Explore the vast range of titles available.

To describe the protocol of a prospective study to test the validity of intermuscular coherence (IMC) as a diagnostic tool and biomarker of upper motor neuron degeneration in amyotrophic lateral sclerosis (ALS). This is a multicenter, prospective study. IMC of muscle pairs in the upper and lower limbs is gathered in ∼650 subjects across three groups using surface electrodes and conventional electromyography (EMG) machines. The following subjects will be tested: 1) neurotypical controls; 2) patients with symptomatology suggestive for early ALS but not meeting probable or definite ALS by Awaji Criteria; 3) patients with a known ALS mimic. The recruitment period is between 3/31/2021 and 12/31/2025. Written consent will be sought from the subject or the subject's legally authorized representative during enrollment. The endpoints of this study include: 1) whether adding IMC to the Awaji ALS criteria improve its sensitivity in early ALS and can allow for diagnosis earlier; 2) constructing a database of IMC across different ages, genders, and ethnicities. This study may validate a new inexpensive, painless, and widely available tool for the diagnosis of ALS.

Theta oscillations are implicated in regulating information flow within cortico-hippocampal networks to support memory and cognition. However, causal evidence tying theta oscillations to network communication in humans is lacking. Here we report experimental findings using a closed-loop, phase-locking algorithm to apply direct electrical stimulation to neocortical nodes of the hippocampal network precisely timed to ongoing hippocampal theta rhythms in human neurosurgical patients. We show that repetitive stimulation of lateral temporal cortex synchronized to hippocampal theta increases hippocampal theta while it is delivered, suggesting theta entrainment of hippocampal neural activity. After stimulation, network connectivity is persistently increased relative to baseline, as indicated by theta-phase synchrony of hippocampus to neocortex and increased amplitudes of the hippocampal evoked response to isolated neocortical stimulation. These indicators of network connectivity are not affected by control stimulation delivered with approximately the same rhythm but without phase locking to hippocampal theta. These findings support the causal role of theta oscillations in routing neural signals across the hippocampal network and suggest phase-synchronized stimulation as a promising method to modulate theta- and hippocampal-dependent behaviors. Closed-loop brain stimulation of the human hippocampal theta rhythm produces lasting enhancement of network communication. This implicates theta rhythms in human hippocampal network communication and provides a possible route to memory modulation.

ObjectiveTo determine the outcomes of combined stereo-electroencephalography-guided and MRI-guided stereotactic laser interstitial thermal therapy (LITT) in the treatment of patients with drug-resistant mesial temporal lobe epilepsy (mTLE).MethodsWe prospectively assessed the surgical and neuropsychological outcomes in 21 patients with medically refractory mTLE who underwent LITT at the University of Chicago Medical Center. We further compared the surgical outcomes in patients with and without mesial temporal sclerosis (MTS).ResultsOf the 21 patients, 19 (90%) underwent Invasive EEG study and 11 (52%) achieved freedom from disabling seizures with a mean duration of postoperative follow-up of 24±11 months after LITT. Eight (73%) of 11 patients with MTS achieved freedom from disabling seizures, whereas 3 (30 %) of 10 patients without MTS achieved freedom from disabling seizures. Patients with MTS were significantly more likely to become seizure-free, as compared with those without MTS (P=0.002). There was no significant difference in total ablation volume and the percentage of the ablated amygdalohippocampal complex between seizure-free and non-seizure-free patients. Presurgical and postsurgical neuropsychological assessments were obtained in 10 of 21 patients. While there was no group decline in any neuropsychological assessment, a significant postoperative decline in verbal memory and confrontational naming was observed in individual patients.ConclusionsMRI-guided LITT is a safe and effective alternative to selective amygdalohippocampectomy and anterior temporal lobectomy for mTLE with MTS. Nevertheless, its efficacy in those without MTS seems modest. Large multicentre and prospective studies are warranted to further determine the efficacy and safety of LITT.

Background The mechanism of sudden unexpected death in epilepsy remains poorly understood. Seizure induced cardiac arrhythmia, central and obstructive apneas have been proposed as possible causes of death. Here we report a unique case of seizure related sudden unexpected death in a patient whose airway was fully protected by intubation and mechanic ventilation in the absence of fatal cardiac arrhythmia. Case presentation A 70-year-old woman was undergoing mechanical ventilation and video-electroencephalography (EEG) monitoring following two convulsive seizures with ictal hypoventilation and hypoxemia. Several hours after intubation, she suffered another generalized tonic clonic seizure lasted for 3 min and developed postictal generalized EEG suppression in the presence of stable vital signs with SpO 2  > 90%. EEG suppression persisted throughout the postictal phase. There was a significant fluctuation of systolic blood pressure between 50 and 180 mmHg with several bouts of hypotension < 60 mmHg. She remained unresponsive after the convulsive seizure and died of diffuse cerebral edema 12 h later. Autopsy revealed no clear cause of death, except for possible hypoxic and ischemic injury leading to the diffuse cerebral edema. Conclusion Given the reliable periictal airway protection, neither seizure induced central apnea nor obstructive apnea appeared to be the direct cause of death in this unique case. In the absence of fatal cardiac arrhythmia, diffuse cerebral edema secondary to seizure-induced autonomic dysfunction, hypotension and hypoxemia might be the cause of death, highlighting the etiological heterogeneity of sudden unexpected death in epilepsy.

