Spontaneous intracranial hypotension

Cerebral Venous Thrombosis in Two Patients with Spontaneous Intracranial Hypotension

“…A review published in 2008 [ 17 ] noted that SIH is a risk factor for CVT, but CVT is found in only 2% of patients with SIH. As we have seen in our cases, the presence or development of CVT in SIH may be associated with little or no change in the characteristics of the headache [ 17 ].…”

“…Second, SIH is associated with rostrocaudal sagging of the brain due to the loss of CSF buoyancy [ 3 ], resulting in a negative intracranial pressure gradient that may damage the venous endothelial lining by stretching the cerebral vessels [ 17 ]. Third, the loss of CSF reduces absorption of CSF into the cerebral venous sinuses, resulting in increased blood viscosity in the venous compartment [ 34 ], which could contribute to dural sinus thrombosis in patients with risk factors for thrombosis, such as hereditary thrombophilia (mainly the factor V Leiden mutation (15%–17% of cases) and the prothrombin-gene-mutation 20210GA (10%–12% of cases); by contrast, antithrombin III-, protein C-, and protein S-deficiency are found in only 2%–6% of cases), anti-cardiolipin antibodies, hyperhomocysteinemia, cesarean delivery, pregnancy-related hypertension, and the use of oral contraceptives.…”

Pontine bleeding following drainage of subdural hematoma in craniospinal hypotension

“…In case of dural puncture, it is called iatrogenic CSH. It is an uncommon syndrome known as Schaltenbrand syndrome or spontaneous aliquorrhea [1] . The great majority of patients are in the fifth or sixth decade of life, and the mean age is the early 40s [2] .…”

“…The classic clinical hallmark of CSH is a postural or orthostatic headache that is exacerbated by standing and is relieved in the recumbent position. Patients may also present with diplopia, tinnitus, vertigo, dizziness, stiff neck, nausea, vomiting, hyperacusis, deafness, and visual loss [1] , [3] . Imaging studies, especially magnetic resonance imaging (MRI), are helpful in confirming the diagnosis and ruling out other entities.…”

“…Imaging studies, especially magnetic resonance imaging (MRI), are helpful in confirming the diagnosis and ruling out other entities. Imaging findings can be normal or include caudal displacement of cerebrum below tentorium, diffuse intense pachymeningeal enhancement, dural sinus distention, subdural effusion or hematomas, cerebellar tonsillar herniation, enlarged edematous pituitary gland, obliteration of suprasellar and perimesencephalic cistern, dural sinus thrombosis due to long standing dural sinus distention, and spinal epidural congestion [1] , [4] , [5] . Imaging findings are easily explained by Monro-Kellie hypothesis, which states that the craniospinal and its constituents (blood, CSF, and parenchyma) create a state of volume equilibrium, such that any decrease in volume of one of the cranial constituents must be compensated by an increase in volume of another constituent or vice versa [6] .…”