‘Bad Trips’: Airplane Headache not Just in Airplanes?

Abstract

A type of headache associated with altitude variations in airplane travellers is increasingly reported and has recently become a subject of debate for experts. We present a patient with headache related to altitude variations in two different settings: airplane and mountain descent, suggesting that different kinds of triggers for pressure variation can cause the same type of pain.

Introduction

Altitude headache is a common symptom of high-altitude exposure and has been recognized in the 2nd edition of the International Classification of Headache Disorders (1) as a secondary-type headache attributed to homoeostatic disorders. Another type of headache, less frequently described in the literature, but coming more to experts' attention, is associated with variations in altitude rather than high altitude itself. Several reports (2–6) of this type of pain have recently been published, a total of 13 cases so far.

The physiopathological mechanism underlying this type of headache is uncertain. It has been proposed (3) that barotrauma caused by pressure changes could affect the ethmoidal nerves (branching from the ophthalmic branch of the trigeminal nerve) and/or the nociceptors in the ethmoidal arteries, activating the trigeminovascular system and causing headache.

We present a patient with a long-standing history of headaches with a clear-cut association with altitude variations.

Case report

The patient is a 57-year-old man, an industrial technician, who presented to our clinic in February 2007. He reported that 20 years earlier he had had a very intense sudden left frontal headache, which he described as a ‘bee sting’ type of pain. It had lasted between 5 and 10 min and occurred while driving down from Serra da Estrela—mainland Portugal's highest peak (around 2000 m). The pain had subsided as he reached the base of the mountain. Since then, during each airplane journey, he had had headaches with similar features (he flies 8–10 times each year). The pain, always in the left frontal region, appeared during aircraft descent, starting at an altitude of 1000–2000 m and disappearing during landing. It was not associated with phono- or photophobia, nausea, vomiting or dysautonomic signs, such has tearing, rhinorrhoea or ocular manifestations. He had no visual disturbance or other focal neurological symptoms. The headache also appeared during each descent when visiting the mountain. Apart from those episodes, he had had no headaches of any sort. The patient had been in the Portuguese Air Force in 1964–1968, when he made several asymptomatic flights on airplanes and helicopters. The patient's medical history was unremarkable, including no history of sinus pathology, and there was no regular use of medications. The family history was non-contributory. Neurological examination was normal. Ear, nose and throat examination showed no evidence of sinus pathology. Brain magnetic resonance imaging (MRI) to exclude structural lesions and sinus pathology, namely sinus barotrauma, was normal.

Discussion

The present case is another example of the existence of headache related to altitude variations. To our knowledge, it is the only case with the same type of headache occurring in two different circumstances of altitude variation—during airplane descent and high mountain descent—suggesting that in more predisposed individuals this kind of pain can be triggered even with lesser degrees of pressure increase. The pain described has the characteristics of the majority of cases published so far and fulfils the criteria recently proposed (5) for classification: at least two attacks of pain during airplane travel, lasting < 20 min, without accompanying symptoms (although nasal congestion, stuffy feeling of face or tearing may occur ipsilaterally), not attributed to other pathologies and with at least two of the following characteristics: (i) severe intensity, (ii) jabbing or stabbing quality (pulsatility may occur), (iii) strict unilaterality and (iv) periorbital location (forehead involvement may occur). So, in the light of the present case, this type of pain should be categorized more broadly as altitude-variation headache.

Interestingly, this patient had had several asymptomatic flight experiences while in the air force. This has been noted in other reports and suggests that altitude variation needs a concomitant factor for pain to occur. In one published case (4), this seemed to be the initiation of a drug, pravastatin. Nevertheless, other factors might also be responsible, i.e. trauma, occupational exposure or infection. During a first episode, it is also important to exclude other pathologies by MRI, especially sinus barotrauma, since this entity has been associated with a similar type of pain in the same context (7).

In conclusion, it is necessary to know more about this type of headache, both causative and precipitating factors as well as possible preventive treatments.