A somatic missense mutation in GNAQ causes capillary malformation
Purpose of review Capillary malformations, the most common type of vascular malformation, are caused by a somatic mosaic mutation in GNAQ, which encodes the Gαq subunit of heterotrimeric G-proteins. How the single amino acid change – predicted to activate Gαq – causes capillary malformations is not known but recent advances are helping to unravel the mechanisms. Recent findings The GNAQ R183Q mutation is present not only in endothelial cells isolated from skin and brain capillary malformations but also in brain tissue underlying the capillary malformation, raising questions about the origin of capillary malformation-causing cells. Insights from computational analyses shed light on the mechanisms of constitutive activation and new basic science shows Gαq plays roles in sensing shear stress and in regulating cerebral blood flow. Summary Several studies confirm the GNAQ R183Q mutation in 90% of nonsyndromic and Sturge–Weber syndrome (SWS) capillary malformations. The mutation is enriched in endothelial cells and blood vessels isolated from skin, brain, and choroidal capillary malformations, but whether the mutation resides in other cell types must be determined. Further, the mechanisms by which the R183Q mutation alters microvascular architecture and blood flow must be uncovered to develop new treatment strategies for SWS in particular, a devastating disease for which there is no cure.
We present the case of a girl who underwent VPH for hemimegalencephaly in early infancy. Postoperatively, she developed unexpected seizures of mesio-temporal origin. Stereo-EEG provided arguments for an amygdalar origin. High-resolution MRI with tractography confirmed the presence of the amygdalo-fugal pathway to be responsible of epileptic discharges propagation. She became seizure-free after temporal resection.
ConclusionWe successfully utilized biportal endoscopy to decompress the combined lumbar lateral recess, foraminal, and extraforaminal lesions using a contralateral sublaminar approach.
We describe a patient with a long history of seizures and a remote status epilepticus event. On magnetic resonance imaging, a presumed left temporal lobe tumor was observed. On neurosurgical consultation, the lesion was identified as a chronic mesial temporal lobe herniation. The patient lacked history that would suggest risk of cerebral herniation. Accurately identifying the patient ’s chronic temporal lobe herniation radiographically likely saved this patient from unnecessary surgery or biopsy and allowed the patient to receive appropriate conservative care.
ConclusionsThe study represents the much-needed, large-volume, epidemiological profile of HI from an LMIC, highlighting the suboptimal utilization of peripheral healthcare systems. Strengthening and integrating these facilities with the tertiary centers in a hub and enhanced spoke model, task sharing design, and efficient back-referrals promise effective neurotrauma care while avoiding overburden in the tertiary centers. Better implementation of road safety laws also has the potential to reduce the burden of HI.