ventricular enlargement following head injury is a frequent finding but cases that require shunt operation are relatively rare.2 ) hydrocephalus following traumatic brain injury ( tbi ) or post - traumatic hydrocephalus ( pth ) is not just a ventricular enlargement but an active and progressive disorder of cerebrospinal fluid ( csf ) accumulation in the ventricular system , causing compression of the brain parenchyme.4 ) it increases the rates of morbidity and mortality in tbi patients , but it is a treatable complication of tbi.11420 ) most patients with pth underwent shunt operation have had favorable outcomes.20 ) many studies have reported various incidences and risk factors , under different diagnostic criteria , but few studies have focused on factors influencing outcome of shunt operation for pth . in this study , we analyzed the incidence , major clinical injuries prior to shunt operation , and factors influencing outcome of shunt operation for patients diagnosed with hydrocephalus following tbi at our institution .
from january 2007 to december 2012 , the subjects were the 1,142 consecutive patients suffering from tbi . the main diseases / conditions were skull fracture , cerebral contusion ( including diffuse axonal injury ) or traumatic intracerebral hematoma ( t - ich ) , epidural hematoma ( edh ) , subdural hematoma ( sdh ) , and traumatic subarachnoid hemorrhage ( t - sah ) .
23 patients underwent shunt operations . the presenting symptoms or syndrome for considering shunt operation were mental deterioration during improvement , failure to improve ( neurologic plateau ) for unconscious patients , decline in functions of daily living , headache , gait disturbance , urinary incontinence , confusion , and emotional lability etc .
all patients were checked or followed up serially by brain computed tomography ( ct ) , brain magnetic resonance imaging ( mri ) , radionuclide isotope ( ri ) cisternography , and serial lumbar drainage ( 20 to 40 cc per drainage , 1-day to 1-week intervals , more than twice ) .
indicated brain ct findings were ventricular enlargement with periventricular low density , cortical sulci effacement , and basal cistern obliteration .
the outcomes of shunt operation were evaluated with the glasgow outcome score ( gos ) ( table 1 ) .
evaluation times were just before the shunt operation , and at 14 days , 3 months , and 6 months after the shunt operation .
the 23 ( 2.01% ) analyzed subjects were those who underwent shunt operation among 1,142 tbi patients .
thus , males were about three times more common than females , but this did not differ from the whole tbi patient group ( 2.6:1 ) . for the main clinical disease ,
sdh was the most common ( 56.5% ) , followed by t - sah ( 21.7% ) , and t - ich or cerebral contusions ( 17.4% ) , in that order ( table 2 ) . among the 23 pth patients ,
16 had undergone open cranial operation for the removal of hematomas before the shunt operation ( figure 1 ) .
one was ventriculoperitoneal and the other was shunt malfunction . the interval between trauma and shunt operation was analyzed : 2 within 1 month , 7 in a 1 - 2 months ( most common ) , 3 in 3 months , 4 in 4 months , 2 in 5 months , 1 in 6 months , and 4 after over 6 months . among them , 1 patient was followed for 1 to 2 years and underwent shunt operation ( figure 2 ) . in the analysis of outcomes related the interval time of shunt operation , 2 of 2 who underwent shunt operation within 1 month improved , 8 of 9 who underwent the operation in 1 to 3 months improved , and 10 of 12 who underwent the operation after 3 months also improved .
thus , it seemed that the interval time between shunt operation and trauma had no effect ( p>0.05 ) .
outcomes related to csf pressure at lumbar spinal tapping prior to shunt operation were analyzed .
the group was divided into two : csf pressure above and below 160 mmh2o.13 ) of 15 patients who showed csf pressures below 160 mmh2o , 13 improved , as did 7 of 8 patients who had csf pressures above 160 mmh2o ( p=0.955 ) .
thus , intracranial pressure ( icp ) prior to the shunt operation also seemed to have no significant relationship with prognosis .
the glasgow coma scale ( gcs ) score at admission was classified as gcs 5 to 8 , 9 to 12 , and 13 to 15 groups .
two of 4 ( 8.7% ) in the gcs 5 to 8 group , 7 of 8 ( 4.4% ) in the gcs 9 to 12 group , and all patients in the 13 to 15 group improved ( p=0.039 , which is statistically significant ) .
