Reversible cerebral vasoconstriction syndrome precipitated by airplane descent: Case report

Abstract

Background

Reversible cerebral vasoconstriction syndrome (RCVS) is characterized by segmental vasospasm. Vasoactive agents and childbirth have been reported as precipitating factors for RCVS; however, RCVS induced by altitude change or air travel has rarely been reported.

Case

We present a case of a 74-year-old woman who presented with thunderclap headache during airplane descent. Magnetic resonance angiography demonstrated segmental vasoconstriction that improved 9 days after onset.

Conclusion

These findings indicate that airplane descent may be a trigger of RCVS. The time course of headache in the present case was similar to that of prolonged headache attributed to airplane travel, indicating that RCVS during air travel may have previously been overlooked and that some headache attributed to airplane travel cases may represent a milder form of RCVS.

Introduction

Reversible cerebral vasoconstriction syndrome (RCVS) is characterized by severe headaches with or without additional neurological symptoms, and segmental and multifocal vasoconstriction of the cerebral arteries resolving spontaneously within 1–3 months (1). Vasoactive agents and childbirth have been reported as precipitating factors for RCVS; however, RCVS induced by altitude change or airplane travel has previously been extremely rarely reported. Herein, we present a case of RCVS during air travel. The possible mechanisms responsible for RCVS in the present case and the association between RCVS and headache attributed to airplane travel are also discussed.

Case presentation

A 74-year-old woman with no history of migraine developed a sudden and extremely severe headache, reported to be the worst she had ever experienced, during airplane descent while travelling by airplane from Ishigakizima to Haneda (2171 km, Japanese domestic flight). The patient described her headache as similar to being hit in the temporal head region with a baseball bat, and her headache was of maximum intensity at onset. She experienced no photophobia, fear, autonomic features such as rhinorrhea, or ocular manifestations. She had to vomit after landing. She had previously travelled by airplane on approximately 40 occasions with no such problems. Her previous medical history included numbness of the lower extremities for 19 years and a benign neurinoma in the lumbosacral area (confirmed by biopsy at 62 years of age). She had not received any vasoactive drugs. Although the headache resolved 2 days after onset, she was referred to the emergency room of our hospital 3 days after the onset of symptoms. Her blood pressure was 129/78 mmHg. Neurological examinations revealed no abnormalities other than pre-existing sensory disturbance affecting the lower extremities bilaterally due to a benign neurinoma. Brain computed tomography findings were negative but could not exclude a subarachnoid hemorrhage. Lumbar puncture was considered contraindicated due to the presence of a massive lumbosacral neurinoma. Brain magnetic resonance imaging findings were negative for intracranial hemorrhage, subarachnoid hemorrhage, brain edema and cerebral infarction. However, brain magnetic resonance angiography (MRA) demonstrated segmental constriction of the bilateral posterior cerebral arteries and right vertebral artery (Figure 1A and 1B). Her symptoms did not worsen or relapse despite calcium-channel blockers and other agents not being administered. MRA on day 9 after the onset of symptoms demonstrated resolution of vascular abnormalities (Figure 1C and 1D). A clinical diagnosis of RCVS was made accordingly.

Figure 1.

Initial magnetic resonance angiography findings (A, B) demonstrating focal constriction of the bilateral posterior cerebral arteries and right vertebral artery (arrowhead), with recovery 9 days after the onset of symptoms (C, D).

Discussion

Our patient experienced a thunderclap headache during airplane descent, with MRA abnormalities and substantial improvement of vasoconstriction even in the absence of specific treatments, indicating a diagnosis of RCVS. These findings indicate airplane descent may be a trigger of RCVS. Moreover, the present case suggests that RCVS may be the cause in some cases of the so-called ‘airplane headache’ that may have previously been considered benign headache.

