PubMed Health⌕ Search

Biomedical subjects

Julene K Johnson

Publications and source records attributed to Julene K Johnson.

13 recordsLinked to original sources
PubMed2006

Multiple cognitive deficits in amnestic mild cognitive impairment.

OBJECTIVE: To determine if more widespread cognitive deficits are present in a narrowly defined group of patients with the amnestic form of mild cognitive impairment (MCI). METHODS: From a larger sample of patients clinically diagnosed as meeting the criteria of Petersen et al. for amnestic MCI, we selected 22 subjects who had Clinical Dementia Rating scores of zero on all domains besides memory and orientation. These MCI subjects with presumably isolated memory impairments were compared to 35 age-matched normal controls and 33 very mild Alzheimer's disease (AD) patients on a battery of neuropsychological tests. RESULT: In addition to the expected deficits in episodic memory, the amnestic MCI group performed less well than the controls but better than the AD group on design fluency, category fluency, a set shifting task and the Stroop interference condition. Over half the amnestic MCI group (vs. none of the normal controls) scored at least 1 standard deviation below control means on 4 or more of the nonmemory cognitive tasks. CONCLUSIONS: Isolated memory impairment may be fairly uncommon in clinically diagnosed amnestic MCI patients, even when the criteria for amnestic MCI are fairly narrow. Additional cognitive impairments are likely to include fluency and executive functioning. These more diffuse deficits argue for comprehensive cognitive assessments, even when the patient and family are reporting only memory decline, and are consistent with the increase in attention paid to the heterogeneity of MCI.

Aged↗
PubMed2006

Anti-GAD antibody cerebellar ataxia mimicking Creutzfeldt-Jakob disease.

In a patient with a rapidly progressive neurological condition with ataxia and cognitive complaints, Creutzfeldt-Jakob disease (CJD) is often high in the differential, particularly when there is an elevated CSF 14-3-3 protein level. We present a case of anti-glutamic acid decarboxylase antibody (anti-GAD65) positive cerebellar ataxia associated with cognitive complaints and elevated CSF 14-3-3 protein.

14-3-3 Proteins↗
PubMed2006

Frontotemporal dementia: clinicopathological correlations.

OBJECTIVE: Frontotemporal lobar degeneration (FTLD) is characterized by impairments in social, behavioral, and/or language function, but postmortem studies indicate that multiple neuropathological entities lead to FTLD. This study assessed whether specific clinical features predict the underlying pathology. METHODS: A clinicopathological correlation was performed on 90 consecutive patients with a pathological diagnosis of frontotemporal dementia and was compared with an additional 24 cases accrued during the same time period with a clinical diagnosis of FTLD, but with pathology not typically associated with frontotemporal dementia. RESULTS: Postmortem examination showed multiple pathologies including tauopathies (46%), FTLD with ubiquitin-positive inclusions (29%), and Alzheimer's disease (17%). The pathological groups manifested some distinct demographic, clinical, and neuropsychological features, although these attributes showed only a statistical association with the underlying pathology. FTLD with ubiquitin-positive inclusions was more likely to present with both social and language dysfunction, and motor neuron disease was more likely to emerge in these patients. Tauopathies were more commonly associated with an extrapyramidal disorder. Alzheimer's disease was associated with relatively greater deficits in memory and executive function. INTERPRETATION: Clinical and neuropsychological features contribute to delineating the spectrum of pathology underlying a patient diagnosed with FTLD, but biomarkers are needed that, together with the clinical phenotype, can predict the underlying neuropathology.

Adult↗
PubMed2005

Presenilin 1 Glu318Gly polymorphism: interpret with caution.

BACKGROUND: The significance of the presenilin 1 (PSEN1) Glu318Gly polymorphism has been described as either a causal mutation with reduced penetrance or a benign polymorphism. When this polymorphism is found in a symptomatic person with a family history of dementia, counseling on recurrence risk becomes very problematic. OBJECTIVE: To demonstrate that the PSEN1 Glu318Gly polymorphism should be interpreted cautiously. DESIGN: Case histories of 2 patients with presenile dementia and family histories of dementia are described. The PSEN1 gene was sequenced in the patients and in 11 family members of patient 1. RESULTS: Two patients with presenile dementia and personality change were found to carry the PSEN1 Glu318Gly polymorphism. The presence of the polymorphism was confirmed in several family members of patient 1 but was absent in 1 symptomatic relative. CONCLUSIONS: The Glu318Gly polymorphism may be associated with risk for neurodegenerative disease; however, in the cases described here, it did not appear to be a risk factor. Until there is consensus on whether it is associated with disease, families should be informed that the clinical significance of the polymorphism is uncertain.

