Lesson 4 Psychosurgery

Psychosurgery

Psychosurgery Psychosurgery-the use of surgery on the brain to treat psychological functions. Egas Moniz pioneered the technique and it was developed by Walter Freeman. Based on 2 observations : A lab chimp pacified by operation on frontal lobes. Tumour operation on a human frontal lobe without causing intellectual damage.

Techniques Leucotomy o A narrow device was inserted (via holes made in the skull) into the frontal lobe. o The blade of the leucotome was then extended and rotated to lesion a core of tissue. o This was repeated several times to destroy pieces of prefrontal cortex.

Techniques Transorbital lobotomy o Used a special knife called an ‘ice pick’. o Inserted under the eye lid and into the back of the eye socket. o This was used to break through the skull into the brain & was moved around to destroy connections between the prefrontal area & other brain areas. o This was repeated on both hemispheres.

Why used? Used on patients who were emotionally unstable and violent & did not respond to other forms of therapy. It generally had the effect of relieving emotional distress & anxiety and calmed the patient down. As a result the surgery became common. Tooth & Newton (1961) reported that more than 10,000 operations were performed in the UK.

Side effects Such procedures are now rare because of their severe side effects. Problems include:  Changes in personality.  Lethargic, apathetic, irresponsible, socailly withdrawn.  Lacked ability to plan their own behaviour.

Evaluation • Evidence for which lobotomies were based was very limited. Findings from the chimpanzee may not be relevant to humans due to brain structure & function. • Findings from the human case may not be generalisable, as the medical reason for the lobotomy was a physical not a psychological one.

Evaluation • The rapid growth of the technique was based on its use for reducing stress & making difficult individuals more manageable for staff in institutions. This is unethical. • Moniz & Freeman claimed high success rates for their operations. This was supported by Pippard(1955) who found worthwhile or good results for 62% of leucotomised depressive patients & good results with 50% of those with affective disorders. • In 95% of these cases Pippard reported no more than slight personality changes. • However, many other sources reported severe side effects and original procedures were abandoned.

Current Procedures Bilateral cingulotomy is now occasionally performed. Used to help very depressed patients, sufferers of OCD & to reduce pain in cancer patients. This techniques uses very accurate MRI to assist surgeons to identify the exact location of the area to be lesioned. A fine electrode destroys the tissue directly.

Evaluation of current procedures • Mixed evidence. Seems to reduce pain, it does not appear to affect the pain threshold. • Similar side effects. Cohen et al (1999) compared the pre-operative performance of 12 cingulotomoy patients being treated for chronic pain with 20 control patients also with chronic pain. Over 60% of the cingulotomy patients reported less pain post operatively and most required less medication to control their pain. However, Cohen et al found some consistent post-operative problems. On average these patients lacked the ability to spontaneously initiate responses (such as verbal responses) & showed deficits in attention compared with the controls.

Evaluation of current procedures • Investigating the use of cingulotomy for OCD, Baer et al (1995) followed 44 patients. They found the treatment to be effective in 32% of cases and partially in a further 14%. Some patients reporter side effects including seizures. • Mashour et al(2005) suggests that psychosurgery is a much safer & ethically sound approach because of the usefulness of modern elecrical brain-stimulation techniques.