Darrin Lee, MD, a neurological surgeon at Keck Medicine of USC, reviews various functional neurosurgery techniques — including deep brain stimulation, vagus nerve stimulation, lesioning and CSF diversion — used to treat a range of cognitive and psychiatric conditions.
Yeah. Hello. My name is Darren Lee, and I'm an assistant professor of neurosurgery at the University of Southern California. My primary focus is in stereotyping and functional neurosurgery and have a keen interest in neuromodulation for cognitive and psychiatric disorders. I have no disclosures. However, my funding as is blow. Yeah, So, as a functional neurosurgeon, uh, we were involved in a number of procedures that have to do with either neuromodulation lesion ing, uh, as well as, uh, CSF diversion specifically with regards to neuromodulation. Uh, I focus on deep brain stimulation, responsive, responsive neuro stimulation, vagal nerve stimulation, spinal cord stimulation and peripheral nerve stimulation. Some of the leading procedures that are performed here are perkiness Prasad Amis by a lot, Amis in Court Adami's. And then with respect to our CSF diversion, uh, I focus on, uh, particular parent, Neal Schon slum a parent notions. And to stop it there, ventricular, Assamese and endoscopic ministrations. Um, some of the diseases that we, uh treat here include movement disorders such as Parkinson's disease, essential tremor and Estonia. Uh, we also do a wide range of surgical's treatments for epilepsy, including, uh, scg. Deeper information. RNs, VNS and surgical sections. Additionally, uh, perform a number of pain procedures, uh, for either trigeminal neuralgia or various forms of low back pain. We also are, uh, keenly involved with a number of hydrocephalus, or CSF flow problems, including normal pressure hydrocephalus, uh, idiopathic intracranial hypertension and various types of cysts. Additionally, I'm interested in psychiatric disorders such as obsessive compulsive disorder. We're currently also involved in a number of investigational studies, uh, using neuromodulation for either Alzheimer's disease and schizophrenia. So, uh, as a functioning neurosurgeon were very interested in, uh, brain circuit dysfunction, um, embraces circuit. The function is impaired. A number of cognitive and psychiatric disorders includes, including things like Parkinson's disease, Alzheimer's disease, disease, epilepsy and other psychiatric disorders like O. C. D. Addiction and depression. Uh, there's a number of my clinical and research interests are focused on these circuit dysfunctions in these cognitive and psychiatric realms. Now, our movement disorder, uh, specialty very much relies on a multidisciplinary approach. Yeah, including this team are neurologist, neuropsychologist and neurosurgeons. Uh, a Such were involved in deeper and stimulation for things like Parkinson's disease, essential tremor, and Estonia, specifically with regard to Parkinson's disease. Uh, it's the second most common progressive nerd identity disorder. And the predominant symptoms are kind of these, uh Brady Tunisia resting tremor and rigidity. Uh, Now, while most treatment medication and surgical are focused on these kind of clinical core symptoms or cardinal symptoms off parking disease, uh, number these patients also suffer from cognitive decline, uh, in a number of cognitive domains, including executive function, attention processing, processing speed, episodic memory and visual spatial processing. Um, now, the current stimulation parameters are a high frequency stimulation anywhere between 101 180 hertz. However, most physiologic oscillations or the lower lower range I'm We're particularly interested in some of the low frequency oscillations, particularly in the data range, which is 35 to 12 ft range. Because these air implicated, uh, mechanism spatial and episodic memory. Um, one of the targets for deeper and stimulation for Parkinson's disease is the sub atomic nucleus. And these low frequency or theta oscillations are significantly involved in, uh, uh, executive function. Uh, such a verbal fluency, working memory response inhibition and sensory motor conflict. No, with that in mind, uh, were interesting. Uh, as one of our kind of research is looking at seeing it to see if there are various ways to alter stimulation parameters to potentially improve some of these cognitive domains. Here we see some research that we've done at USC were actually able to improve verbal fluency with low frequency stimulation as opposed to the standard high frequency stimulation parameters. Uh, therefore, currently, we are involved in a number of clinical studies, uh, potentially