Objective: The presented case report aims to show the possible overlap between causes of neurocognitive decline and the importance of considering comorbidities when discussing anti-amyloid monoclonal antibodies therapies for neurocognitive decline.
Background: Mild neurocognitive disorder is memory loss that does not impair activities of daily living. Alzheimer’s disease (AD), Dementia with Lewy Bodies (DLB), and Parkinson’s Disease (PD), can cause mild neurocognitive decline, but are not often seen in literature as co-occurring. In addition, ApoE mutations (characteristic of genetic predisposition to AD) are not associated with PD development.
Method: We describe a patient diagnosed with clinical PD who was found to have biomarkers of AD.
Results: A 63-year old male presented with memory difficulties for 3.5 years, resting tremor, and stiff movement. Examination included a mild amplitude action tremor of the right hand. Patient walked with normal stride length and reduced arm swing on the right side in comparison to the left. On MOCA, patient scored 28/30 due to ⅗ words correct on delayed recall.
Neuropsychology testing demonstrated mild neurocognitive dysfunction. PET amyloid showed “positive exam consistent with moderate to frequent amyloid cortical neuritic plaques.” DAT Scan showed “significant decreased radiotracer activity in the bilateral caudate and bilateral putamen characteristic for Parkinsonian Syndrome.” Patient also had A/T/N biomarker abnormalities with a score of +7, homozygosity for ApoE 4 mutation, and elevations in p-tau181 beta-amyloid 42/40 and beta-amyloid. Patient was started on donepezil. Initiation of dopaminergic therapy was deferred, as his movement abnormalities had little effect on ADLs. Anti-amyloid treatment was deferred.
Conclusion: Co-occurrence of ApoE mutations with Parkinsonian symptoms and positive DAT scan is rare in literature, and because of this there is limited research into best treatments and the safety profile of anti-amyloid monoclonal antibodies for these patients and their prognosis. This case represents one such instance of abnormal imaging and genetic findings in early-onset neurocognitive decline with movement abnormalities, and demonstrates the necessity of counseling patients on possible treatments as well as researching the safety of new therapies in patients with multifactorial dementias.
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To cite this abstract in AMA style:
A. Mason, R. Payne, N. Shneyder, E. Baldinger. Co-Occurrence of DAT Scan, Amyloid PET Scan, and Alzheimer’s Genetic Screening Abnormalities in Patient with Early-Onset Neurocognitive Decline: A Case Report [abstract]. Mov Disord. 2025; 40 (suppl 1). https://www.mdsabstracts.org/abstract/co-occurrence-of-dat-scan-amyloid-pet-scan-and-alzheimers-genetic-screening-abnormalities-in-patient-with-early-onset-neurocognitive-decline-a-case-report/. Accessed October 5, 2025.« Back to 2025 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/co-occurrence-of-dat-scan-amyloid-pet-scan-and-alzheimers-genetic-screening-abnormalities-in-patient-with-early-onset-neurocognitive-decline-a-case-report/