Change in cabin pressure may represent a potential mechanism underlying the development of RCVS. In fact, passenger cabins are pressurized to an altitude of 1524–2438 m, at which hypobaric hypoxia occurs (2). However, while hypoxia can increase cerebral blood flow, hypocapnea decreases cerebral blood flow due to hypocapneic vasoconstriction (3), indicating that hypoxia itself may not be a trigger of cerebral vasoconstriction. To our knowledge, only one case of RCVS during airplane travel has previously been reported (4). Besides airplane descent, RCVS has been associated with high altitude regions (5) and altitude change (6), suggesting hypocapneic vasoconstriction as a potential trigger of RCVS. However, unlike high altitude conditions, pCO₂ does not change during flight in healthy subjects (7). In this regard, acute altitude changes, including air travel, may induce changes in arterial tone and be a trigger of the development of RCVS, whereas changes in hypoxia or carbonate levels themselves may not be trigger of RCVS. Other than the cerebral artery, the occurrence of arterial vasoconstriction has been reported in other organs, with pulmonary artery pressure reportedly increasing during commercial air travel as a result of vasoconstriction in healthy passengers (8).

The present case also indicates that RCVS is an important differential diagnosis of headache attributed to airplane travel. Headache attributed to airplane travel was first reported in 2004 as a new type of headache, with a reportedly increasing incidence (9) and has been recently codified in The International Classification of Headache Disorders, 3rd edition (beta version) (10). Headache attributed to airplane travel can typically be severe or extremely severe, occurs suddenly, and most frequently occurs as airplanes descend, but it can also occur during take-off. Such headaches usually spontaneously subside after 15–30 minutes. However, headache may last for hours or days in few patients (9). Although headache attributed to airplane travel is typically not bilateral, the time course of headache in the present case is similar to that of prolonged headache attributed to airplane travel. In RCVS, thunderclap headache and vasoconstriction observed on MRA have different time courses. A large study reported that six of 59 patients with RCVS had normal MRA findings on the first MRA, with changes only detectable on a second MRA (1). In cases of headache attributed to airplane travel, normal findings on initial MRA do not rule out the possibility of RCVS. In fact, it has recently been reported that considerable numbers of patients with other primary headaches have RCVS, with a study of patients with headaches associated with sexual activity reporting that 18 of 30 cases are due to RCVS (11). Further studies investigating the frequency of RCVS in cases of headache attributed to airplane travel using serial MRA are required. Some cases of headache attributed to airplane travel may represent a milder form of RCVS, with vasoconstriction not visible on initial MRA. However, the most important differences between typical headache attributed to airplane travel and “secondary headache attributed to airplane travel,” which is due to RCVS, is the duration of the headache. Although a proportion of headache attributed to airplane travel cases are considered associated with sinus barotrauma (9,12), the most likely pathophysiology for headache attributed to airplane travel appears related to a variety of contributory multimodal factors, such as anatomical, environmental, and temporary concurrent parameters (12). Such pathophysiology may be associated with headaches of short duration in headache attributed to airplane travel, mostly lasting for >30 minutes, which are very different from those of typical RCVS. Therefore, a typical headache attributed to airplane travel of short duration is considered not associated with RCVS, and in the clinical setting, MRA may only be indicated in patients with headache attributed to airplane travel whose headache is prolonged or who have other atypical presentations.

Conclusion

Patients with RCVS frequently present with only a headache, with MRA findings required to confirm a diagnosis of RCVS. The actual incidence of RCVS triggered by airplane travel is therefore unknown. RCVS during air travel may have previously been overlooked as headache attributed to airplane travel and may therefore be more common than current perception. Serial MRA studies should be performed in suspected cases of headache attributed to airplane travel to rule out RCVS.

Clinical implications

Airplane descent can be a trigger of RCVS.

RCVS may be the cause in some cases of headache attributed to airplane travel that may have previously been considered benign headache.

Serial MRA, in addition to MRI, appears to have greatest utility in identifying RCVS due to airplane descent.