We developed a novel method to differentiate physiological "healty and normal" ripples from
pathological ripples and identify the more pathological fast ripples
We also found the in epileptic regions ripple and fast ripple temporal
correlations are reduced. Ripple temporal coupling is important in
memory consolidation during sleep. This may be why epilepsy
patients have accelerated long term forgetting.
We have taught an invention that can differentiate different types of
ripples and fast ripples and can reduce seizures and improve memory.
Memory Research Portfolio
We found that in left Brodmann area 40 (also known as the left supramarginal gyrus). Bursts of
high-gamma and beta could accurately decode whether a person with epilepsy was accurately
encoding or recalling words in a verbal free recall task. We teach how this finding could be able
to develop a invasive device to improve human memory
Epileptiform spikes are very important in diagnosing epilepsy, and interfere with normal
brain function.
We found that fast ripple oscillations that precede epileptiform spikes are associated with
increased excitability and prime epileptiform spikes to occur next.
These measures could indeed predict in which patients the removal of brain did not help the patient
and when implanting a RNS(tm) device in the brain was less helpful.
We conceptualized two graph theoretical measures to quantify fast ripple networks in patients
implanted with brain electrodes to help better plan their operation.
Ripples are important in learning and memory but can also be involved in epilepsy.
Fast ripples and spikes are generated in epileptogenic regions and networks.
Focal regions of brain that generate seizures can be theorized as a discrete zone or
a interacting communicating network.
The Weiss lab is dedicated to patients with epilepsy and memory disorders.
We are focused on understanding the basic mechanisms underlying
epileptogenesis (i.e., the transformative process by which a brain region
becomes capable of generating a seizure), and seizure genesis (i.e., the
process in which normal brain activity becomes seizure activity). We are
also interested in studying biomarkers of attention to memory and memory.
Our research in epilepsy utilizes intracranial EEG, microelectrode, and neuro-
imaging from patients undergoing pre-surgical evaluation at various hospitals
around the world. We have developed a data opensource processing pipeline
for identifying biomarkers of epileptogenic tissue in this data. All our
epilepsy research code is opensource. Using this data processing strategy
we have found that spatial and temporal correlational networks of fast ripple
(200-600 Hz) oscillations can be used to predict whether a surgical approach
for drug resistant epilepsy will succeed or fail. Our future research will
identify the clinical factors that also are important for this approach
to succeed prospectively, so more patients benefit from epilepsy surgery.
Our research in memory disorders has focused on the left supramarginal
gyrus. The left supramarginal gyrus is a unique structure to humans and is
involved in attention to memory. We have found that high-gamma and beta
oscillations recorded from the left supramarginal gyrus can differentiate
encoding from recall states and whether encoding or recall is good or poor.
We are also involved in developing and testing a semi-invasive device
RAMgate(tm).
Research
Research
Weiss Lab of Computational Neurophysiology Research at SUNY Stonybrook
Weiss Lab of Computational Neurophysiology
Research at SUNY Downstate
Current Lab Members
is an assistant professor of Neurology and Physiology and Pharmacology at
SUNY Downstate and is the principal investigator.
Nicolas Sawczuk University of Buenos Aires, Department of Computer Science, MS
Nitish Seenarine SUNY Downstate MS3
Prior Lab Members
Tomas Pastore M.S. (University of Buenos Aires)
Daniel Rubinstein Ph.D. (Thomas Jefferson University)
Liliana Camirillo Rodriguez M.D., Ph.D. (Thomas Jefferson University)
Zachary Waldman M.S. (Thomas Jefferson University)
Inkyung Song Ph.D. (Thomas Jefferson University)
Current Collaborators
Richard Staba Ph.D. is a professor of Neurology at the David Geffen School of Medicine at UCLA.
Jerome Engel M.D., Ph.D. is a professor of Neurology, Psychiatry, and Biobehavioral Sciences at the
David Geffen School of Medicine at UCLA and the Semel Institute for Neuroscience and Human
Behavior, and the Brain Research Institute. He is Director of the UCLA Seizure Disorder Center.
Itzhak Fried M.D., Ph.D. is a professor of Neurosurgery at the David Geffen School of Medicine at
UCLA.
Anatol Bragin Ph.D. is a professor of Neurology at the David Geffen School of Medicine at UCLA.
Yuval Nir Ph.D. is a professor of Physiology & Pharmacology, Sackler Faculty of Medicine at Tel Aviv University, Israel
Laurent Sheybani M.D., Ph.D. University of College London Honorary Senior Research Fellow, EEG and Epilepsy
Unit / Neurology, Department of Clinical Neuroscience, University Hospitals and Faculty of Medicine of University
of Geneva, Geneva, Switzerland.
Michael Sperling M.D., is a professor of Neurology at Thomas Jefferson University and Chief of Epilepsy
Ashwini Sharan M.D. is a professor of Neurosurgery at Thomas Jefferson University
Chengyuan Wu M.D. M.S is a associate professor of Neurosurgery and Neuroradiology at Thomas
Jefferson University
Diego Slezak Ph.D. is a professor of Computer Science at the University of Buenos Aires, Argentina
Lin Li Ph.D. is a assistant professor of Biomedical Engineering at North Texas University
Anli Liu M.D. is an associate professor of Neurology at New York University
Shuang Wang M.D. is an associate professor of Neurology at Zhejiang University, China.
We propose a theoretical and mechanistic model for why the physiological and pathological
HFOs are generated at different phases of slow wave excitability in this article
and a comprehensize review article.
The lab found that in patients with seizures starting in the hippocampus, the seizures began with
fast ripples that incrementally grew in size. This suggests activated clusters of pNeurons can
grow until treashold for seizure generation is reached.
The lab also found that in patients with seizures that begin with a common morphology called
low-voltage fast, at the time and region where the seizure begins, inhibitory neurons are
active before excitatory neurons. The morphology can suggest spread and the region
of actual seizure onset may be very small and could have been missed.
An important substrate of epileptic networks are fast ripples. We found that fast ripples
propagate through the brain.
We found that propagating fast ripples were more likely to be associated with an after-
going epileptiform discharge. This also suggests fast ripples are an important substrate
of epileptic networks.
Patients with epilepsy often have memory problems but for many reasons. We found that in many people with
epilepsy spontaneous epileptiform spikes in certain brain regions interfere with memory function.