Idiopathic Intracranial Hypertension

Idiopathic intracranial hypertension occurred after spinal surgery: report of two rare cases and systematic review of the literature

BACKGROUND

Idiopathic intracranial hypertension (IIH) is a relatively rare syndrome of increased intracranial pressure of unknown etiology. It is characterized by cerebrospinal fluid (CSF) opening pressure more than 250 mmH₂O, with normal cranial imaging and CSF content. IIH occurred after spinal surgery is extremely rare.

METHODS

We present two IIH cases occurred after spinal surgery and conduct a systematic review of articles reporting IIH occurred after spinal surgery.

RESULTS

The first patient underwent a posterior decompression and fixation for cervical fractures. IIH symptoms appeared 3 days postoperatively and gradually resolved with appropriate medication. The second patient underwent posterior spinal fusion with segmental instrumentation for congenital scoliosis. IIH symptoms appeared 5 days postoperatively and the patient died due to the irreversible intracranial hypertension although underwent intensive care and treatment. The literature review revealed that there were only five cases of IIH occurred after spinal surgery reported till date.

CONCLUSIONS

IIH occurred after spinal surgery is relatively rare; the diagnosis is based upon exclusion of other diseases. IIH should be kept in mind in patients underwent spinal surgery as it could develop into irreversible intracranial hypertension.

Bariatric surgery for the treatment of idiopathic intracranial hypertension

Object

The purpose of this study was to review the literature on the effectiveness of bariatric surgery for obese patients with idiopathic intracranial hypertension (IIH) with regard to both symptom resolution and resolution of visual deficits.

Methods

The published literature was reviewed using manual and electronic search techniques. Data from each relevant manuscript were gathered, analyzed, and compared. These included demographic data, pre- and postoperative symptoms, pre- and postoperative visual field deficits, bariatric procedure type, absolute weight loss, changes in body mass index, and changes in CSF opening pressure.

Results

Eleven relevant publications (including 6 individual case reports) were found, reporting on a total of 62 patients. The Roux-en-Y gastric bypass was the most common bariatric procedure performed. Fifty-six (92%) of 61 patients with recorded postoperative clinical history had resolution of their presenting IIH symptoms following bariatric surgery. Thirty-four (97%) of 35 patients who had undergone pre- and postoperative funduscopy were found to have resolution of papilledema postoperatively. Eleven (92%) of 12 patients who had undergone pre- and postoperative formal visual field testing had complete or nearly complete resolution of visual field deficits, and the remaining patient had stabilization of previously progressive vision loss. In 13 patients both pre- and postoperative CSF pressures were recorded, with an average postoperative pressure decrease of 254 mm H2O. Changes in weight loss and body mass index varied depending on the reported postoperative follow-up interval.

Conclusions

The published Class IV evidence suggests that bariatric surgery may be an effective treatment for IIH in obese patients, both in terms of symptom resolution and visual outcome. Prospective, controlled studies are necessary for better elucidation of its role.

Idiopathic intracranial hypertension and facial palsy: case report and review of the literature

We present the case of an 11-year-old obese girl who presented with idiopathic intracranial hypertension affecting first the lateral abducens nerve. She received acetazolamide, but 5 days later she developed lateral, peripheral facial palsy. Imaging evaluation was normal, which primarily excluded cerebral venous thrombosis and sustained the initial diagnosis. Despite some complicating factors (obesity, elevated intracranial pressure), prednisolone was administered for a short-term period to counteract the facial palsy. Ophthalmological residuals resolved within almost 1.5 months, while facial palsy receded after 4 months. Peripheral facial palsy is an extremely rare, but not unknown condition in idiopathic intracranial hypertension. As a symptom, it should be investigated thoroughly, primarily to exclude cerebral venous sinus thrombosis, before it can be attributed to idiopathic intracranial hypertension. As far as treatment is concerned, corticosteroids can be added to the initial treatment with acetazolamide, without worsening already elevated intracranial hypertension or ophthalmologic findings.

Endoscopic free electron laser technique development for minimally invasive optic nerve sheath fenestration

PURPOSE

This study proposed to develop a technique for efficiently accessing the posterior orbital space using endoscopy and attempted application of free electron laser (FEL) energy, biopsy forceps, electrocautery, and CO(2) insufflation to posterior orbital tissues.

