Wednesday, October 17, 2012

Panic With A Twist



The 28-year-old naval aviator Tomcat pilot appeared chagrined as he entered my flight surgeon office on the aircraft carrier. His demeanor lacked the typical elan of a tactical jet pilot; the love of flying that we see in the attached video was absent from his eyes and voice.

"Doc," he said, "I think I'm afraid to fly."

"How does a trained naval aviator with over 600 hours total flight time, 300 in the Tomcat, suddenly become afraid to fly?" I wondered, especially one with an above-average flight performance record.

He described a pattern of anxiety dating back 18 months to an episode while flying level at 16,000 feet. He had suddenly felt hot, flushed, and nauseated; but the symptoms abated when he removed his oxygen mask and decreased the cockpit air temperature. (The fact that he waited for 18 months and several more episodes before reporting to the flight surgeon says something about the inherent fear that most aviators harbor about flight surgeons. A stroke of the doctor's pen can end a flying career.)

Six months later while flying over water he experienced another attack. Again he felt hot and flushed, and severely apprehensive over his ability to control the airplane. He became intensely anxious over the welfare of the radar intercept officer in the back seat, whose life depended on the pilot's ability to fly the jet. Our pilot remained anxious until landing was assured, and then the symptoms went away.

Two more episodes occurred in the subsequent year, each time on a long cross-country flight at altitude in bad weather. Each time, he became hot and flushed, and felt a powerful desire to divert and land the airplane. He completed the missions only by intense concentration on the flying tasks. But as soon as landing was certain, his symptoms disappeared.

I asked him the usual questions. No, he did not have any serious life stressors. His five-year marriage had gone through a tough period -- including a two-month separation -- but had weathered the storm through counseling. He was able to compartmentalize, a vital trait for aviators wherein they concentrate only on flying without intrusion by thoughts of other aspects of their lives. He denied nocturnal panic attacks, and stated that aside from recent pre-flight anxiety he only experienced the symptoms while flying at a distance from a landing site.

Then he mentioned some other symptoms, visual and physical disturbances while flying. He would see "shooting stars" in the periphery of his vision, and feel dizzy and disoriented. Those symptoms would occur only when he rotated his head while pulling positive Gs in a high performance maneuver. (The video sequences between 1:16 and 2:05 show that environment from inside the cockpit.) The symptoms would abate when he straightened his head. He said that those symptoms, like the anxiety, had gotten worse over time.

I figured this aviator had a limited symptom panic disorder, but I could not reconcile that diagnosis with the visual and physical symptoms. I referred him to an aviation neurologist for further evaluation. After a series of tests, the neurologist discovered that the aviator had congenital narrowing of his left vertebral artery. (Most people have two normal-sized vertebral arteries that join to form the basilar artery that brings blood to the brain stem, which controls vital life functions.) This aviator's physical symptoms were caused by occlusion of his one good vertebral artery with head turning in a high-G flight profile, interrupting blood flow to his basilar artery. His anxiety symptoms were secondary to his physical anomaly, because he recognized but did not understand the threat to his ability to control the aircraft.

We managed to salvage this pilot's career by getting him reassigned to non-tactical naval aircraft, where he would not be subjected to high-G flight maneuvers. Relieved of his anxiety-producing symptoms, he once again was free to relish the beauty of flight.


No comments: