Faculty Bibliography

Clinical and neuropathological staging of Alzheimer's disease (AD) neurodegeneration and neuronal loss dynamics is the baseline for identification of treatment targets and timing. The aim of this study of 14 brain regions in 25 subjects diagnosed with AD and 13 age-matched control subjects was to establish the pattern of neurodegeneration, and the severity and rate of neuronal loss in mild cognitive impairment/mild AD (Functional Assessment Staging [FAST] test 3-4), moderate to moderately severe AD (FAST 5-6), and severe AD (FAST 7). The study revealed (1) the most severe neuronal loss in FAST 3-4; (2) the highest rate of neuronal loss in FAST 5-6, to the "critical" point limiting further increase in neuronal loss; (3) progression of neurofibrillary degeneration, but decline of neuronal loss to a floor level in FAST 7; and (4) structure-specific rate of neuronal loss caused by neurofibrillary degeneration and a large pool of neuronal loss caused by other mechanisms. This study defines a range and speed of progression of AD pathology and functional decline that might potentially be prevented by the arrest of neuronal loss, both related and unrelated to neurofibrillary degeneration, during the 9-year duration of mild cognitive impairment/mild AD.

Persistent post-traumatic headache (PPTH) is often the most common injury post mild traumatic brain injury (mTBI), reported by 47%-95% of patients. Progressive muscle relaxation (PMR) has level A evidence in preventing migraine and tension headaches. However, research on this behavioral therapy for PPTH, let alone smartphone-delivered, is limited. We performed a single-arm study of prospective patients calling our Concussion Center between June 2017-July 2018. Inclusion criteria were that subjects had to meet ICHD-3 criteria for PPTH secondary to mTBI, have four or more headache days a month, be age 18-85 and 3-12 months post injury, own a smartphone and not tried headache behavioral therapy within the year. We recorded baseline headache and neuropsychiatric data. Using the RELAXaHEAD smartphone application, which has a headache diary and PMR audio files, participants were instructed to record headache symptoms and practice 20 minutes of PMR daily. There were three monthly follow-up assessments. There were 49 subjects enrolled. Basic demographics were: 33 (67%) female with mean age 40.1±14.6 [20,75]. Of the 49 subjects, 15 (31%) had pre-existing headaches. In 11 (22%) subjects, mTBI was sports-related. Subjects reported 17.7±9.3 [4,31] headache days in the month before enrollment, and 49 (100%) experienced over three concussion symptoms. Participants inputted data in the RELAXaHEAD app on average 18.3±12.0 days [0,31] the first month. Number of participants who did PMR over 4 times/week was 12 (24.5%) the first month, 9 (22.5 %) the second month, and 6 (15%) the third month. After three months, 17 (42.5 %) participants continued doing PMR. Participants cited time constraints, forgetfulness, application glitches and repetitiveness as obstacles to practicing PMR. It is feasible to get PPTH subjects to practice behavioral therapy through low-cost smartphone-based PMR two times weekly. Future work will assess efficacy and examine how to optimize barriers to PMR.

The dialogue between cortex and hippocampus is known to be crucial for sleep-dependent memory consolidation. During slow wave sleep, memory replay depends on slow oscillation (SO) and spindles in the (neo)cortex and sharp wave-ripples (SWRs) in the hippocampus. The mechanisms underlying interaction of these rhythms are poorly understood. We examined the interaction between cortical SO and hippocampal SWRs in a model of the hippocampo-cortico-thalamic network and compared the results with human intracranial recordings during sleep. We observed that ripple occurrence peaked following the onset of an Up-state of SO and that cortical input to hippocampus was crucial to maintain this relationship. A small fraction of ripples occurred during the Down-state and controlled initiation of the next Up-state. We observed that the effect of ripple depends on its precise timing, which supports the idea that ripples occurring at different phases of SO might serve different functions, particularly in the context of encoding the new and reactivation of the old memories during memory consolidation. The study revealed complex bidirectional interaction of SWRs and SO in which early hippocampal ripples influence transitions to Up-state, while cortical Up-states control occurrence of the later ripples, which in turn influence transition to Down-state.

PURPOSE OF REVIEW/OBJECTIVE:The mental health toll on populations exposed to COVID-19 is alarming, and there is a need to address this with urgency. This current review provides insights on how individuals, communities, and specific populations, such as healthcare workers and patients are leveraging pre-COVID-19 and peri-COVID-19 factors to reinforce their psychological resilience during the global public health crisis. RECENT FINDINGS/RESULTS:Examination of the extant literature indicated that populations around the world rely often on support from their loved-ones, closed significant others, outdoor and physical activities, and spirituality to cope with the COVID-19-related distress. Increased sense of meaning/purpose since the COVID-19 pandemic was also reported. SUMMARY/CONCLUSIONS:A portion of publications provided intervention models to reinforce resilience among specific populations during the COVID-19 pandemic. Nevertheless, it is not convincing that some of these models can be applied universally. Additionally, it is important to note that in this category, translational data was scarce.

OBJECTIVE:Intraoperative neuromonitoring (IONM) techniques aim to identify and potentially prevent nerve injury during surgeries. Prior studies into the efficacy of recurrent laryngeal nerve (RLN) IONM convey mixed results, with some claiming equivalence between IONM and no monitoring at all. The goal of the current study was to compare continuous RLN monitoring using the laryngeal adductor reflex (LAR) to intermittent RLN monitoring (intermittent IONM) to determine whether continuous monitoring reduces the incidence of intraoperative RLN injury during neck endocrine surgeries. METHODS:In this observational, historical case-control study, a historical cohort of patients monitored with intermittent-IONM (group 1, n = 130) were compared to prospectively collected data from consecutive nerves-at-risk monitored continuously with the LAR (LAR-CIONM, group 2, n = 205), at a single center by a single surgeon. The test benefit ratio and relative risk reduction (RRR) for LAR-CIONM over intermittent IONM were calculated. RESULTS:For group 1, nine nerves at risk exhibited intraoperative LOS with transient postoperative vocal fold (VF) hypomobility (n = 2) or immobility (VFI, n = 7). For group 2, two nerves at risk (0.98%) had sudden intraoperative LAR LOS following bipolar cautery, resulting in postoperative transient VFI (P = .004). In each group, there was one case of permanent postoperative VFI. The test benefit rate ratio for LAR-CIONM demonstrated a dramatic effect at 5.23, with an RRR of 81.0%. CONCLUSION/CONCLUSIONS:LAR-CIONM significantly decreased rates of postoperative transient VF paralysis and paresis over intermittent IONM alone (P = .004). Surgeons should be aware of the benefits and limitations of intermittent IONM versus CIONM. Intermittent IONM, although useful in nerve mapping and intraoperative decision making, has minimal benefit for the prevention of nerve injury, whereas CIONM can potentially reduce nerve injury rates and improve patient outcomes. LEVEL OF EVIDENCE/METHODS:3 Laryngoscope, 2020.