Final answer:
The best test for a young patient with new onset headaches, periods of visual obscuration, and papilledema is a lumbar puncture.
Step-by-step explanation:
The best test for a young patient with new onset headaches, periods of visual obscuration, and papilledema is a lumbar puncture (also known as a spinal tap).
Lumbar puncture is performed to measure the pressure of the cerebrospinal fluid (CSF) surrounding the brain and spinal cord. In patients with headaches, visual symptoms, and papilledema (swelling of the optic disc), a lumbar puncture can help diagnose conditions such as idiopathic intracranial hypertension (IIH), also known as pseudotumor cerebri.
During a lumbar puncture, a needle is inserted into the lower back area to collect a sample of the CSF. The pressure of the CSF can be measured and evaluated for signs of increased pressure, which can indicate IIH.