Inclusion Criteria:

- Children without central nervous system tumors who are undergoing a neurosurgical
procedure to address hydrocephalus during which CSF will be obtained

- Between the ages of 1 year and 21 years

- Patients must be having blood draws, lumbar punctures or CSF sampling from Ommaya
reservoirs or VPS as part of routine clinical care.

Exclusion Criteria:

- Patients who do not require routine blood draws and/or CSF collection as part of
their routine clinical care

- Patients who are considered too ill to participate as determined by their treating
physician

- Patients with documented bacterial of viral infections of the CSF, brain parenchyma
and/or neurosurgical devices and/or

- Patients with suspected de-myelinating conditions

- Patients who are pregnant or lactating.