Severe OCD is often nonresponsive to pharmacological and behavioral therapies and thus surgical interventions are emerging. Surgical interventions have proven to be efficacious for treating refractory OCD, however limited publications suggest 22–40% of patients experience transient apathy and disinhibition post-surgery (McLaughlin et al., 2021). Apathy is highly associated with the same brain regions, the prefrontal cortex, striatum, and thalamus, which have also been implicated in OCD symptoms (Le Heron et al., 2018). Prior research noting post-surgical changes in apathy in OCD either used physician observations or less precise surgical methods (i.e., gamma knife or radiofrequency ablation). Apathy has also been highly associated with depression and executive dysfunction (Raffard et al, 2020) and often not co-assessed in prior studies. The newest intervention, cutting-edge MR-guided laser interstitial thermal therapy (LITT), limits damage outside the region of interest by precise control of thermal application in real-time. Thus, the current case series aims to investigate objective patient-reported change in apathy, disinhibition, depression, and executive dysfunction following anterior capsulotomy via this newest surgical approach for OCD.

In this retrospective study, the responses of ten consecutive patients pre- and post-LITT on the following measures were examined: Frontal Systems Behavior Scale (FrSBe), Beck Depression Inventory-II (BDI-II), and Yale Brown Obsessive-Compulsive Scale (Y-BOCS). Reliable Change Index (RCI) was used to evaluate meaningful change in pre- and post-LITT self-reported levels of apathy, disinhibition, executive dysfunction, along with depressive symptoms. Per prior published guidelines, patient-reported Y-BOCS (range 0–40) scores were used to measure OCD symptoms with 24–34 % score reduction representing partial and 35% or greater score reduction representing full response (Pepper et al., 2019).

Seven patients (70%) were male, with a sample mean age of 38.4 (SD=13.6) and a mean of 14.6 (SD =2.27) years of education. Mean Y-BOCS score decreased from 32 (SD=5.3) before surgery to 18.8 (SD=11.1) after. Over 65% had partial or full response in OCD symptoms post-surgery. Six patients endorsed increased apathy, with others endorsing no change. Half of the non-responders reported this increase in apathy. The cohort remained relatively stable in disinhibition and executive dysfunction. Over half the cohort demonstrated a significant decrease in depressive symptoms. Interestingly, two of the non-responders and one responder endorsed increased apathy despite stable or improving depressive symptoms, disinhibition, and executive dysfunction.

Surgical interventions for psychiatric disorders are emerging quickly and being refined daily. In this cohort, anterior capsulotomy via LITT provided full or partial OCD recovery for most patients. However, most patients reported significant increases in apathy, despite experiencing a decrease in depressive symptoms, with stable disinhibition and executive dysfunction. Despite these promising improvements in OCD symptomatology via LITT, impact of surgery on apathy levels is clearly warranted using objective, quantifiable methods. As apathy has consistently been related to functional impairment and poorer quality of life, understanding this outcome is imperative in larger trials. Better understanding of this finding and underlying circuity will allow patients to be fully informed regarding this promising surgical intervention.