Lecture 10 - Psycho-surgery Flashcards
What is the general idea of psycho-surgery?
Remove a part of the brain in an attempt to improve symptoms of an otherwise treatment-resistant disorder.
What did modern psycho-surgery (19th century) use as a basis for further research/evidence that it could work?
Lesions gave insights into the role of brain structure:
- Broca lost the ability to speak after lesions to the posterior IFG (now called Broca’s area)
- Phineas Gage had severe personality changes after frontal lobe trauma.
Who is ‘the father’ of modern day psycho surgery, and what was his first surgery?
Gottlieb Burckhardt.
1988 - removed parts (tracts) of the frontal, parietal and temporal cortices in supposed schizophrenia (patients with similar symptoms). Claimed success in 3/6 patients. Side effects, e.g. infection, and didn’t keep official/consistent records so actual success rates are contentious.
What was the idea of ECT?
Person in coma, brain cells would die. Only the ‘strong’ brain cells survive, improving the patients’ condition
What does ECT stand for
Electroconvulsive therapy
Who came up with the term psycho surgery, and what did their first experiments aim to do?
Neurologist Egas Moniz
Wanted to treat conditions believed to be resulting from frontal abnormalities, by cutting up afferent and efferent fibres of the frontal cortex.
First experiments used a rod that had a retractable wire loop. Inserted into brain and rotated to slice up brain tissue. Tool was called a leucotom.
What was the improved version of the leucotom?
American-made, (Freeman) trans-orbital frontal lobotomy. This was cheaper and did not require a surgeon to perform.
Why did Freeman’s psycho surgery procedure catch on?
- overcrowded asylums
- large social and financial burden caused by mentally ill
- no drugs involved
- was based on research which won a nobel prize
What were some of the side effects of Freeman’s psychosurgery procedure?
Seizures, comatose state - made it worse than the original disease.
What was the final nail in the coffin for Freeman’s psycho surgery procedure?
The first anti-psychotic came out.
What is stereotactic surgery?
Stereotactic surgery is a minimally invasive form of surgical intervention that makes use of a 3D coordinate system to locate small targets inside the body and perform actions such as ablation (removal) and biopsy (examination)
Very specific areas and pathways can be targeted. Vast majority targets the frontal cortex (dlPFC, ACC and OFC). Specifically targets pathways between these frontal regions, and the basal ganglia (caudate, globus pallidus) and thalamus - is therefore predominantly used to treat OCD currently.
What is an anterior cingulotomy?
Select lesions to the medial frontal cortex (cingulum) by using thermocoagulation (hot electrode). Appears to work in 1/3 of patients.
Side effects of seizures and memory deficits.
What is subcaudate tractotomy?
Pathway between frontal cortex and basal ganglia is lesioned, using a scolding electrode.
Side effects of seizures, and changes in personality
What is limbic leukotomy?
Lesions to medial frontal cortex AND cutting pathway between frontal cortex and basal ganglia - combination of anterior cingulotomy and subcaudate tractotomy.
Response rate of 50% in those with OCD, no reports of seizures or deaths.
Side effects of headaches, lethargy, apathy and incontinence
What do lesions of the anterior capsule involve?
Pathways within the basal ganglia (between striatum and GPi/SNr) are lesioned. Either thermolesions, using small hot wires, or radiosurgery with gamma knives (gamma radiation thrown around, and converged at a specific, mm region). Performed in UK still.
Better efficacy than all the other stereotactic surgeries.
Side effects of weight gain, apathy, and loss of some
executive functions.
