Pseudotumour Cerebri Idiopathic Intracranial Hypertension and Vascular Intracranial Hypertension

Romanian Neurosurgery (2015) XXIX 4: 397 - 409 397

DOI: 10.1515/romneu-2015-0055 Pseudotumour cerebri Idiopathic intracranial hypertension and vascular intracranial hypertension

St.M. Iencean1, A.St. Iencean 2, A. Tascu 3

1“Grigore T. Popa” University of Medicine and Pharmacy, Iasi, Romania 2Neurosurgery, “N. Oblu” Emergency Hospital Iasi, Romania 3Pediatric Neurosurgical Department, “Bagdasar-Arseni” Clinical Hospital, Bucharest, Romania

Abstract : From the first to use of “ pseudotumor cerebri ” by Nonne in 1904, the historic evolution of the knowledge on pseudotumor cerebri has been marked by several periods (the otologic stage, the neurosurgical stage, the neuro-ophthalmologic stage); today there are clear diagnosis criteria for the idiopathic intracranial hypertension, there is a clear differentiation between idiopathic intracranial hypertension and vascular intracranial hypertension, also the comprehension of the illness pathogeny is based on the dynamics of the intracranial fluids, which allows the auto-regulation of the cerebral circulation within quasi-normal limits, despite the very high intracranial pressure. Key words : idiopathic intracranial hypertension, pseudotumor cerebri, vascular intracranial hypertension

Vascular intracranial hypertension The volume of the cerebral parenchyma Intracranial hypertension can occur in increases due to the modifications occurred at cerebral-vascular illnesses due to sanguine, the level of the cerebral sanguine capillaries, cerebral or extra-cerebral, circulatory which leads to: disorders, which modify the dynamics of the - the occurrence of the extracellular brain intracranial fluids and cause the intracranial edema due to the increased quantity of pressure increase. There are disorders in the interstitial fluid: auto-regulation of the cerebral hemodynamics - extracellular edema produced by a and the cerebral parenchyma volume hydrostatic mechanism (ultra-filtration) in continues to increase due to the brain edema severe arterial hypertension, or to the increase in the cerebral sanguine - extracellular edema with oncotic volume (brain swelling) with the secondary induction (vasogenic edema) due to an increase in the intracranial pressure. increased permeability of the brain blood

398 Iencean et al Pseudotumour cerebri

barrier (open brain-blood barrier) anorexia concomitantly to areas of venous - cerebral congestive edematization with an congestive edematization, and the cellular increase in the volume of the cerebral cerebral (cytotoxic) edema occurs, as well as parenchyma by vascular dilatation. the oncotic extracellular (vasogenic) edema, The vascular types of intracranial which evolves to a mixed brain edema. The hypertension have characteristic etiologies venous sinuses also ensure the resorption of and they occur by: the cerebrospinal fluid, and the thrombosis of - slowing down or decreasing the the venous sinuses leads to a diminished intracranial venous flux in thrombophlebites drainage of the cerebrospinal fluid. Therefore, and cerebral venous thrombosis, the decrease a progressive intra-ventricular accumulation in the venous flux at the level of the superior of cerebrospinal fluid occurs, with a pressure longitudinal sinus (SLS) directly in increase in the ventricular system and the compressive lesions (hollowing fracture, etc.) occurrence of the hydrocephalic brain edema. or in SLS shunting by an intracranial arterial- These phenomena happen slowly, in varied venous malformation, or the extra-cranial successions, but the evolution is progressive illnesses that block the returning venous towards an intracranial pressure increase. circulation at the cervical level, reduce the The iatrogenic thrombosis of the internal cerebral venous drainage and cause the jugular veins is quoted in cases of prolonged decrease in the absorption of the cranial-spinal use of the jugular catheters for the intravenous fluid and then the occurrence of the brain administration of medication. In such cases, edema. the same pathogenic processes occur, and the - in hypertensive encephalopathy, when ICH syndrome may appear. the hydrostatic brain edema occurs (by ultra- The symptomatology is caused by the filtration), as well as a brain swelling (by initial causal lesion, after which neurological vasodilatation). focal symptoms may occur related to the - the cerebral ischemia or the ischemic progression of the venous thrombosis, as well stroke reduces the arterial sanguine as symptoms caused by the intracranial contribution and causes an ischemic brain pressure increase. A venous infarct often edema, which is a mixed brain edema, both a happens, which is associated to a cerebral cellular edema (cytotoxic) and an extracellular hemorrhage, which also aggravates the brain edema with oncotic induction neurological clinical presentation. (vasogenic). Usually, the clinic evolves to an incomplete Cerebral venous thrombosis or complete syndrome of intracranial Cerebral venous thrombosis reduce the hypertension. returning venous circulation from the brain The main characteristics of the intracranial and the skull, a venous stasis is produced and pressure increase in cerebral venous the cerebral sanguine circulation is slowed thrombosis are: down. There are areas of cerebral hypo- - a slow increase in the intracranial

