Idiopathic intracranial hypertension is also called pseudotumor cerebri because just like with a brain tumor, the pressure is increased inside the skull. This condition usually presents with a headache and sometimes with visual symptoms. Increased intracranial pressure is not only a very painful condition, but also, if left untreated, can cause loss of vision and strokes.
An observational study just published in JAMA Neurology reports on 165 patients with pseudotumor seen by a group of neurologists and ophthalmologists across the country. The mean age of these patients was 29 and only 4 were men. The vast majority of them were obese with an average body mass index of 40, while normal is below 25. Headache was present in 84% of patients and 68% reported transient loss of vision. Half of them had back pains and pulse-like noise in the ears (pulsatile tinnitus) was reported by 52%. Visual loss was found in 32% and it was usually loss of the peripheral vision with an enlarged blind spot in the middle.
The authors concluded that pseudotumor cerebri mostly occurs in young obese women. The importance of this report is in reminding physicians to consider this diagnosis in young obese women with headaches. The diagnosis is confirmed by performing a lumbar puncture (spinal tap), which is the only way to measure intracranial pressure. An MRI scan is also always done (before the spinal tap), to make sure that it is not a real tumor that is causing increased pressure and to visualize ventricles (fluid-filled spaces) inside the brain. These ventricles are usually small in patients with pseudotumor. Performing the lumbar puncture involves draining of the cerebrospinal fluid, which can immediately relieve the headache and also improve vision. Some patients require regular spinal taps or placement of a draining shunt (usually from one of the brain’s ventricle or spinal canal to the abdominal cavity).
However, many patients respond to medications, such as acetazolamide (Diamox) or topiramate (Topamax). Weight loss is the most effective, albeit difficult treatment. The same group of physicians reported that acetazolamide combined with weight loss was somewhat more effective than weight loss alone. Only rarely, when vision is acutely threatened, a surgical procedure to relieve pressure inside the optic nerve is performed by an ophthalmologist (the procedure is called optic nerve sheath fenestration).
In summary, increased intracranial pressure is often mistaken for chronic migraine and should be considered in every young female obese headache sufferer.