METHODS

Through an inferior transconjunctival incision, access to the posterior orbital space was attempted in 14 eyes of 7 non-survival pigs. FEL energy (6.1 microm, 30 Hz, delivered via 250 microm hollow-glass waveguide), biopsy forceps, and monopolar electrocautery application were endoscopically attempted in the posterior orbit. CO(2) gas insufflation effects were assessed by analyzing arterial blood gases at 30-minute intervals for 1.5 hours.

RESULTS

The posterior orbit was accessed in 13 of 14 eyes, the optic nerve was encountered, and FEL energy was applied in 8 of 14 eyes. Use of biopsy forceps and electrocautery were successful. Although ANOVA results for arterial blood gas changes were not statistically significant, visibility was adequate without CO(2) insufflation.

CONCLUSIONS

The posterior orbit was endoscopically accessed and the optic nerve was exposed and successfully treated with FEL energy. CO(2) insufflation did not alter blood gases, but did not further enhance visibility in this study.

Changes in weight, papilledema, headache, visual field, and life status in response to diet and metformin in women with idiopathic intracranial hypertension with and without concurrent polycystic ovary syndrome or hyperinsulinemia

The authors hypothesized that a metformin (MET)-diet would improve symptoms of idiopathic intracranial hypertension (IIH) in women who also had polycystic ovary syndrome (PCOS) or hyperinsulinemia without PCOS. Changes in weight, papilledema, headache, visual fields, and overall life status were prospectively assessed in response to 6 to 14 months on 2.25 g/day MET-diet or diet alone in 36 women with IIH, 23 with PCOS, selected by baseline body mass index (BMI) > or = 25, and no previous surgery for IIH. Overall life status was graded using a self-reported 1-5 scale (1 = well, normal activities; 2 = unwell, usual activities; 3 = poor, usual activities; 4 = poor, no usual activities; 5 = totally disabled). Conventional treatment for IIH was maintained unchanged during MET-diet intervention. The diet was hypocaloric (1500 calories/day), high protein (26% of calories), and low carbohydrate (44%). Of the 23 women with PCOS, 20 received MET-diet and 3 diet only (could not tolerate MET). Of the 13 women without PCOS, 7 were hyperinsulinemic and received MET-diet and 6 received diet alone. The 3 treatment groups (diet only [n = 9], PCOS-MET-diet [n = 20], and hyperinsulinemia-MET-diet [n = 7]) did not differ by median entry BMI (33.3, 37.6, and 35.7 kg/m(2)) or by duration of treatment (10.2, 11.4, and 10.9 months). Median percent weight loss was greatest in the PCOS-MET group (7.7%, P = 0.0015), was 3.3% in the diet only group, and 2.4% (P = 0.04) in the hyperinsulinemia-MET group. Papilledema significantly improved in the diet-alone group from 100% at baseline to 13% (P = 0.03), and in the PCOS-MET group from 95% to 30% (P = 0.002). If headache persisted on therapy, it was less intense-less frequent (P = 0.03) in the diet-only group and in the PCOS-MET group (P = 0.04). As many women with IIH have PCOS, and because weight loss is central to IIH treatment, diet-MET is a novel approach to treat IIH in women with concurrent PCOS or hyperinsulinemia without PCOS.

Optic nerve sheath fenestration with endoscopic accessory instruments versus the free electron laser (FEL)

BACKGROUND AND OBJECTIVE

The free electron laser (FEL) can efficiently produce an optic nerve sheath fenestration using an endoscopic approach. To develop a surgical protocol, this study compared effectiveness of available accessory endoscopic instruments to endoscopic FEL delivery effectiveness in producing optic nerve sheath fenestrations.

STUDY DESIGN/MATERIALS AND METHODS

An endoscope was used to perform optic nerve sheath fenestrations on goat optic nerves. Accessory endoscopic instruments and glass-hollow waveguides (250 and 320 microm in diameter) were inserted into the instrument channel for comparison. FEL energy (6.45 microm, 30 Hz) was delivered to the tissue through the waveguides and histological analysis was performed.

RESULTS

The endoscopic instruments alone were unable to incise the optic nerve sheath. The FEL successfully incised the sheath and the biopsy forceps extricated the circular flap.

CONCLUSIONS

Endoscopic optic nerve sheath fenestration using FEL energy followed by biopsy forceps for sheath extrication produced good results, thereby creating a feasible protocol for optic nerve sheath fenestration.