Functional neurosurgery for intractable mental disorder: long term effects on mental health, neuropsychological performance, social function, and quality of life
Aims and Objectives
1) To evaluate the long-term effects of neurosurgery for mental disorder (NMD) on: Mental health and quality of life.
2) To evaluate the effects of NMD on cognitive functions such as learning and memory, and personality.
28 out of 31 individuals who had undergone Anterior Capsulotomy (ACAPS) or Anterior Cingulotomy (ACING) for Treatment-Refractory Depression (TRD) or Obsessive-Compulsive Disorder (OCD) in Dundee since 1992 were assessed using a detailed battery of clinical assessments; clinical and computerised neuropsychological testing; and Magnetic Resonance (MR) imaging.
The mean (± SD) duration of follow-up was 336.0 ± 193.6 weeks. The primary indication for surgery was unipolar depression in 73.3%, bipolar depression in 10%, and OCD in 16.7%. The numbers of procedures were: ACAPS (20); ACING (5). Seven individuals underwent a subsequent ACING. At long-term follow-up, when both procedures were combined, 48% of patients met pre-defined criteria for response, and 40% met criteria for remission. Mean reduction in MADRS score was 42%. Forty-four percent of participants had achieved ‘Clinically Significant Change’ as described by Jacobsen & Truax, 1991. Forty-three percent met criteria for response after a second procedure. Validated measures of quality of life all improved following neurosurgery. No detrimental effect on personality could be identified and there was a non-significant reduction in neuroticism. General intelligence, memory, and executive function were not significantly impaired at long-term follow-up. There was a trend towards improvement in a number of areas. MR imaging analysis revealed a putative relationship between ACING lesion location, volume, and outcome. The burden of adverse effects was low, with most (e.g. headache, confusion) being predictable and of short duration. One patient experienced seizures in the post-op period. One patient experienced a severe intra-operative haemorrhage. There were no deaths and no suicides associated with the neurosurgery.
Both Anterior Capsulotomy and Anterior Cingulotomy appear to be relatively safe procedures which can result in clinically significant improvement in symptoms in over 40% of patients with TRD or OCD. A relationship appears to exist between lesion location and outcome for ACING. This is the first study of the outcomes of Anterior Capsulotomy for depression since 1961, and it is also one of the largest prospective studies conducted of clinical and neuropsychological outcome. The findings may offer guidance on when a second procedure may be indicated and the putative relationship between lesion characteristics and outcome after ACING may have major implications for future surgery. Larger, and possibly double-blind, randomised trials of lesion placement should be considered and collaboration between different NMD centres will afford a greater sample size with which to assess the relationship between capsulotomy lesions and outcome.