Romanian Neurosurgery (2015) XXIX 4: 397 - 409 399

DOI: 10.1515/romneu-2015-0055 pressure up to the normal limit value of 20 mm malformation and the cerebrospinal fluid Hg, usually during a period of a few days, resorption is diminished by the occurrence of - over the value of 20 mm Hg, the ICP the hydrocephalus. In infants and small increase continues to be progressive, and it children, the dominating symptomatology is may reach maximum values of approximately the cardiac disorder due to the increased 30 mm Hg in a few hours or days. venous return, while the ICH syndrome also This gradual increase allows the occurs in older children. compensating mechanisms to act more - in the case of a median intrusive cranial efficiently, and also for the applied therapy to fracture, which interests the third posterior encourage the intracranial pressure decrease part of the SLS. and the improvement of the cerebral sanguine - in children with craniostenoses, there circulation. may be anomalies of the venous drainage, - the maximum values that may be reached which interests the sigmoid sinus and the in cases of intracranial hypertension syndrome jugular vein, which may cause a venous are of approximately 30- 35 mm Hg hypertension, with a diminished drainage of (sometimes the maximum values may be of 40 the cerebrospinal fluid and the increase in the mm Hg) and intracranial pressure. Usually, the - the pathological pressure values may last phenomenon occurs up to the age of 6 years for several weeks, with a slow return to normal old, after which a collateral venous drainage is pressure values and period of intermittent developed by the stylomastoid plexus, leading increases, to the normalization of the intracranial - usually, there is a recurrence to pressure. intracranial pressure values of about and Hypertensive encephalopathy above 20 mm Hg, which causes the persistency High blood pressure is the most important of a prolonged attenuated symptomatology. predisposing factor for cerebral-vascular The treatment of the venous thrombosis illnesses, and the most frequent complication with an ICH syndrome is: is the cerebral hemorrhage. The exaggerated - etiological and pathogenic for the increase in the values of the systemic blood vascular disorder, when possible, pressure also causes disorders of the cerebral - pathogenic for the intracranial circulation auto-regulation, with other hypertension syndrome. secondary cerebral suffering. A particular pathogenic mechanism is the Hypertensive encephalopathy is defined in reduction of the venous flux at the level of the the clinical presentation of induced superior longitudinal sinus (SLS) with an intracranial hypertension by an acute episode important blockage of the CSF resorption: of arterial hypertension. - in the case of arterial-venous 1. The acute hypertensive encephalopathy malformations of the Galien vein (Galien vein is caused by the acute blood pressure increase aneurisms), when there is a SLS shunting by in:

