When a person with hydrocephalus experiences symptoms such as headache<\/a>, vomiting, changes in alertness, or walking difficulties, doctors must determine whether the shunt<\/a> or endoscopic third ventriculostomy (ETV)<\/a> is working properly. Because no single test provides all the answers, neurosurgeons use a combination of symptoms, medical history, and diagnostic tests to confirm whether there is a malfunction.<\/p>\n The diagnostic process usually begins with a careful review of symptoms and a physical examination. Your doctor will look for changes in alertness, balance, coordination, or vision and compare them to your normal baseline. This evaluation helps guide which imaging or diagnostic tests should be performed next.<\/p>\n The specific tests ordered may depend on your age, the type of shunt<\/a> you have\u2014ventriculoperitoneal (VP), ventriculoatrial (VA), ventriculopleural (VPL), or lumboperitoneal (LP)<\/strong>\u2014or whether you have an endoscopic third ventriculostomy (ETV)<\/strong>, as well as the symptoms you\u2019re experiencing.<\/p>\n For those with lumbar-peritoneal (LP) shunts, imaging may be limited to the lower spine and abdomen to evaluate tubing placement and integrity.<\/p>\n Doctors often compare the new scans to previous \u201cbaseline\u201d images taken when the shunt or ETV was felt to be functioning properly, and thus to detect even small changes.<\/p>\n An MRI may also be used to check CSF flow. There are different MRI sequences that can show the presence or absence of flow.\u00a0 \u201cCine studies<\/strong> provide a set of moving images that show the spinal fluid flow; other sequences show \u2018flow void\u2019 changes that show fluid movement.<\/p>\n These studies can define the flow or absence of flow through an ETV opening at the bottom of the third ventricle, or fluid flow through the normal small passages in the brain.<\/p>\n Because there is a risk of infection, this test is performed only by trained professionals under controlled (aseptic) conditions.<\/p>\n For individuals with an endoscopic third ventriculostomy (ETV), testing focuses on confirming that the surgical opening (stoma) is still open and CSF is flowing normally. MR Imaging (either cine flow or other flow determining images) is the primary imaging tool used to visualize this flow. If symptoms return and imaging shows reduced or no flow through the stoma, the ETV may be partially or completely closed.<\/p>\n When to Seek Immediate Medical Care<\/strong><\/p>\n Seek emergency evaluation if you or your child experiences:<\/p>\n Prompt testing and medical attention are essential\u2014shunt malfunction<\/a> or ETV failure<\/a> can progress quickly and requires urgent care.<\/strong><\/p>\n If testing shows a blockage or malfunction, your neurosurgical team will discuss next steps. Treatment may include revising or replacing the shunt, reopening the ETV, or temporarily placing an external drain while the cause is identified. With prompt care, most people recover well after the appropriate intervention.<\/p>\n Diagnosing a shunt or ETV malfunction involves multiple tests that work together to provide a clear picture.<\/p>\n Your healthcare team will combine results from imaging, fluid analysis, and pressure monitoring with your symptoms and medical history to determine the best plan for your care.<\/p>\n Information you can trust! This article was produced by the Hydrocephalus Association, copyright 2025. We would like to thank\u00a0Bruce A. Kaufman, MD<\/a> for his valuable contribution and expert input.<\/em><\/p>\n This article is designed to provide helpful information on the subjects discussed. It is not intended as a substitute for treatment advice from a medical professional. For diagnosis or treatment of any medical condition, consult your doctor.<\/i><\/em><\/p>\n\r\n
\nClinical Evaluation and Symptom Review<\/h2>\n
\nImaging of the Brain and Body<\/h2>\n
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\nTesting Cerebrospinal Fluid (CSF) and Blood<\/h2>\n
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\nElevated white blood cells or other markers may suggest a shunt infection or systemic illness.<\/li>\n<\/ol>\n
\nTests That Directly Evaluate Fluid Flow or Pressure<\/h2>\n
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\nAdditional Testing for ETV Patients<\/h2>\n
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\nWhat Happens Next<\/h2>\n
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