5.3.3\ Cingulotomy

5.3.3.1\ Discussion

Cingulotomy is a form of psychosurgery that is used to treat conditions, such as intractable obsessive-compulsive disorder. The procedure can be performed in a minimally invasive manner via thermal ablation. This process results in necrosis of the surrounding brain tissue, which appears as concentric rings of signal abnormality

Fig. 5.33  Bilateral anterior cingulotomy. The patient has a history of medically intractable obsessive-compulsive disorder treated with bilateral stereotactic microelectrode-­ guided anterior dorsal cingulotomy. Axial T2-weighted (a) and coronal (b) and sagittal (c) T1-weighted MR images show concentric rings of signal changes at each

(Fig. 5.33). There can be T1 hyperintensity due to petechial hemorrhage, as well as T2 hyperintensity from edema and restricted ­diffusion due to ischemia during the early postoperative period, which then evolves over time. Diffusion tensor imaging is also useful for confirming interruption of the cingulum. In particular, the dorsolateral region of the cingulotomy lesion is associated with improved behavior.

microelectrode insertion site in the bilateral anterior cingulate­ gyri. The diffusion-­weighted image (d) and ADC map (e) show circular zones of restricted diffusion consistent with ischemia. The color fractional anisotropy map (f) shows interruption of the bilateral anterior cingulate fiber tracts

5.3.4\ Subcaudate Tractotomy

and Limbic Leucotomy

5.3.4.1\ Discussion

Stereotactic subcaudate tractotomy is performed for treating severe cases of obsessive-compulsive disorder. The procedure consists of disrupting the fiber tracts between the orbitofrontal cortex and the thalamus, which are located approximately 5 mm anterior to the sella, 15 mm from

a

the midline, and 10–11 mm above the planum sphenoidale (Fig. 5.34). Limbic leucotomy is a combination of cingulotomy and a ventral lesion similar to that of subcaudate tractotomy (Fig. 5.35). Following subcaudate tractotomy and limbic leucotomy, rostral atrophy can be identified on conventional imaging. In addition, diffusion tensor imaging can depict the absence of normal communicating white matter tracts between the inferior frontal lobes.

b

Fig. 5.34  Subcaudate tractotomy. The patient has a history of medically intractable obsessive-compulsive disorder. Axial (a) CT image shows paired hypoattenuating lesions in the bilateral subcaudate nucleus. T2-weighted images (b) demonstrate concentric T2 hyperintense zones

surrounding the microelectrode insertion sites. Diffusion-­ weighted imaging (c) and corresponding ADC map (d) show that these zones have restricted diffusion, consistent with acute lesions

Fig. 5.35  Limbic leucotomy. Axial FLAIR (a), coronal T1-weighted (b), sagittal T1-weighted (c), and diffusion tensor directional color map (d) MR images show chronic

lesions in the bilateral anterior cingulate gyri (arrowheads) and region of the anterior perforated substance (arrows). There is also atrophy of the fornices