400 Iencean et al Pseudotumour cerebri

- severe high blood pressure, chronic extracellular brain edema: hydrostatic - uncontrolled / untreated high blood brain edema combined with the oncotic brain pressurein pregnancy (eclampsia), edema. - high blood pressure in The intracranial pressure increase in acute glomerulonephritis, pheochromocytoma, etc. hypertensive encephalopathies are The acute increase in the sanguine pressure characterized by: values leads to the inefficiency of the cerebral - the relatively high speed with which the vascular auto-regulation, a generalized intracranial pressure reaches the normal cerebral vascular dilatation occurs and / or threshold value in approximately a few hours there is an increased permeability of the - the ICP continues to increase above the cerebral capillaries. The increased normal values for a period that is usually permeability in the brain blood barrier has shorter than the previous interval, of few hours been constant more frequently at the level of only the gray matter. - the maximum values that the ICP may Therefore, the increase in the volume of the reach are of 30 – 50 mm Hg and cerebral parenchyma is caused by: - the period with pathologic intracranial - brain swelling by vasodilatation, pressure values is usually of several hours, - hydrostatic extracellular brain edema, by rarely of several days. The anti-hypertensive ultra-filtration when the brain blood barrier is treatment improves the clinical condition. intact (close brain-blood barrier) The unmonitored hypertensive patients, - oncotic (vasogenic) extracellular brain or those who are incompletely treated may edema by an injury of the brain blood barrier present repeated episodes of hypertensive (open brain-blood barrier). encephalopathy, or they may suffer from the The posterior reversible encephalopathy most frequent complication, which is the syndrome (PRES) or the reversible posterior cerebral hemorrhage. leuco-encephalopathy syndrome (RPLS) with The clinical evolution of hypertensive a hypertensive etiology is included in the acute encephalopathy is up to an incomplete form of vascular etiopathogeny ICH. The syndrome of intracranial hypertension, and it clinical presentationis typical and the DWI has a regressive aspect. In the pathogeny of the exploration shows an extracellular brain syndrome, there is an auto-limiting edema by the increase in the water mobility mechanism: the intracranial pressure increase with a posterior bilateral location, and a sub- caused by the increase in the sanguine blood cortical interest in the white matter too. The pressure and by occurrence of the cerebral treatment consists of decreasing the systemic vasodilatation generated the collapse of the blood pressure. walls of the intracranial sanguine vessels, and, 2. The chronic hypertensive to a certain extent, to a diminished cerebral encephalopathy (Binswanger encephalopathy) sanguine volume. The mechanism consists of is a rare cerebral-vascular illness with a the direct action of the increased intracranial

Romanian Neurosurgery (2015) XXIX 4: 397 - 409 401

DOI: 10.1515/romneu-2015-0055 pressure over a functional disorder that is In the case of the cerebral hemispheric secondary to the exceeded auto-regulation of ischemic stroke, the decreased sanguine flow the cerebral circulation, and it has a limited in the territory of the middle cerebral artery value. leads to the occurrence of certain ischemic The treatment of the hypertensive metabolic disorders at the level of the affected encephalopathy is both etiologic and cerebral parenchyma. The permeability of the pathogenic: cerebral capillaries increases (open brain- - the treatment of the hypertensive episode, blood barrier) and the extracellular oncotic as an etiologic aspect, and (vasogenic) edema occurs. The evolution is - the pathogenic treatment of the usually a rapid one, with the extension of the intracranial hypertension syndrome. brain edema, the increase in the intracranial Ischaemic stroke pressure and the occurrence of the sub- The ischemic stroke represents 85 % of falciform cerebral hernia (median line the cerebral-vascular illnesses. The large movement towards the unaffected cerebral ischemic cerebral lesions are accompanied by hemisphere). Although the intracranial the brain edema with cerebral herniation (sub- pressure increasing mechanism is based on the falciform) and by the intracranial pressure cerebral ischemia with a hypoxic brain edema, increase. which is characteristic for the parenchymatous The extended cerebral ischemic infarct lesions, while the etiology is represented by the with phenomena of intracranial hypertension impacts on a great cerebral artery, and it is caused by the occlusion or stenosis of a great includes the ischemic stroke on vascular cerebral artery: the internal carotid artery or a intracranial hypertension. terminal branch that irrigates a vast territory, Since the moment of the arterial occlusion, such as the middle cerebral artery. The the intracranial pressure increase is: extended ischemic infarct of the Sylvian artery - rapid until it reaches the normal pressure occurs in approximately 10 % of the patients limit of 20 mm Hg, by the progression of the with acute cerebral circulatory insufficiency, brain edema and the surpassing of the pressure and it has been designated as the malign compensating possibilities, with a duration of infarct of the Sylvian artery due to the up to several hours increased mortality, of up to 80 % of cases, - above the normal pressure values, the ICP despite the therapeutic means used. The increase is also a rapid one, and the maximum massive cerebellum ischemic infarct can cause values are reached within a short interval of the collapse of the 4th ventricle with the time: half an hour – several hours occurrence of an acute obstructive - the maximum values of the intracranial hydrocephalus and an acute ICH syndrome, pressure are of approximately 40 – 50 mm Hg and it has a direct compressive effect on the and brainstem with the manifestation of vegetative - the duration of these pathological values disorders. is of several days and it corresponds to the

