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Biomedical subjects

Richard K Olney

Publications and source records attributed to Richard K Olney.

8 recordsLinked to original sources

Dysphagia in patients with frontotemporal lobar dementia.

BACKGROUND: Hyperorality, compulsive eating and aspiration because of food gorging, has been described in patients with frontotemporal lobar dementia (FTLD), but swallowing function in this population has not been reported. OBJECTIVE: To identify the swallowing status in a sample of patients with FTLD. DESIGN: Case series. SETTING: Referral center, ambulatory care. PATIENTS: A consecutive series of referred patients with 3 variants of FTLD were asked to participate. Twenty-one patients were enrolled, including 9 with frontotemporal dementia, 7 with progressive nonfluent aphasia, and 5 with semantic dementia. INTERVENTION: The patients underwent a fiberoptic endoscopic examination of swallowing to assess their ability to swallow liquids and food. MAIN OUTCOME MEASURES: Presence of dysphagia and nature of impaired swallowing. RESULTS: Of the 21 patients, 4 caretakers reported swallowing difficulties. An instrumental examination revealed moderate swallowing abnormalities in 12 of the 21 patients. These abnormalities were not explained by compulsive eating behaviors, but seemed to reflect deficits in cortical and subcortical pathways connecting with the brainstem swallowing center. CONCLUSIONS: When assessed via instrumentation, swallowing abnormalities are found in many patients with FTLD. The appearance of dysphagia signals progression of FTLD to brainstem systems.

Adult↗

Proposed modification to data analysis for statistical motor unit number estimate.

Motor unit number estimation (MUNE) is an important electrophysiological technique for quantitative measurement of motor neuron loss. Although commonly used, there is no consensus concerning the optimal procedure for statistical MUNE, particularly regarding several operator-dependent variables. To assess the variables, we analyzed 500 sequential, submaximal compound muscle action potential (CMAP) responses at three or four stimulus intensities in 10 controls and 10 patients with amyotrophic lateral sclerosis (ALS). In both controls and ALS patients, we found that posttest filtering data based on 20% or 25% windows or 2, 2.5, or 3 SD excludes <5% of data. Windows of 10% or 15% excluded <5% of data in controls but not in ALS patients. Excluding data based on +/-2 SD, the coefficient of variation for final MUNE was 12% in controls and 6% in ALS patients. Group sizes of 30 or 50 and sample sizes of 300 to 500 sequential CMAP responses per run yielded the lowest coefficient of variation. We propose that statistical MUNE data should be analyzed based on excluding data >2 SD from the mean, because this is operator independent, includes the majority of data, effectively excludes clearly outlying data, such as fasciculations or movement artifact, and has a reasonable coefficient of variation.

Adult↗

Consensus criteria for the diagnosis of multifocal motor neuropathy.

At this time, there are no widely accepted criteria for the diagnosis of multifocal motor neuropathy. Furthermore, there is insufficient empirical data to define clinical and laboratory features that may reliably separate certain lower motor neuron syndromes with overlapping features as distinct. The AAEM therefore developed five criteria through a formal consensus process that are described in this document to act as a guide for diagnosing multifocal motor neuropathy with a high level of confidence (definite multifocal motor neuropathy) or with a moderate level of confidence (probable motor neuropathy). In brief, the diagnosis requires clinical weakness without objective sensory loss or upper motor neuron signs in the distribution of two or more named nerves that is due to conduction block in two or more motor nerves outside of common entrapment sites. Furthermore, normal results are required for sensory nerve conduction studies.

Consensus↗

Charcot-Marie-Tooth disease and related neuropathies: mutation distribution and genotype-phenotype correlation.

Charcot-Marie-Tooth disease (CMT) is a genetically heterogeneous disorder that has been associated with alterations of several proteins: peripheral myelin protein 22, myelin protein zero, connexin 32, early growth response factor 2, periaxin, myotubularin related protein 2, N-myc downstream regulated gene 1 product, neurofilament light chain, and kinesin 1B. To determine the frequency of mutations in these genes among patients with CMT or a related peripheral neuropathy, we identified 153 unrelated patients who enrolled prior to the availability of clinical testing, 79 had a 17p12 duplication (CMT1A duplication), 11 a connexin 32 mutation, 5 a myelin protein zero mutation, 5 a peripheral myelin protein 22 mutation, 1 an early growth response factor 2 mutation, 1 a periaxin mutation, 0 a myotubularin related protein 2 mutation, 1 a neurofilament light chain mutation, and 50 had no identifiable mutation; the N-myc downstream regulated gene 1 and the kinesin 1B gene were not screened for mutations. In the process of screening the above cohort of patients as well as other patients for CMT-causative mutations, we identified several previously unreported mutant alleles: two for connexin 32, three for myelin protein zero, and two for peripheral myelin protein 22. The peripheral myelin protein 22 mutation W28R was associated with CMT1 and profound deafness. One patient with a CMT2 clinical phenotype had three myelin protein zero mutations (I89N+V92M+I162M). Because one-third of the mutations we report arose de novo and thereby caused chronic sporadic neuropathy, we conclude that molecular diagnosis is a necessary adjunct for clinical diagnosis and management of inherited and sporadic neuropathy.

Adolescent↗