A AB BS ST TR RA AC CT T Cavum septi pellucidi (CSP), cavum vergae (CV) and cavum veli interpositi (CVİ), which are congenital midline brain cysts which are rare, and still have controversial etiologies, developments and treatments. In this paper, it was aimed to introduce the case of detecting CSP cysts and applying medical treatment for the patients who developed loss of consciousness and loss of power in the left limbs, 6 hours after a septoplasty and adenoidectomy. As a result; One should take into account that CSP and CV cysts sometimes could become symptomatic, acute cerebrovascular events could occur during and after the surgical intervention, so that the one should be careful regarding the management of anaesthesia.K Ke ey y W Wo or rd ds s: : Anesthesia, general; brain ischemia Ö ÖZ ZE ET T Cavum septi pellucidi (CSP), cavum vergae (CV) ve cavum veli interpositi (CV), nadir konjenital orta hat beyin kistleri olup, ve hala etyolojisi, gelişmesi ve tedavisi hala tartışmalıdır. Bu yazıda, septoplasti ve adenoidektomiden 6 saat sonra sol bacakta güç kaybı ve bilinç kaybı gelişen hastada CSP kistinin tespiti ve uygulanan medikal tedavinin sunulması amaçlanmıştır. Sonuç olarak; cerrahi sırasında ve sonrasında semptomatik olabileceği ve akut serebrovasküler olaylar oluşa-bileceğinden CSP ve CVI kistleri dikkate alınmalıdır, bu yüzden anestezi uygulamasında dikkatli olmak gerekmektedir.A An na ah ht ta ar r K Ke el li im me el le er r: : Anestezi, genel; beyin iskemisi T Tu ur rk ki iy ye e K Kl li in ni ik kl le er ri i J J C Ca as se e R Re ep p 2 20 01 16 6; ;2 24 4( (4 4) 1-6 They rarely create significant neurological dysfunctions. These cysts usually carry no clinical importance. 7,8 Few cases have been reported in the literature that has gone in symptomatic expansion and treated. [1][2][3][4]6,9 In this case report, it was aimed to introduce the case of a loss of consciousness and strength in the left extremities, within the 6 th hour following a septoplasty and adenoidectomy operation under general anesthesia and the identification of CSP et vergae with the examinations which is followed by medical treatment.