recurrent shunt malfunction is a known complication after ventriculoperitoneal ( vp ) shunt surgeries . in chronic meningitis with hydrocephalus , we present an interesting case of chronic meningitis with shunt malfunction , presenting with expanding central canal syrinx and quadriparesis . this case was investigated with a contrast ventriculogram to demonstrate a communicating central canal syrinx . the present case illustrates that a historical investigation like ventriculogram can still aid in diagnosis and management even in this modern era . relevant english literature on shunt malfunction presenting with syringomyelia along with pathophysiology , its management and the role of contrast ventriculogram have been discussed . a 2-year - old toddler presented to us with chronic fever and raised icp without any deficits in march 1998 . he was evaluated with computed tomography ( ct ) of the head and was found to have mild communicating panventriculomegaly . a provisional diagnosis of tubercular meningitis was made and he was started on empirical antitubercular therapy . his symptoms resolved then , but he presented back after 6 months with headache due to raised icp . his repeat ct head revealed an increase in the size of ventricles for which he underwent a vp shunt . he had an episode of shunt malfunction after 3 months , and the vp shunt was revised . nine months later he underwent laparoscopic repositioning of the abdominal end of the shunt due to loculated ascites ( pseudocyst ) . he had multiple episodes of shunt malfunction in the next year , for which he underwent removal of peritoneal shunt and placement of a ventriculoatrial ( va ) shunt . six years later , he presented to our institute again with quadriparesis and truncal ataxia . on examination he was noted to have hypotonic quadriparesis , c5-d4 segmental dissociative sensory loss and absent reflexes . he was investigated with a craniospinal magnetic resonance imaging ( mri ) [ figure 1a ] , which showed a cervicodorsal expanding syrinx and dilated 4 ventricle . as he had no features of raised icp , shunt malfunction was not thought of , and he underwent a syringopleural shunt . he was lost to follow - up only to present back after 5 years with recurrence of quadriparesis . craniospinal mri [ figure 1b ] showed reappearance of the syrinx with dilated 4 ventricle . the case was reviewed at this time , and the scans revealed that 4 ventricular size was seen progressively increasing , without a distinct communication between the central canal and 4 ventricle on comparison with previous mri . hence , a contrast ventriculogram [ figure 2 ] was performed through an external ventricular catheter to delineate the communication pattern . it demonstrated a mild ventriculomegaly with dilated 4 ventricle communicating with the dilated central canal of the spinal cord exceptionally well . subsequently shunt malfunction was thought of , and he underwent removal of the va shunt and placement of a fresh ventriculopleural shunt ( as he had an abdominal pseudocyst ) . the patient 's weakness improved in the postoperative period , and he was doing well at the last follow - up ( 1-year ) . preoperative magnetic resonance imaging of craniovertebral junction ( a ) done in 2004 showing - dilated fourth ventricle with syringomyelia for which he underwent a syringopleural shunt ( b ) done in 2009 showing - dilated fourth ventricle with reappearance of syrinx computed tomography contrast ventriculogram showing a fourth ventricular communication with the spinal canal ( a ) axial image at the level of the fourth ventricle with contrast ( b ) coronal image showing craniospinal canal communication ( c ) sagittal image showing contrast in the spinal canal follow - up magnetic resonance imaging with resolved syrinx ( a ) sagittal image with normal fourth ventricle and resolved syrinx ( b ) axial cuts showing normal fourth ventricle ( c ) sagittal spine image with resolved syrinx ventriculoperitoneal shunt malfunction is a commonly faced problem , and a number of cases undergo shunt revision . shunts in tubercular meningitis with hydrocephalus tend to malfunction more than others , especially if csf proteins are high . in the pediatric age group have reported on uncommon presenting features of shunt malfunction , and it includes seizures , vision loss , parkinsonian rigidity and syringomyelia ( 2 cases ) . this includes common congenital anomalies such as chiari malformations , spinal cord injury , spinal arachnoiditis and sometimes tumors . our patient had tubercular meningitis with arachnoiditis which causes arachnoids scarring at the basal cisterns leading to communicating hydrocephalus . probable 4 ventricular outlet obstruction at foramina of luschka might have pushed the csf into a patent central spinal canal ( 5 or terminal ventricle ) , which had been in communication with the 4 ventricle . progressive dilation of the 4 ventricle and altered csf flows across the foramen magnum would have caused the spinal syrinx to expand and propagate . if a shunt malfunctions , ventricular dilation is expected with symptoms of raised icp . the following mechanism may be proposed for this phenomenon . in long standing cases as in tubercular meningitis with arachnoiditis , the compliance of the ventricular system might have reduced , and it may not enlarge sufficiently . furthermore , as spinal cords compliance is better - maintained , the central spinal canal may enlarge preferentially and cause the symptoms accordingly . milhorat et al . in 2003 have reported a patient of chiari 1 malformation presenting with shunt malfunction causing acute quadriparesis and syringomyelia within 3 days . beswick et al . in 2005 have described a similar case of postmeningitic hydrocephalus who presented 9 years after initial presentation with syringomyelia . lee et al . in their article on unique clinical presentation of paediatric shunt malfunction have reported that 2 ( of 70 consecutive cases ) had syringomyelia . the review suggests that the primary pathology is mostly chiari malformation or long standing meningitis like tubercular / posthemorrhagic meningitis . syrinx is a late complication of shunt - malfunction with an average duration of around 10 years ( the range being 6 months to 19 years ) . multiple shunt revisions and posterior fossa decompressions are also common before shunt malfunction is diagnosed . cases of syringomyelia secondary to shunt malfunction all the cases in this review should have had ventricle communicate with syringomyelia as the syrinx resolved after shunt surgery . absence of ventricular communication with syrinx makes the posterior fossa decompression and other syrinx surgeries a necessity . the communication could be demonstrated in many , but not in all cases . when the communication is not clearly demonstrable , they have staged hydrocephalus as well as postshunt isolation of compartments . among their 9 patients , 4 had holocord dilatation and hydrocephalus , and syringomyelia did not improve in 2 of them after a vp shunt . interestingly , the case reported by muthukumar had anatomical communication ( as per mri ) , but shunt revision did not resolve the syrinx . hence , their patient had to undergo posterior fossa decompression . this has been explained by the presence of an isolated compartment and hypothetical ventriculosyringeal valve at the proximal central canal . in the english literature , two other cases have been reported in which contrast ventriculogram was used in similar scenarios . kudo et al . used it to confirm the communication between the 3 and 4 ventricle in their case . injected contrast through the shunt to see whether the ventricular or the peritoneal catheter got blocked . in our case too , the contrast was injected through an external ventricular catheter to confirm the communication between the syrinx and 4 ventricle , as mri was unclear . a number of these secondary syrinxes end up with repeat posterior fossa decompression surgery or syringosubarachnoid / pleural / atrial shunts , as in our case . though csf flow studies may aid in the diagnoses , interpretation may be difficult at times . we believe that the diagnosis of communicating syringomyelia ( hydromyelia ) can be definitely established by demonstrating communication between the ventricles and the dilated central canal by positive contrast ventriculography . patients with vp shunt with late onset syringomyelia need to be evaluated for shunt malfunction . there seems to be a 4 ventricular outlet obstruction and its communication with a central canal which can sometimes be demonstrated by a contrast ventriculogram . recognizing this condition is very important as a simple shunt revision benefits the patient .
ventriculoperitoneal ( vp ) shunt malfunction commonly presents as raised intracranial pressure . 
 rarely , when the central canal of the spinal cord communicates with the 4th ventricle , shunt malfunction can present as an expanding syrinx . the diagnosis is often delayed , resulting in severe morbidity . 
 some of these patients undergo repeated syrinx surgeries without much benefits . 
 we report a case of chronic tuberculous meningitis with shunt malfunction presenting as an expanding spinal canal syrinx and quadriparesis . 
 fourth ventricular communication with syrinx was demonstrated with the help of a contrast ventriculogram . 
 after shunt revision , syrinx resolved completely and the patient made significant improvement in his neurological deficits . 
 the present case illustrates that a historical and rarely used investigation like contrast ventriculogram aids in the diagnosis and management even in the current neurosurgical practice . 
 all patients with late onset syrinx and a previous vp shunt need to be investigated for shunt malfunction before considering syrinx surgery . 
 a simple shunt revision resolves the syrinx in such conditions and avoids more complex procedures like foramen magnum decompression . 
 relevant literature has been reviewed ; pathophysiology and management options have been discussed .