Shunt implantation in a special sub-group of post-traumatic hydrocephalus--patients have normal intracranial pressure without clinical representations of hydrocephalus.

Background: Post-traumatic hydrocephalus (PTH) is a frequent complication secondary to traumatic brain injury (TBI) and controversy remains over whether to perform a shunt placement for patients with normal pressure hydrocephalus when the patient is too injured to display symptoms or has atypical symptoms. Method: A hospital-based retrospective study was performed in patients who developed normal pressure hydrocephalus, without atypical symptoms, from January 2004 to June 2007. Information regarding patients' demographics, TBI, hydrocephalus and outcome was collected. Results: A total of 31 patients were involved in this study. At the 12-month follow-up, 20 patients (64.5%) showed clear improvement. Among the 10 patients who developed PTH after decompressive craniectomy, cranioplasty was performed after shunt implantation and clinical improvement was observed in nine patients. Additionally, in this series, the patients' age and the severity of hydrocephalus, assessed by CT imaging before shunt placement, significantly correlated with improvement. Conclusion: Although the effect was not definitively established, many patients in the sub-group of PTH patients described here would benefit from shunt placement, especially when they simultaneously have large cranial defects after surgical decompression and underwent cranioplasties after shunt placement. Additionally, younger patients and those with less severe hydrocephalus before shunt placement may expect a better outcome after shunt placement.