The Use of Event Related Potentials to Predict Amyloid PET Status Among Patients from a Memory Disorders Clinic.

Background: Amyloid positron emission tomography (PET) scans provide in vivo evidence of Alzheimer's disease (AD); however, their high cost limits their use in standard clinical care. Event related potentials (ERPs) may represent an inexpensive and non-invasive additional method for detecting AD pathology. Objective: We investigated whether ERPs, along with neuropsychological data, serve as predictors of amyloid PET status in patients with memory complaints. Methods: Veterans aged 50-100 were recruited from a memory disorders clinic. Participants underwent a neuropsychological battery and an ERP auditory oddball protocol. Twenty-eight patients had a positive amyloid PET scan, and thirty-nine patients had a negative scan. Results: ERP-P200 target amplitude and P200 standard latency were predictors of amyloid PET status. When submitting to ROC analysis, P200 standard latency exhibited the highest specificity and sensitivity in predicting amyloid PET positivity, correctly classifying the amyloid PET status for 86% of patients. Conclusions: ERP-P200 measures are strong indicators of amyloid-ß presence in patients from a memory disorder clinic. Increased P200 amplitude and decreased P200 latency in patients with a positive amyloid PET scan may be attributed to hyperactivation of perceptual bottom-up processes compensating for AD-related synaptic loss in the fronto-parietal networks.

Glial Fibrillary Acidic Protein (GFAP) Astrocytopathy: An Emerging Cause of Meningoencephalomyelitis in Children and Adolescents.

Introduction: We describe 5 children with GFAP astrocytopathy with the goal of further characterizing this rare form of meningoencephalomyelitis. Methods: Retrospective chart review of patients diagnosed with GFAP astrocytopathy between 2019 and 2021. Results: Patients were 8-17 years old, and all were male. Fever, headache, and vomiting were common presenting symptoms, and weakness, tremor, and ataxia were common initial examination findings. Initial magnetic resonance imaging (MRI) showed spinal cord abnormalities in 2 patients and leptomeningeal enhancement in 1. Most patients had cerebral spinal fluid pleocytosis, and all screened negative for malignancy. Three patients progressed to coma, and all were treated with immunosuppressant therapy. By discharge, all patients had improved over their clinical nadir, although none had returned to baseline. Discussion: GFAP astrocytopathy is a recently recognized cause of meningoencephalomyelitis in children. Here, we expand our understanding of this entity with the goal of aiding those treating children with GFAP astrocytopathy.

Bilateral Retinal and Lateral Geniculate Nucleus Infarction in an Adolescent With Influenza.

We describe a 13-year-old female with influenza complicated by bilateral vision loss due to retinal and lateral geniculate nucleus (LGN) infarctions. She continues to have near-total vision loss in her left eye 3.5 years later. This is the second reported case of bilateral retinal and LGN infarctions in the setting of influenza. The mechanism of infarction remains to be determined, but it is important to recognize this entity and counsel patients appropriately as visual recovery may be poor.

Distinguishing Between Genuine and Feigned Dementia Using Event-related Potentials.

BACKGROUND: Individuals with probable Alzheimer disease (AD) may perform below cutoffs on traditional, memory-based performance validity tests. Previous studies have found success using event-related potentials (ERPs) to detect feigned neurocognitive impairment in younger populations. OBJECTIVE: To evaluate the utility of an auditory oddball task in conjunction with the P3b peak amplitude to distinguish probable AD from simulated dementia. METHOD: Twenty individuals with probable AD and 20 older healthy controls (HC) underwent an ERP auditory oddball protocol and the Test of Memory Malingering (TOMM). The HC were asked to perform honestly for one condition and to simulate dementia for the other. The individuals with probable AD were asked to perform honestly. The P3b peak amplitude and button press accuracy were collected from each participant and were analyzed to determine their effectiveness in detecting performance validity. RESULTS: The P3b peak amplitude remained stable regardless of behavioral condition in the HC group. When combined with the TOMM Trial 2 score, the P3b peak amplitude further improved the ability to correctly differentiate individuals with probable AD from HC simulating dementia with 100% sensitivity and 90% specificity. CONCLUSION: The P3b peak amplitude was found to be an effective physiologic measure of cognitive impairment in individuals with probable AD compared with HC simulating dementia. When combined with the TOMM Trial 2 score, the P3b peak amplitude served as a promising performance validity measure for differentiating individuals with probable AD from HC simulating dementia.

Head Injury Exposure in Veterans Presenting to Memory Disorders Clinic: An Observational Study of Clinical Characteristics and Relationship of Event-Related Potentials and Imaging Markers.

Objective: Traumatic brain injury (TBI) and repetitive head impacts (RHI) related to blasts or contact sports are commonly reported among military service members. However, the clinical implications of remote TBI and RHI in veterans remains a challenge when evaluating older veterans at risk of neurodegenerative conditions including Alzheimer's disease (AD) and Chronic Traumatic Encephalopathy (CTE). This study aimed to test the hypothesis that veterans in a memory disorders clinic with remote head injury would be more likely to have neurodegenerative clinical diagnoses, increased rates of amyloid PET positivity, higher prevalence of cavum septum pellucidi/vergae, and alterations in event-related potential (ERP) middle latency auditory evoked potentials (MLAEPs) and long latency ERP responses compared to those without head injuries. Methods: Older veterans aged 50-100 were recruited from a memory disorders clinic at VA Boston Healthcare system with a history of head injury (n = 72) and without head injury history (n = 52). Patients were classified as reporting prior head injury including TBI and/or RHI exposure based on self-report and chart review. Participants underwent MRI to determine presence/absence of cavum and an ERP auditory oddball protocol. Results: The head injury group was equally likely to have a positive amyloid PET compared to the non-head injury group. Additionally, the head injury group were less likely to have a diagnosis of a neurodegenerative condition than those without head injury. P200 target amplitude and MLAEP amplitudes for standard and target tones were decreased in the head injury group compared to the non-head injury group while P3b amplitude did not differ. Conclusions: Veterans with reported remote head injury evaluated in a memory disorders clinic were not more likely to have a neurodegenerative diagnosis or imaging markers of neurodegeneration than those without head injury. Decreased P200 target and MLAEP target and standard tone amplitudes in the head injury group may be relevant as potential diagnostic markers of remote head injury.

Cold Atmospheric Plasma as an Adjunct to Immunotherapy for Glioblastoma Multiforme.

Glioblastoma multiforme (GBM) is the most common and aggressive form of brain cancer in adults. GBM carries a dismal prognosis because of its proliferative, invasive, and angiogenic capabilities and because of its ability to downregulate the immune system. Immune-based therapies under investigation for GBM have been unsuccessful in vivo because of this downregulation. Cold atmospheric plasma (CAP) is a high-energy state of matter that can be applied directly or indirectly to tumor tissue to serve as an adjunct to immunotherapy in the treatment of GBM because it upregulates the immune system by the induction of reactive oxygen species. CAP has the potential to improve the efficacy of existing and investigative immunotherapies for GBM.