Faculty Bibliography

AIM/OBJECTIVE:To evaluate long-term effects of levodopa-carbidopa intestinal gel on dyskinesia burden. PATIENTS & METHODS/METHODS:Posthoc analysis of the GLORIA registry assessed subgroups of advanced Parkinson's disease patients with <4 and ≥4 h/day of levodopa-induced dyskinesia at baseline. RESULTS & CONCLUSIONS/CONCLUSIONS:Mean dyskinesia duration significantly (p < 0.0001) decreased by 3.5 h in patients with ≥4 h baseline dyskinesia; conversely, dyskinesia duration increased by 1.6 h in patients with <4 h baseline dyskinesia. Quality of life improved in both subgroups. Adverse drug reactions occurred at similar rates in both subgroups. Despite increases in levodopa dose, levodopa-carbidopa intestinal gel treatment led to significant and sustained reductions in dyskinesia time, severity and associated pain in advanced Parkinson's disease patients with high baseline dyskinesia burden.

Electrocorticography (ECoG) is becoming more prevalent due to improvements in fabrication and recording technology as well as its ease of implantation compared to intracortical electrophysiology, larger cortical coverage, and potential advantages for use in long term chronic implantation. Given the flexibility in the design of ECoG grids, which is only increasing, it remains an open question what geometry of the electrodes is optimal for an application. Conductive polymer, PEDOT:PSS, coated microelectrodes have an advantage that they can be made very small without losing low impedance. This makes them suitable for evaluating the required granularity of ECoG recording in humans and experimental animals. We used two-dimensional (2D) micro-ECoG grids to record intra-operatively in humans and during acute implantations in mouse with separation distance between neighboring electrodes (i.e., pitch) of 0.4 mm and 0.2/0.25 mm respectively. To assess the spatial properties of the signals, we used the average correlation between electrodes as a function of the pitch. In agreement with prior studies, we find a strong frequency dependence in the spatial scale of correlation. By applying independent component analysis (ICA), we find that the spatial pattern of correlation is largely due to contributions from multiple spatially extended, time-locked sources present at any given time. Our analysis indicates the presence of spatially structured activity down to the sub-millimeter spatial scale in ECoG despite the effects of volume conduction, justifying the use of dense micro-ECoG grids.

BACKGROUND AND PURPOSE/OBJECTIVE:New-onset refractory status epilepticus is a clinical condition characterized by acute and prolonged pharmacoresistant seizures without a pre-existing relevant neurologic disorder, prior epilepsy, or clear structural, toxic, or metabolic cause. New-onset refractory status epilepticus is often associated with antineuronal antibodies and may respond to early immunosuppressive therapy, reflecting an inflammatory element of the condition. FDG-PET is a useful diagnostic tool in inflammatory and noninflammatory encephalitis. We report here FDG-PET findings in new-onset refractory status epilepticus and their correlation to disease activity, other imaging findings, and outcomes. MATERIALS AND METHODS/METHODS:Twelve patients who met the criteria for new-onset refractory status epilepticus and who had FDG-PET and MR imaging scans and electroencephalography at a single academic medical center between 2008 and 2017 were retrospectively identified. Images were independently reviewed by 2 radiologists specialized in nuclear imaging. Clinical characteristics and outcome measures were collected through chart review. RESULTS:= .028). CONCLUSIONS:Both FDG-PET hypometabolism and hypermetabolism are seen in the setting of new-onset refractory status epilepticus and may represent markers of disease activity.

BACKGROUND:There are no clear guidelines on how to treat posttraumatic headache (PTH) or post-concussive symptoms (PCS). However, behavioral interventions such as cognitive behavioral therapy, biofeedback, and relaxation are Level-A evidence-based treatments for headache prevention. To understand how to develop and study further mind-body interventions (MBIs) and behavioral therapies for PTH and PCS, we developed the following question using the PICO framework: Are behavioral therapies and MBIs effective for treating PTH and PCS? METHODS:We conducted a systematic search of 3 databases (Medline, PsycINFO, and EMBASE) for behavioral interventions and MBIs with the subject headings and keywords for PTH, concussion, and traumatic brain injury (TBI). Inclusion criteria were (1) randomized controlled trials, (2) the majority of the intervention had to be behavioral or mind-body therapy focused, (3) the majority of the participants (>50%) had to have had a mild TBI (not a moderate or severe TBI), (4) published in a peer-reviewed publication, and (5) meeting pre-specified primary and/or secondary outcomes. Primary outcome(s): whether there was a significant change in concussion symptom severity (yes/no) based on the symptom severity checklist/scale used, whether there was a 50% reduction in headache days and/or disability; secondary outcome(s): sleep variables, cognitive complaints, depression, and anxiety. The search identified 917 individual studies. Two independent reviewers screened citations and full-text articles independently. Nineteen articles were pulled for full article review. Seven articles met the final inclusion criteria. The systematic review was registered in Prospero (CRD42017070072). RESULTS:Overall, there was vast heterogeneity across the studies, making it difficult to fully assess efficacy. The heterogeneity ranged from differences in patient populations, the timing of when the interventions were initiated, the types of intervention implemented, and the measures used to assess outcomes. Seven studies were identified as meeting final inclusion criteria, resulting in a total of 1108 adult participants ranging from 18 to 80. Sixty-nine percent were male. Of the 7 studies, 3 were focused on military staff (retired and active). Time post-injury for inclusion into the studies varied from 48 hours post-injury to more than 2 years post-injury. One of the 7 studies did not include time post-TBI in the inclusion criteria. Two studies recruited patients who had visited their emergency departments, 4 of the studies recruited subjects through outpatient referrals, and 1 study recruited patients who had been in a prior traffic accident with resulting chronic PTH directly from a headache center. Group cognitive behavioral therapy (CBT) sessions and telephonic counseling or communication were common intervention methods used in the studies, with group CBT being used in 2 of the studies and telephonic counseling being used in 3. Other intervention methods used included individual CBT, cognitive training, psychoeducation, and computer-based and/or therapist-directed cognitive rehabilitation. CONCLUSIONS:Many of the interventions offered vastly different methods of delivery of intervention and doses of intervention. Many of the negative studies were done after an extended duration post-injury (>1-year posttraumatic brain injury [TBI]). In addition, the participants were lumped together regardless of their pre-concussion comorbidities, their mechanism of injury, their symptoms, and the duration from injury to the start of the intervention. The mass heterogeneity found between the studies led to inconclusive findings. Thus, there are various considerations for the design of the intervention for future behavioral/MBI studies for PTH and concussion that must be addressed before the leading question of this review may be effectively answered.

Tuberculosis is the leading infectious cause of death globally and extra-pulmonary disease occurs in 15% of incident cases annually. Tuberculous meningitis (TBM) is arguably the most lethal form of tuberculosis and requires prompt diagnosis and initiation of treatment to prevent death and serious neurological disability. The development of rapid diagnostic tests using polymerase chain reaction (PCR) technology for the detection of Mycobacterium tuberculosis (MTB), including the World Health Organization (WHO) - endorsed Xpert MTB/RIF Ultra assay, has allowed earlier definite diagnosis of TBM than conventional culture methods which usually take two weeks or longer for positive identification of MTB. Detection of MTB in cerebrospinal fluid (CSF) using PCR assays requires special attention to the collection, handling, and processing of CSF. Herein we present best practices guidance to maximize the detection rate of MTB in CSF using Xpert MTB/RIF Ultra.