402 Iencean et al Pseudotumour cerebri

intensive care period. - decompressive craniectomy and the The evolution is rapid towards the evacuation of a cerebral hemispheric massive decompensation of the intracranial infarct, which may diminish the intracranial hypertension with almost 80% unfavorable hypertension, but the surviving patients is left results despite the applied treatments. There is with major neurological deficits. an attempt in using the etiological treatment of A particular case of generalized cerebral the arterial obstruction and the pathogenic ischemia is met in the post-resuscitation treatment for the ICH syndrome. During the syndrome when the sanguine flux disorder first three hours from the beginning, there may includes the entire brain, with a complete be an intravenous administration of ischemia throughout the stroke, followed by recombined tissue plasminogen activator reperfusion disorders. (rtPA) in a dose of 0.9 mg/kg, maximum 90 The consequence of this cerebral mg; the administration of streptokinase or of circulatory failure, primary – before and other thrombolytic agents does not have the during cardiopulmonary resuscitation, and same efficiency as rtPA. The brain edema secondary ischemic damage, during receives a pathogenic treatment with osmotic reperfusion is the development of the mixed diuretics (mannitol), and hyperventilation if brain edema: both cytotoxic and vasogenic, there is an imminent decompensation of concomitantly to the production of the glial- intracranial hypertension and the production neuronal necrosis. The hyperemic reperfusion of a brain herniation etc. may exacerbate the brain edema. The mixed Sometimes, there is an attempt of a surgical brain edema accentuates the elevated intervention: intracranial pressure and it exacerbates the - decompressive craniectomy of posterior brain injury. The treatment is complex and the cerebral fosse and of evacuation of a results do not compensate the efforts. cerebellum infarct with a compressive effect on the brainstem, perhaps with a ventricular drainage, TABLE I Etio-pathogenic and evolutionary characteristics of the various forms of vascular ICH Cerebral venous thrombosis Hypertensive encephalopathy Ischemic stroke Cerebral vascular pathology: Cerebral vascular pathology: Cerebral vascular pathology: - thrombosis of dural sinuses - dilatation of cerebral arteries - infarct of Sylvian artery - thrombosis of cortical veins - massive cerebellum infarct Cerebral blood flow : Cerebral blood flow : Cerebral blood flow : Reduced venous outflow Increase arterial inflow Reduced arterial inflow Pathogenesis: Pathogenesis: Pathogenesis: - venous dilatation; open BBB and - dilatation of cerebral vessels; closed BBB - ischemic increased capillary vasogenic brain edema and hydrostatic brain edema, and permeability ; open BBB and and vasogenic brain edema

Romanian Neurosurgery (2015) XXIX 4: 397 - 409 403

DOI: 10.1515/romneu-2015-0055

- diminished CSF drainage with -increased vascular permeability with hydrocephalic brain edema open BBB and vasogenic brain edema ICP increase: ICP increase: ICP increase: - slow to the normal limit - rapid to the normal limit - rapid to the normal limit - slow above the normal limit - slow above the normal limit - rapid above the normal limit

Sub-acute and chronic evolution Acute and sub-acute evolution Acute evolution Possible decompensation Rarely decompensation Usually decompensation Pathogenic treatment Pathogenic and etiologic treatment Etiologic and pathogenic treatment, Decompressive craniectomy