thus , initial gcs score would seem to be related to the outcome of shunt operation .
the interval between trauma and shunt operation was analyzed : 2 within 1 month , 7 in a 1 - 2 months ( most common ) , 3 in 3 months , 4 in 4 months , 2 in 5 months , 1 in 6 months , and 4 after over 6 months . among them , 1 patient was followed for 1 to 2 years and underwent shunt operation ( figure 2 ) . in the analysis of outcomes related the interval time of shunt operation , 2 of 2 who underwent shunt operation within 1 month improved ,
8 of 9 who underwent the operation in 1 to 3 months improved , and 10 of 12 who underwent the operation after 3 months also improved .
thus , it seemed that the interval time between shunt operation and trauma had no effect ( p>0.05 ) .
outcomes related to csf pressure at lumbar spinal tapping prior to shunt operation were analyzed .
the group was divided into two : csf pressure above and below 160 mmh2o.13 ) of 15 patients who showed csf pressures below 160 mmh2o , 13 improved , as did 7 of 8 patients who had csf pressures above 160 mmh2o ( p=0.955 ) . thus , intracranial pressure ( icp ) prior to the shunt operation also seemed to have no significant relationship with prognosis .
the glasgow coma scale ( gcs ) score at admission was classified as gcs 5 to 8 , 9 to 12 , and 13 to 15 groups .
two of 4 ( 8.7% ) in the gcs 5 to 8 group , 7 of 8 ( 4.4% ) in the gcs 9 to 12 group , and all patients in the 13 to 15 group improved ( p=0.039 , which is statistically significant ) .
thus , initial gcs score would seem to be related to the outcome of shunt operation .
pth as a clinicopathologic entity has been recognized since dandy and blackfan 's report6 ) in 1964 .
the incidence rates of symptomatic pth in the literature vary widely , ranging from 0.7% to 29%.3912 ) if the ct criterion of ventriculomegaly is used , the reported incidence ranges from 30% to 86%.1018 ) gudeman et al.10 ) reported the incidence of ventricular enlargement after tbi between 1.5% to 29% , when evaluated by ct .
but the incidence rate of pth requiring shunt operation was only 1% to 4%.2 ) in the present study , 1,142 patients were admitted to our institution following significant head trauma . of them ,
tribl and oder20 ) reported that out of 3,426 severe head - injury patients , 48 ( 1.4% ) underwent implantation of ventricular shunt .
risk factors for pth are not yet fully identified but data suggested severity of injury , age , duration of coma , and decompressive craniectomy ( dc ) increased the risk.5 ) previous studies suggested that factors such as altered icp dynamics , mechanical blockage , and inflammation of the arachnoid granulation by postsurgical debris may induce pth.781721 ) waziri et al.21 ) suggested that dc may play a role in the flattening of the normally dicrotic icp waveform in patients having the procedure , due to the transmission of the pressure pulse out through the open cranium .
the size of dc and repeated operation may promote pth in severe head trauma patients who undergo dc.4 ) in the present study , 16 ( 70% ) patients underwent decompressive operation before shunt operation .
general risks related to shunt surgery include infection , bleeding , csf leakage , seizures , and neurological deficits .
there is an estimated 3% to 4% risk for intracerebral hemorrhage and an estimated 1% to 2% risk for coma and mortality.14 ) in contrast , tribl and oder20 ) reported that 15 ( 31.3% ) patients showed postoperative complication .
reasons for the low incidence of complications may be affected by the small number of patients and short follow - up period .
sah has been cited as the most important pathology leading to the development of pth.1314 ) we found sdh in 13 ( 56.5% ) patients and sah in 5 ( 21.7% ) .
of the 23 patients , 22 ( 96% ) had intradural pathology . for skull fracture patient
sdh was the most commonly found issue in initial ct scans in pth patients who underwent shunt operation .
the reason that sdh is the most common preceding injury for shunt operation suspected that sdh is the largest number of intradural lesion in our tbi pool ( table 2 ) .
one of the predictive parameters for outcome after shunt implantation appeared to be pre - operative clinical status .
patients in better clinical condition generally had a better outcome.1420 ) in the gcs 13 - 15 group , 11 ( 100% ) patients showed improved outcomes . however , in the gcs 5 to 8 group , 2 ( 50% ) patients showed improved outcomes .
