Migraine and stroke

Migraine and Stroke: What's the Link? What to Do?

Migraine and stroke are common, disabling neurologic disorders, with a high socioeconomic burden. A link between them has been proposed years ago, and various theories have been proposed to explain this bidirectional relation. However, the precise causes remain unclear. We briefly summarize existing hypotheses of this correlation seeking for recommendations for stroke prevention in migraineurs, if any exist. Among the strongest suggested theories of migraine-stroke association are cortical spreading depression, endovascular dysfunction, vasoconstriction, neurogenic inflammation, hypercoagulability, increased prevalence of vascular risk factors, shared genetic defects, cervical artery dissection, and patent foramen ovale. There is no evidence that any preventive therapy in migraineurs should be used to decrease stroke risk, even in most predisposed subset of patients. However, a woman with migraine with aura should be encouraged to cease smoking and avoid taking oral contraceptives with high estrogen doses. We need further investigation to better understand the complexity of migraine-stroke association and to make firm recommendations for the future.

High asymmetric dimethylarginine, symmetric dimethylarginine and L-arginine levels in migraine patients

Experimental and clinical data strongly suggests that nitric oxide (NO) plays a pivotal role in migraine. This is also supported by studies of migraine induced by substances that release NO. NO is synthesized from L-arginine by endothelial NO synthase (NOS). Asymmetric dimethylarginine (ADMA) is the major endogenous competitive inhibitor of NOS. Symmetric dimethylarginine (SDMA) is an inactive stereoisomer of ADMA. It may reduce NO production by competing with arginine for cellular uptake. The aim of this study was to measure the levels of ADMA, SDMA and L-arginine in migraine patients during the interictal period. One hundred migraine patients and 100 healthy volunteers were recruited. The patients were in the interictal period and classified into two groups as having migraine with aura and migraine without aura. Their serum ADMA, SDMA and L-arginine levels were measured by high-performance liquid chromotography (HPLC) method. ADMA, SDMA and L-arginine levels were significantly higher in migraine patients compared to the control group. But there was no difference between the patients with and without aura. These results suggest that NOS inhibitors and L-arginine/NO pathway plays an important role in migraine pathopysiology.

Utility of point of care assessment of platelet reactivity (using the PFA-100®) to aid in diagnosis of stroke

BACKGROUND

Rapid and accurate diagnosis of patients presenting with symptoms of stroke is needed to facilitate the timely delivery of proven effective treatment for patients with acute ischemic stroke (AIS). The aim of this study was to determine whether early assessment of platelet reactivity in patients presenting with symptoms of AIS was associated with a diagnosis of AIS, transient ischemic attack (TIA), or stroke mimic.

METHODS

This prospective study included patients with symptoms of AIS treated at an inner-city emergency department (ED). Blood samples were obtained and assayed for platelet reactivity (quantified by closure time). Patients were grouped by discharge diagnosis into: AIS, TIA, or stroke mimic. Binary logistic regression model was used to predict the association of closure time with the final diagnosis of 1) either AIS or TIA or, 2) stroke mimic.

RESULTS

Of 114 patients enrolled, 32 were diagnosed with AIS, 33 TIA, and 49 were diagnosed as a stroke mimic. There was no significant difference in closure times among patients with a diagnosis of AIS or TIA versus stroke mimic. A history of migraines and history of seizures were independently associated with lower odds of an AIS or TIA diagnosis (OR 0.31, 95% CI 0.10 to 0.94 and OR 0.08, 95% CI 0.01 to 0.88, respectively).

CONCLUSION

Closure time was not found to be a clinically reliable differentiator of patients with a diagnosis of AIS, TIA, or stroke mimic in the ED.

The Prevalence of Magnetic Resonance Imaging Hyperintensity in Migraine Patients and Its Association with Migraine Headache Characteristics and Cardiovascular Risk Factors

OBJECTIVES

To determine the frequency of hyperintense foci in migraine patients and the relationship with migraine headache characteristics and cardiovascular risk factors.

METHODS

Ninety patients with migraine headache (70 without aura and 20 with aura) were enrolled and interviewed. Information on their headache (severity, frequency, and mean disease duration) and other related data was obtained by completing a clinical checklist. Subsequently, brain magnetic resonance imaging (MRI) was performed and each patient was then evaluated for hyperintense lesions.

RESULTS

Of the 90 patients, 29 (32%) had silent hyperintense lesions on their MRI. The mean age of the patients with hyperintense foci was 41 years while those with no lesions was 33 years (p<0.010). Supratentorial hyperintense lesions represented the majority of lesions in the patients (n=46, 63%). Moreover, 56.3% of the lesions (n=41) were located within the right hemisphere. Cardiovascular risk factors such as smoking, serum cholesterol, oral contraceptive pills use, and body mass index (BMI) were not significantly different in these two groups (p>0.050). The lesions were found significantly more frequently in the patients who experienced chronic migraine (p=0.032).

