Ocular exam including pupillary examination, ocular motility, assessment for dyschromatopsia (color plates). Also obtain systemic vitals such as blood pressure and temperature
CT (negative or slit-like ventricles).
Typically, MRI and MR venogram of the orbit and brain to rule out secondary causes of<unk>  pressure such as cerebral venous sinus thrombosis. If normal, the patient may need LP to determine opening pressure and r/o other causes of optic nerve edema.
Consider ocular ultrasound (simple, non-invasive) to assess optic nerve diameter
LP (Opening pressure >25 cm H2O)
CSF lab studies by lumbar puncture are negative
No special CSF studies need to be sent, unless differential includes etiologies for infection, hemorrhage, etc
Recognize that in rare cases, LP's can cause reactive meningeal enhancement (which is why some practitioners delay LP until after MRI). This practice might not be supported in cases where LP is necessary
Outpatient visual field testing is the most important method for following these patients (Humphrey VF's)
CSF lab studies by lumbar puncture are negative
No special CSF studies need to be sent, unless differential includes etiologies for infection, hemorrhage, etc
Recognize that in rare cases, LP's can cause reactive meningeal enhancement (which is why some practitioners delay LP until after MRI). This practice might not be supported in cases where LP is necessary
Idiopathic intracranial hypertension
Migraine headache
Subarachnoid hemorrhage
Tension headache
Post-lumbar puncture headache
Cluster headache
Subdural hemorrhage
Meningitis/encephalitis