Recurrence may occur as addressed below. The outcome of the recurrences should not be expected to differ significantly from the initial episode. Sometimes all therapeutic attempts fail and the patients remain frustratingly symptomatic and work disabled. Fortunately, such cases are only a small minority. Not uncommonly, with time or with therapeutic attempts, patients’ symptoms may decrease to the point that they will be asymptomatic most of the time, can work and

do most of their usual activities, but will have such manifestations as CDH, Valsalva-induced headaches, or headaches in the second half of the day. In these cases, likely a low-grade slow-flow leak persists[27] and may continue for variable periods this website of time, even years. These can occur with variable frequency and with variable intervals

from the previous leak, ranging from weeks to years, sometimes from the same site and sometimes from a different site. Data on surgical patients[66] may not be applicable to all patients with spontaneous leaks as the large majority do not come to surgery and likely have a different course and outcome. Accurate data are not available but it is possible, although not formally studied or proven, that those with disorders of connective tissue matrix might be at a somewhat higher risk for the recurrence. Orthostatic headaches are the hallmark of CSF leaks. However, as discussed earlier, not all headaches of CSF leaks are orthostatic and also not all orthostatic headaches are due to CSF leaks. Orthostatic headaches Carbohydrate without CSF leak may be seen in connection with

several other conditions: Postural orthostatic tachycardia syndrome (POTS): In some of the Akt inhibitor patients with POTS, an orthostatic headache can be the prominent, or one of the prominent, clinical features of the disorder.[67] After surgery for Chiari malformation: A small minority of patients who have undergone decompressive surgery for Chiari malformation may develop an orthostatic headache without any CSF leak. The “syndrome of the trephined”: Sometimes patients, who have undergone large decompressive craniectomies for massive life-threatening cerebral edema, should they survive the life-threatening event, may complain of orthostatic headache that can be severe. Sometimes these headaches, along with the residual deficits from the original injury, can create substantial disability. Such patients sometimes show drastic improvement after cranioplasty.[68] Increased compliance of the dural sac,[69] especially in those with generous lumbar dural sacs and stigmata of disorders of connective tissue matrix. Headache is the most common symptom of colloid cysts of the third ventricle, a rare tumor comprising less than 0.5% of brain tumors. Although these lack any particular outstanding features, they can be present when standing and relieved by lying down.[70] From this extensive review, several conclusions can be drawn: SIH almost always results from spontaneous CSF leaks.