**Question:** For severe intractable obsessional neurosis the psychosurgery of choice is:

A. Cingulotomy
B. Subgenual cingulate gyrus stimulation
C. Prefrontal lobectomy
D. Thalamotomy

**Correct Answer:** .

**Core Concept:**
Obsessional neurosis is a psychiatric disorder characterized by recurrent, persistent, and intrusive thoughts, impulses, or images that cause significant distress or impairment in daily functioning. Psychosurgery refers to surgical interventions performed on the brain to treat intractable psychiatric disorders.

**Why the Correct Answer is Right:**
The correct answer, **C. Prefrontal lobectomy**, refers to the removal of the prefrontal cortex, a region of the brain involved in executive functions, decision-making, and emotional regulation. In severe cases of obsessional neurosis, prefrontal lobectomy can help alleviate obsessive thoughts and improve overall functioning.

**Why Each Wrong Option is Incorrect:**

A. **Cingulotomy**: This involves cutting the cingulate gyrus, which plays a role in emotional processing, mood regulation, and attention. While cingulotomy can have some therapeutic effects in obsessional neurosis, it is less effective than prefrontal lobectomy in severe cases.

B. **Subgenual cingulate gyrus stimulation**: This option refers to deep brain stimulation (DBS) of the subgenual cingulate gyrus. Although DBS has shown some promise in treating obsessional neurosis, it is not as effective as prefrontal lobectomy for severe cases.

C. **Thalamotomy**: Thalamotomy involves the surgical ablation of the thalamus, which is involved in modulating sensory and motor functions. While thalamotomy may have some therapeutic effects, it is less effective than prefrontal lobectomy in severe cases of obsessional neurosis.

D. **Thalamotomy**: Similar to the previous explanation for option C, thalamotomy is less effective than prefrontal lobectomy in treating severe obsessional neurosis.

**Clinical Pearl:**
Prefrontal lobectomy is a more effective option for treating severe obsessional neurosis compared to the other options, as it directly targets the prefrontal cortex responsible for executive functions and emotional regulation, which are directly impacted in obsessional neurosis. In contrast, the other options primarily target different brain regions and have lesser efficacy in severe cases of obsessional neurosis.