Table of Contents
Washington University Experience | NEURODEGENERATION | Alzheimer Disease | Gross Pathology | 6A0 Case 6 History
Case 6 History ---- In August 2005, at age 60y, this laboratory manager at Washington University Medical Center was referred by her internist to the Memory Diagnostic Center (MDC) for evaluation of presumptive “posterior cortical dysfunction” (PCD). At age 55 y, there was the gradual onset of uncharacteristically poor judgement and forgetfulness, geographic disorientation when driving, and language difficulty (unable to write in cursive; spelling errors). Her ability to make even simple calculations deteriorated. She also developed emotional “flatness”, decreased initiative, and was more withdrawn in social situations. The patient reported feelings of sadness. There were moderate-to-severe deficits in visuospatial abilities, reading and writing, calculations, and working memory; there were milder deficits in learning and retention. MRI in April 2005 showed mild-to-moderate diffuse cerebral atrophy. The visuospatial deficits, language problems, and dyscalculia were attributed to PCD; the accompanying but milder deficits in memory and executive function were considered to represent underlying AD. Her final MDC visit was in October 2009, at age 64y. She had disturbing visual hallucinations (“spiders”) that were successfully treated with quetiapine. She recently had been incontinent of stool and she required total care for dressing, grooming, and bathing. She experienced a generalized tonic-clonic seizure in November 2009 and was admitted to a nursing facility in November 2010. She became “cortically blind” and wheelchair dependent. She expired, presumably of inanition in August 2015 at age 70 y, following a 15 year course of progressive PCD and global dementia. ---- This patient was thought to suffer from three clinical phenotypes. The first phenotype was PCD with visuospatial deficits (documented by neuropsychological testing in July 2015) as manifested by topographical disorientation (environmental agnosia), simultanagnosia, and/or visuospatial neglect, optic ataxia, and cortical blindness, which localize to the bilateral occipito-parietal and occipital lobes. Her dressing apraxia also localizes to the occipito-parietal lobes. She also had Gerstmann’s syndrome (nonfluent aphasia with dysgraphia, dyscalculia, and right-left disorientation), implicating the angular gyrus of the dominant inferior parietal lobe. The second phenotype was global dementia with progressive deficits in memory and executive function that resulted in interference with her performance of accustomed activities (employment, self-care). The third phenotype (potentially) was possibly dementia with Lewy bodies (DLB) as she developed visual hallucinations and extrapyramidal features (cogwheel rigidity, parkinsonian gait). However, the hallucinations were not an early manifestation of her illness (appeared 7 years or so after symptomatic onset). Thus, the DLB phenotype is less well-established than PCD superimposed on the global dementia. Additional features included depression early in her clinical course and later visual hallucinations; myoclonus (by report), and a generalized tonic-clonic seizure (all can occur as complications of late-stage AD dementia). Neuropathological substrates of progressive PCD include AD (most frequent), the Parkinson disease PD/DLB spectrum, corticobasal degeneration, and prion-associated disease (PMID: 15477534) ---- The patient died in August 2015. The clinical cause of death was inanition.