CONCLUSION

Our study adds weight to the theory that disease duration has a key role in the formation of hyperintense brain lesions. Certain cardiovascular risk factors such as sex, smoking, serum cholesterol, and BMI, do not affect the presence or absence of such lesions, suggesting that the relationship between migraine and these lesions may be directly due to the effects of migraine itself.

Migraine and stroke: "vascular" comorbidity

Several comorbidities are associated to migraine. Recent meta-analyses have consistently demonstrated a relationship between migraine and stroke, which is well-defined for ischemic stroke and migraine with aura (MA), even stronger in females on oral contraceptives or smokers. However, there seems to be no clear-cut association between stroke in migraineurs and the common vascular risk factors, at least in the young adult population. Migraineurs also run an increased risk of hemorrhagic stroke, while the association between migraine and cardiovascular disease remains poorly defined. Another aspect is the relationship between migraine and the presence of silent brain lesions. It has been demonstrated that there is an increased frequency of ischemic lesions in the white matter of migraineurs, especially silent infarcts in the posterior circulation territory in patients with at least 10 attacks per month. Although there is a higher prevalence of patent foramen ovale (PFO) in migraineurs, the relationship between migraine and PFO remains controversial and PFO closure is not a recommended procedure to prevent migraine. As an increased frequency of cervical artery dissections has been observed in migrainous patients, it has been hypothesized that migraine may represent a predisposing factor for cervical artery dissection. There still remains the question as to whether migraine should be considered a true “vascular disease” or if the comorbidity between migraine and cerebrovascular disease may have underlying shared risk factors or pathophysiological mechanisms. Although further studies are required to clarify this issue, current evidence supports a clinical management where MA patients should be screened for other concomitant vascular risk factors and treated accordingly.

Migraine attack restores the response of vascular smooth muscle cells to nitric oxide but not to norepinephrine

AIM: To clarify whether the vasoconstrictory response is impaired and to study vascular function in patients with migraine during the headache attack.

METHODS: We studied vascular reactivity in the resistance arteries by using the forearm perfusion technique associated with plethysmography. We measured forearm blood flow by strain-gauge plethysmography during intra-brachial infusion of acetylcholine, sodium nitroprusside or norepinephrine in 11 controls and 13 patients with migraine, 11 of them (M) in the interval between the migraine attacks and 4 during a headache attack (MH). Written informed consent was obtained from patients and healthy controls, and the study was approved by the Ethics Committee of the University Federico II.

RESULTS: Compared to healthy control subjects, in patients with migraine studied during the interictal period, the vasodilating effect of acetylcholine, that acts through the stimulation of endothelial cells and the release of nitric oxide, was markedly reduced, but became normal during the headache attack (P < 0.05 by analysis of variance). The response to nitroprusside, which directly relaxes vascular smooth muscle cells (VSMCs), was depressed in patients with migraine studied during the interictal period, but normal during the headache attack (P < 0.005). During norepinephrine infusion, forearm blood flow decreased in control subjects (-40% ± 5%, P < 0.001). In contrast, in patients with migraine, either when studied during or free of the headache attack forearm blood flow did not change compared to the baseline value (-3% ± 13% and -10.4% ± 15%, P > 0.05).

CONCLUSION: In migrainers, the impaired relaxation of VSMCs is restored during the headache attack. The vasoconstrictory response is impaired and remains unchanged during the migraine attack.

Prevalence and extent of right-to-left shunt in migraine: a survey of 217 Chinese patients

BACKGROUND

Recently, contrast-enhanced transcranial Doppler (cTCD) studies have shown that right-to-left shunt (RLS) may be a risk factor for migraine in Westerners; however, limited data in the literature describes the prevalence of RLS in Chinese patients with migraine.

OBJECTIVE

To assess the prevalence of RLS in patients with migraine in China and to evaluate the relationship between the extent of RLS and migraine.

METHODS

A total of 217 consecutive patients with a diagnosis of migraine and 100 volunteers were recruited. cTCD was used to assess the prevalence and the extent of RLS in all subjects.

RESULTS

In the migraine group, the rate of positive RLS was 44.2% (96/217), with 23.5% (51/217) of these being large. In the healthy group, 28.0% (28/100) were positive for RLS overall, and 5.0% (5/100) were large (P = 0.006; P < 0.001). In patients having migraines with aura (MwA), 66.1% (39/59) were positive for RLS overall, and 37.3% (22/59) were large, which was significantly higher when compared with the healthy group (P < 0.001; P < 0.001); in patients having migraines without aura (MwoA), 36.1% (57/158) were positive for RLS overall, and 18.4% (29/158) were large, which was against significantly higher (P < 0.001; P = 0.003). In the MwoA group, the large RLS rate was also higher than in the healthy group (P = 0.002).

CONCLUSIONS

A close correlation has been documented between RLS and migraine, especially MwA, but these relationships exist only when the shunts were large.