Reader Response: Blood Brain Barrier Permeability in Patients With Reversible Cerebral Vasoconstriction Syndrome Assessed With Dynamic Contrast-Enhanced MRI
Vinod KGupta, Physician-Medical Director, GUPTA MEDICAL CENTRE, MIGRAINE-HEADACHE INSTITUTE, S-407, Greater Kailash-Part Two, New Delhi, INDIA-110048
Submitted October 30, 2021
Wu et al. present increased microscopic brain permeability during the acute stage of reversible cerebral vasoconstriction syndrome (RCVS) as a marker of putatively pathogenetic blood-brain barrier disruption.1 Despite emphasis on a uniphasic course,2 there is a striking temporal gap between a key clinical feature of thunderclap headache (TCH) (peaking in ˂1 minute) and MRA-detected maximum vasoconstriction of branches of middle cerebral arteries, occurring a mean of 16 days after clinical onset. Delayed segmental cerebrovascular vasoconstriction, enhanced resistance, or enhanced microvascular brain permeability are highly unlikely to reflect primary pathogenetic aberration(s) of RCVS. Similarly, white matter hyperintensities are epiphenomenal,1 having no role in the genesis of nociceptive ophthalmic nerve traffic underlying TCH3—the truly acute phenomenon of RCVS. Generalization is essential to maintain hypothetical beliefs.3
Several triggers for RCVS including defecation, coughing, laughing, sudden bending down, and urination involve the Valsalva maneuver (VM).2 VM has a prominent influence on the hemodynamic functioning of the human eye, including generation of cephalalogenic ophthalmic nerve traffic.3,4 For further evolution of RCVS, the post-partum period must be divided into caesarean-section and vaginal delivery subtypes. Caesarean-section is rarely complicated with RCVS,5 while vaginal delivery is the most intense, prolonged, and repetitive VM known to humans.
Disclosure
The authors report no relevant disclosures. Contact journal@neurology.org for full disclosures.
References
Wu CH, Lirng JF, Wu HM, et al. Blood-Brain Barrier Permeability in Patients With Reversible Cerebral Vasoconstriction Syndrome Assessed With Dynamic Contrast-Enhanced MRI. Neurology. 2021;97(18):e1847-e1859. doi:10.1212/WNL.0000000000012776
Ducros A. Reversible cerebral vasoconstriction syndrome. Lancet Neurol. 2012;11(10):906-917. doi:10.1016/S1474-4422(12)70135-7
Gupta VK. Pathophysiology of migraine: an increasingly complex narrative to 2020. Fut Neurol. 2019:14. DOI.org/10.2217/fnl-2019- 0003.
Gupta VK. Constipation-related migraine is linked to the effect of the Valsalva maneuver on the eye: A case report and a mechanistic review. WebmedCentral. 2010;1(12):WMC001433. [doi: 10.9754/journal.wmc.2010.001433]
Safran SL, Balmer C, Savoldelli G. Reversible cerebral vasoconstriction syndrome during caesarean section. BMJ Case Rep. 2019;12(12):e230606. Published 2019 Dec 5. doi:10.1136/bcr-2019-230606
Wu et al. present increased microscopic brain permeability during the acute stage of reversible cerebral vasoconstriction syndrome (RCVS) as a marker of putatively pathogenetic blood-brain barrier disruption.1 Despite emphasis on a uniphasic course,2 there is a striking temporal gap between a key clinical feature of thunderclap headache (TCH) (peaking in ˂1 minute) and MRA-detected maximum vasoconstriction of branches of middle cerebral arteries, occurring a mean of 16 days after clinical onset. Delayed segmental cerebrovascular vasoconstriction, enhanced resistance, or enhanced microvascular brain permeability are highly unlikely to reflect primary pathogenetic aberration(s) of RCVS. Similarly, white matter hyperintensities are epiphenomenal,1 having no role in the genesis of nociceptive ophthalmic nerve traffic underlying TCH3—the truly acute phenomenon of RCVS. Generalization is essential to maintain hypothetical beliefs.3
Several triggers for RCVS including defecation, coughing, laughing, sudden bending down, and urination involve the Valsalva maneuver (VM).2 VM has a prominent influence on the hemodynamic functioning of the human eye, including generation of cephalalogenic ophthalmic nerve traffic.3,4 For further evolution of RCVS, the post-partum period must be divided into caesarean-section and vaginal delivery subtypes. Caesarean-section is rarely complicated with RCVS,5 while vaginal delivery is the most intense, prolonged, and repetitive VM known to humans.
Disclosure
The authors report no relevant disclosures. Contact journal@neurology.org for full disclosures.
References