Cavum vergae cyst presenting with headache

The 14-year male was referred for an MRI brain for more than six months of persistent headaches

T1 weighted sagittal midline image shows a large midline, fluid intensity, cerebral malformation inferior to corpus callosum extending anteroposteriorly from rostrum to genu of the corpus callosum. T2 weighted axial images show a large midline, fluid intensity lesion extending anteroposteriorly from rostrum to genu of the corpus callosum with widened fornices. Outward displacement of leaves of septum pellucidum was also seen. Two small hyperintense cysts are also seen involving bilateral choroid plexuses. Flair axial images show suppression of lesions. The diffusion-weighted axial image doesn't show any restricted diffusion.3D T1 post-contrast axial images show no post-contrast enhancement. The maximum transverse diameter between the leaves of the septum pellucidum was 2.6 cm.

Cavum vergae cysts are midline cerebral malformations, usually with no clinical manifestations; however, in rare cases, a noncommunicating cyst may produce symptoms owing to CSF flow obstruction [1]. A cavum vergae cyst is when the Cavum septum vergae measures more than 1 cm in transverse diameter or when the outer margins are convex [2].

The most common symptom is a headache which is thought to be due to intermittent hydrocephalus provoked by positional changes, Valsalva and straining. Though the direct association of headache to the cyst is not documented, no response to pharmacotherapy and resolution of headache and other symptoms after cyst drainage suggests an indirect association [3]. In one case report, a 25-year-old male with a rapidly expanding cyst of septum pellucidum presented with a headache refractory to pharmacological treatment. He was treated with endoscopic fenestration of the cyst, which resulted in the complete resolution of his symptoms [4]. Another case report suggested symptoms were directly related to the size of the noncommunicating cyst and its expansion by accumulating CSF. The maximum width of the cyst, in that case, was 3.0 cm and in our case, it is 2.6 cm [5].

Further, a 17-year-old female with a CSP cyst and CVC presented with sudden headache, cervicobrachialgia, ptosis, visual changes and facial paralysis. She was treated with trans-frontal endoscopic intraventricular septostomy and monro foraminoplasty [6]. After surgery, the patient remained asymptomatic. Adjunct to this, six patients with CSP cysts presented with intermittent headaches in a case series.

Antenatal and neonatal ultrasound can detect the midline cyst under the corpus callosum measuring >1 cm in transverse diameter. CT helps demonstrate the characteristics and location of the lesion. MRI is excellent in depicting the extension of a cyst and its anatomical relationships. The cyst is seen in between the leaves of the septum pellucidum anteriorly and extends posteriorly up to the splenium of the corpus callosum [1]. Noncommunicating cysts and rapid enlargement of cysts can be easily followed-up.

Asymptomatic cases do not require any treatment; however, symptomatic cysts with hydrocephalus, cysts drainage (transventriculer), or ventricular-atrial/ventriculoperitoneal shunt placement is the preferred method [1]. Open or endoscopic cysts-ventriculostomy is also a surgical option.

Take home message

Cavum septum pellucidum cysts are rare; however, they should be kept in imaging differential when the patient presents with a positional headache. Rapid progression of the size of non-communicable cysts can be followed up and referred for symptomatic treatment.