Stereotactic & Functional Neurosurgery

Surgery that treats disorders of brain and nerve function — movement disorders, epilepsy, severe psychiatric illness, and chronic pain — by precisely modulating or interrupting the circuits responsible. An independent educational overview for patients and referring clinicians.

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Explore each area below, or reach out directly.
Overview

What functional neurosurgery is

Most neurosurgery treats a structural problem — a tumor, a bleed, a compressed nerve. Functional neurosurgery is different: it treats disorders of how the nervous system works. The anatomy may look normal, but a circuit is misfiring — producing a tremor, a seizure, an obsession, or relentless pain. The goal is to correct that activity while preserving everything else.

The work is stereotactic: targets deep in the brain are reached with millimeter precision using image-guided planning, often through a small opening or, increasingly, with no incision at all. Two strategies run through the whole field — modulating a circuit with an adjustable, reversible implanted device, or interrupting it with a small, precise lesion. The same toolbox — deep brain stimulation, focused ultrasound, radiosurgery, and connectivity-guided targeting — is applied across four broad areas.

This site is an independent educational overview. Each area links to a dedicated, in-depth guide.


Areas of care

Four areas, one approach

Functional neurosurgery is organized around the kind of problem being treated. Each area below has its own detailed guide — the conditions it covers, how candidates are evaluated, and the specific procedures available.

Movement Disorders
When medication can no longer control tremor, stiffness, slowness, or involuntary movements, deep brain stimulation and focused ultrasound can restore function.
Covers: Parkinson's disease · essential tremor · dystonia
Detailed guide
Epilepsy
For drug-resistant focal epilepsy, surgery can remove, disconnect, ablate, or modulate the network that generates seizures — guided by modern intracranial mapping.
Covers: drug-resistant focal epilepsy · SEEG/ECoG · resection, ablation, RNS/DBS/VNS
Detailed guide
Psychiatric Neurosurgery
For severe, treatment-resistant illness, neuromodulation and precise lesioning can modulate the circuits whose dysregulation drives disabling symptoms.
Covers: treatment-resistant OCD · depression · PTSD
Detailed guide
Chronic Pain
For pain that no longer responds to other care, neuromodulation, targeted treatment of trigeminal neuralgia, and precise procedures can offer durable relief.
Covers: trigeminal neuralgia · neuropathic pain · cancer & refractory pain
Detailed guide

The circuit view

One idea connects all four

Movement disorders, epilepsy, severe psychiatric illness, and chronic pain look like entirely different problems — but they share a logic. Each is, at its core, a disorder of a circuit: a network of brain regions and the pathways between them, firing in a pattern that produces symptoms. Functional neurosurgery intervenes at a precise node of that circuit.

Increasingly, the target is chosen not from anatomy alone but from each patient's own structural connectivity — tractography that maps the white-matter pathways a given target engages, so an intervention reaches the intended network and spares the rest. This connectivity-guided approach is a focus of the research program at the Neuronium Neuroscience Institute, and it runs through all four areas of care.

Map the circuit
High-resolution imaging and tractography reconstruct the network involved and the precise target within it.
Modulate or interrupt
An adjustable, reversible device stimulates the circuit — or, where preferred, a precise lesion interrupts it.
Preserve function
Throughout, the aim is to relieve symptoms while protecting movement, language, memory, and personality.

Technology

A shared toolbox

The same core technologies appear across movement, epilepsy, psychiatric, and pain surgery — applied to different targets for different conditions.

Deep Brain Stimulation (DBS)
Thin electrodes deliver adjustable, reversible stimulation to a precise deep target. The workhorse of movement-disorder and psychiatric surgery.
MR-Guided Focused Ultrasound
Hundreds of ultrasound beams converge to make a precise lesion deep in the brain — with no incision and no implant — under real-time MRI thermometry.
Stereotactic Radiosurgery
Focused radiation treats a target without opening the skull, used for tremor, trigeminal neuralgia, and selected lesions.
Radiofrequency Lesioning
A stereotactically placed probe makes a controlled, precise lesion — for tremor, pain pathways, and seizure foci.
Implanted Neuromodulation
Responsive and scheduled stimulation systems — from spinal cord and nerve stimulators to closed-loop brain devices.
Connectivity-Guided Targeting
Each patient's tractography refines the target so stimulation or lesioning engages the intended network and limits side effects.

About the author

Who wrote this site

AFA

Ahmet Fatih Atik, MD

Neurosurgeon · stereotactic and functional neurosurgery

Dr. Atik is a neurosurgeon whose practice focuses on stereotactic and functional neurosurgery across its full range — deep brain stimulation and focused ultrasound for movement disorders, surgery for drug-resistant epilepsy, neuromodulation and lesioning for treatment-resistant psychiatric illness, and procedures for chronic pain.

Alongside clinical work, he conducts research on network-level analysis of brain circuits and on integrating each patient's structural connectivity into surgical targeting. This research program is housed at the Neuronium Neuroscience Institute, an independent research entity.

This site is independent and educational. It is not affiliated with any hospital or health system and does not, by itself, constitute medical advice.


Consultation

Request a consultation

If you are a patient or family member exploring whether functional neurosurgery might help — or a clinician considering a referral — you can use the form below to start a conversation. If you already know your area of interest, the dedicated guides (movement, epilepsy, psychiatric, pain) each have their own contact form. Please share only what you are comfortable putting in writing.

Please note. This form is for general inquiries and is not a substitute for emergency or urgent care. If you or someone you know may be in danger, call your local emergency number right away. Submitting this form does not create a doctor-patient relationship and does not guarantee an appointment. Please avoid sending detailed medical records or sensitive personal health information through this form.