ABSTRACT

CORRESPONDING AUTHOR:
Dr. Basavaraju M. M,
No. 16, 24th Block,
Manasinagara, Hanchya Layout,
Mysore-570029.
Email: basavarajumm@gmail.com

ABSTRACT: BACKGROUND AND OBJECTIVES:IIH is a disease characterized by raised intracranial pressure without ventricular enlargement or intracranial mass on imaging, with normal cerebrospinal fluid constituents. Objective of the study was to study the clinical profile of patients who fulfilled the criteria for IIH admitted at MMC&RI, Mysore. METHOD AND RESULTS: 20 subjects who fulfilled the Modified Dandy’s criteria for IIH underwent detailed neurological evaluation and papilledema was reconfirmed by the ophthalmologist and were subjected to necessary neuroimaging and then underwent lumbar puncture and CSF opening pressure was measured. After the diagnosis, patients were started on adequate doses of mannitol and acetazolamide. Patients were followed regularly for dose titration of acetazolamide. In our study most subjects were in the age of 3^rd or 4^th decade and 80% of the subjects were women. 15% of patients were obese. 50% of subjects had lateral rectus palsy. Mean CSF pressure was 282mm of water. In our study 95% of the patients improved with medications and only 1 patient had to undergo shunting. CONCLUSION: Idiopathic Intracranial Hypertension (IIH) is a disease more common in obese women of 3^rd and 4^th decade, is a potentially reversible cause of vision loss, calls for more alertness and a responsible approach towards patients presenting with headache, more so when it is an obese woman in her 3^rd /4^th decade.

KEYWORDS: Idiopathic intracranial hypertension, papilledema.

INTRODUCTION: Idiopathic intracranial hypertension (IIH) was first described by Quincke under the name ‘meningitis serosa’ in 1897.¹ IIH is a disease characterized by raised intracranial pressure without ventricular enlargement or intracranial mass on imaging, with normal cerebrospinal fluid constituents. It often presents with headaches, and is usually associated with bilateral papilledema and may have sixth cranial nerve palsy as a false localizing sign.² Patients are usually young obese females presenting with headache, sub-acute to chronic progressive blurring of vision, diplopia. Radha Krishnan et al found incidence of 19-21 per 1, 00, 000 among adolescent females as compared to an incidence of 1-2 per 1, 00, 000 in general population.³

The disease is defined by modified Dandy’s criteria⁴:

• Symptoms and signs of raised ICP in an awake and alert patient.
• No localising signs, other than unilateral or bilateral sixth cranial nerve paresis
• CSF opening pressure of ≥250 mm of water for obese and >200 for non-obese, but a normal composition of CSF.
• No evidence of hydrocephalus, mass lesion or intracranial sinus-venous thrombosis on MRI and MRV
• Every other cause of intracranial hypertension excluded.

OBJECTIVE OF THE STUDY: To study the clinical profile of patients who fulfilled the modified Dandy’s criteria for IIH admitted under neurology and medical wards at MMC&RI.

MATERIALS AND METHODS: A prospective clinical case study was undertaken in patients who presented with headache and features of increased intracranial pressure between February 2011 and January 2012. Among those patients, 20 subjects fulfilled the Modified Dandy’s criteria for IIH were included in the study.

All patients underwent detailed neurological evaluation and papilledema was reconfirmed by the ophthalmologist. Blind spot mapping at the time of evaluation was done in all the patients by our ophthalmologist. Lumbar puncture procedure was done following the standard protocol in all the patients.

CSF opening pressure was measured using Central Venous Pressure manometer, which was attached to the Lumbar Puncture needle after the removal of the stylet (figure 1A&B). Cut off of 200mm of water was fixed as raised Intracranial Pressure. All patients were subjected for neuroimaging, either CT scan of head (plain and contrast enhanced) or MRI of brain (gadolinium enhanced and MRV was done whenever it was needed). Routine blood biochemistry, thyroid function tests, complete hemogram was done in all subjects.

Fig. 1A

Fig. 1B

RESULTS:

Fig. 2

Fig. 3: Age wise distribution

Fig. 4: Lateral rectus palsy

Fig. 5: CSF opening pressure

MANAGEMENT: After the diagnosis of idiopathic intracranial hypertension was made, patients were started on adequate dose of mannitol for duration of 10-14 days, along with acetazolamide. Upon improvement, patients were discharged on adequate dose of acetazolamide and were asked to be on regular follow up for further titration of doses and to watch for relapse. Patients who did not respond to this standard line of medical management were advised ventriculo-peritoneal shunt.

Fig.  6

DISCUSSION: In our study most subjects were in the age of 3^rd or 4^th decade and 80% of the subjects were women similar to the study done by Ambika et al where the mean age was 32.8yrs and also 80% of patients in were women.⁵ Many previous studies have shown significant association between obesity and IIH. In the study done by Mitchell et al 94% of the patients with IIH were obese.⁶ In our study only 15% of patients were obese.

Fig.  7

Only false localizing signs of abducens palsy are acceptable as far as IIH diagnosis is concerned, presence of other localizing signs should prompt search for other causes of raised intracranial pressure. In our study only abducens palsy, no cases of 3^rd nerve, seventh nerve palsy or torticollis were reported. Though, these findings were reported in some case studies.

Study done by Ambika et al showed that in most of the patients CSF opening pressure is between 250-300 mm of water.⁵ In our study we had a mean CSF pressure of 282mm of water.

Many Indian studies like the one by NN Baheti et al, said that there was no much association between CSF opening pressure and clinical course/visual outcome.⁷ We found higher CSF pressure among patients with significant visual symptoms as well as signs, similar to Bruce et al study.⁸

Discussion: Management: In our study, we had very good outcome with medical line of management compared to the study done by Ambika et al where 30% of the patients failed to improve with medications.⁵ In our study 95% of the patients improved with medications and only 1 patient had to undergo shunting. Fulminant IIH, where papilledema rapidly progresses than usually seen, warrants surgical line of management.

CONCLUSION: Idiopathic Intracranial Hypertension (IIH) is a disease more common in obese women of 3^rd and 4^th decade, is a potentially reversible cause of vision loss, calls for more alertness and a responsible approach towards patients presenting with headache, more so when it is an obese woman in her 3^rd /4^th decade. Delay may cost patient her/his eyesight.

As vital is the stethoscope for cough, so is Ophthalmoscope for headache.

REFERENCES:

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