© Springer International Publishing Switzerland 2015. A clear trend towards better outcomes in patients with normal pressure hydrocephalus (NPH) has been shown in studies published in the last decade. This is due in part to the availability of more sophisticated hardware and a better understanding of the risks and characteristics of these fragile patients. Because there is no robust evidence showing the superiority of specific type of valve, neurosurgeons face a dilemma in choosing the most adequate shunt, an essential step in improving outcome and avoiding “shunt-patient mismatch.” The most commonly known consequence of hydrodynamic mismatch is shunt overdrainage. However, a lesser-known consequence of poor hardware selection is occult shunt dysfunction, which can cause lack of improvement or later deterioration after initial improvement. Shunt selection must be based on the fact that intracranial pressure (ICP) and CSF dynamics are highly heterogeneous in NPH. Patients may present active hydrocephalus (mean ICP >12 mmHg), compensated hydrocephalus (mean ICP of 5–12 mmHg), or even low-pressure hydrocephalus (ICP <5 mmHg). In addition to the valve, which has a specific opening pressure and resistance, the shunt system must include a gravitational device. Clinical symptoms and neuroimaging studies are sufficient to diagnose complications related with overdrainage. However, continuous ICP monitoring helps to identify possible cases of underdrainage that result in a lack of improvement in certain patients. In the management of patients with NPH, ICP values and intra-abdominal pressure, as well as the hydrodynamic proprieties of the shunt system selected, must be considered.
|Title of host publication||Complications of CSF Shunting in Hydrocephalus: Prevention, Identification, and Management|
|Number of pages||16|
|Publication status||Published - 1 Jan 2015|