Hypertension intracrânienne bénigne : place du traitement médical

[Idiopathic intracranial hypertension: a rare case related to pregnancy]

We report the case of a 25-year old primipara whose pregnancy was complicated by idiopathic intracranial hypertension (ICHT) associated with visual impairment in the first quarter. She underwent lumboperitoneal shunt without obstetric consequences. This study aimed to determine the features of this rare pathological entity whose pathophysiological mechanism is poorly elucidated. It would be caused by poor absorption of cerebrospinal fluid (CSF) through the arachnoid granulations. Major risk factors are: obesity, polycystic ovary syndrome, thrombophilia and hyperfibrinolyse. Diagnosis is based on modified Dandy criteria after negative clinico-biological and radiological assessment. Visual prognosis is compromised, as in the case of « classical » ICHT. However, there is no risk for cerebral involvements which could be life-threatening. In addition, this disease does not influence pregnancy outcome. This said, rapid and effective treatment should be implemented in order to preserve visual function in these patients.

Uncommon Presentation of Idiopathic Intracranial Hypertension in a Patient with Polycystic Ovary Syndrome: A Case Report

INTRODUCTION

Idiopathic intracranial hypertension is a rare condition characterized by increased intracranial pressure without clinical, laboratory, or radiological evidence of intracranial pathology. Early management could prevent irreversible outcomes.

CASE PRESENTATION

A 17-year-old single Arabian female of Arab origin presented with a 2-day complaint of horizontal diplopia and transient visual obscurations. She denied any history of headache or decreased vision. The patient was diagnosed with polycystic ovary syndrome a year prior to presentation. Examination revealed bilateral moderate papilledema and limited left eye abduction. However, visual acuity and fields were normal. Increased intracranial pressure was confirmed by lumbar puncture opening pressure (550 mm H<Sub>2</Sub>O). The cerebrospinal fluid composition and imaging of brain and cerebral venous system were normal. The diagnosis of idiopathic intracranial hypertension was confirmed and the patient was treated with acetazolamide 500 mg twice per day. The symptoms totally resolved within 3 days and the papilledema disappeared after 2 months.

CONCLUSION

Awareness of such uncommon presentation of idiopathic intracranial hypertension emphasizes the critical importance of detailed ophthalmic examination and shows the good prognosis of early management.

Idiopathic intracranial hypertension: case report

Idiopathic intracranial hypertension - IIH (synonymous old terms: benign intracranial hypertension - BIH, pseudotumor-cerebri - PTC) it’s a syndrome, related to elevated intracranial pressure, of unknown cause, sometimes cerebral emergency, occuring in all age groups, especially in children and young obese womans, in the absence of an underlying expansive intracranial lesion, despite extensive investigations. Although initial symptoms can resolve, IIH displays a high risk of recurrence several months or years later, even if initial symptoms resolved. Results: A 20-year-old male, obese since two years (body mass index 30, 9), was admitted for three months intense headache, vomiting, diplopia, progressive visual acuity loss. Neurologic examination confirmed diplopia by left abducens nerve palsy, papilledema right > left. At admission, cerebral CT scan and cerebral MRI with angio MRI 3DTOF and 2D venous TOF was normal. Despite treatment with acetazolamide (Diamox), corticosteroid, antidepressants (Amitriptyline), anticonvulsivants (Topiramate) three weeks later headache, diplopia persist and vision become worse, confirmed by visual field assessment, visual evoked potential (VEP). A cerebral arteriography demonstrate filling defect of the superior sagittal sinus in the 1/3 proximal part and very week filling of the transverse right sinus on venous time. Trombophylic profile has revealed a heterozygote V factor Leyden mutation, a homozygote MTHFR and PAI mutation justifying an anticoagulant treatment initiated to the patient. The MRI showed a superior sagittal sinus, right transverse and sigmoid sinus thrombosis, dilatation and buckling of the optic nerve sheaths with increased perineural fluid especially retrobulbar, discrete flattening of the posterior segment of the eyeballs, spinal MRI showed posterior epidural space with dilated venous branches, with mass effect on the spinal cord, that occurs pushed anterior on sagittal T1/T2 sequences cervical and thoracic. The opening pression of lumbar puncture, done with the patient in the lateral decubitus position, was 60 cm H2O, the cytochemical CSF study were normal. The patient was operated: a lombo-peritoneal with a variable pressure valve was inserted. Two months after the patient general condition improved: he was without headache, abducens palsy and the visual field assessment, ocular motility examination, ophthalmoscopy were normal. Conclusion: IHH is rare, variable in evolution, and in many cases it disappears on its own within 6 months without affecting life expectancy. Weight loss, fluid or salt restriction, in conjunction with medical treatment, angioplasty and venous stenting across the sinus stenosis under general anesthesia and surgical treatment (shunting, optic nerve sheath decompression and fenestration, gastric by-pass surgery) are treatment alternatives. Such disorder should be closed monitored because 10 to 25% of cases could be affected by recurrencies or by permanent vision loss to those patients with resistant papilledema despite treatment.