Human accomplishments depend on learning, and effective learning depends on consolidation. Consolidation is the process whereby new memories are gradually stored in an enduring way in the brain so that they can be available when needed. For factual or event knowledge, consolidation is thought to progress during sleep as well as during waking states and to be mediated by interactions between hippocampal and neocortical networks. However, consolidation is difficult to observe directly but rather is inferred through behavioral observations. Here, we investigated overnight memory change by measuring electrical activity in and near the hippocampus. Electroencephalographic (EEG) recordings were made in five patients from electrodes implanted to determine whether a surgical treatment could relieve their seizure disorders. One night, while each patient slept in a hospital monitoring room, we recorded electrophysiological responses to 10 to 20 specific sounds that were presented very quietly, to avoid arousal. Half of the sounds had been associated with objects and their precise spatial locations that patients learned before sleep. After sleep, we found systematic improvements in spatial recall, replicating prior results. We assume that when the sounds were presented during sleep, they reactivated and strengthened corresponding spatial memories. Notably, the sounds also elicited oscillatory intracranial EEG activity, including increases in theta, sigma, and gamma EEG bands. Gamma responses, in particular, were consistently associated with the degree of improvement in spatial memory exhibited after sleep.We thus conclude that this electrophysiological activity in the hippocampus and adjacent medial temporal cortex reflects sleep-based enhancement of memory storage.

BACKGROUND AND IMPORTANCE:Corpus callosotomy is an effective palliative treatment for medically intractable Lennox-Gastaut syndrome (LGS) that disrupts the interhemispheric synchronization of epileptiform discharges. However, traditional open corpus callosotomy carries a significant risk of surgical complications associated with craniotomy and a parafalcine approach to the corpus callosum. Here, we report 2 cases of anterior corpus callosotomy using MRI-guided stereotactic laser interstitial thermal therapy (LITT) as a minimally invasive technique for mitigating the risks of craniotomy while achieving favorable outcomes. CLINICAL PRESENTATION:Two patients with medically intractable LGS underwent stereotactic laser anterior corpus callosotomy using a 2 laser-fiber approach. Ablation of 70%-80% of the corpus callosum was confirmed by postoperative MRI diffusion tensor imaging and volumetric analysis. Marked reduction of epileptiform activity was observed in both patients during postoperative video-EEG studies as compared to preoperative video-EEG studies. Freedom from disabling seizures including drop attacks was achieved in 1 patient for 18 mo, and more than a 90% reduction of disabling seizures was achieved in the other patient for 7 mo with cognitive improvement and without surgical complications. CONCLUSION:These early data demonstrate the technical feasibility, safety, and favorable outcomes of MRI-guided stereotactic laser anterior corpus callosotomy in patients with LGS, making it a potentially safe and effective alternative to traditional open corpus callosotomy and other stereotactic methods including radiofrequency ablation and radiosurgery due to the ability to monitor the ablation in real time with MRI.

Background Intracranial pressure (ICP) can be continuously and reliably measured using invasive monitoring through an external ventricular catheter or an intraparenchymal probe. We explore electroencephalography (EEG) to identify a reliable real-time noninvasive ICP correlate. Methods Using a previously described porcine model of intracranial hypertension, we examined the cross correlation between ICP time series and the slope of the EEG power spectral density as described by ϕ. We calculated ϕ as tan −1 (slope of power spectral density) and normalized it by π , where slope is that of the power-law fit (log frequency vs. log power) to the power spectral density of the EEG signal. Additionally, we explored the relationship between the ϕ time series and cerebral perfusion pressure. A total of 11 intracranial hypertension episodes across three different animals were studied. Results The mean correlation between ϕ angle and ICP was − 0.85 (0.15); the mean correlation with cerebral perfusion pressure was 0.92 (0.02). Significant correlation occurred at zero lag. In the absence of intracranial hypertension, the absolute value of the ϕ angle was greater than 0.9 (mean 0.936 radians). However, during extreme intracranial hypertension causing cerebral circulatory arrest, the ϕ angle is on average below 0.9 radians (mean 0.855 radians). Conclusions EEG ϕ angle is a promising real-time noninvasive measure of ICP/cerebral perfusion using surface electroencephalography.

Spinocerebellar ataxias (SCAs) are familial neurodegenerative diseases involving the cerebellum and spinocerebellar tracts. While there is variable involvement of corticospinal tracts (CST), dorsal root ganglia, and motor neurons in SCA3, SCA6 is characterized by a pure, late-onset ataxia. Abnormal intermuscular coherence in the beta-gamma frequency range (IMCβγ) implies a lack of integrity of CST or the afferent input from the acting muscles. We test the hypothesis that IMCβγ has the potential to be a biomarker of disease activity in SCA3 but not SCA6. Intermuscular coherence between biceps brachii and brachioradialis muscles was measured from surface EMG waveforms in SCA3 ( N = 16) and SCA6 ( N = 20) patients and in neurotypical subjects ( N = 23). IMC peak frequencies were present in the β range in SCA patients and in the γ range in neurotypical subjects. The difference between IMC amplitudes in the γ and β ranges was significant when comparing neurotypical control subjects to SCA3 ( p < 0.01) and SCA6 ( p = 0.01) patients. IMCβγ amplitude was smaller in SCA3 patients compared to neurotypical subjects ( p < 0.05), but not different between SCA3 and SCA6 patients or between SCA6 and neurotypical subjects. IMC metrics can differentiate SCA patients from normal controls.

POEMS syndrome is a rare, multisystem disorder characterized by polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, and/or skin changes. Here we present an unusual case of a patient with POEMS syndrome who exhibited a prominent autonomic neuropathy.