trying to look and see if we can alter or improve cognitive cognition and verbal fluency with DBS for parking disease, including looking at, uh, alternative anatomical target for DBS as well as alternative stimulation parameters for DBS. As I mentioned before, we're interested in, uh, using neuromodulation for, uh, to improve cognition. Uh, one of the studies that were involved in is a deeper and stimulation for Alzheimer's disease trial. Currently, there's a Phase three clinical trial called the Advanced to Trial. Looking at bilateral for Maciel Deeper and stimulation. Uh, we're using this by a little pharmacy so GPS for in patients with mild Alzheimer's disease, things a perspective multi center, double blind randomized trial. Uh, where were one of, uh, about 20 sites trying to roll? Uh, about 210 mild Alzheimer's patients for this DBS study. Uh, in this particular study, we're looking at, uh, doing a random my organization between no stimulation, low frequency stimulation and high frequency stimulation in these Alzheimer's patients, as seen below. So in addition to using DBS for cognitive disorders or cognition, issues like Parkinson's and Alzheimer's disease were also involved. We also developed a cerebrospinal fluid diversion center. This also is a multidisciplinary team with a number of subspecialty, including neurology nor radiology, ophthalmology, neurology, R p t n ot colleagues and neurosurgery. Uh, in this center we do, uh, treat a number of disorders like normal pressure hydrocephalus, obstructive hydrocephalus. Uh, pseudo tumor and Iraq know exists. We have a particular interest, actually, in normal pressure. Hydrocephalus. This is ah, typically disease process, um, with a triad of symptoms including gait, disturbance, urinary incontinence and cognitive deterioration. Interesting enough, though. This is one of the Onley dementia syndrome that's actually reversible, uh, through, uh, CSF diversion, including ventricular peritoneal shunt and lumbar peritoneal shuns. Therefore, we have a keen interest in really trying to understand the underlying mechanism. Currently, it is, uh, unknown. However, we are doing a number of studies looking at the differences in potentially blood brain barrier dysfunction, uh, looking at CSF and serum bark biomarkers as well as looking at advanced imaging, including diffusion weighted arterial spin labeling, um, to help with quantification of, ah, water exchange rates across the blood brain barrier in addition to cognitive and movement disorders. Uh, we also interest in pain neurosurgery, uh, with specific interest in things like trigeminal neuralgia, a swells, back pain and neuropathic pain. With regards to trigeminal neuralgia, we have a number of ways to treat, uh, this disease process, including micro open surgery. Uh, including open surgery, uh, such as microvascular decompression lesion ing, including gamma knife, radiosurgery per containers, Rosana me and direct Amis. Finally, we have neuro modulate Ori techniques, including personal nervous stimulation to help with the treatment of trigeminal neuralgia. With regards to, uh, back pain neuropathic pain, I have a specialty in, uh, neuromodulation, including spinal cord stimulation. The underlying mechanism of pain is not clearly understood. Therefore, we have a keen interest in studying and understanding the underlying causes of pain. Atyou SC, we have ah at U S. C. We have current studies using advanced imaging techniques, including memory such as track ta graffiti as well as functional connectivity studies to understand the unlearning uh, causes of pain. Additionally, we have advanced imaging or functional ultrasound imaging to look at the underlying, uh, mechanism for spinal cord stimulation. Finally, I'd like to briefly discuss some of the advantages done in Norma Jean from psychiatric indications at U. S. C. We have a DBS for O. C. D multidisciplinary group that also includes a psychologist and psychiatrist in additional. In addition, way have active investigational studies looking at deeper instigation for schizophrenia. Ah, lot of my translational neuroscience work in the lab looks at various forms of DBS for schizophrenia. In that vein, we also have parallel studies using transcranial magnetic stimulation for various aspects of schizophrenia. I'd like to thank all of my collaborators, including all of those in my basic science lab as well as the U. S. Senior Neural Restoration Center. Are my collaborators that in psychiatry, neurology and the Lonnie Imaging Institute. I'd also like to thank our collaborators and at the University of Toronto at Caltech at U C. Riverside. Thank you