Human and behavioral factors contibuting to spine-based neurological cockpit injuries in pilots of high-performance aircraft: Recommendations for management and prevention

Military Medicine, Jan 2000 by Jones, Jeffrey A

Case 2

History of Present //ness

A 35-year-old reserve pilot with > 1,200 hours in the F/A- 18A had a history of episodic "stiff necks" for 15 years beginning early in his career in the F/A- 18. The onset of symptoms commenced within 12 hours after flying combat training sorties; the symptoms were mainly soreness and stiffness in the posteriorlateral neck musculature, worsened with extreme rotary movements, especially to the right, but associated with soreness and stiffness in both sides of the neck and in both shoulders. These pain episodes were managed with the application of cold, then heat, plus anti-inflammatory agents and even chiropractic manipulation. Slowly, the symptoms would abate until the next episode.

A single event in May 1997, immediately after a rapid-onset, high-g turn while checking six to the right, with his right hand on the stick and no hands on the rail or cockpit handle, produced a pop sensation in his neck during the flight. He experienced only minimal pain during the flight, so the engagement was continued. After returning to the ground, he noted progressive sharp, severe pain in the right lateral neck associated with muscle spasms in the right shoulder blade and weakness and twitching in the right forearm.

Physical Examination

Evaluation conducted by the squadron flight surgeon and neurologist, who suspected cervical nerve root radiculopathy, found weakness in the flexor carpi radialis and diminished brachioradialis reflex. Magnetic resonance imaging revealed a C6-7 disc bulge but no frank herniation.

Orthopedic consultation recommended an anterior diskectomy and removal of the pilot from the high-g environment. After much discussion, the pilot was given a medical downchit (removed from flying duties), and a trial of conservative therapy was instituted. After 2 months, the symptoms resolved. The pilot was given an upchit and has flown all scheduled sorties without symptoms for the past 8 months.

Methods

A modified cross-sectional survey design was used retrospectively to evaluate a cross-section of pilots of multiple aircraft types for the presence or absence of spinal injury or disease symptoms. The study made use of an anonymous, self-administered written questionnaire that was taken to individual squadrons across the United States and explained to the pilots or the squadron commander by the authors. Stamped self-addressed envelopes were given to the pilots to return the completed questionnaires. The questionnaire consisted of 20 questions that sought to evaluate the presence, nature, severity, and timing of symptoms, the head position at the time of onset, the factors in the cockpit contributing to the symptoms, and the behavioral characteristics of the pilot predisposing to symptom occurrence, and finally to acquire information for management and prevention strategy recommendations. A visual analog pain scale was used and explained to the pilots or commander before completion.

A broad cross-section of pilots were surveyed by squadron and individually, including pilots of the following aircraft: C-26, G-2, KC-135 (parabolic, zero-g route) T-38, and F-14, F-15, F- 16, and F/A- 18 fighters. A total of 95 surveys were administered, with 70 partial and 58 full responses. The working hypothesis postulated a larger prevalence of spine-related symptoms in fighter pilots than previously reported and the presence of characteristics unique to the F-16 and F/A-18 aircraft and their pilots that make spinal injury more likely.