Background: Surgical resection of pituitary adenomas is associated with a 10 to 30% rate of temporary diabetes insipidus with ~50% resolving within 1 week and 80% resolving at 3 months.[1] Adrenal insufficiency occurs in ~ 5 % of patients and can result in an Addisonian crisis if left undiagnosed postoperatively.[1] [2] Many studies have been performed looking at readmission rates after pituitary surgery. A review of over 1,200 cases demonstrated a readmission rate of 8.5% with the most common cause being hyponatremia (29.5%).[3] To reduce the rate of readmission for hyponatremia, some groups have demonstrated the effective use of outpatient fluid restriction criteria during the first week post-op.[4] These guidelines are intended for the management of standard postoperative hormonal fluctuations which do not necessitate endocrine consultation during hospitalization.
Objective(s): Retrospectively evaluate patients undergoing endoscopic endonasal resection of pituitary adenomas to identify areas for quality improvement through the development of more standardized postoperative guidelines.
Method(s): A retrospective review of 75 patients who underwent endoscopic endonasal resection of pituitary adenomas at a single academic center from 2013 to 2018. We evaluated the average length of stay, number of laboratory studies performed, need for hormone supplementation long term and short term, rate of gross-total resection, rate of cerebrospinal fluid leak, rate of infection, and 30-day readmission rate ([Table 1]). From this, we have developed a change in guidelines aimed at reducing length of stay, redundant laboratory studies, and reduced rate of readmission.
Conclusion(s): Although our current outcomes for resection of pituitary adenoma are on par with published data, we have identified areas of possible quality improvement which have since been implemented

Neuropsychiatric symptoms (NPS) are common in Alzheimer's disease (AD)-associated neurodegeneration. However, NPS lack a consistent relationship with AD pathology. It is unknown whether any common neural circuits can link these clinically disparate while mechanistically similar features with AD pathology. Here, we explored the neural circuits of NPS in AD-associated neurodegeneration using multivariate pattern analysis (MVPA) of resting-state functional MRI data. Data from 98 subjects (70 amnestic mild cognitive impairment and 28 AD subjects) were obtained. The top 10 regions differentiating symptom presence across NPS were identified, which were mostly the fronto-limbic regions (medial prefrontal cortex, caudate, etc.). These 10 regions' functional connectivity classified symptomatic subjects across individual NPS at 69.46-81.27%, and predicted multiple NPS (indexed by Neuropsychiatric Symptom Questionnaire-Inventory) and AD pathology (indexed by baseline and change of beta-amyloid/pTau ratio) all above 70%. Our findings suggest a fronto-limbic dominated neural circuit that links multiple NPS and AD pathology. With further examination of the structural and pathological changes within the circuit, the circuit may shed light on linking behavioral disturbances with AD-associated neurodegeneration.

OBJECTIVE:Behavior is encoded across multiple spatiotemporal scales of brain activity. Modern technology can simultaneously record various scales, from spiking of individual neurons to large neural populations measured with field activity. This capability necessitates developing multiscale modeling and decoding algorithms for spike-field activity, which is challenging because of the fundamental differences in statistical characteristics and time-scales of these signals. Spikes are binary-valued with a millisecond time-scale while fields are continuous-valued with slower time-scales. APPROACH/METHODS:We develop a multiscale encoding model, adaptive learning algorithm, and decoder that explicitly incorporate the different statistical profiles and time-scales of spikes and fields. The multiscale model consists of combined point process and Gaussian process likelihood functions. The multiscale filter (MSF) for decoding runs at the millisecond time-scale of spikes while adding information from fields at their slower time-scales. The adaptive algorithm learns all spike-field multiscale model parameters simultaneously, in real time, and at their different time-scales. MAIN RESULTS/RESULTS:We validated the multiscale framework within motor tasks using both closed-loop brain-machine interface (BMI) simulations and non-human primate (NHP) spike and local field potential (LFP) motor cortical activity during a naturalistic 3D reach task. Our closed-loop simulations show that the MSF can add information across scales and that the adaptive MSF can accurately learn all parameters in real time. We also decoded the seven joint angular trajectories of the NHP arm using spike-LFP activity. These data showed that the MSF outperformed single-scale decoding, this improvement was due to the addition of information across scales rather than the dominance of one scale and was largest in the low-information regime, and the improvement was similar regardless of the degree of overlap between spike and LFP channels. SIGNIFICANCE/CONCLUSIONS:This multiscale framework provides a tool to study encoding across scales and may help enhance future neurotechnologies such as motor BMIs.