his patients in a better pre - operation level of gos 3 improved in 63.3% of cases , whereas 36.7% did not improve .
however , only one - third of patients with gos 2 before shunt implantation improved within 3 months ; two - thirds did not .
all current neurosurgical and neurocritical care interventions target the delayed effects of secondary injuries and secondary insults .
more severe brain injury occurred more often after the development of pth . even though the csf flow disorder was treated by the shunt surgery ,
so , higher gcs patients improved after the shunt operation . in our study , all patients were evaluated by brain ct and ri cisternography .
the initial lumbar csf pressures were divided two groups , less than 160 mmh2o ( 15 patients ) and higher than 160 mmh2o ( 8 patients).13 ) in the less than 160 mmh2o group , 13 ( 56.2% ) patients showed improved outcomes . in the higher than 160 mmh2o group , 7 ( 30.4% ) patients showed improved outcomes .
this result is consistent with the results reported by kim et al.14 ) they reported outcomes of 64 pth patients requiring shunt .
symptoms improved after shunt operation in 46 patients ( 90% ) with normal pressure hydrocephalus .
this outcome was better than the improvement seen in only 6 ( 46.1% ) patients who had higher than 180 mmh2o of spinal pressure before the shunt operation .
the timing of treatment also remains controversial.11 ) pth can present acute , subacute , and syndrome of normal pressure hydrocephalus .
kishore et al.15 ) reported that more than 93% of cases of ventriculomegaly presented within 2 weeks post - injury .
marmarou et al.16 ) suggested that most cases of ventriculomegaly will present by 1 month post - injury .
most of our patients received shunt operation within 6 months after trauma . in this study ,
interval time and postoperative improvement showed no correlation . on the other hand , this result showed that most patients were improved after shunt operation , regardless of the operation interval time .
wood et al.22 ) insisted that patients with clinical symptoms of hydrocephalus for less than 6 months had a better prognosis .
however , sheffler et al.19 ) presented a case of pth that improved with a shunting procedure after having clinical symptoms of pth for 11 months after a closed head injury .
brain injury patients commonly have other severe injuries ( e.g. , long bone fracture , intestine organ rupture ) . for these patients ,
we often found pth in patients with head trauma during the follow - up period . in these cases , contrary to assuming a poor prognosis due to the possibility of delayed shunt surgery , we suggest to do shunt operation regardless of the interval time with trauma .
finally , this study has the limitations of being a retrospective study with a small sample size and lack of natural history of pth .
however , we found no correlation between the outcome of shunt operation and initial lumbar csf pressure or the interval time of the shunt operation after the trauma .
 objectiveventricular enlargement following head injury is a frequent finding but cases requiring shunt operation are rare . 
 the incidence and developing factors of post - traumatic hydrocephalus ( pth ) have been variously reported , but studies for factors influencing outcomes of shunt operation for pth are rare . the incidence of pth requiring shunt operation , causing injuries , and factors influencing outcome of shunt operation 
 need to be identified.methodsin total , 1,142 patients suffering from traumatic brain injury ( tbi ) between january 2007 and december 2012 were admitted to our department . of them , 
 23 patients underwent shunt operation for diagnosed pth . in this clinical study 
 , we reviewed retrospectively our tbi database and in the 23 patients , we evaluated outcomes with glasgow outcome score just before the operation , at 14 days , 3 months , and 6 months according to initial glasgow coma scale ( gcs ) score , interval time between shunt operation and trauma , and lumbar cerebrospinal fluid ( csf ) pressure.resultsthe incidence of pth treated with shunt operation was 2.01% . 
 subdural hematoma ( sdh ) was the most common preceding head injury . 
 the outcomes of shunt operation were not related with lumbar csf pressure or interval time from trauma , but initial gcs score correlated with the outcome.conclusionin present study , 2.01% of tbi patients underwent shunt operation . 
 sdh was the most common preceding injury . 
 admission gcs score was related to the outcome of shunt operation . 
 however , there were no correlation between the outcome of shunt operation and initial lumbar csf pressure or interval time of shunt operation after the trauma . 
Introduction
Materials and Methods
Results
Interval time (
Lumbar cerebrospinal fluid pressure (
GCS at admission (
Discussion
Conclusion