Idiopathic intracranial hypertension syndrome as follows: “prolonged intracranial Idiopathic intracranial hypertension is a hypertension without ventricular syndrome characterized by the intracranial modifications, without focal neurological pressure increase in the absence of an signs, without consciousness or intellectual expansive intracranial process, of disorders, the most important symptoms hydrocephalus, of an intracranial infection, of being a moderate cephalea, blurred sight, dural venous sinus thrombosis, of diplopia and sometimes tinnitus. The only hypertensive encephalopathy and without a signs are the papillary edema and the abducens neurotoxic etiology. The idiopathic paralysis. The cerebrospinal fluid has a normal intracranial hypertension partially composition. The prognosis is favorable, and corresponds to the old designation of the symptoms progressively diminish in pseudotumor cerebri; the term of benign several weeks or months.” intracranial hypertension has also been used, According to Foley’s classic definition, but it was subsequently dropped as it was 1955, the idiopathic intracranial hypertension noticed that the evolution of this illness can be occurs as a diagnosis that may be established accompanied by complications that exclude only by exclusion; moreover, even in Dandy’s the idea of benignity (visual acuity decrease to diagnosis criteria, modified by Wall, one of the cecity in some cases). diagnosis elements is the non-identification of This medical condition is described as a another cause for the intracranial pressure specific entity in Quincke’s papers from 1893 increase. The diagnosis of idiopathic and 1897 and then by Nonne in 1904, who is intracranial hypertension can be given only the first to use the term of pseudotumor after the intracranial pressure has been cerebri. Various hypotheses are delivered in measured and after a complete neuro- order to explain the causes and the pathogenic imagistic exploration. mechanisms of the illness. The diagnosis criteria of the idiopathic In 1955, Foley uses the term “benign intracranial hypertension, which are intracranial hypertension”, which is to be used standardized by Friedman and Jacobson, and for several decades, and he defines this which are currently accepted are:

404 Iencean et al Pseudotumour cerebri

- the pressure of the cerebrospinal fluid is of idiopathic intracranial hypertension reaches higher than 25 cm H2O, that is higher than 18 19-25 cases / 100,000. - 20 mm Hg (by lumbar manometry The idiopathic intracranial hypertension is performed after the CT or MRI exploration), defined by the clinical existence of the the cerebrospinal fluid has a normal intracranial hypertension syndrome, with very composition: normal or reduced cerebrospinal high ICP values and with a papillary edema in fluid proteins and normal cellularity, uncertain etiological conditions and due to - there are symptoms caused by the pathogenic mechanisms that are difficult to increased intracranial pressure: papillary establish. The term “associated factors” is used edema, cephalea, with the absence of the for the very diverse situations when the neurological location signs (the abducens idiopathic intracranial hypertension occurs, paresis is not a focal sign). without an etiopathogenic relationship. - the cerebral exploration using CT scan or The pathological conditions where the MRI reveals normal cranial-cerebral aspects, a idiopathic intracranial hypertension occurs ventricular system with reduced dimensions are numerous: may also be revealed (with a collapsed aspect) - metabolic and endocrine disorders: – without significance, or an empty sella; - if the global incidence of intracranial moreover, there is no clinical or neuro- hypertension is estimated at 1 - 2/100,000, in imagistic suspicion of an intracranial venous young and obese women the incidence of sinus thrombosis. idiopathic intracranial hypertension reaches These criteria limit the diagnosis of 19 - 25/100,000. idiopathic intracranial hypertension to - hypothyroidism, parathyroid anomalies, patients who have an increased cerebrospinal - hypovitaminosis A; anemia due to Fe fluid pressure without a noticeable etiology. deficiency; system illnesses – lupus Although it is not a diagnosis criteria, a eritematos; guiding element is the predominance of the - medicines: - nalidixic acid, tetracycline, feminine sex, with a women / men proportion vitamin A, lithium carbonate, etc., of approximately 2-8 / 1, with an interest in the In numerous cases, a possible association age groups 20 - 50 years old, and with the can be determined with various conditions maximum incidence in the third decade of age. that are pathogenically suggestive, with not [10, 11, 12, 13] etiological notification; but there are plenty of Various pathologic conditions can also be cases when no etio-pathogenic relation can be taken into account, when the idiopathic revealed. intracranial hypertension occurs more The pathogenic mechanisms are based on frequently: thus the global incidence of the the dynamics of the intracranial fluids, and idiopathic ICH is considered to be 1 - 2 cases / they correspond to the circuit of the fluids that 100,000 but, in the case of young and obese justify the increased pressure of the women, it has been noticed that the incidence cerebrospinal fluid and allow the maintenance

