Abstract
Primary exertional headache is coded as a separate entity within the International Headache Society's (IHS) classification system (1), but the pathophysiological mechanisms underlying this clinical headache subtype are unknown. The IHS criteria for this diagnosis require the exclusion of systemic or intracranial disorders (Table 1).
Primary exertional headache (4.3)
Moreover, the significantly higher prevalence of venous outflow obstruction as an aetiological factor of idiopathic intracranial hypertension (IIH) has been previously suggested, based on manometry and neuroradiological findings, and led to stent placement with promising results (2). These preliminary results were very recently confirmed (3). However, the safety and efficacy of this technique should be evaluated further in larger series with longer follow-up to be definitely validated.
We report one case of severe exertional headache for which venous magnetic resonance (VMR) led to the discovery of bilateral transverse sinus stenosis.
Case report
A 27-year-old woman was evaluated in our neurosurgical department in April 2005. The headaches had started suddenly 2 years earlier: after practising stomach exercise, she experienced the sudden onset of severe throbbing orbital and temporal right pain lasting 4 days. The pain was described as unusual, but did not have the characteristics of thunderclap headache. Later on, each effort, even at low intensity, immediately induced a severe headache. The pain was pulsatile, and no accompanying symptoms were reported. She complained also sometimes of headache following coughing and laughing.
The patient also described a different type of headache syndrome that had begun earlier in life and showed features consistent with the IHS criteria for migraine without aura. Migraine attack frequency was four per month, and the patient successfully used paracetamol, caffeine and dextropropoxyphene to treat these attacks. Migraine attacks were not induced by exertion.
Brain and cervical magnetic resonance imaging (MRI) were normal and eliminated the presence of Chiari malformation. Fundus examination was normal. Treatment with propranolol reduced the frequency and severity of the migraine attacks, but not of exertional headache. Indomethacin 150 mg/day was ineffective.
As the exertional headache was intractable, further investigations were discussed. VenoMRI revealed bilateral transverse stenosis. Venography of the transverse sinuses revealed stenosis in the midlateral portion of the right transverse sinus and a left hypoplasic transverse sinus (Fig. 1).
Preoperative venography. Oblique frontal view after selective injection of iodium contrast medium into the intracranial sinuses. A right lateral sinus stenosis is demonstrated (black arrow). The left transverse sinus is hypoplastic (white arrow) compared with the sigmoid sinus (double arrow).
Manometry was performed: with normal breathing, a pressure of 20 mmHg was found in the superior longitudinal sinus; this pressure rose to 60 mmHg with Valsalva manoeuvre. The pressure gradient was 40 mmHg. Downstream of the transverse stenosis, the pressure in the sigmoid sinus and the jugular vein was similar and < 20 mmHg. The pressure gradient upstream and downstream of the transverse sinus stenosis was > 20 mmHg during the Valsalva manoeuvre. When the catheter crossed to the right transverse stenosis, the patient complained of pain similar to that initially described. Venous stenting at the level of the right transverse sinus stenosis led to complete disappearance of exertional headache at 1 year's follow-up. To our knowledge, this is the first case of stenting for exertional headache.
Discussion
Exertional headache is usually considered as a relatively rare condition.
Pascual et al. (4) described a series of 28 patients with exertional headache and distinguished a benign form (16 patients) and a symptomatic form (12 patients with diagnosis of subarachnoid haemorrhage, cerebral metastasis and pansinusitis). The link between exertional headache and Chiari malformation is classical and may be explained by dural traction (5). Both primary exertional headache (6) and Chiari-associated exertional headache may respond to treatment with indomethacin (7).
The first case of exertional headache was described in 1932 by Tinel (8), who underlined the venous origin of this type of headache, defining exertional headache as a painful distension of intracranial veins. He reported some patients who developed severe pain with manoeuvres that increased the intrathoracic pressure. Our case, conforming to Tinel's description, began after a specific provocative mechanism corresponding to intense physical activity leading to severe headache. However, this is an unusual case of exertional headache. Our patient had the IHS criteria for exertional headache, except for the duration of the headache. Classically, indomethacin is one of the treatments of choice for exertional headache, but as this headache is rare, no study has described the efficacy of indomethacin in exertional headache with strong methodological methods.
If, within the past few years, increased venous sinus pressure has been hypothesized to be one of the main causes of exertional headache, the role and mechanisms of venous sinus stenoses are still controversial. The very recent publication of Doepp et al. (9) has given another argument for the venogenic theory of exertional headache. In fact, the authors reported a significantly higher prevalence of incompetence of internal jugular valve in patients with primary exertional headache.
The role of venous stenosis in the aetiology of ‘primary’ headache is probably underestimated. In addition to the results obtained, stenting treatment appears particularly interesting because the therapeutic strategy used possibly improves patients’ clinical status via a pathogenic rather than a symptomatic approach.
Conclusion
The origin of exertional headache may be classified as either venogenic or non-venogenic. We recommend systematic exploration of patients with severe exertional headache with VMR or veno-computed tomography scan when Chiari malformation has been eliminated. In cases with high disability, and if a venous stenosis is detected, direct retrograde cerebral venography and manometry are necessary. When a pressure gradient is confirmed, stenting may be discussed. Stenting is a new approach in intractable exertional headache and should be evaluated in other studies to be definitively validated.
Although a suggestive finding, sinus stenoses cannot explain all aspects of exertional headache. In fact, it is well-known that stenosis of the transversal sinus is not rare and that, in most cases, exertional headache often resolves without treatment. As the pathophysiological mechanisms of exertional headache are incompletely elucidated, this haemodynamic and manometric approach may contribute to a better understanding of the phenomenon that subtends this pathological entity.