One Patient, One Procedure: Right Amygdala Tied to PTSD

How doctors mapped and silenced the tissue

The team used stereoelectroencephalography-guided radiofrequency ablation. Thin wire electrodes implanted deep in the brain record electrical activity and locate seizure sources. High-frequency current then heats selected contacts to roughly 58 to 60 degrees Celsius, permanently inactivating a three- to seven-millimeter zone while the patient stays awake.

Doctors placed seven electrode contacts in his right amygdala and three in his left. They compared him against 16 epilepsy patients without PTSD — seven men, nine women, average age 37 — monitored at the same hospital.

Before ablation, he completed 252 trials of a facial emotion task; controls did about 260 on average. Participants saw faces for one second, morphed from fully happy to fully fearful, with 50 percent marking an ambiguous expression, then labeled each face and rated their confidence.

What changed immediately after ablation?

Before the procedure, the patient judged ambiguous 50-percent faces as fearful far more often than controls — a statistically significant gap versus the male controls but not the female controls. His right lateral amygdala recordings showed late-phase brain waves (350 to 650 milliseconds after each face) that exceeded the 90th percentile of controls.

Pre-ablation stimulation also revealed a left-right split. Mild 1.5 to 2.0 milliampere currents in three right-amygdala subregions evoked tingling chills and euphoria. Left-amygdala stimulation produced nothing until 3.0 milliamperes, which triggered a pleasant childhood memory.

That afternoon, doctors ablated tissue around five right-amygdala contacts, sparing more than 99.9 percent of the right hippocampus. Twenty minutes later, across 336 trials, he labeled ambiguous and moderately fearful faces as fearful much less often, matching controls on intermediate expressions. His reaction times slowed from 0.7 to 1.1 seconds, and the late-phase electrical gap between fearful and happy faces vanished across the right amygdala. A new distinction emerged in his intact left amygdala, which the authors suggest may reflect slower, more deliberate emotional evaluation.

Relief without seizure control

His seizure rate held steady at roughly 10 per month for two months, dropping below one per month only after the later hippocampus surgery. That stability means the PTSD relief wasn't a byproduct of seizure control.

"The remarkable result was evidence of immediate widespread changes in behavior, brain dynamics, and PTSD benefit without dependency on other traditional therapies such as medications or cognitive behavioral therapy," Willie said. Gains spanned intrusive memories, avoidance, negative mood and hyperarousal, with milder drops in anxiety and depression.

"The novelty of the study is that this is the first clear demonstration of a specific causal role for the right amygdala in maintaining PTSD," Willie said, noting it is "an early feasibility study that could lead to future larger studies."

The caveats

One patient, years of epilepsy and antiseizure medications — his neural wiring may not represent most people with PTSD. Awake surgery can't be blinded, so expectation or task familiarity may have influenced results. The slowed judgments and shifted ratings at both emotional extremes hint the ablation may blunt overall emotional calibration, not threat bias alone. Durability beyond two months is unknown, though he still reported relief a year later.

"Readers should be cautioned that amygdala ablation has not been sufficiently studied to offer this widely as a therapy for PTSD," Willie emphasized. Larger controlled trials, and reversible techniques like focused ultrasound or stimulation, must come first. His team now studies how the amygdala recognizes safety versus threat in epilepsy patients undergoing brain monitoring.

Bottom line: silencing one overactive brain region briefly rewired a man's threat perception and eased severe PTSD — a clue, not a cure.