Weight-reducing side effects of the antiepileptic agents topiramate and zonisamide

Drug-induced weight alteration can be a serious side effect that applies to several therapeutic agents and must be referred to in the respective approved labeling texts. The side effect may become health threatening in case of significant weight change in either direction. Several antiepileptic drugs (AEDs) are associated with weight gain such as gabapentin, pregabalin, valproic acid, and vigabatrin and to some extent carbamazepine. Others are weight neutral such as lamotrigine, levetiracetam, and phenytoin or associated with slight weight loss as, e.g., felbamate. The focus of this chapter is on the two AEDs causing strong weight loss: topiramate and zonisamide. For both drugs, several molecular mechanisms of actions are published. We provide a review of these potential mechanisms, some of which are based on in vivo studies in animal models for obesity, and of clinical studies exploring these two drugs as single entities or in combinations with other agents.

[Treatment and prognosis of idiopathic intracranial hypertension in children. Retrospective study (1995-2009) and literature review]

AIM

Idiopathic intracranial hypertension (IIH) may cause severe visual loss due to the optic nerve damage. Routine management involves mainly medical treatment. The aim of this study was to improve diagnosis and management of IIH in children.

METHODS

The medical records of all patients with definite IIH seen at the children's hospital of Toulouse between 1995 and 2009 were reviewed. Cases of secondary intracranial hypertension were included because they did not present any cerebral lesions and underwent a similar therapeutic approach. The clinical and ophthalmological data at the beginning and at the end of their treatment was collected.

RESULTS

Eighteen children were included in this study. The average age was 10 years and the sex-ratio was equal to 1. There were 3 cases of secondary idiopathic intracranial hypertension in this pediatric group. The main features encountered were headache (15 children) and diplopia (8 children). Abnormal neurological examination was found for 11 patients with abducens nerve paresis in 8 cases, rachialgia in 6 cases, and neurogenic pains (neuralgia, dysesthesia, paresthesia, hyperesthesia) in the other cases. Papilledema was noted in 16 patients. At the initial phase, loss of visual acuity was documented in 6 patients and altered visual field in nine patients. All patients had a medical treatment. When recurrence occurred, each new treatment was documented, for a total of 23 treatments analyzed. Lumbar puncture was the only treatment for 2 patients. In 16 cases, first-line treatment was acetazolamide and it was the second choice in 1 case, with an average dosage of 11.2mg/kg and a mean duration of 2.5 months (15 treatments could be analyzed). This treatment was effective in 11 cases out of 15. Steroids were the initial treatment in 4 cases and second-line treatment in 4 cases (after failed acetazolamide therapy). The dosage was 1.5-2mg/kg for a mean duration of 1.5 months (6 treatments could be analyzed). This treatment was effective in 5 patients out of 6. One patient had dual therapy. No surgical procedure was necessary in this pediatric cohort. Three patients presented relapses of IIH. The outcome was good with no residual visual impairment in the 13 patients analyzed. One patient was still under medication.

COMMENTS

Therapeutic management of IIH in a pediatric population is essentially medical, in some cases limited to lumbar puncture. The first-line treatment is acetazolamide, but this study shows that low doses and short duration are usually chosen. Doses must be increased and treatment prolonged to avoid the use of corticosteroids as a second-line treatment and prevent possible relapses that require close monitoring of visual function.

CONCLUSION

The visual prognosis is generally better for this age group compared to adults and no risk factors for visual sequelae were identified. A standardized protocol for management of IIH was proposed.