These criteria also require that the lumbar puncture is performed with the person lying sideways, as a lumbar puncture performed in the upright sitting position can lead to artificially high pressure measurements. Friedman and Jacobson also do not insist on MR venography for every person; rather, this is only required in atypical cases (see "diagnosis" above). Treatment
The primary goal in treatment of IIH is the prevention of visual loss and blindness, as well as symptom control. IIH is treated mainly through the reduction of CSF pressure and. IIH may resolve after initial treatment, may go into spontaneous remission (although it can still relapse at a later stage), or may continue chronically. Lumbar puncture
The first step in symptom control is drainage of cerebrospinal fluid by lumbar puncture. If necessary, this may be performed at the same time as a diagnostic LP (such as done in search of a CSF infection). In some cases, this is sufficient to control the symptoms, and no further treatment is needed.The procedure can be repeated if necessary, but this is generally taken as a clue that additional treatments may be required to control the symptoms and preserve vision. Repeated lumbar punctures are regarded as unpleasant by people, and they present a danger of introducing spinal infections if done too often. Repeated lumbar punctures are sometimes needed to control the ICP urgently if the persons vision deteriorates rapidly.
The Monro–Kellie rule states that the intracranial pressure is determined by the amount of brain tissue, cerebrospinal fluid (CSF) and blood inside the bony cranial vault. Three theories therefore exist as to why the pressure might be raised in IIH: an excess of CSF production, increased volume of blood or brain tissue, or obstruction of the veins that drain blood from the brain.The first theory, that of increased production of cerebrospinal fluid, was proposed in early descriptions of the disease. However, there is no experimental data that supports a role for this process in IIH.The second theory posits that either increased blood flow to the brain or increase in the brain tissue itself may result in the raised pressure. Little evidence has accumulated to support the suggestion that increased blood flow plays a role, but recently Bateman et al. in phase contrast MRA studies have quantified cerebral blood flow (CBF) in vivo and suggests that CBF is abnormally elevated in many people with IIH. Both biopsy samples and various types of brain scans have shown an increased water content of the brain tissue. It remains unclear why this might be the case.The third theory suggests that restricted venous drainage from the brain may be impaired resulting in congestion. Many people with IIH have narrowing of the transverse sinuses. It is not clear whether this narrowing is the pathogenesis of the disease or a secondary phenomenon.