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

Physical Examination

Rotatory movement of the head was limited to 75 degrees to the right and 85 degrees to the left due to discomfort in the base of the neck and the upper right shoulder region. Flexion of the neck was limited to 60 degrees, at which point there were some paresthesias induced in the right thumb and index finger. The right shoulder at 90 degrees of elevation was able to be internally rotated 165 degrees forward and beyond 0 degrees backward without significant discomfort. However, abduction to 70 degrees produced pain in the base of the neck and shoulder.

Straight leg raising was negative bilaterally to 90 degrees of hip flexion bilaterally. There was no evidence of diminished pinprick sensation in the upper and lower extremities bilaterally. However, there was slight diminution of two-point discrimination in the ring and little fingers of the right hand. There were no other abnormalities noted in the rest of the dermatomal distribution of the right upper extremity. The deep tendon reflex examination revealed normal left patellar and Achilles' tendon and normal light patellar tendon reflexes, with a decreased light Achilles' tendon reflex. The left upper extremity had normal biceps, triceps, and brachioradialis. The right upper extremity had diminished biceps and brachioradialis deep tendon reflexes but normal triceps reflexes.

The initial impression was injury to right cervical spine nerve roots secondary to g-loading with highly rotated head position; cervical disc herniation or nerve root entrapment was ruled out. The level of injury was not clear from the patient's symptomatology and neurological examination, because the C6 and C8 sensory dermatomes were affected but there was sparing of the C7 dermatome. The motor component of C6 appeared to be mainly affected, again sparing C5 and Tl.

Therefore, magnetic resonance imaging with a 1.5-tesla magnet imaging unit revealed degenerative disk disease at C6-7, with mild reduction in disc height and spondylosis both anteriorly and posteriorly. There was a small left paracentric protrusion of the C6-7 disc that slightly indented the thecal sac and abutted the C7 nerve root; this protrusion appeared chronic in nature. There was mild osseous foraminal narrowing bilaterally at this level. There was also degenerative changes at C2-3 and C3-4.

A neurosurgeon consulted about the case felt that a nerve root injury had occurred when the g-forces compressed the C6-7 disc, further narrowing an already narrowed neural foramen. A robust conservative management strategy was recommended that included duties not to include flying for 3 months; a rigid cervical collar for 2 weeks, followed by a soft collar for 2 weeks; nonsteroidal anti-inflammatory medication; ibuprofen 800 mg tid for 4 weeks; and cyclobenzaprine 10 mg qid for 10 days. A cervical pillow was prescribed for nighttime use. The pain resolved completely in 2 weeks; however, physical therapy was not instituted until I month after the injury. At I month, there was normal sensory testing, Adson's testing was negative, muscle strength testing in the upper extremities was symmetrical, as were upper extremity deep tendon reflexes. There was spasm in the paraspinal musculature innervated by C5-7, as well as in the right levator scapulae and rhomboid. Trigger-point massage therapy was instituted, and after the spasms were relieved, the MacKenzie protocol and stretching exercises of the thoracic and cervical spine were used in the second month after injury. In the third month, cervical and upper body strengthening exercises, with special emphasis on the right rotator cuff, were taught to the pilot by a physical therapist and supervised for the first week. After completion of the strengthening program, the pilot was placed back in flying status, but for non-air combat maneuvering or BFM flights. After 2 weeks with no symptom recurrence, the pilot was placed back on full flight status and has flown all missions without symptom recurrence for more than 3 months.