Alzheimer Disease↗
PubMed2005

Frontotemporal lobar degeneration: demographic characteristics of 353 patients.

BACKGROUND: Until recently, frontotemporal lobar degeneration (FTLD) was considered a rare neurodegenerative disorder that was difficult to diagnose. The publication of consensus criteria for FTLD, however, prompted systematic studies. The criteria categorize FTLD into 3 subgroups: frontotemporal dementia, semantic dementia, and progressive nonfluent aphasia. OBJECTIVE: To compare demographic characteristics of patients in the 3 FTLD subgroups. DESIGN: We compared diagnostic breakdown, age at onset, sex, Mini-Mental State Examination score at first visit, education, and neuropathological diagnoses in a large sample of FTLD patients from 3 different university dementia clinics, including 2 neurologic clinics in the United States and 1 psychiatric clinic in Germany. RESULTS: The frontotemporal dementia subgroup represented approximately half of all FTLD diagnoses. Patients diagnosed as having frontotemporal dementia (mean age, 57.5 years) and semantic dementia (mean age, 59.3 years) had an earlier age at onset than patients diagnosed as having progressive nonfluent aphasia (mean age, 63.0 years). There were significantly more men diagnosed as having frontotemporal dementia (63.5%) and semantic dementia (66.7%) when compared with progressive nonfluent aphasia (39.1%) (P = .005 for frontotemporal dementia vs progressive nonfluent aphasia and P = .002 for semantic dementia vs progressive nonfluent aphasia). Generally, the demographic features and diagnostic categories of the patient populations across the 3 sites were comparable. There were 68 deaths and 37 autopsies. Frontotemporal lobar degeneration with ubiquitin-positive tau-negative inclusions (48.5%), dementia lacking distinctive histopathological features (18.2%), and Pick disease (15.2%) were the most common neuropathological diagnoses. CONCLUSIONS: These findings show that cohorts of patients can be combined using new research criteria for FTLD and demonstrate striking demographic differences among FTLD subgroups. The sex and age-at-onset differences suggest that there may be biological differences among FTLD subgroups. In this sample, FTLD with ubiquitin-positive inclusions accounted for half of all neuropathological diagnoses.

Adult↗
PubMed2005

Learning and memory as a function of age in Down syndrome: a study using animal-based tasks.

Individuals with Down syndrome (DS) are at a high risk for developing Alzheimer disease (AD) after the age 40; however, low levels of intellectual functioning, coupled with impaired language ability, confound the detection of AD. Comparative neuropsychological tests developed in animal models of aging and cognition do not require intact language function and can be useful for detecting changes in cognition. Experimental paradigms used to detect age-dependent cognitive deficits in animal models were applied in the present study to measure cognitive function in a group of 20 adults with DS ranging in age from 22 to 58 years. Object discrimination, reversal learning, and spatial and object memory were administered using a modified Wisconsin General Testing Apparatus and reinforcement (penny rewards). When considering age as the only clinical variable to parallel the animal studies, age was significantly correlated with performance on object memory and marginally related to performance on reversal learning and spatial memory. However, when evaluating multiple clinical variables including age, a measure of intellectual ability (FSIQ), scores on the Dementia Questionnaire for Persons with Mental Retardation (DMR), and gender using regression analysis, scores on the DMR were the best predictors of errors of reversal learning, whereas FSIQ was the best predictor of performance on object memory. These results suggest that while age may be related to performance on learning and memory tasks, other clinical variables may be stronger predictors of performance in adults with DS. These changes may reflect prefrontal and medial temporal lobe dysfunction that is associated with the development of AD pathology in DS.

Adult↗
PubMed2004

Cognition and anatomy in three variants of primary progressive aphasia.

