Casey Halpern, M.D. (@halpernc) is a neurosurgeon and Chief of Stereotactic and Functional Neurosurgery and Professor of Neurosurgery at the Perelman School of Medicine at the University of Pennsylvania. Dr. Halpern’s research and clinical practice focus on using deep brain stimulation to treat compulsive and movement disorders (e.g., binge eating disorders, bulimia, obsessive-compulsive disorder (OCD) and Parkinson’s disease essential tremor, dystonia)
In this episode, Andrew Huberman & Casey Halpern dive into deep brain stimulation, what it is, and its application for people who suffer from movement & compulsive disorders, as well as potential use binge eating, OCD, tremor, and anorexia. The future of these non-invasive brain stimulation technologies are also discussed for potential as therapeutic treatments for psychiatric illness, and much more.
Host: Andrew Huberman (@hubermanlab)
Deep brain stimulation (DBS) involves a procedure in which a wire is inserted in the part of the brain involved in the disorder then that wire is connected to a battery pack implanted in the chest and electrical signals are sent
DBS can be used for Parkinson’s disease and movement disorders to alleviate tremors but there’s also an added benefit of reducing impulse and depression in many patients
The outcome of DBS surgery for Parkinson’s disease and movement disorders is overwhelmingly positive – there are potential applications for DBS to be used for obesity, eating disorders, OCD, and mental health
The brain’s two main functions: (1) make sure biological systems are working properly; (2) predict what’s going to happen next based on knowledge of past
Cortical control areas don’t function properly in people with OCD, they’re often hyperfunctioning or hypo-functioning (it’s dysregulation of circuitry in either direction)
OCD is somewhat of a spectrum disorder – it’s possible to have some of the elements of the disease that are controllable or manageable, but on the other hand it can be debilitating if uncontrollable
Hallmark features of obsessive-compulsive disorder: intrusive obsessions, meaning the person doesn’t want to have them
Every time one engages in a compulsion (action) related to the obsession (thought), the obsession becomes stronger in a powerful and debilitating loop
Cortico-striatal thalamic loop: the circuits and loops active in OCD as identified by imaging studies – cortex (involved in perception and understanding what’s happening), striatum (involved in action selection and go-no go behavior), thalamus (relays and filters information from environment to brain)
Activation of cortico-striatal thalamic loop in rats without OCD actually generates persistent OCD-like behavior
Therapeutic medications target the serotonin system (SSRIs) but it’s hard to predict how medications will work for each individual because the serotonin system doesn’t work alone – it’s also going to impact dopamine
Cognitive behavioral therapy: the goal of cognitive behavior therapy in the context of OCD is to uncover the underlying fear driving the OCD then take the patient to the highest anxiety point and disrupt the neural circuit between the processing and action parts of the brain to tolerate the anxiety and avoid the compulsion
Surgical option: ablation surgery on part of the brain that’s safe to destroy without side effects this can be controversial because the rate of success is about 50% so may be aggressive
Not everyone with an eating disorder is obese and not everyone who’s obese has an eating disorder
Nucleus accumbens: part of the brain known as the hub of reward circuits – but it’s unclear what part (it’s almost 1 cm large which is big for brain space)
About 20% of people with obesity have a true “loss of control” like you see in addicts
Fatty foods can hijack the nucleus accumbens and encourage the behavior
There are promising trials in mice where manipulation of the nucleus accumbens shuts down overeating and seeking of fatty foods
Binge eating affects 3-5% of the population
Binge eaters usually binge once per day or 3-4 times per week (this is surprising for most people to learn) – there may be other big meals and “loss of control eating” that don’t qualify as a binge by definition
To meet criteria for “binge” you have to experience loss of control and eat an enormous amount of food at one time
Dysfunction leads to binging – both elevated autonomic arousal and decreased autonomic arousal
DBS is currently being studied for modulation of the nucleus accumbens (by identifying where the craving is originating by provoking craving during surgery) in obese people who have failed gastric bypass surgery
Anorexia is a disruption of reward processes: anorexics have a reflexive hyper-awareness about the fat content of food and default towards low calorie, low fat foods subconsciously and are rewarded by avoiding higher fat, higher calorie foods that sustain weight
Traits of anorexia: loss of muscle mass, low blood pressure, low heart rate, hair growth on the face, loss of bone density, loss of menstruation, disrupted gut and immune symptoms, high cholesterol, hyper-focus on details within environment, distortion of appearance versus reality
Anorexia, bulimia, and binge eating are all distortions in relationship to food where reward and habit are disrupted beyond control
Anorexia is more habit based while binge eating and bulimia cause food to be hyper attractive (like driving a car with no breaks)
Anorexia is the most dangerous psychiatric disorder because it has the highest mortality of eating disorders and mental health disorders, including depression
Anorexia overrides all homeostatic processes driving people towards food
Anorexia has a biological underpinning: anorexics feel good by approaching foods that are low fat, low calorie and rewarded more than if eating in a healthier way to support weight
Anorexia typically starts in adolescence when youth find food aversive
Males do suffer from anorexia, but women struggle with anorexia about 10x more
Rates of anorexia in the past 10-20 years are not increasing – and have actually stayed similar as compared to first discovery in the 1600s
Transcranial magnetic stimulation (TMS): if done while patient is having intrusive thought, the stimulation can disrupt the compulsive behavior during and after treatment by intervening the automatic nature of OCD
  • There’s a lot of excitement about TMS in combination with SSRIs or CBT but it’s still early days
TMS has been FDA approved for depression
There may be a TMS target for eating disorders and anorexia in the future, but more research needs to be done to identify where needs to be targeted
Ultrasound is also FDA approved to deliver ablation to the brain, non-invasively – currently being used to treat tremor (essential tremor & Parkinson’s disease); in the future it’s possible you can open the blood-brain barrier to deliver medicine or treat mental health disorder
Ultrasound is being studied for obesity, addiction, depression, and other disorders; the focus is trying to find the right target to treat
Currently, studies are being done in which psychiatrists are triggering food craving under video surveillance and while connected to electrodes in attempt to identify the regions of the brain involved while watching visual cues in attempts to sync the timing
Pilot study of responsive nucleus accumbens deep brain stimulation for loss-of-control eating (Nature Medicine)