(Idiopathic) Intercranial Hypertension (IIH), medically known as Pseudotumor Cerebri for its imitation symptomatically of a cerebral tumor, is a condition of increased pressure in the fluid surrounding the brain in the subarachnoid space. Reasons for this occuring are not fully known although research is pointing to a possible link to hormone levels as the condition is markedly more prevalent in women between 20-39, and usualy diagnosed during a period of weight gain.
The most common symptoms found in relation to IIH is headache, followed by transient blurriness, pulse synchronous tinnitis otherwise known as pulsatile intercranial noises- hearing a "wooshing" sound that goes along with pulse rate, double vision (caused by limited lateral movement of the eye), and vision loss. Vision loss is the most serious symptom afflicting an IIH sufferer, however only approxamately 5% of patients lose vision completely in at least one eye, and that is almost directly correlated with those who do not follow up with a physician. Diagnosis is typically achieved by noting the afforementioned symptoms, along with noting high pressure in cerebrospinal fluid, done through a spinal tap, and swelling of the optic nerves (papilledema), and finally a normal CT (cat scan) or MRI showing that there is no actual tumor present.
As stated vision loss is the main dibilitating and most serious symptom. This is directly related to increased pressure around the optic nerve, as it shares the subarachnoid space and is thereby compressed by the fluid when pressure increases making it more difficult to send signals to the brain appropriately. This can be treated in two ways- medically and surgically. The medical treatment typically consists of weight loss, some people attributing to the idea that the loss of fluid, along with the added weight, reduces pressure- however this has not been concretely proven. Along with wight loss diuretics (water pills) are typically prescribed the two most common being Furosemide (Lasix)& Acetazolamide (Diamax). This causes the body to expel more flud through urination, thereby augmenting weight loss and causing the body to hold less fluid stores.
The sugical remedy is only used in situations where the patient does not respond well to the less invasive medical procedures and can be preformed in two ways, depending on the individual patients needs and condition. The first is optic nerve sheath fenestraton. This is a procedure in which slits are cut in the sheath that surrounds the optic nerve. This allows excess fluid to escape, reducing the pressure placed on the nerve, and restoring vision. This does not however permanantly resolve the problem as further buildup of fluid will recreate the symptoms, as the slits will heal eventually, and is usually followed up with continuing the medical treatment of weight loss and prescribed diuretics.
The second method of relieving vision loss due to IIH is through lumbar-peritoneal shunting, where a tube is placed leading from the cerebrospinal column (where the spinal tap was done)into the abdomen at the peritoneum. This bleeds the excess fluid off once again taking pressure off the brain and optic nerve thereby restoring vision. This procedure however comes with several complications, the most common being a complication of all shunting, which is occlusion of the shunt. The patient must then reundergo a follow up procedure to either clear or replace the shunt. Prognosis overall for the diagnosis and treatment of Idiopathic Intracranial Hypertension is generally positive, with most patients reporting full or partial vision restoration. This however is dependent on how long the loss of vision was present.