Idiopathic Intracranial Hypertension

What is Idiopathic Intracranial Hypertension (IIH)? Idiopathic intracranial hypertension (IIH) — also known as benign intracranial hypertension or pseudotumour cerebri — is a neurological condition in which pressure inside the skull (intracranial pressure) becomes abnormally high without a detectable cause, such as a brain tumour or infection. The increased pressure can compress the brain and cause swelling of the optic nerves (papilloedema). If IIH is not treated in time, it can lead to permanent vision loss, making early diagnosis and management essential. The term idiopathic means that the exact cause is unknown. Types of Idiopathic Intracranial Hypertension 1. Primary (Idiopathic) IIH The most common form No identifiable underlying cause Often affects women of childbearing age, particularly those who are overweight 2. Secondary IIH Occurs due to an underlying condition or trigger, such as: Certain medications Hormonal disorders Systemic medical conditions Symptoms of Idiopathic Intracranial Hypertension Symptoms may develop gradually or suddenly and often worsen over time: Persistent, severe headaches, often throbbing and worse with movement or straining Visual disturbances, including: Blurred vision Double vision (diplopia) Temporary vision loss or “blackouts” (visual obscurations) Papilloedema (optic nerve swelling seen on eye examination) Pulsatile tinnitus, described as a whooshing or heartbeat sound in the ears Nausea and vomiting, linked to raised pressure Neck and shoulder pain Balance and coordination difficulties ⚠️ Any visual symptoms should be assessed urgently. What Causes Idiopathic Intracranial Hypertension? Although the precise cause is unknown, several factors are strongly associated with IIH: Obesity, especially in women of reproductive age Hormonal influences, including: Pregnancy Menstrual irregularities Polycystic ovary syndrome (PCOS) Medications, such as: Tetracycline antibiotics Oral contraceptives Steroids (especially withdrawal) Excess vitamin A or retinoid-based treatments Associated medical conditions, including: Sleep apnoea Kidney disease Certain autoimmune disorders Complications of Idiopathic Intracranial Hypertension If IIH is not properly treated, it can lead to serious complications: Permanent vision loss due to optic nerve damage Chronic, disabling headaches that impair daily functioning Persistent papilloedema, causing progressive visual decline Reduced quality of life due to ongoing neurological symptoms How Can Idiopathic Intracranial Hypertension Be Prevented? There is no guaranteed way to prevent IIH, but risk can be reduced by: Maintaining a healthy weight, particularly for those at higher risk Reviewing medications with a healthcare provider to avoid known triggers Managing underlying conditions, such as sleep apnoea or hormonal disorders Regular medical and eye check-ups, especially if headaches or vision changes occur