TAP test
Diagnostic procedure involving removal of cerebrospinal fluid to assess for normal pressure hydrocephalus.
Full Definition
The TAP test (lumbar puncture test or cerebrospinal fluid tap test) is a diagnostic procedure used to evaluate patients suspected of having normal pressure hydrocephalus (NPH). The test involves removing 30-50 mL of cerebrospinal fluid via lumbar puncture and observing for temporary improvement in the classic NPH triad of gait disturbance, cognitive impairment, and urinary incontinence. A positive response to CSF removal suggests that the patient may benefit from ventriculoperitoneal shunt placement. The test helps distinguish NPH from other causes of dementia and gait disorders in elderly patients.
Usage
Usage note: TAP can be lowercase (tap test) when referring to the general procedure concept.
In Context
- "The TAP test showed marked improvement in gait, supporting the diagnosis of NPH." — Normal pressure hydrocephalus evaluation
- "A negative TAP test does not completely exclude the possibility of shunt-responsive NPH." — Neurosurgical consultation note