Chaotic. Extreme. Barbaric. Irresponsible.
Our modern understanding of functional neuroanatomy, combined with advances in stereotactic technology and functional imaging, creates a setting in which neurosurgery may offer a minimally invasive and highly selective treatment option for a variety of psychiatric illnesses.
Consequently, the performance of surgery to control the haunting symptoms of a disturbed mind may very well be a viable option in the future of psychiatric treatment.
Technical Neurosurgical Procedures for Behavioral- Based Disorders
The rich history and evolution of psychosurgery has finally lead to the acceptance of 4 commonly employed neurosurgical procedures used to treat psychiatric disease. Although they each differ in their technique and methodology, each procedure is performed bilaterally and under stereotactic conditions, which allows for precise lesioning of the targeted structures.
This procedure was designed in England by Geoffrey Knight in 1964 as a method of minimizing frontal lobe lesioning by interrupting fibers from the frontal lobes to subcortical structures such as the amygdala. The site of the lesion is the substantia innominata, just below the head of the caudate nucleus. In a study of 208 patients in the 1970s, approximately 2/3 of patients with depression or anxiety had post-operative improvement, while 50% of obsessive patients also demonstrated improvemen. Nine female patients with bipolar disorder were studied 4 years post operation, and 5 demonstrated marked improvement, while 4 showed mild improvement.
The anterior cingulum was first suggested as a surgical target for the treatment of psychiatric disease in 1947. This was based on evidence that stimulation of the anterior cingulum in monkeys produced autonomic responses associated with emotion. Lesions in this region significantly resulted in less fearful and more aggressive animal. This procedure is currently used to treat refractory major affective disorder, severe chronic pain, chronic anxiety states or OCD. The cingulate cortex is an important structure in the anatomical-behavioral circuit which Papez outlined. MRI guided stereotactic techniques are used to properly isolate target coordinates, and lesions are created via thermocoagulation. The day after surgery, a post-operative MRI scan is obtained to visualize the placement and extent of the lesions.
Introduced in 1973 by Dr. Nita Mitchell-Heggs and Dr. Desmond Kelly, this procedure is essentially the combination of stereotactic lesions created in the subcaudate tractotomy and anterior cingulotomy in order to disconnect orbital-frontal-thalamic pathways. The lesions are created using a either cryoprobe or thermocoagulation and up to 14 cryogenic lesions are made in the brain. Price et al., has demonstrated 36–50% of patients with major depressive disorder and OCD showed improvements with little adverse side effects from the procedure, while 4/5 patients who were engaged in self mutilation showed sustained reduction in self-injurious behavior post operative follow-up at 32 month.
This procedure was designed in the late 1940s. Due to the innovation of the Swedish neurosurgeon Leksell, it currently uses thermocoagulation or gamma-knife stereotaxis to lesion the fronto-limbic fibers that pass in the internal capsule as it courses between the caudate and putamen nuclei of the basal ganglia. Clinical indications for capsulotomy initially included schizophrenia, depression, chronic anxiety states and obsessional neurosis. Leskell initially operated on 116 patients with a variety of psychiatric disorders; 50% of patients with obsessional neurosis and 48% of depressed patients had a satisfactory response, while 20% of patients with anxiety neurosis and 14% of patients with schizophrenia also showed improvement.