Lesion analysis for cingulotomy and limbic leucotomy: comparison and correlation with clinical outcomes

Abstract

Object Cingulotomy and limbic leucotomy are lesioning surgeries with demonstrated benefit for medically intractable psychiatric illnesses. They represent significant refinements of the prefrontal lobotomy used from the 1930s through the 1950s. However, the associations between anatomical characterization of these lesions and outcome data are not well understood. To elucidate these procedures and associations, the authors sought to define and compare the neuroanatomy of cingulotomy and limbic leucotomy and to test a method that uses neuroanatomical data and voxel-based lesion–symptom mapping (VLSM) to reveal potential refinements to modern psychiatric neurosurgical procedures. Methods T1-weighted MR images of patients who had undergone cingulotomy and limbic leucotomy were segmented and registered onto the Montreal Neurological Institute T1-weighted template brain MNI152. Using an atlas-based approach, the authors calculated, by case, the percentage of each anatomical structure affected by the lesion. Because of the infrequency of modern lesion procedures and the requirement for higher-resolution clinical imaging, the sample size was small. The pilot study correlated cingulotomy and limbic leucotomy lesion characteristics with clinical outcomes for patients with obsessive-compulsive disorder. For this study, preoperative and postoperative Yale-Brown Obsessive Compulsive Scale scores for 11 cingulotomy patients and 8 limbic leucotomy patients were obtained, and lesion masks were defined and compared anatomically by using an atlas-based method. Statistically significant voxels were additionally calculated by using VLSM techniques that correlated lesion characteristics with postoperative scores. Results Mean lesion volumes were 13.3 ml for cingulotomy and 11.8 ml for limbic leucotomy. As expected, cingulotomy was isolated to the anterior cingulum. The subcaudate tractotomy portion of limbic leucotomy additionally affected Brodmann area 25, the medial orbitofrontal cortex, and the nucleus accumbens. Initial results indicated that the dorsolateral regions of the cingulotomy lesion and the posteroventral regions of the subcaudate tractotomy lesion were associated with improved postoperative Yale-Brown Obsessive Compulsive Scale scores. Conclusions Cingulotomy and limbic leucotomy are lesioning surgeries that target pathological circuits implicated in psychiatric disease. Lesion analysis and VLSM contextualize outcome data and have the potential to be useful for improving lesioning neurosurgical procedures.

Subcaudate Tractotomy White Matter Anatomy and Variability: A Diffusion Tensor Imaging Study

“…We present here a detailed assessment of the tract anatomy, anatomical variability, and locations of the white matter fibres likely disrupted by subcaudate tractotomy, using native (non-normalized) diffusion tensor imaging (DTI) data from healthy controls. This work builds upon the prior excellent work of Yang et al [3, 7], from 2014 and 2015, that was based on normalized DTI data.…”

“…The procedure is often performed in conjunction or secondary to dorsal anterior cingulotomy, the combination of which is termed limbic leucotomy [2, 3]. First described by the British neurosurgeon Geoffrey Knight in 1965 using radio-active yttrium-90 rods, then later adapted by Malhi and Bartlett [4] in London as well as Bourne et al [2] at Massachusetts General Hospital with the use of stereotactic electrode thermocoagulation [3, 5], the target is the white matter structures ventral to the heads of the caudate nuclei.…”

“…Lesion mapping of the subcaudate tractotomy ablation zones from patients who have undergone this procedure implicates disruption of both grey and white matter structures including the nucleus accumbens, subgenual cingulate gyrus, orbitofrontal cortex, anterior thalamic radiation, uncinate fasciculus, medial forebrain bundle, and corticostriatal fibres [3, 7]. …”

“…There is significant overlap between the tracts implicated in successful response to BA25 DBS and those tracts likely disrupted by subcaudate tractotomy [3, 7, 12], including the uncinate fasciculi and corticostriatal fibres arising from the ventromedial and orbitofrontal cortex. Given both techniques have shown moderate response rates for treatment-resistant depression, it is feasible that they represent 2 different anatomical approaches to modulating a shared set of underlying white matter tracts.…”

Diffusion Tensor Imaging Investigation of Uncinate Fasciculus Anatomy in Healthy Controls: Description of a Subgenual Stem

“…The temporal component connects with the uncus, anterior temporal pole, and basolateral amygdala [13], and extends posteriorly/caudally prior to the U-shaped hook. From here the tract runs medially to the insula and ventrally/inferiorly to the head of the caudate nucleus (a location that would have likely been targeted in the once performed subcaudate tractotomy) -see Figure 1a [1,14]. Upon arrival in the prefrontal region, the traditional description has been a division into 2 prefrontal stems, extending to the lateral orbital gyri and the frontopolar cortex, respectively [15].…”