to demystify the brain one-millisecond at a time
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Clinical AI should be judged by more than a headline accuracy score. This editorial examines class imbalance, rare events, validation, and the human–machine partnership required for responsible neurological care.
Read MoreThirty electrical-stimulation studies, 887 patients, and 3,028 implanted cingulate contacts—941 producing positive responses—were synthesized into a functional map of movement, sensation, affect, laughter, autonomic responses, vision, speech, and vestibular experience.
Read MoreUsing six minutes of free-running intracranial EEG during sleep, an optimized neural-network model provided proof of concept for identifying sensorimotor cortex and the anterior lip of the central sulcus.
Read MoreA rhythmic EEG pattern may look ictal while being generated outside the brain. This report shows how chest-vest respiratory therapy can imitate electrographic seizure activity.
Read MoreElectrical stimulation elicited a sensation of floating or weightlessness, while intracranial EEG, CCEP, and fMRI traced a distributed vestibular–cingulate–cerebral network.
Read MoreAbstract
We test the performance of a novel operator-independent EEG-based method for passive identification of the central sulcus (CS) and sensorimotor (SM) cortex. We studied seven patients with intractable epilepsy undergoing intracranial EEG (icEEG) monitoring, in whom CS localization was accomplished by standard methods. Our innovative approach takes advantage of intrinsic properties of the primary motor cortex (MC), which exhibits enhanced icEEG band-power and coherence across the CS. For each contact, we computed a composite power, coherence, and entropy values for activity in the high gamma band (80–115) Hz of 6–10 min of NREM sleep. Statistically transformed EEG data values that did not reach a threshold (th) were set to 0. We computed a metric M based on the transformed values and the mean Euclidian distance of each contact from contacts with Z-scores higher than 0. The last step was implemented to accentuate local network activity. The SM cortex exhibited higher EEG-band-power than non-SM cortex (P < 0.0002). There was no significant difference between the motor/premotor and sensory cortices (P < 0.47). CS was localized in all patients with 0.4 < th < 0.6. The primary hand and leg motor areas showed the highest metric values followed by the tongue motor area. Higher threshold values were specific (94%) for the anterior bank of the CS but not sensitive (42%). Intermediate threshold values achieved an acceptable trade-off (0.4: 89% specific and 70% sensitive).
Read MoreTo that end, we report on a profound illusionary alteration of time and duration perceptions. We analyze the cortical and subcortical networks relating to that experience.
To our knowledge, this account is the first original of a human’s experience of time dilation during direct cortical stimulation.
Read MoreA literature review examines how anesthetic agents alter electrocorticographic signals and what those effects mean for reliable localization during epilepsy surgery.
Read MoreThe traditional view of the tongue as a dipole-generator of scalp GKA is simplistic and does not account for the findings reported herein. The tongue is most probably the education and the design of tongue-computer interfaces. >>>
Read MoreFrom Volta and Galvani to Penfield, this historical review traces how electrical stimulation helped reveal the organization and function of the human cortex.
Read MoreA network-based Connectivity Index offers a way to grade epileptogenicity and sharpen localization of the seizure-onset network from intracranial EEG.
Read MoreBrainEx experiments restored circulation and selected cellular functions in postmortem pig brains, reshaping questions about viability, irreversibility, and brain research.
Read MoreAn updated perspective on brain–computer-interface methods for mapping epileptic networks with intracranial EEG—and the work still needed for clinical translation.
Read MoreA commentary on restored circulation and selected cellular functions in postmortem brain tissue, and the conceptual questions it raises for neuroscience and medicine.
Read MoreThis foundational review explores how BCI approaches can use intracranial EEG to map epileptic brain networks and support future clinical decision-making.
Read MoreThis commentary examines whether very-high-frequency oscillations above 500 Hz can improve interictal localization of epileptogenic brain tissue—and why faster recording still requires physiological context.
Read MoreAuthors: Alkawadri R, Burgess RC, Kakisaka Y, Mosher JC, Alexopoulos AV.
To read the full article please visit JAMA Neurology website
Key Points
Question What is the chance of recording a seizure and the localizing yield of seizures recorded during routine magnetoencephalography (MEG) studies?
Findings In this medical record analysis of 44 patients, MEG provided unique and more focal localization information, including in some electroencephalography and interictal MEG silent cases and in some cases that were nonlocalizable otherwise. Extended-source localization was more suitable for analysis of ictal rhythms than commonly used single-point solutions.
Meaning If feasible, ictal MEG should be sought and considered in presurgical evaluation of drug-resistant epilepsy.
Read MoreAuthors: Alkawadri R, Gaspard N
To read the full article refer to Epileptic Disorders
To demonstrate the importance of averaging in time-frequency space and the added localizing value in time and space in a case of cortical myoclonus. One hundred myoclonic jerks were averaged in time series and in spectral domain. For the latter, we chose 100 (10-second) segments from interictal background and used the unpaired t-test for the jerk-related and control spectral data to obtain the t value and corresponding p value at each pixel. We corrected for multiple comparisons using false discovery rate procedure. We generated maps of spectral significance per electrode. All insignificant t-values were converted to 0 for easier visual analysis. Standard back-averaging of 100 jerks disclosed a single spike preceding EMG activity by 19-27 milliseconds. No other definite ictal patterns were discernible in the time domain. Statistical analysis of the same 100 epochs in the time-frequency domain disclosed a greater temporal extent of the seizure, as well as a more detailed rendering of rhythms and frequencies involved. Valproate was added and led to substantial improvement. Averaging in the spectral domain may reveal frequency-specific changes that may not be otherwise appreciated in the time domain. Future studies may elucidate the effect on the sensitivity of diagnosis of simple partial seizures and auras.
Read MoreWe report a case of impairment of consciousness (IOC) induced by electrical cortical stimulation (ECS) of homologous regions within the lateral frontal convexities in a patient with medically intractable epilepsy. The patient had mixed features of idiopathic generalized and focal epilepsy. On intracranial EEG recording, interictal and ictal discharges showed a high degree of synchrony across widespread bilateral fronto-parietal areas. We identified regions in the lateral frontal lobes that reliably and produced loss of consciousness by ECS.
Read MoreAuthors: Alkawadri R, Gonzalez-Martinez J, Gaspard N, Alexopoulos AV
Read the full article here
We present a case of lesional mid-cingulate epilepsy confirmed by stereotactically implanted intracranial depth electrodes and subsequent surgical resection. Hypermotor symptomatology was seen during the first seven seconds of seizure onset while the seizure was still confined to the mid-cingulate gyrus contacts.