We performed a comprehensive cognitive, neuroimaging, and genetic study of 31 patients with primary progressive aphasia (PPA), a decline in language functions that remains isolated for at least 2 years. Detailed speech and language evaluation was used to identify three different clinical variants: nonfluent progressive aphasia (NFPA; n = 11), semantic dementia (SD; n = 10), and a third variant termed logopenic progressive aphasia (LPA; n = 10). Voxel-based morphometry (VBM) on MRIs showed that, when all 31 PPA patients were analyzed together, the left perisylvian region and the anterior temporal lobes were atrophied. However, when each clinical variant was considered separately, distinctive patterns emerged: (1) NFPA, characterized by apraxia of speech and deficits in processing complex syntax, was associated with left inferior frontal and insular atrophy; (2) SD, characterized by fluent speech and semantic memory deficits, was associated with anterior temporal damage; and (3) LPA, characterized by slow speech and impaired syntactic comprehension and naming, showed atrophy in the left posterior temporal cortex and inferior parietal lobule. Apolipoprotein E epsilon4 haplotype frequency was 20% in NFPA, 0% in SD, and 67% in LPA. Cognitive, genetic, and anatomical features indicate that different PPA clinical variants may correspond to different underlying pathological processes.

Aged↗
PubMed2004

Isolated executive impairment and associated frontal neuropathology.

Cognitive impairment in the absence of dementia is common in elderly individuals and is most often studied in the context of an isolated impairment in memory. In the current study, we report the neuropsychological and neuropathological features of a nondemented elderly individual with isolated impairment on a test of executive function (i.e., Trail Making Test) and preserved memory, language, and visuospatial function. Postmortem studies indicated that cortical neurofibrillary tangles (NFT) varied considerably, and some regions contained large numbers of neuritic senile plaques. Semiquantitative immunohistochemistry showed higher NFT and amyloid-beta (Abeta) loads in the frontal cortex relative to the temporal, entorhinal, occipital, and parietal cortices. A survey of the entire cingulate gyrus showed a wide dispersion of Abeta42 with the highest concentration in the perigenual part of the anterior cingulate cortex; Abeta appeared to be linked with neuron loss and did not overlap with the heaviest neuritic degeneration. The current case may represent a nonmemory presentation of mild cognitive impairment (executive mild cognitive impairment) that is associated with frontal and anterior cingulate pathology and may be an early stage of the frontal variant of Alzheimer disease.

Aged↗
PubMed2003

August Knoblauch and amusia: a nineteenth-century cognitive model of music.

Early models of human cognition can be traced to nineteenth-century investigations of brain and behavior. Influential neurologists such as Wernicke, Kussmaul, and Lichtheim constructed diagrammatic models to illustrate current theories of cognition. Language was the most commonly studied cognitive function during this time; however, investigators also studied other cognitive functions, such as music and visual processing. While a number of nineteenth-century neurologists made observations about music abilities in aphasic patients, August Knoblauch, a German physician and anatomist, was the first to propose a diagrammatic model of music (1888/1890). He described a detailed cognitive model of music processing, hypothesized the existence of nine disorders of music production and perception, and coined the term "amusia." Knoblauch's model is the earliest cognitive model of music and is largely unrecognized as an important part of the history of neurology, neuropsychology, and music cognition.

Agnosia↗
PubMed2003

Distinctive neuropsychological patterns in frontotemporal dementia, semantic dementia, and Alzheimer disease.

OBJECTIVE: To assess the ability of a brief neuropsychological bedside screening battery to discriminate between Alzheimer disease, frontotemporal dementia, and semantic dementia. METHODS: Subjects were 21 patients with frontotemporal dementia, 14 patients with semantic dementia, and 30 patients with Alzheimer disease comparable in terms of Mini Mental Status Examination score, age, and education. Frontotemporal dementia and semantic dementia diagnoses were made clinically using the consensus criteria of Neary et al. 1 Subjects were administered a brief neuropsychological screening assessing episodic memory, working memory, executive function, naming, spatial ability, abstract reasoning, and calculations. RESULTS: Both the Alzheimer disease and semantic dementia groups were significantly impaired relative to the frontotemporal dementia group on verbal memory, whereas only the Alzheimer disease group was impaired on visual memory. Frontotemporal dementia patients performed significantly worse on backward digit span and made significantly more executive errors than Alzheimer disease and semantic dementia patients. Semantic dementia patients were more impaired than Alzheimer disease and frontotemporal dementia patients on confrontation naming. Discriminant function analyses identified the 5 most discriminating variables that correctly classified 89.2% of cases. CONCLUSIONS: Frontotemporal dementia, semantic dementia, and Alzheimer disease are associated with distinct neuropsychological profiles that classify these dementia syndromes with considerable success. The neuropsychological profiles highlight the distinctiveness between the 3 syndromes, are consistent with the known loci of neuropathology in these conditions, and can potentially serve as an adjunct to the current clinical criteria.

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↗