Idiopathic Intracranial Hypertension in the Young Obese Female Patient

1. Idiopathic Intracranial Hypertension in the Young Obese Female Patient With Adult Chiari Malformation Nataliya Yakovleva M.D. Department of Medicine, Good Samaritan Hospital, Baltimore, MD INTRODUCTION: Idiopathic Intracranial Hypertension refers to increased intracranial pressure (ICP) with normal cerebrospinal fluid content. Neuro-imaging can be normal, or show dilated ventricles. Physical examination can reveal signs of cranial nerve VI palsy and the risk of visual loss. DIFFERENTIAL DIAGNOSIS OF SECONDARY CAUSES OF PSEUDOTUMOR CEREBRI HISTORY: A 25 year old African- American female without significant past medical history presented with recurring headaches over the past year. There is no past history of headaches. She was seen in the Emergency Department for this headache and new onset of double vision. The patient was referred to an ophthalmologist for evaluation. Dilated retinal examination revealed papilledema, and she was admitted for further evaluation. PHYSICAL EXAM: There was double vision on upward gaze. The remainder of the examination was benign. Figure 1. MRI of the brain, saggital view. Arrow indicates Arnold-Chiari Malformation. LAB AND IMAGING STUDIES: Routine laboratory studies, including blood cell count, chemistry, and urinalysis were normal. Pregnancy test was negative. MRI scan of the brain showed mild degree of Arnold-Chiari malformation. HOSPITAL COURSE: Patient was started on acetazolamide, which did not help her headaches. The lumbar puncture (LP) opening pressure was 40 cm H20, which decreased with repeated LP’s. Because of severe metabolic acidosis, it was decided that the acetazolamide would not be a potential long-term treatment. Therefore, the patient underwent ventriculoperitoneal shunt placement, which relieved her headaches and resolved her symptoms of diplopia. • Referrences: • 1: Expert Rev Neurother. 2008 Mar;8(3):397-407. Pseudotumor cerebri presenting as headache.Friedman DI. • 2: Neurology. 2008 Feb 19;70(8):641-7. Endovascular treatment of idiopathic intracranial hypertension: clinical and radiologic outcome of 10 consecutive patients.Donnet A, Metellus P, Levrier O, Mekkaoui C, Fuentes S, Dufour H, Conrath J, Grisoli F. • 3: Adv Tech Stand Neurosurg. 1998;24:261-305. Links,Benign intracranial hypertension. Pseudotumour cerebri: idiopathic intracranial hypertension.Sussman JD, Sarkies N, Pickard JD. • 4:Current Diagnosis & Treatment: Emergency Medicine, 6th EdIdiopathic Intracranial Hypertension (Pseudotumor Cerebri)Sections: Essentials of Diagnosis, Clinical Findings, Treatment & Disposition • 5:Skau M et al. What is new about idiopathic intracranial hypertenn? An updated review of mechanism and treatment. Cephalalgia. 2006 Apr;26(4):384-99. [PMID: 16556239] DISCUSSION: When a secondary cause is not identified, the condition is classified as “idiopathic intracranial hypertension.” There are significant similarities between the Adult Chiari Malformation (ACM) and Idiopathic Intracranial Hypertension (IIH). They include similar demographics, clinical presentation, and response to treatment. There is an eightfold increase in the incidence of significant tonsillar herniation in patients with IIH. The craniocephalic disproportion will occasionally lead to tonsillar ectopia and alteration of the brain compliance, ultimately leading to symptomatology similar to our patient’s case. Figure 2. CT of the brain, axial view. Arrows indicate VP shunt. CONCLUSION: Idiopathic intracranial hypertension is a diagnosis of exclusion. It is important to rule out other causes of increased ICP because the treatment modalities are different in all cases.