Can Benign Increased Intracranial Pressure cause Unilateral Papilledema? – A Case Report

Benign Increased Intracranial Pressure: also called Idiopathic intracranial hypertension or Pseudotumor Cerebri is a condition in which there is elevation of cerebrospinal fluid pressure with unknown aetiology (so, idiopathic). This disorder usually affects women in childbearing period. With this disorder, there is No diagnosed exact pathology causing this problem. There are also no abnormalities in CSF pathways within the ventricles. Neuro-radiological diagnostic studies are also normal except those denoting high cerebrospinal fluid pressure. Also, there is no evidence of other secondary causes of increased intracranial pressure can be detected. We present a case of benign increased intracranial pressure in a young obese female presented with Unilateral papilledema and sudden unilateral deterioration of vision.


Introduction
Benign Increased intracranial pressure usually presents with bilateral papilledema. However, presenting by unilateral or highly asymmetric papilledema is a rare occurrence. Occurrence of this rare presentation may mislead treating physicians away from reaching the proper diagnosis and early help of patients to save their vision. The most common causes of Unilateral papilledema are local causes of the optic nerve or intraocular pathology.

Case Report
Female pt, 30 ys old, obese with body mass index 32. 6, not It usually occurs in obese females in childbearing age period [2].

There is No clear etiology of benign increased intracranial pressure.
However, it may occur due to alteration in one or more of the following: intrasagittal sinus pressure, decreased absorption of CSF by arachnoid villi, increased rate of CSF production, and compliance of CSF space. Occurrence in obese young women may be caused partially by raised CSF production [3][4][5]. Symptoms of intracranial hypertension include headache, pulsatile tinnitus, amaurosis fugax (brief loss of vision or blackouts) and loss of vision. Signs of intracranial hypertension include Diplopia if there is abducent nerve palsy or paresis, swelling of optic disc and visual loss [2]. Bilateral papilledema and absence of intracranial pathology including hydrocephalus are the common presentation of Benign increased intracranial pressure [6]. However, Unilateral papilledema is a rare occurrence with Benign increased Intracranial Pressure [7].
reported a case report of unilateral papilledema in a female pt aged 25ys old and diagnosed as benign increased intracranial pressure [10]. King & Floyd reported a case of Benign increased Intracranial pressure with Unilateral Papilledema [11]. In another case report by Brosh & Strassman, there was unilateral papilledema in a female patient 25ys old with benign increased intracranial pressure [8]. The actual incidence of Unilateral papilledema with benign increased intracranial pressure is undetermined. Bruntse conducted a review study and found 25 out of 1346 patients with benign increased intracranial pressure had unilateral papilledema [12]. In another study conducted by Frederick, 6 out of 26 patients had unilateral or highly asymmetric papilledema [13]. The actual cause of occurrence of unilateral papilledema in benign increased intracranial pressure is still unknown. There are some hypotheses explaining the cause of unilateral papilledema. One of them supposed presence of anomaly of optic nerve sheath that may protect one optic nerve from the effect of intracranial hypertension. However, in a study conducted by Huna-Barn et al, there was 11 cases of unilateral papilledema and there was no evidence of differences between optic nerve sheaths on CT scan or MRI [3]. Another hypothesis postulated that there is a difference in lamina cribrosa of two optic discs [8] and this hypothesis was supported by another study that found axoplasmic blockage at the level of lamina cribrosa following experimental elevation of intracranial pressure [4].

Conclusion
Although rare, Unilateral papilledema can occur with Benign increased intracranial pressure. It should be kept in mind during differential diagnosis of unilateral papilledema and unilateral visual loss. Early diagnosis of these cases may help in avoidance of complications. We report this case to increase awareness that Unilateral papilledema may be a presentation of benign increased intracranial pressure.