Romanian Neurosurgery (2015) XXIX 4: 397 - 409 405

DOI: 10.1515/romneu-2015-0055 of the cerebral circulatory auto-regulation The increased production of cerebrospinal with a normal nervous functioning. fluid at the level of the choroid plexuses, and The dynamics of the intracranial fluids in then with increased resorption, cannot explain the case of the idiopathic intracranial the brain edema and the pressure equilibrium hypertension can include several fluid circuits at the level of the nervous parenchyma – that concord to the brain edema and to the ventricular system. increased parenchymatous pressure, which is The brain edema occurs due to the impact equal to the increased pressure of the on the brain-blood barrier, generating an cerebrospinal fluid, concomitantly to the increased flux of interstitial fluid, with an maintenance of the cerebral sanguine increase in the intra-parenchymatous circulation, which may explain the good pressure. clinical condition: The maintenance of the cerebral sanguine - hyper-production of interstitial fluid with circulation within normal limits imposes the increased resorption at the level of the brain decrease in the parenchymatous pressure, blood barrier – which explains the increased which can be achieved through an increased parenchymatous pressure and the hyper- resorption of the interstitial fluid and / or by production of cerebrospinal fluid, which may the trans-ependyma passage in ventricles, and explain the increased pressure of the a trans-pial passage in the sub-arachnoid cerebrospinal fluid, with increased resorption space. The resulting increased quantity of at the level of the venous sinuses, as well as cerebrospinal fluid does not cause a intense and rapid exchanges from the ventricular dilatation because an increased interstitial fluid towards the cerebrospinal resorption occurs; the ventricular system is fluid at the level of the ventricular wall, trans- usually reduced in volume, which suggests the ependyma, and at the trans-cerebral pial level, fact that the trans-ependyma fluid circuit is which explains the pressure equilibrium predominant for the increase in the volume of between the cerebral parenchyma – ventricles, cerebrospinal fluid, compared to the with a rapid venous drainage; production at the level of the choroid plexuses. - hyper-production of cerebrospinal fluid, The increased resorption of the cerebrospinal increased resorption at the level of venous fluid corresponds quantitatively to the trans- sinuses with rapid venous drainage; ependyma exchange from the volume - hyper-production of interstitial fluid by increased interstitial fluid, ensuring the modification of the brain-blood barrier, intracranial circuit of fluids. normal production of cerebrospinal fluid, but The dynamics of the relations intracranial with increased exchanges from the interstitial pressure – intracranial volume is expressed by fluid towards the trans-ependyma the circulation of fluids, which allows the cerebrospinal fluid and at the trans-cerebral existence of an increased fluid pressure, pial level, with a rapid venous drainage. although this pressure does not act significantly on the endocranial structures and

406 Iencean et al Pseudotumour cerebri

on the cerebral circulation, which is allows the cerebral circulatory auto-regulation maintained within normal limits. when there is a progressive injury of the brain- The most probable pathogenic mechanism blood barrier, the interstitial fluid volume is the impacts on the brain blood barrier of the increases slowly and the brain edema is also hyper-production of interstitial fluid and an gradually installed. extracellular brain edema; the cerebrospinal The trans-ependyma and trans-pial circuit fluid is produced normally; there are increased of the interstitial fluid towards the exchanges from the interstitial fluid towards cerebrospinal fluid is the fundamental element the cerebrospinal fluid at the trans-ependyma for this compensating mechanism of pressure level and at the trans-cerebral pial level; an increase. increased resorption of the cerebrospinal fluid The increase in the intracranial pressure is is produced, and there is a rapid venous efflux. extremely slow, with a chronic aspect. This The trans-ependyma exchange between the very slow increase in the intracranial pressure interstitial fluid of the edema from the cerebral allows good pressure compensation and an parenchyma towards the cerebrospinal fluid, almost normal maintenance of the cerebral by means of which pressure is equalized, is sanguine flux. The pathogenic ICP values are followed by the increased resorption of the very high, of up to 60 - 80 mm Hg, values that cerebrospinal fluid, maintaining the cerebral may be maintained on a plateau for long circulation, and representing a compensating periods. mechanism. This mechanism is efficient and it

