Neuromodulation Flashcards
Where did the whole idea behind convulsive therapy come from?
Jauregg’s giving malaria to patients with neurosyphilis. Fevers / convulsions appeared to help things. Chemically induced seizures helped patients with catatonic schizophrenia when nothing had ever helped before.
Why was ECT first developed?
A more reliable and safe way to induce seizures vs. malaria / chemicals.
Does ECT work well for depression?
Yes, actually.
The meta-analysis cited is weird though… as a lot of the studies listed are from before the advent of SSRIs.
Indications for ECT? (8 are listed…)
MDD bipolar schizophrenia and schizoaffective disorder catatonia neuroleptic malignant syndrome sever autism status epilepticus Parkinson's disease
Why don’t you want to use ECT in people with unstable CV disease?
ECT causes release of catecholamines -> sympathetics -> tachycardia/arrhythmias
Why do you have to be careful with ECT when patient has past skull fracture or craniotomy?
Can cause burns.
Why don’t you want to use ECT for patients with cognitive impairment?
It can make that impairment worse.
For which personality disorder do you not want to use ECT?
Borderline
Hand-waving plausible mechanisms for ECT activity?
Changes in monaminergic, glutaminergic, and glutaminergic neurons. Maybe increased BDNF.
One mechanism by which ECT may help depression that is supported by imaging?
“Reduced functional connectivity” in left dlPFC. (correlation… not proven to be causal)
Why pre-oxygenate when using ECT?
Increased metabolic demand during induced seizure?
What kind of anesthesia is used for ECT?
Short-acting IV anesthesia, often propofol.
Plus a muscle relaxant.
What are 3 electrode placements in order of least effective/fewest side effects to most effective/most side effects?
Right unilateral
Bifrontal
Bitemporal
What about the waveform?
Square, short, wave pulses of AC current are better than sine waves.
How common is relapse (for all conditions) after ECT?
Very common, but can be mitigate with pharmacotherapy +/- maintenance ECT.
How does transcranial magnetic stimulation (TMS) contrast from ECT?
TMS allows you to stimulate specific parts of cortex by inducing a current in it.
Main advantage of TMS over ECT? (3)
No cognitive effects.
Doesn’t cause seizure.
Safer.
Things that TMS might treat that ECT doesn’t?
Pain syndromes, tinnitus, ADHD.
Is TMS proven to work for depression?
Technically, yes, but the significance was borderline.
3 factors shown by meta-analysis to influence the effectiveness of TMS for depression?
Duration, intensity, # of pulses.
Advantages of Magnetic Seizure Therapy over ECT?
More focal, fewer cognitve side effects, less post-ictal confusion.
(Dr. Bhati says it’s likely not as effect as ECT…)
When is vagal nerve stimulation (VNS) indicated? Major drawback?
For depression that has not responded to 4 or more drugs.
Takes months for full effect.
What area of the brain might the vagal nerve stimulation hit?
the orbitofrontal cortex.
How does deep brain stimulation (DBS) contrast from VNS? Which areas of the
Electrodes actually go into brain.
Ant. cingulate, ventral striatum, nucleus accumbens.
Indications for DBS? (2 are approved)
Severe OCD, essential tremor and epilepsy.
Use in depression, obesity, addiction, etc. is being studied
What’s the major risk of DBS?
Somewhat obviously, intracerebral hemorrhage.
Why was area 25 of the cingulate gyrus targeted in DBS for depression? Did it work?
Because this area changed from hyperactive to less active in people successfully treated for depression with CBT or fluoxetine.
It worked in an open-label study, but that doesn’t tell you much.
