Psychosurgery

• What is deep brain stimulation?

  Uses electrical stimulation to 'deactivate' part of brain, rather than removing it (no tissue destruction). Thin electrode inserted into brain- connected to battery pack implanted in chest (wires embedded in brain). Batteries produce adjustable high-frequency current that interrupts brain circuitry involved in e.g, OCD. If doesn't work, can be turned off.
• What is stereotactic psychosurgery?

  MRI scans locate exact points within brain and sever connections precisely. Uses anaesthetic. E.g, in OCD, circuit linking orbital frontal lobe to deeper structures in brain such as thalamus, appears more active than normal. Bilateral cingulotomy surgically interrupts circuit. Either burn away tissue by heating tip of electrode, or use non-invasive gamma knife, to focus beams of radiation at target site.
• What is capsulotomy?

  Type of stereotactic surgery. Surgeons insert probes through top of skull & down into capsule (region near hypothalamus that's part of circuit). Heat tips of probes, burning away tiny portions of tissue.
• What is a prefrontal lobotomy?

  Selective destruction of nerve fibres performed on frontal lobe (involved in impulse control & mood regulation). Initially performed on those with affective disorders & severe OCD- less successfully scz.
• What is a prefrontal leucotomy?

  Type of prefrontal lobotomy. Egas Moniz (1930s)- drilling hole on each side of skull & inserting instrument resembling ice pick to destroy nerve fibres underneath. Technique refined with leucotome (instrument with retractable wire loop)- could cut into white matter of brain & sever nerve fibres. Hoped that cutting into nerve pathways that carry thoughts would relieve patients of distressing thoughts & behaviours.
• What happened to Howard Dully?

  12 year old boy received transorbital lobotomy after his step-mother claimed he was, 'badly behaved'. He did not consent.
• What happened to Mary Lou Zimmerman?

  Received psychosurgery (cingulotomy & capsulotomy) for untreatable OCD. Resulted in crippling brain damage rather than cure. Family sued US clinic, claiming they had not been informed of dangerous & experimental nature of the surgery. Awarded $7.5 million in damages by jury.
• Mayberg et al (2005)


  DBS effective in patients suffering from severe depression. 4/6 patients with this disorder had striking improvements noted, following treatment involving stimulation of a small area of the frontal cortex.
• Cosgrove & Rauch (2001)


  Cingulotomy effective in 56% of OCD patients & capsulotomy effective in 67%. In major affective disorder, cingulotomy effective in 65%, & capsulotomy 55%. However, only 25 patients per year treated this way in USA, so number of patients studied small.
• Bridges et al (1994)


  Pointed out that as psychosurgery is a treatment of last resort, no controlled trial against a comparable treatment is possible.
• Szasz (1978)


  Criticised psychosurgery as person's psychological self is not something physical & therefore it's illogical to suggest it can be operated on.
• What are the future directions with DBS?

  DBS evolving as research tool & treatment. Can provide researcher info that other scanning methods can't. E.g, EEG can tell us when activity in brain is happening, but not where. FMRI tells us where activity is, but too slow to pinpoint when. DBS gives precise info about both things.
• How was psychosurgery used in the past?

  Mental asylums & prisons- no valid consent to operations. E.g, patients with severe depression not in right state to give fully informed consent. 1983 Britain, the MHA (mental health act) incorporated more stringent provisions regarding consent to treatments. E.g, those who are detained under MHA but not committed a crime have same rights to consent as people not detained.
• Explain irreversible damage:

  Early procedures resulted in significant changes to person's cognitive capabilities such as memory loss & severe blunting of emotions. Zombie-like, devoid of emotions. Modern methods reduced risk of severe damage to brain due to techniques targeting precise locations in brain. Procedures such as DBS still carry risks of long-term side effects such as seizures & altered states of mood.
• Comer (2002)


  Early surgery lobotomies had fatality rate up to 6% and range of side effects such as seizures & lack of emotional responsiveness.
• What are lobotomies rarely used to treat?

  Rarely used to treat phobias, and not used to treat scz.