Minimally invasive technologies can not still ensure implementation of all surgical manipulations for correction of the vertebral-medullary anomaly. Surgical treatment of congenital anomalies of the spinal cord in adults proved to be reasonable and effective.

A clinical case of a 12 year-old girl with hydrocephalus complicated by rare condition, lateral ventricular diverticulum, is reported. Progression of the diverticulum was followed up according to MRI. The diverticulum of the lateral ventricular wall has emerged in the interval of 1 year (14 months have passed between the two MRI examinations) and spread towards the quadrigeminal cistern. In addition, compression of cerebellum, aqueductus cerebri Sylvii, and the fourth ventricle of the brain have emerged. A surgical treatment was suggested after the hydrocephalus had been initially revealed (when the diverticulum had not been formed yet); however, the child's parents refused the therapy. One year later, a series of epileptic seizures emerged, and MR scans showed a cystic neoplasm in the postcranial fossa above the cerebellum. The genesis of the cyst and its nature were unclear and additional invasive examination methods were required. MSCT ventriculography confirmed the diverticulum of the right lateral ventricle towards the quadrigeminal cistern.

Substantiation of the shunt failure diagnosis and subsequent consideration of indications for surgical elimination of the malfunction is a laborious and challenging process. Identification of a malfunction in doubtful cases requires, in addition to standard examinations, extra diagnostic procedures, which may delay making a decision for several weeks to several months. The article describes a case of mechanical CSF shunt malfunction (breakage and failure of a peritoneal catheter in a 7-year-old girl) with intracranial hypertension symptoms, but without typical enlargement of the brain ventricles. According to the medical history, congenital hydrocephalus in the child was accompanied by an inflammatory process of bacterial and viral etiology. The absence of brain ventricle enlargement was shown not to exclude a probability of shunt malfunction. In this case, a specific phenomenon, an intraparenchymatous cerebrospinal fluid "lake" surrounding a ventricular catheter, was observed. Shunting recovery did not lead to a significant reduction in the phenomenon size. Causes underlying this phenomenon require further investigation.