Neurocysticercosis (NCC) is one the common parasitic infestation of the central nervous system caused by the larval stage of taenia solium (T. Solium). It is endemic in most developing countries as well as in industrialized nations. Humans are incidental intermediate hosts in the life cycle of the T. solium10,12,14). Among the NCC, intraventricular form accounts for 10-20%14). One of the acute presentations of the intra ventricular NCC is life threatening intermittent hydrocephalus (Bruns Phenomena), which can occur due to cyst induced cerebrospinal fluid (CSF) flow obstruction from a ball valve mechanism19). At times, this can cause brain herniation leading to sudden death1,3,7,8,9,13,17,18,19). These cases require emergency management to avoid any serious complications. Authors reported two cases of third ventricular NCC presented with features suggestive of Bruns syndrome, and discussed their management with emergency endoscopic surgery.

NCC is the commonest parasitic infestations of the human central nervous system (CNS) and can involve any area of the CNS5,9,16). Intra parenchymal NCC is common and other forms are intraventricular, cisternal and spinal NCC5). Among all these, IVNCC is a potentially life threatening problem. Sometimes, IVNCC can be associated with acute obstructive hydrocephalus leading to brain herniation and sudden death, emphasizing the need for early detection and emergency treatment1,3,5,7,8,9,13,15,16,17,18,19). Large IVNCC with their free movement in the ventricular system can lead to intermittent acute occlusion of foramen of Monroe or aqueduct of sylvius due to ball valve mechanism, which is also known as Bruns syndrome19). Both these cases reported by authors, presented with features of raised intra cranial pressure in emergency.

The diagnosis of NCC is a multimodality approach and includes systematic evaluation of clinical features, neuroimaging and serology5,15). Serological analysis has a limited role in case of emergency due to their limited sensitivity and specificity5,7,13,18). The only reliable tool for diagnosis of IVNCC is imaging by computed tomography (CT) or magnetic resonance imaging trans(MRI)5,12,15,16). CT is less sensitive than MRI, as there is slight variation between CT attenuation values of cyst fluid and CSF. MRI with CSF flow study and Three dimensional Constructive Interference in Study State (3D CISS) sequence for the demonstration of an intraventricular cyst will provide proper diagnosis15). In critical situations one has to plan the emergency treatment based on the regular CT scan than MRI. Both the cases authors reported, did not have the requisite time for careful MRI evaluation due to the poor neurological level and were subjected for emergency endoscopic surgery.

In CT scan, author could demonstrate the cyst outline in the dilated third ventricle. Along with third ventricular dilation, there was gross dilatation of both lateral ventricles. Based on the clinical features and CT imaging, the IVNCC was the first differential diagnosis. Other possibilities could be intraventricular arachnoid cyst or post infective hydrocephalus due to TBM2,11).

The treatment options are medical management, ventriculo peritoneal shunt (VPS), microsurgery and endoscopic surgery alone or in combination7,9,15,18). Medical management alone is out of favor because of the limited effectiveness of albendazole and praziquentel. Though there is no general consensus regarding ideal surgical treatment of intraventricular NCC, neuroendoscopy is preferred over microsurgery and VPS18,19). Microsurgery for NCC removal needs craniotomy, more brain invasion, increases operative time, blood loss, increased hospital stay and expenses1,7). On the other hand, VPS is associated with more post operative complications like shunt malfunction, repeat surgeries2,6,7). Because of its minimal invasive nature, endoscopic surgery has less brain injury, operative time and blood loss. Moreover, endoscopy allows a quick and relatively easy approach to the single or multiple cysts located within the ventricles8,13). By using endoscope, one can remove the cysts, and as well do ETV to prevent the delayed hydrocephalus. Delayed hydrocephalus commonly seen in cases treated by microsurgery or VPS2,6). Even in emergency, endoscopy plays a role in intra operative diagnosis of these lesions with their distinct features like "full moon" sign (Fig. 2, 7)14). Ramos-Zúñiga et al.14) reported the specific features and consistent correlation between macroscopic endoscopic view of the intraventricular vesicular stage NCC and appearance of the full moon. This unique analogy was also seen by authors and allowed the diagnosis of IVNCC. They also opined that, this endoscopic sign is not seen in other intraventricular cysts or tumors. Implications of such findings are not only clinically relevant for the diagnostic clarification but also help in therapeutic planning. Hence, neuroendoscopic removal of the IVNCC with hydrocephalus is the preferred surgery where ever the expertise is available14,18,19).

Both the cases were reported by authors presented with acute hydrocephalus with altered sensorium. Patients reported to the author with a CT scan done already from other peripheral centers. An emergency endoscopic surgery and cyst removal was done. In both the cases, presumptive clinic-radiological diagnosis of the IVNCC was reinforced with endoscopic imaging features of full moon sign. After cyst removal, 30° and 45° angled endoscopes are used for detailed examination of ventricles. Opposite left lateral ventricle was visualized with the use of small septostomy. In first case ETV was done at the end as there were features of diffuse ependymitis to prevent the delayed hydrocephalus due to fibrosis and aqueductal stenosis. In second case as the ventricle was appearing healthy without the evidence of ependymitis, ETV was not done. First case at two years and the second one at six months follow up period did not show hydrocephalus or recurrence of symptoms.

Even though the neuroendoscopic excision of the NCC is safe, effective and less invasive, at times may be difficult to perform ETV in cases of severe ependymitis. Potential complications like bleeding, vascular injury and cerebral infarction4,11) are reported with ETV.

Intraventricular NCC with acute hydrocephalus continues to be a potentially fatal condition if not addressed well in time. Although active and vesicular NCC does not produce host reaction, they can hinder CSF movement with ball valve mechanism, leading to the complex clinicopathological entity of hydrocephalus known as "Bruns syndrome". Emergency neuroendoscopy helps in diagnosing the IV NCC with their distinct features like full moon sign. It also helps in removal of the cyst and establishment of alternative CSF flow channel by ETV to prevent the delayed hydrocephalus. Thus, where ever the facilities are available, neuroendoscopic surgery should be the modality of first choice for treatment of IVNCC with hydrocephalus.