Hypertension intra-cranienne benigne

ABSTRACT

Benign intracranial hypertension [BICH]. We have accepted 3 criteries to define the BICH - Existence of an ICH clinical syndrome.- Existence of a high I.C.P. - Absence of clinical ICH etiologies that would wate known physiopthological mechanisms such as a neovolume, brain oedema or hydrocephalus. A study of 35 observations meeting this definition has allowed us to conclude that the BICH hes become more and more frequent in neurosurgical practice [6% of the total ICH in general and 7% of secondary ICH with an expansive intracranial development]. It is a disease that is to be found more frequently within young and obese women [4 women for 3 men, 22 years old, 71 kg for 1 m 61 in average for women]. Reasons for this disease are multiple and variable. They can be divided in 2 groups * A group of patients with antecedents of which the cause-effect relationship seems to be arguable Among these * 17 patients of our study, had in their antecedents a cranio-facial pathology with 6 quiet important head injuries, 8 O.R.L. diseases with 2 M.C.O.; 2 ophtalmological fits and a meningitis going back to childhood. * 4 patients had obstetrical and endocrinal antecedents, a thyroidal goitre, a dysmenorrhoea, a repeating gravidic toximia and recurring abortions. - Within 27 patients of our study we have noticed antecedents due to use of drugs, among them solycil [4 times], cyclines [Twin], penicillin [5 times], corticoids [6 times], contraceptive pills [twin] and A vitamin [once] without nevertheless being able to incriminate one of these factors in the BICH genesis. * 11 patients of our study have directly accused some decompensating factors which were immediately followed by the appearance of BICH symptoms that is how we have noticed amomg the triggering causes, 5 BEHCET diseases, 4 pregnancies, a head injury, tonsilitis treated with G penicillin, and a salpingitis treated with the Bactrim. The BICH symptomatology is one of an ICH without any localization signs associating a visual symptomatology of which the papilledema is one of the constant elements. Subjective visual troubles have been reported by the majority of our patients in the form of a decline in the visual acuity, a diplopia [11 cases], unsharp vision episodes [9 cases], transitory amaurosis [3 times]; and photophobia [3 times]. Four patients have reported having ear-humming and 8 others troubles in standing up and walking. The ophthalmological attack is the most important element in the objective symptomatology. This needs a particular attention as it determines the pronosis. The drop in the visual acuity from the very first test has been detected 24 times out of 33; 12 patients were unfortunately blind, seven had a very altered visual acuity [1/10 to 4/10], 5 an altered visual acuity [5/10 to 7/10] and only 9 had a normal visual acuity on their admission; out of the 14 indicating a carried out visual fields; 9 had campimetric defects extending from the simple expansion of the blind sport [6 times], to the global contraction of the isopters [1 case], to a systematized amputation evoking a bitemporal hemianopsia [1 case] or even a reduction of the visual field to a simple islet of central vision. The C.S.F. study appears mostly normal. Albumin rate was superior to 0,60 g/l in 6 cases but has never exceeded 1 g/l, Cytology has been in all cases inferior to 10 BE/mm3. Always systematically carried out and analysed, simple brain X-rays have shown ICH signs in 10 cases [28%] such as sutures disjunctions [7 times], finger-like impressions [5 times] and small modifications of the sella turcica [3 times]. The angiography have been carried out 32 times out of 35. The phlebographical times have clearly indicated a pathology of the intracranial veinous sinuses within 12 patients. It was either a size reduction, or a bad visualization, or an absence of injection of one or several of the sinuses. The pneumencephalography, ventriculography and the T.A.C. have been carried out in 31 cases. To measure the ventricular volume we have used the EVANS ratio whose normal volumes are in between 0,25 and 0,34 [24 cases]. 3 patients have shown a slight increase of the ventricular size and in 4 others, ventricles were inferior to the normal. In two cases, we have noticed the aspect of an empty sella on the T.A.C. The continuous recording of the ICP has allowed us to confirm the ICH in all cases. The average pressure in our study varied from 15 to 61 cm H20. 23 patients had an average ICP between 25 and 50 cm H20. We have had recourse to 3 symptomatic and therapeutic methods: - The brain anti-edema treatment [used in 27 cases] with in order of frequency in the use of corticoides [in 77%], the osmotherapy [17%] and the diuretics [14%]. - The repeated substractions of the C.S.F. have been carried out in all cases with an average number of 4 substractions per patient. - The external derivations of C.S.F. have been carried out with 14 patients of our study among which 2 have become complicated by a thrombosis of the superior vena cava on atrial catheter, in two cases, it was ICH on BEHCET diseases. The total follow up of the B.I.C.H. usually happens towards the clinical and manometric stabilisation in a delay going from 1 month to two years and a half after one or several attacks, The fonctional signs disappear first, after a general 4 months evolution, that is about 1 month before the normalization of the ICP [average time of evolution = 5 months]. The ophtalmological signs are the last to disapear 6 months and a half in general after the manometric remission. However few observations are to be stated as far as the stabilization of the BICH is concerned. 1 - From the manometric point of view, 4 patients in our study have remained with a quite high I.C.P. [20 cm H20] in spite of the clinical and ophthalmological remissin. These 4 patients are in fact still in danger of falling into hypertensive fits on the smallest triggering factor. 2 - 6 patients of our study [18%] have had a relapse from their BICH and this in a delay of evolution which didn't exceed one year. 3 - If the majority of our patients have positively followed up, in particular on the ophthalmological level, thanks to an adequate and timely treatment; this has not unfortunately prevented an after - effect atrophy within 11 patients among whom 7 [20%] have kept their initial blindness. This leads.us to wonder about the qualificative " benign " associated with this type of ICH specially that 2 other patients of our study have been hospitalized and treated in emergency in a pre-engagement state. In the last chapter we have reported 4 physiopathogenic hypothesis classicaly accepted a trouble in the resorption of the C.S.F., increase of the blood brain volume, cerebral edema, increase in the secretion of C.S.F. It seems that these 4 factors have an inter relationship with each other to give birth to the B.I.C.H. but the trouble in the resorption of C.S.F. appears to be the most important factor. A better knowledge of the physiopathogenic phenomena in the genesis of this disease should allow for a better knowledge of this disease and thus to foresee a better codified therapeutic approach: