The N1 auditory event-related potential (ERP) is reduced in chronic schizophrenia, as is the P2 to attended tones. N1 reduction may be endophenotypic for schizophrenia, being reduced in twins of schizophrenic patients and showing heritability. Results in family members, however, are equivocal, with abnormally small N1 (consistent with an endophenotype) and abnormally large N1 (inconsistent with an endophenotype) reported. P2 has been little studied in schizophrenia or family members. One crucial step in establishing endophenotypes is to rule out causal chronicity factors. We examined schizophrenia patients within 1 year of first hospitalization (most within 2 wk), chronically ill patients, and matched controls to examine N1 and P2 reductions and disease stage. Two active target detection oddball tasks were used, one with 97-dB tones against 70-dB white masking noise, the second with 97-dB tones without noise. Results from 8 samples are reported: first-hospitalized patients and matched controls and chronic patients and matched controls for the 2 tasks. N1 and P2 were measured from the standard stimuli. N1 and P2 were significantly reduced in chronic patients, as expected, and reduced in first-hospitalized patients. Because N1 and P2 are reduced even at the first hospitalization for schizophrenia, they may serve as viable electrophysiological endophenotypes for the disorder. However, deficit early in the disease is necessary but not sufficient to establish these ERPs as endophenotypes. Deficits must next be demonstrated in at least a subset of unaffected family members, a crucial criterion for an endophenotype.

Traumatic brain injury (TBI) is the commonest cause of disability in under-40-year-olds. Vestibular features of dizziness (illusory self-motion) or imbalance which affects 50% of TBI patients at 5 years, increases unemployment threefold in TBI survivors. Unfortunately, vestibular diagnoses are cryptogenic in 25% of chronic TBI cases, impeding therapy. We hypothesized that chronic adaptive brain mechanisms uncouple vestibular symptoms from signs. This predicts a masking of vestibular diagnoses chronically but not acutely. Hence, defining the spectrum of vestibular diagnoses in acute TBI should clarify vestibular diagnoses in chronic TBI. There are, however, no relevant acute TBI data. Of 111 Major Trauma Ward adult admissions screened (median 38-years-old), 96 patients (87%) had subjective dizziness (illusory self-motion) and/or objective imbalance were referred to the senior author (BMS). Symptoms included: feeling unbalanced (58%), headache (50%) and dizziness (40%). In the 47 cases assessed by BMS, gait ataxia was the commonest sign (62%) with half of these cases denying imbalance when asked. Diagnoses included BPPV (38%), acute peripheral unilateral vestibular loss (19%), and migraine phenotype headache (34%), another potential source of vestibular symptoms. In acute TBI, vestibular signs are common, with gait ataxia being the most frequent one. However, patients underreport symptoms. The uncoupling of symptoms from signs likely arises from TBI affecting perceptual mechanisms. Hence, the cryptogenic nature of vestibular symptoms in TBI (acute or chronic) relates to a complex interaction between injury (to peripheral and central vestibular structures and perceptual mechanisms) and brain-adaptation, emphasizing the need for acute prospective, mechanistic studies.

Older men exhibit poorer adaptation to aging with MS than older women.

Background This study reports on the results of a screening program for Chagas disease in East Boston. Methods Based at the East Boston Neighborhood Health Center, the Strong Hearts Program offers continuing medical education sessions on Chagas disease to providers in Adult Medicine, Pediatrics, Family Medicine and Obstetrics. Providers are encouraged to offer one-time screening for Chagas disease for all patients who lived in Mexico, South or Central America for ≥6 months, at their discretion. A commercial lab performs the initial screening test using the Hemagen ELISA while confirmatory testing is performed at the US CDC. For each patient, completion of screening requires a multi-step process consisting of splitting the serum sample to save a frozen aliquot for send out to CDC if the ELISA is positive/indeterminate, monitoring screening results to send the saved aliquot to the CDC if indicated, filling out the CDC requisition, shipping the serum aliquot, and monitoring the result returning from the CDC. Patients diagnosed with confirmed Chagas disease are referred to Boston Medical Center for further evaluation and treatment if indicated. Results From 3/21/2017 – 5/18/2020, 8,142 patients were screened. 423 (5.2%) patients had an initial positive test, 7,669 (94.2%) initially tested negative and 50 were indeterminate (0.6%). Among those with a positive screening result, 76 were confirmed to have T. cruzi infection for an overall prevalence of 0.93% in this population. 293 (69.3%) patients with positive screening tests had a negative (discordant) confirmatory test, 18 (4.3%) had an indeterminate test, and 36 (8.5%) had results that were unavailable or pending as of this analysis. None of the indeterminate screening tests were positive upon confirmation. Conclusion Prevalence of infection with T. cruzi was nearly 1% among patients in East Boston who had lived in Latin America. Diagnosis of Chagas was challenging due to a large number of false positive screening tests. The resource burden imposed by current screening options is itself a barrier to addressing Chagas disease. Given the significant prevalence of Chagas disease in the US, increased access to tests (i.e., two-step screening conducted through commercial laboratories) and screening assays with improved specificity are needed. Disclosures All Authors: No reported disclosures