The purpose of the study is to determine if the ShuntCheck test can correctly identify flow or no flow in a ventriculoperitoneal shunt in patients with pseudotumor cerebri.

The purpose of the study is to determine if the ShuntCheck test can correctly identify flow or no flow in a ventriculoperitoneal shunt in patients with pseudotumor cerebri.

Flow may be limited due to slit ventricles

Inclusion Criteria:

• 18 years old or older Adult men or women who possess a VP shunt placed for PTC;
• Capable of providing valid signed informed consent, or has a legal guardian, health care agent, or surrogate decision maker (according to local statutes, and collectively referred to as "surrogates" in this protocol) capable of providing valid, signed informed consent;
• Subjects will be asymptomatic visiting for routine care at 2-4 weeks post op

Exclusion Criteria:

• Presence of multiple shunts, or presence of more than one distal shunt catheter (regardless of function) crossing the clavicle ipsilateral to the shunt with suspected obstruction;
• ShuntCheck test would interfere with standard patient care, or emergency shunt surgery that cannot be delayed is indicated;
• Presence of an interfering open wound or edema over any portion of the VP shunt.

The study population will consist of asymptomatic PTC research subjects who have a VP shunt with a single ventricular catheter implanted for PTC and are visiting for routine care.

At present there is no plan to share any individual participant data.