Spontaneous Cerebrospinal Fluid Leaks: From Intracranial Hypotension to Cerebrospinal Fluid Hypovolemia—Evolution of a Concept

Spontaneous intracranial hypotension with pituitary adenoma

“…Nausea/vomiting, tinnitus, vertigo, photophobia, visual field defects, neck traction and cranial nerve palsies are among the other clinical features [2,3]. CSF pressure evaluation is a reliable method for the diagnosis of SIH and the pressure is usually less than 5-6 cm H 2O [4,5]. CSF analysis can be normal or it may reveal increased protein and white cell count [2-4, 6, 7].…”

Intracranial Hypotension Causing Reversible Frontotemporal Dementia and Coma

“…The CSF pressure decreases when the rate of CSF volume loss cannot be further compensated by these mechanisms 7 . Loss of CSF volume also results in decreased buoyant action, which increases the weight burden and traction on brain anchoring vascular structures and neuronal pathways [3][4][5]7 . Nocioceptive receptors on these dural and intracranial vessels are sensitive to this dilatation and stretch, resulting in the postural nature of headaches seen in SIH 4,7 .…”

“…Cerebral spinal fluid pressures less than 60 mm H 2 0 may not be present; in fact, normal CSF pressures have been reported in 18-46% of cases [4][5][6] . Current understanding suggests that the etiology of SIH is CSF volume loss through a dural CSF leak, and that the clinical features, imaging abnormalities and CSF pressures depend on the extent of this CSF volume loss 7 .…”

“…Current understanding suggests that the etiology of SIH is CSF volume loss through a dural CSF leak, and that the clinical features, imaging abnormalities and CSF pressures depend on the extent of this CSF volume loss 7 . As such, alternative names of "CSF hypovolemia syndrome" and "spontaneous spinal CSF leak" have been proposed [4][5][6][7][8][9] . However, not all cases are "spontaneous", and underlying culprit lesions such as subarachnoid (Tarlov) cysts, other anatomical defects 3,5,[10][11][12][13] , or dural micro tears from minor trauma, neck manipulation and violent coughing 3,14,15 can lead to CSF leaks.…”

“…Nausea, vomiting, dizziness and posterior neck pain are all common. Neurological manifestations include visual symptoms such as diplopia, visual blurring, field defects, or photophobia 16 , hearing abnormalities including tinnitus, distortions and sensory neural hearing loss 15,16 , various cranial nerve palsies, and even peripheral manifestations of interscapular pain or radicular symptoms 2,5,12,14 . Unusual clinical manifestations have been described in case reports and include parkinsonism, gait abnormalities, cerebellar ataxia 17 , bipolar disorder 18 , encephalopathy, cognitive changes (including one case of frontotemporal dementia [FTD]) 19 , obtundation and coma 11,[20][21][22][23] .…”