Making Recommendations for an Evaluation and Treatment Algorithm for Patients with Ear Fullness and No Objective Abnormalities.

OBJECTIVE: To make recommendations for evaluation, approach to counseling and treatment for patients who present with ear fullness without abnormalities on otomicroscopic examination, standard audiometric studies, or imaging results. METHODS: Retrospective chart review of adult patients in a tertiary referral center presenting with ear fullness and/or otalgia without external, middle, and/or inner ear pathologies. Data collected include demographics (age and gender), laterality and duration of symptoms, co-morbid conditions and final diagnoses of temporomandibular joint (TMJ) dysfunction, intermittent Eustachian tube dysfunction (iETD), migraine disorder, and anxiety. RESULTS: In the span of 8 years of a single neurotologist's practice, 964 patients presented with ear fullness. After excluding all instances where external, middle, and inner ear disorders were identified and where audiometric and radiologic findings were abnormal, 263 patients had ear fullness and no objective causes. Women were more likely than men to complain of ear fullness and/or otalgia and were also more likely to present with no objective abnormalities ( p < 0.05). Patients who reported isolated ear fullness were more likely to be diagnosed with iETD, whereas patients who reported pain were more likely to be diagnosed with TMJ dysfunction (TMJD). Fourteen patients (5.3%) had completely unexplained sensation of ear fullness. CONCLUSIONS: There were 94.7% of the patients presenting with unexplained ear fullness were diagnosed as having a possible contribution of TMJ dysfunction, IETD, migraine disorder, anxiety, or a combination of these conditions to their symptomatology. Directing treatments toward these diagnoses may alleviate symptoms of ear fullness or, if unsuccessful, provide an avenue for counseling in the framework of functional neurologic disorders.

Biomarker-guided neuromodulation aids memory in traumatic brain injury.

Traumatic brain injury (TBI) is a leading cause of cognitive disability in adults, often characterized by marked deficits in episodic memory and executive function. Prior studies have found that direct electrical stimulation of the temporal cortex yielded improved memory in epilepsy patients, but it is not clear if these results generalize to patients with a specific history of TBI. Here we asked whether applying closed-loop, direct electrical stimulation to lateral temporal cortex could reliably improve memory in a TBI cohort. Among a larger group of patients undergoing neurosurgical evaluation for refractory epilepsy, we recruited a subset of patients with a history of moderate-to-severe TBI. By analyzing neural data from indwelling electrodes as patients studied and recalled lists of words, we trained personalized machine-learning classifiers to predict momentary fluctuations in mnemonic function in each patient. We subsequently used these classifiers to trigger high-frequency stimulation of the lateral temporal cortex (LTC) at moments when memory was predicted to fail. This strategy yielded a 19% boost in recall performance on stimulated as compared with non-stimulated lists (P = 0.012). These results provide a proof-of-concept for using closed-loop stimulation of the brain in treatment of TBI-related memory impairment.

Calcium imaging and analysis of the jugular-nodose ganglia enables identification of distinct vagal sensory neuron subsets.

Objective.Sensory nerves of the peripheral nervous system (PNS) transmit afferent signals from the body to the brain. These peripheral nerves are composed of distinct subsets of fibers and associated cell bodies, which reside in peripheral ganglia distributed throughout the viscera and along the spinal cord. The vagus nerve (cranial nerve X) is a complex polymodal nerve that transmits a wide array of sensory information, including signals related to mechanical, chemical, and noxious stimuli. To understand how stimuli applied to the vagus nerve are encoded by vagal sensory neurons in the jugular-nodose ganglia, we developed a framework for micro-endoscopic calcium imaging and analysis.Approach.We developed novel methods forin vivoimaging of the intact jugular-nodose ganglion using a miniature microscope (Miniscope) in transgenic mice with the genetically-encoded calcium indicator GCaMP6f. We adapted the Python-based analysis package Calcium Imaging Analysis (CaImAn) to process the resulting one-photon fluorescence data into calcium transients for subsequent analysis. Random forest classification was then used to identify specific types of neuronal responders.Results.We demonstrate that recordings from the jugular-nodose ganglia can be accomplished through careful surgical dissection and ganglia stabilization. Using a customized acquisition and analysis pipeline, we show that subsets of vagal sensory neurons respond to different chemical stimuli applied to the vagus nerve. Successful classification of the responses with a random forest model indicates that certain calcium transient features, such as amplitude and duration, are important for encoding these stimuli by sensory neurons.Significance.This experimental approach presents a new framework for investigating how individual vagal sensory neurons encode various stimuli on the vagus nerve. Our surgical and analytical approach can be applied to other PNS ganglia in rodents and other small animal species to elucidate previously unexplored roles for peripheral neurons in a diverse set of physiological functions.

