If you suffer symptoms such as painful headaches and vision problems—the cause of which may be elevated intracranial pressure—your doctor may refer you to an ophthalmologist for a comprehensive eye and vision exam. Intracranial hypertension (IH), also known as pseudotumor cerebri and benign intracranial hypertension, occurs when the pressure of cerebrospinal fluid (CSF) inside the skull elevates above normal levels.
Although IH is a rare disorder, if left untreated, the condition can lead to permanent vision loss or blindness. Therefore, it's important to recognize the signs and then see your doctor for diagnosis and proper treatment before the problem becomes more serious.
Primary Intracranial Hypertension
Idiopathic intracranial hypertension (IIH)—or primary intracranial hypertension—commonly occurs in overweight females during their childbearing years. However, the condition can occur in children and in men. In fact, one study found that men with IIH are twice as likely as women to suffer vision loss. But regardless of your gender or age, problems arise when the brain produces too much CSF and the body can't reabsorb the higher-than-normal levels of fluid.
Symptoms of intracranial hypertension generally include severe headaches that vary in location and frequency, double vision, a rhythmic thumping sound in the ears, and visual-field loss. A headache can last for days or weeks, but in rare cases, you may not experience headaches or any of these other symptoms.
Visual symptoms related to papilledema—swelling of the optic nerve caused by increased intracranial pressure—may include blurring and distortion of central vision, progressive loss of peripheral vision in one or both eyes, sudden vision loss, or transient loss of vision. Other symptoms not related to vision that you may experience include dizziness, nausea, and vomiting.
Diagnosis of IIH requires a neurological examination and vision testing that includes visual-field assessment, tests of eye position and movement, and an ophthalmoscopy to examine the back of the eye and detect retina problems or swelling of the optic nerve.
Your doctor may also order laboratory testing or imaging studies such as an MRI or CT of the brain to rule out other causes of increased intracranial pressure. Some doctors perform a lumbar puncture as part of the diagnostic process.
In addition to weight loss and exercise, management of increased intracranial pressure may include taking the oral diuretic acetazolamide to remove excess fluid in the body and lower intracranial pressure. Common side effects of this medication include loss of appetite, nausea, vomiting, diarrhea, ringing in the ears, and numbness and tingling in the arms and legs.
When monitoring vision and optic nerve swelling, your doctor may prescribe the short-term use of corticosteroids, especially if you suffer considerable visual impairment. Preventive migraine therapy is another option for managing high intracranial pressure. In this situation, your doctor may prescribe medications such as amitriptyline, propranolol, or topiramate.
Surgery is an option if your vision worsens despite your taking medications. Surgical intervention may include decompression of the fluid surrounding the optic nerve or use of a shunt to drain and redirect fluid that has built up around the brain and spinal cord.
Secondary Intracranial Hypertension
Secondary intracranial hypertension is another form of intracranial hypertension. Unlike primary IH, the cause of which is unknown, secondary intracranial hypertension has a number of known causes, including:
- Acute liver and renal failure
- Cancer of the blood or bone marrow
- Blockage in the flow of cerebrospinal fluid at the base of the skull
- Medications such as lithium, tetracycline, oral steroids, vitamin A–derived oral acne medications, oral contraceptives, and some chemotherapy drugs
- Sleep apnea
While these factors can cause IH, the exact mechanism through which IH is effected remains unknown. Further, regardless of the underlying trigger, the symptoms of secondary intracranial hypertension can be chronic, and the condition causes the same problems as primary IH does. Treatments can be similar, though in the case of secondary IH, interventions related to the cause of the IH may also help.
Because the consequences of IH can be severe regardless of what type a patient has, patients need appropriate treatment to prevent vision loss associated with the condition. In fact, even once your symptoms are brought under control, you should continue to schedule follow-up eye exams.
If you've been experiencing vision problems accompanied by persistent headaches, the eye care specialists at Absolute Vision Care can examine your eyes for signs of increased intracranial pressure.