Figure 1 - Hydrodynamic model of pathogeny in idiopathic intracranial hypertension

Romanian Neurosurgery (2015) XXIX 4: 397 - 409 407

DOI: 10.1515/romneu-2015-0055

This pathogenic mechanism, which is dexamethasone, or diuretics (acetazolamide, based on the compensation of the fluid furosemide) in order to decrease the pressure increase by means of a gradual intracranial pressure. In some cases of obese accentuation of the trans-ependyma circuit patients, the weight loss is followed by an functioning and the trans-pial transfer of the obvious clinical improvement, and by the interstitial fluid towards the cerebrospinal progressive reduction of the papillary edema. fluid, explains: Moreover, repeated lumbar punctures and - the absence of hydrocephalus despite the lumbar-peritoneal shunting have been used increased pressure of the cerebrospinal fluid, with good clinical results. An approximate through increased fluid resorption, quantity of 30 ml CSF is evacuated by lumbar - the small dimensions of the ventricular puncture or the cerebrospinal fluid is drained system due to the initially increased pressure until the intracranial pressure, which is at the level of the nervous parenchyma, and measured by the lumbar method, is seen to subsequently balanced by the transfer of the have decreased to approximately half of the interstitial fluid towards the cerebrospinal initial value. The lumbar peritoneal shunting fluid, drains the excessive CSF and the - the good clinical condition due to the symptomatology disappears within less than a auto-regulation of the cerebral circulation, month; the shunting revising rate may reach to because the increased intracranial pressure has 50 %. In some cases of significant visual acuity a reduced action on the endocranial structures decrease, there has been an attempt to in the dynamic conditions of the rapid fluid decompress the optic nerve by performing circuit; fenestrations at the level of the optic nerve - the brain edema frequently exists due to sheath in order to produce a decrease of the the dysfunction of the brain blood barrier and papillary edema, but the results are not always to the existence of an increased quantity of favorable. interstitial fluid; at the same time, in some cases, the brain edema may be reduced or even Comparison between idiopathic ICH absent because the fluid transfer towards the and the vascular type of ICH cerebrospinal fluid is sufficiently rapid and The recent literature data and the the above intense for the brain edema not to be presentations allow the differentiation significant. between the vascular type of ICH and Treatment : the therapy is applied idiopathic ICH. The name hyperemic ICH has depending on the possible associated factors – been suggested but the designation of vascular metabolic and hormonal corrections, ICH covers the etiology and pathogenesis exclusion of certain medication, etc. A better and more completely. symptomatic treatment is applied for Although the symptoms may be similar in cephalea, and cerebral anti-edematous these two diseases, the imaging findings, substances are administered, such as therapy and evolution are different; therefore,

