Faculty Bibliography

OBJECTIVES/OBJECTIVE:Late-onset epilepsy has the highest incidence among all age groups affected by epilepsy and often occurs in the absence of known clinical risk factors such as stroke and dementia. There is increasing evidence that brain changes contributing to epileptogenesis likely start years before disease onset, and we aim to relate cognitive and imaging correlates of subclinical brain injury to incident late-onset epilepsy in a large, community-based cohort. METHODS:We studied Offspring Cohort of the Framingham Heart Study participants 45 years or older, who were free of prevalent stroke, dementia, or epilepsy, and had neuropsychological (NP) evaluation and brain magnetic resonance imaging (MRI). Cognitive measures included Visual Reproduction Delayed Recall, Logical Memory Delayed Recall, Similarities, Trail Making Test B minus A (TrTB-TrTA; attention and executive function), and a global measure of cognition derived from principal component analysis. MRI measures included total cerebral brain volume, cortical gray matter volume (CGMV), white matter hyperintensity volume (WMHV), and hippocampal volume. Incident epilepsy was identified through a review of administrative data and medical records. Cox proportional hazards regression models were used for the analyses. All analyses were adjusted for age, sex, and educational level (cognition only). RESULTS:Among participants who underwent NP testing (n = 2349, 45.81% male), 31 incident epilepsy cases were identified during follow-up. Better performance on the TrTB-TrTA was associated with a lower risk of developing epilepsy (hazard ratio [HR] .25, 95% confidence interval [CI] .08-.73; p = .011). In the subgroup of participants with MRI (n = 2056, 46.01% male), 27 developed epilepsy. Higher WMHV was associated with higher epilepsy risk (HR 1.5, 95%CI 1.01-2.20; p = .042), but higher CGMV (HR .73, 95% CI .57-.93; p = .001) was associated with lower incidence of epilepsy. SIGNIFICANCE/CONCLUSIONS:Better performance on the (TrTB-TrTA), a measure of executive function and attention, and higher cortical volumes are associated with lower risk of developing epilepsy. Conversely, higher WMHV, a measure of occult vascular injury, increases the risk. Our study shows that non-invasive tests performed in mid-life may help identify people at risk for developing epilepsy later in life.

Perceptual awareness results from an intricate interaction between external sensory input and the brain's spontaneous activity. Pre-stimulus ongoing activity influencing conscious perception includes both brain oscillations in the alpha (7 to 14 Hz) and beta (14 to 30 Hz) frequency ranges and aperiodic activity in the slow cortical potential (SCP, <5 Hz) range. However, whether brain oscillations and SCPs independently influence conscious perception or do so through shared mechanisms remains unknown. Here, we addressed this question in 2 independent magnetoencephalography (MEG) data sets involving near-threshold visual perception tasks in humans using low-level (Gabor patches) and high-level (objects, faces, houses, animals) stimuli, respectively. We found that oscillatory power and large-scale SCP activity influence conscious perception through independent mechanisms that do not have shared variance. In addition, through mediation analysis, we show that pre-stimulus oscillatory power and SCP activity have different relations to pupil size-an index of arousal-in their influences on conscious perception. Together, these findings suggest that oscillatory power and SCPs independently contribute to perceptual awareness, with distinct relations to pupil-linked arousal.

Nonlocal self-similarity within images has become an increasingly popular prior in deep-learning models. Despite their successful image restoration performance, such models remain largely uninterpretable due to their black-box construction. Our previous studies have shown that interpretable construction of a fully convolutional denoiser (CDLNet), with performance on par with state-of-the-art black-box counterparts, is achievable by unrolling a convolutional dictionary learning algorithm. In this manuscript, we seek an interpretable construction of a convolutional network with a nonlocal self-similarity prior that performs on par with black-box nonlocal models. We show that such an architecture can be effectively achieved by up-grading the

BACKGROUND/UNASSIGNED:High intensity focused ultrasound (HiFU) is a relatively new incisionless intervention used for treatment of essential tremor and Parkinson's disease tremor. Understanding the indications, benefits, risks and limitations of HiFU, as well as how it compares to deep brain stimulation (DBS), is important in guiding appropriate recommendations for prospective patients. METHODS/UNASSIGNED:Current literature on efficacy and safety of HiFU in essential tremor and Parkinson's disease was reviewed. We additionally reviewed data on the patients who presented to our center for HiFU consultation, including outcomes of patients with low skull density ratios, and distances traveled for the procedure. RESULTS/DISCUSSION/UNASSIGNED:HiFU is an effective and generally well-tolerated treatment for tremor. Adverse events, especially gait instability, are typically temporary but should be discussed with patients. The risk of tremor recurrence in certain patients with Parkinson's disease is also of note. Identifying appropriate candidates for either intervention remains crucial and involves considering each patient's circumstances and preferences, potential adverse effects, and practical aspects like access to follow-up and expectations. Data on bilateral HiFU lesioning, use of HiFU in patients with low skull density ratios, and emerging targets like the pallidothalamic tract are discussed as well.

Chronic inflammatory demyelinating polyneuropathy (CIDP) following viral infections and influenza vaccination has been well documented. However, there have been no confirmed natural influenza A infections leading to development of CIDP. Therefore, we present the case of a 6-year-old male who developed CIDP following a confirmed influenza A infection. Initially presenting with typical flu-like symptoms, the patient experienced a gradual onset of gait instability and leg weakness approximately 1 month later. Despite initial improvement with intravenous immunoglobulin therapy following a diagnosis of Guillain-Barré syndrome, his symptoms relapsed, including lower extremity weakness, incontinence, and sensory loss. Electromyography confirmed a demyelinating polyneuropathy, leading to a diagnosis of CIDP.