Does Compliance or Cost Regulate Effectiveness of Notched Sound Therapy Phone Applications for Tinnitus Relief? Preliminary Data of a Prospective Randomized Control Trial.

OBJECTIVE: The objective of this study is to evaluate compliance with and effectiveness of notched sound therapy (NST) administered through a mobile application in improving symptoms of patients experiencing chronic tinnitus. STUDY DESIGN: A prospective randomized control trial was done. SETTING: The study was done at a tertiary referral center. PATIENTS: Adult patients with tinnitus were monitored. INTERVENTIONS: Patients were randomized at enrollment to either the NST or a standard of care (SOC) group. NST arm included, in addition to SOC, a free subscription to NST mobile application, whereas the SOC arm included NST at subscription cost. MAIN OUTCOME MEASURES: The main outcome measures were continued enrollment in study, compliance with the therapy, frequency and duration of therapy use, and change from the baseline in the Tinnitus Handicap Inventory (THI). RESULTS: Patients in the NST group were 2.25 times more likely to use the NST application for 3 months postenrollment. Only 33% of users in the NST group listened for the prescribed 2 h/d compared with 0% of users in the SOC group. There was a clinically relevant mean decrease in THI from a baseline of 13.5 in the NST group (p = 0.09) and of 14.8 in the SOC group (p = 0.02). There was a positive correlation between initial THI and decrease in THI after 3 months (p = 0.001). CONCLUSIONS: Monitoring tinnitus for 3 months leads to a decrease in subjective symptoms regardless of NST use. Patients who received a free subscription to the application were more likely to continue with therapy, but very few patients were able to comply with 2 hours of listening time per day.

Biomarkers of memory variability in traumatic brain injury.

Traumatic brain injury is a leading cause of cognitive disability and is often associated with significant impairment in episodic memory. In traumatic brain injury survivors, as in healthy controls, there is marked variability between individuals in memory ability. Using recordings from indwelling electrodes, we characterized and compared the oscillatory biomarkers of mnemonic variability in two cohorts of epilepsy patients: a group with a history of moderate-to-severe traumatic brain injury (n = 37) and a group of controls without traumatic brain injury (n = 111) closely matched for demographics and electrode coverage. Analysis of these recordings demonstrated that increased high-frequency power and decreased theta power across a broad set of brain regions mark periods of successful memory formation in both groups. As features in a logistic-regression classifier, spectral power biomarkers effectively predicted recall probability, with little difference between traumatic brain injury patients and controls. The two groups also displayed similar patterns of theta-frequency connectivity during successful encoding periods. These biomarkers of successful memory, highly conserved between traumatic brain injury patients and controls, could serve as the basis for novel therapies that target disordered memory across diverse forms of neurological disease.

Factors correlated with intracranial interictal epileptiform discharges in refractory epilepsy.

OBJECTIVE: This study was undertaken to evaluate the influence that subject-specific factors have on intracranial interictal epileptiform discharge (IED) rates in persons with refractory epilepsy. METHODS: One hundred fifty subjects with intracranial electrodes performed multiple sessions of a free recall memory task; this standardized task controlled for subject attention levels. We utilized a dominance analysis to rank the importance of subject-specific factors based on their relative influence on IED rates. Linear mixed-effects models were employed to comprehensively examine factors with highly ranked importance. RESULTS: Antiseizure medication (ASM) status, time of testing, and seizure onset zone (SOZ) location were the highest-ranking factors in terms of their impact on IED rates. The average IED rate of electrodes in SOZs was 34% higher than the average IED rate of electrodes outside of SOZs (non-SOZ; p < .001). However, non-SOZ electrodes had similar IED rates regardless of the subject's SOZ location (p = .99). Subjects on older generation (p < .001) and combined generation (p < .001) ASM regimens had significantly lower IED rates relative to the group taking no ASMs; newer generation ASM regimens demonstrated a nonsignificant association with IED rates (p = .13). Of the ASMs included in this study, the following ASMs were associated with significant reductions in IED rates: levetiracetam (p < .001), carbamazepine (p < .001), lacosamide (p = .03), zonisamide (p = .01), lamotrigine (p = .03), phenytoin (p = .03), and topiramate (p = .01). We observed a nonsignificant association between time of testing and IED rates (morning-afternoon p = .15, morning-evening p = .85, afternoon-evening p = .26). SIGNIFICANCE: The current study ranks the relative influence that subject-specific factors have on IED rates and highlights the importance of considering certain factors, such as SOZ location and ASM status, when analyzing IEDs for clinical or research purposes.