Can Stereotactic Neurosurgery Help Treat Autism Spectrum Disorders?

What you need to know

• Stereotactic neurosurgery techniques like deep brain stimulation (DBS) show promise for treating certain symptoms in people with autism spectrum disorders (ASD), particularly aggression and obsessive-compulsive behaviors.
• Studies suggest these surgical approaches may help improve social interaction and communication in some people with ASD, though more research is needed.
• While generally safe, there are some risks of complications, especially for patients with severe self-injurious behaviors.

What is stereotactic neurosurgery?

Stereotactic neurosurgery refers to minimally invasive brain surgery techniques that use imaging guidance and a 3D coordinate system to precisely target specific areas deep within the brain. The two main types used for psychiatric and behavioral conditions are:

1. Deep brain stimulation (DBS): Electrodes are surgically implanted to deliver electrical pulses to targeted brain regions. The stimulation can be adjusted over time.

2. Radiofrequency ablation: Targeted brain tissue is destroyed using heat from radio waves. This creates a small, permanent lesion.

These approaches aim to modulate the activity of brain circuits involved in certain symptoms or behaviors. They have shown success in treating movement disorders like Parkinson’s disease and psychiatric conditions like severe obsessive-compulsive disorder (OCD).

How might it help in autism spectrum disorders?

Researchers are exploring whether stereotactic neurosurgery could help treat some of the challenging symptoms and behaviors associated with autism spectrum disorders (ASD). The goals are to:

1. Reduce problematic symptoms like aggression, self-injury, or severe obsessive-compulsive behaviors
2. Potentially improve core autism traits like social communication difficulties

This systematic review looked at 11 studies involving 36 total patients with ASD who underwent stereotactic neurosurgery. Here’s a breakdown of what they found:

Treating aggression and obsessive-compulsive symptoms

The most common reasons for surgery were:

• Aggression (14 patients)
• Obsessive-compulsive disorder (OCD) symptoms (12 patients)
• Both aggression and OCD symptoms (10 patients)

For measuring OCD symptoms, researchers use a scale called the Yale-Brown Obsessive Compulsive Scale (Y-BOCS). Lower scores indicate improvement. In 19 patients:

• Average Y-BOCS score decreased from 31.4 to 18.3
• 63% had a “full response” (35%+ decrease in score)
• 21% had a “partial response”
• 16% had no significant response

For aggression, 15 patients were evaluated using the Overt Aggression Scale (OAS):

• Average OAS score decreased from 11.2 to 4.4
• This represents a 60% improvement on average

These results suggest stereotactic neurosurgery may help reduce severe aggressive behaviors and obsessive-compulsive symptoms in some people with ASD who haven’t responded to other treatments.

Effects on core autism symptoms

A few studies reported improvements in social interaction and communication skills after surgery, particularly with deep brain stimulation. For example:

• Two patients showed small improvements on tests of social skills
• Five patients were described as having better social interactions, communication, or confidence after surgery

However, these reports were mostly subjective or based on limited data. More rigorous research is needed to determine if stereotactic neurosurgery can reliably improve core autism traits.

Which brain areas are targeted?

The most common surgical targets in these studies were:

1. Amygdala: A region involved in processing emotions, particularly fear and aggression. It was targeted in 11 patients, mainly for aggressive behaviors.

2. Ventral anterior limb of internal capsule (vALIC): A bundle of nerve fibers connecting areas involved in emotion and behavior regulation. It was targeted in 6 patients for OCD symptoms.

3. Nucleus accumbens: Part of the brain’s reward system, targeted in 2 patients for OCD and aggression.

Other targets included regions like the hypothalamus and globus pallidus, often chosen based on the specific symptoms being treated.

Safety considerations

Overall, stereotactic neurosurgery appears to be relatively safe in people with ASD, with complications occurring in 7 out of 36 patients (19%). These included:

• Surgical site infections (3 patients)
• Pain or discomfort around the surgical areas (2 patients)
• Device-related issues like lead fracture (1 patient)
• Transient side effects like headache or hallucinations (2 patients)

However, there are some special considerations for people with ASD:

1. Patients with severe self-injurious behaviors may be at higher risk for complications with implanted DBS devices. Ablation procedures may be safer for these individuals.

2. Many people with ASD also have intellectual disabilities, which can make it challenging to cooperate during awake surgeries. Procedures done under general anesthesia may be preferable.

3. Post-operative management and device programming (for DBS) may require extra patience and specialized approaches for patients with communication difficulties or sensory sensitivities.

Conclusions

• Stereotactic neurosurgery shows promise for treating severe aggressive behaviors and obsessive-compulsive symptoms in some people with autism spectrum disorders.
• There’s preliminary evidence it may help improve social interaction and communication in ASD, but more research is needed.
• While generally safe, careful patient selection and specialized management approaches are important to minimize risks in this population.

It’s important to note that this is still an experimental approach. Stereotactic neurosurgery would only be considered for people with very severe symptoms that haven’t responded to other treatments. Much more research is needed to fully understand the benefits and risks in people with ASD.