408 Iencean et al Pseudotumour cerebri

the etiology and pathogenesis are different. encephalopathy, there is a dilatation of brain Vascular ICH has a known etiology, such as arteries with increased arterial inflow, cerebral vascular illness whereas idiopathic increased vascular permeability, and ICH has no known etiology or has various disruption of the braineblood barrier; brain nonspecific factors associated factors (e.g., edema occurs as a result. metabolic and endocrine disorders, In conclusion, ICH caused by hypovitaminosis A, and medications). The intracranial vascular damage is vascular ICH imaging diagnosis for vascular ICH showed a and although it has clinical similarities to cerebral venous sinus thrombosis or stenosis idiopathic ICH, there are important or a cerebral venous thrombosis and either differences: vascular ICH has a known normal images or small ventricles in idiopathic etiology, such as cerebral vascular illness, and ICH. The imaging diagnosis of idiopathic ICH the increase in ICP is faster in vascular ICH, excludes other diseases with similar but the critical ICP values are lower compared symptoms. with idiopathic ICH. Vascular ICH involves vasogenic brain The therapy is etiologic, pathogenic and edema with papillary edema, whereas symptomatic in vascular ICH, but is only idiopathic ICH commonly involves papillary symptomatic in idiopathic ICH. edema and diminished visual acuity in some cases. There is also brain edema in idiopathic Correspondence ICH, but this appears to be balanced by the A.St. Iencean intraventricular pressure. The increase in ICP Neurosurgery, “N. Oblu” Emergency Hospital Iasi, is faster in vascular ICH compared with the Romania E-mail: [email protected] very slow ICP increase in idiopathic ICH, as demonstrated by the longer period until the References complete clinical syndrome has developed. In 1. Pearce JM. From pseudotumour cerebri to idiopathic addition, the ICP values are higher in intracranial hypertension. Pract Neurol 2009;9:353e6. idiopathic ICH. Therefore, the critical ICP 2. Johnston I. The historical development of the values are lower in vascular ICH until the pseudotumor concept. Neurosurg Focus 2001;11:1e9. decompensation of ICH. 3. Degnan AJ, Levy LM. Pseudotumor cerebri: brief review of clinical syndrome and imaging findings. AJNR The treatment is symptomatic, as well as Am J Neuroradiol 2011;32:1986e93. etiologic and pathogenic in vascular ICH but 4. Brazis PW. Pseudotumor cerebri. Curr Neurol only symptomatic in idiopathic ICH Neurosci Rep 2004;4:111e6. (including a lumboperitoneal shunt or 5. Sylaja PN, Ahsan Moosa NV, Radhakrishnan K, decompression of the optic nerve). Sankara Sarma P, Pradeep Kumar S. Differential diagnosis of patients with intracranial sinus venous Vascular ICH may potentially include thrombosis-related isolated intracranial hypertension other syndromes, such as hypertensive from those with idiopathic intracranial hypertension. J encephalopathy, but this classification Neurol Sci 2003;215:9e12. requires further study. In hypertensive

Romanian Neurosurgery (2015) XXIX 4: 397 - 409 409

DOI: 10.1515/romneu-2015-0055

6. Friedman DI, Jacobson DM. Diagnostic criteria for 12. Suzuki H, Takanashi J, Kobayashi K, Nagasawa K, idiopathic intracranial hypertension. Neurology Tashima K,Kohno Y. MR imaging of idiopathic 2002;59:1492e5. intracranial hypertension. Am J Neuroradiol 7. Wall M. Idiopathic intracranial hypertension. Neurol 2001;22:196e9. Clin 2010; 28:593e617. 13. Hoffmann J, Huppertz HJ, Schmidt C, Kunte H, 8. Digre KB, Nakamoto BK, Warner JE, Langeberg WJ, Harms L, Klingebiel R, et al. Morphometric and Baggaley SK, Katz BJ. A comparison of idiopathic volumetric MRI changes in idiopathic intracranial intracranial hypertension with and without papilledema. hypertension. Cephalalgia 2013;33: 1075e84. Headache 2009;49:185e93. 14. Iencean SM. Simultaneous hypersecretion of CSF and 9. Biousse V, Bruce BB, Newman NJ. Update on the of brain interstitial fluid causes idiopathic intracranial pathophysiology and management of idiopathic hypertension.Med Hypotheses 2003;61:529e32. intracranial hypertension. J Neurol Neurosurg Psychiatry 15. Iencean StM, AV Ciurea Intracranial hypertension: 2012;83:488e94. classification and patterns of evolution J Med Life. 2008 10. Friedman DI, Liu GT, Digre KB. Revised diagnostic Apr 15; 1(2): 101–107. criteria for the pseudotumor cerebri syndrome in adults 16. Iencean SM, Poeata I, Iencean AS, Tascu A Cerebral and children. Neurology 2013;81:1159e65. venous etiology of intracranial hypertension and 11. Leker RR, Steiner I. Features of dural sinus thrombosis differentiation from idiopathic intracranial hypertension. simulating pseudotumor cerebri. Eur J Neurol Kaohsiung J Med Sci. 2015 Mar;31(3):156-62. doi: 1999;6:601e4. 10.1016/j.kjms.2014.12.007.