CDR scores were similar to each other. FTD showed no difference in memory or orientation compared with AD but did show more impairment in judgment and problem solving, community affairs, home and hobbies, and personal care compared with AD and SD. Thus, in FTD the CDR reveals functional impairments in a wide variety of domains that are more severe than those seen in AD or SD patients with an equivalent Mini-Mental State Examination.

Aging↗

PubMedDate not supplied

Diffusion-weighted and fluid-attenuated inversion recovery imaging in Creutzfeldt-Jakob disease: high sensitivity and specificity for diagnosis.

BACKGROUND AND PURPOSE: Abnormalities on diffusion-weighted images (DWIs) and fluid-attenuated inversion recovery (FLAIR) images are reported in Creutzfeldt-Jakob disease (CJD). To our knowledge, no large study has been conducted to determine the sensitivity and specificity of DWI and FLAIR imaging for diagnosing CJD. METHODS: Two neuroradiologists, blinded to diagnosis, retrospectively evaluated DWI and FLAIR images from 40 patients with probable or definite CJD and 53 control subjects with other forms of dementia and rated the likelihood of CJD on the basis of the imaging findings. RESULTS: DWI and FLAIR imaging was 91% sensitive, 95% specific, and 94% accurate for CJD. Interrater reliability was high (kappa = 0.93). Sensitivity was higher for DWI than FLAIR imaging. Abnormalities involved cortex and deep gray matter (striatum and/or thalamus) in 68% of patients with CJD, cortex alone in 24%, and deep gray matter alone in 5%. The most typical and specific patterns were corresponding hyperintensity on both FLAIR images and DWIs confined to the gray matter in the cortex, striatum, medial and/or posterior thalamus, or a combination of these areas. Narrow-window soft-copy review of artifact-free DWIs and FLAIR images and recognition of the normal variation in cortical signal intensity proved critical for successful differentiation of CJD from other dementias. CONCLUSION: Because specific patterns of abnormality on DWI and FLAIR images are highly sensitive and specific for CJD, these sequences should be performed whenever CJD is suspected.

Adult↗