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 person's vision deteriorates rapidly. Medication The best-studied medical treatment for intracranial hypertension is acetazolamide (Diamox), which acts by inhibiting the enzyme carbonic anhydrase, and it reduces CSF production by six to 57 percent. It can cause the symptoms of hypokalemia (low blood potassium levels), which include muscle weakness and tingling in the fingers. Acetazolamide cannot be used in pregnancy, since it has been shown to cause embryonic abnormalities in animal studies. Also, in human beings it has been shown to cause metabolic acidosis as well as disruptions in the blood electrolyte levels of newborn babies. The diuretic furosemide is sometimes used for a treatment if acetazolamide is not tolerated, but this drug sometimes has little effect on the ICP. Various analgesics (painkillers) may be used in controlling the headaches of intracranial hypertension. In addition to conventional agents such as paracetamol, a low dose of the antidepressant amitriptyline or the anticonvulsant topiramate have shown some additional benefit for pain relief. The use of steroids in the attempt to reduce the ICP is controversial. These may be used in severe papilledema, but otherwise their use is discouraged. Venous sinus stenting Venous sinus stenoses leading to venous hypertension appear to play a significant part in relation to raised ICP, and stenting of a transverse sinus may resolve venous hypertension, leading to improved CSF resorption, decreased ICP, cure of papilledema and other symptoms of IIH. A self-expanding metal stent is permanently deployed within the dominant transverse sinus across the stenosis under general anaesthesia. In general, people are discharged the next day. People require double antiplatelet therapy for a period of up to 3 months after the procedure and aspirin therapy for up to 1 year. In a systematic analysis of 19 studies with 207 cases, there was an 87%