A Thesis submitted to The University of Arizona College of Medicine - Phoenix in partial fulfillment of the requirements for the Degree of Doctor of Medicine. / Objective: Formed visual hallucinations are a common phenomenon in neurodegenerative disorders such as Parkinson’s Disease (PD), Alzheimer’s disease (AD) and Dementia with Lewy bodies (DLB). While Lewy‐type alpha‐synucleinopathy (LTSis the hallmark neuropathological finding in PD and DLB, amyloid plaques and neurofibrillary tangles are the pathological finding in AD. Previous research has linked complex or formed visual hallucinations (VH) to LTS in neocortical and limbic areas in patients with PD and DLB. As VH also occur in Alzheimer’s disease, and AD pathology often co‐occurs with LTS, we questioned whether this pathology might also be linked to VH.
Methods: We performed a semi‐quantitative neuropathological study across brainstem, limbic,
and cortical structures in subjects with a documented clinical history of VH and a clinicopathological diagnosis of Parkinson’s disease (PD), Alzheimer’s disease (AD), or dementia with Lewy bodies (DLB). 173 subjects – including 50 with VH and 123 without VH – were selected from the Arizona Study of Aging and Neurodegenerative Disorders. Clinical variables examined included the Mini‐mental State Exam, Hoehn & Yahr stage, and total dopaminergic medication dose. Neuropathological variables examined included total and regional LTS and plaque and tangle densities.
Results: A significant relationship was found between the density of LTS and the presence of VH
in all diagnostic groups. Plaque and tangle densities also were associated with VH in PD (p=.003 for plaque and p=.004 for tangles), but not in AD, where densities were high regardless of the presence of hallucinations..
Conclusion: Plaques and tangles as well as LTS may contribute to the pathogenesis of VH. Incident VH may be a clinical indicator of underlying pathological events: the development of plaques and tangles in patients with PD, and LTS in patients with AD.
| Identifer | oai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/535398 |
| Date | 13 April 2015 |
| Creators | Morshed, Trisha |
| Contributors | The University of Arizona College of Medicine - Phoenix, Jacobson, Sandra MD |
| Publisher | The University of Arizona. |
| Source Sets | University of Arizona |
| Language | en_US |
| Detected Language | English |
| Type | Thesis |
| Rights | Copyright © is held by the author. Digital access to this material is made possible by the College of Medicine - Phoenix, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. |
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