BACKGROUND/UNASSIGNED:Can we document that posterior cervical surgery (i.e., Laminoforaminotomy (LF) and Laminectomy (L) with Posterior Fusion (PF)) exposes patients to fewer adverse events (i.e., including negligence, multiple risks, negligence, errors, and mistakes) vs. anterior cervical surgery (i.e., Anterior Cervical Diskectomy/Fusion (ACDF) or Anterior Corpectomy/Fusion (ACF))? METHODS/UNASSIGNED:Posterior cervical surgery avoids many of the adverse events uniquely attributed to anterior cervical operations. These include; avoiding fusions with LF vs. ACDF for disc herniations, a lower rate of pseudarthrosis, the avoidance of direct laceration/indirect traction-related carotid/jugular vascular and/or dysphagia/esophageal injuries, fewer neural/cord injuries, vertebral artery injuries, and cerebrospinal fluid (CSF) leaks/dural tears (i.e., particularly with Ossification of the Posterior Longitudinal Ligament (OPLL)). RESULTS/UNASSIGNED:Posterior cervical surgery also poses no direct risks to the following anteriorly-located nerves: recurrent laryngeal nerve (i.e., vocal cord paralysis), phrenic nerve (i.e., diaphragmatic paralysis), the Vagus nerve (i.e., hypotension, reflux, arrhythmias), and sympathetic trunk (i.e., Horner's Syndrome). However, posterior cervical surgery is generally associated with a higher risk of infection (i.e., 2-10%) vs. anterior surgery (i.e., > 1%), more posterior muscle pain, and a higher risk of kyphosis. CONCLUSIONS/UNASSIGNED:Posterior cervical surgery exposes patients to many fewer adverse events vs. anterior cervical surgery. We therefore recommend that in appropriately chosen patients, posterior cervical surgical approaches should be chosen over anterior surgery.

Access to an academic clinical research center (CRC) in health professional shortage areas (HPSA) can help address healthcare disparities and increase research accessibility and enrollment. Here we describe the development of a community-centered CRC in the underserved area of Sunset Park, Brooklyn, New York, centered within a larger academic health network and the evaluation of its outcomes within the first two years. In addition to resources and space, establishment of the CRC required a culturally competent and multilingual team of healthcare professionals and researchers and buy-in from the community. Between 1/2022 and 12/2023, the CRC opened 21 new trials (10 interventional and 11 noninterventional) with greater than 500 participant visits that reflect the racial and ethnic diversity of the community. These participants represent 110 distinct zip codes; 76% of these zip codes are underserved and designated HPSA. 60% self-identified as non-White and 20% identified as Hispanic, with 12 other distinct ethnicities represented. 28% of participants speak 11 languages other than English. Community-based CRCs can be created with sustainable growth to align with the mission of the National Institutes of Health and U.S. Food and Drug Administration to meet the ever-growing clinical, social, and research needs of the communities they serve.

BACKGROUND/UNASSIGNED:In this short review/perspective, we asked what the frequencies would be for both postoperative spinal epidural hematomas (SpEH) and postoperative surgical site infections (SSI) in predominantly posterior lumbar procedures performed with or without the placement of wound drains? METHODS/UNASSIGNED:Many spine surgeons are trained to use wound drains to decrease the risk of postoperative SpEH, despite the potential increased risk of SSI. Alternatively, avoiding drains may increase the risk of SpEH but likely decrease the potential for SSI. RESULTS/UNASSIGNED:Performing predominantly posterior lumbar procedures with or without wound drains resulted in largely comparable frequencies of postoperative spinal epidural hematomas (SpEH; range of 0.10%-0.69%) and postoperative surgical site infections (SSI: range of 0.75%-7.3%). Notably, however, two studies documented that drains increased transfusion requirements, with one study showing a prolongation of the in-hospital length of stay. Critically, these series emphasized the importance of early/emergent diagnosis (i.e., with MR) and surgical treatment of SpEH to minimize residual neurological deficits. CONCLUSION/UNASSIGNED:Here, we showed that patients undergoing predominantly lumbar spine surgery performed with or without wound drains demonstrated comparable frequencies of postoperative SpEH and SSI. Nevertheless, spine surgeons must assess on a case-by-case basis whether, based on their education, training, and experience, placing a wound drain is appropriate for their particular patient.

There are more than two million amputees in the USA, and almost all will experience phantom limb sensations (PLS), describing the missing limb as still present. They may also experience intense pain, known as phantom limb pain (PLP), a considerable factor in poor quality of life. In some upper extremity amputees and following brachial plexus avulsion injury (BPAI), hand digits can be detected and mapped to distinct facial skin areas, termed hand-to-face remapping. In this study, we analysed PLS following brachial plexus anaesthesia (BPA) administered prior to upper limb surgeries. Our 39 participants had planned shoulder, wrist or hand surgery. We sought to determine the time course for the emergence of phantom limb experiences after BPA up to the following 24 hours in participants with intact limbs. We also investigated whether there was hand-to-face remapping, suggesting potential cortical reorganization, or changes in proprioception before and after the induction of BPA. Twenty (54%) participants reported PLS immediately after the onset of BPA (T2), and 28 (72%) participants altered proprioception (AP) after surgery (T3). However, neither PLP nor hand mapping onto the face was reported or evoked. PLS were seen earlier than AP. We conclude that PLS arise rapidly after BPA-induced temporary deafferentation of the upper limb and might serve as a model for the permanent deafferentation experienced in individuals with a major upper limb amputation or BPAI. These results contribute to defining a time course for changes after BPA and increase our understanding of how phantom limb phenomena might arise following limb amputation or BPAI.