What are the symptoms of Benign Intracranial Hypertension (BIH), also known as Idiopathic Intracranial Hypertension (IIH)?

From the Guidelines

Benign intracranial hypertension typically presents with symptoms such as headache, visual disturbances, pulsatile tinnitus, and neck and shoulder pain, and is more common in women of childbearing age, especially those who are overweight. The most common symptom is headache, which is usually worse in the morning or when lying down, and may be accompanied by nausea and vomiting, as noted in the study by 1. Visual disturbances are another hallmark symptom, including transient visual obscurations (brief episodes of vision loss lasting seconds), blurred vision, double vision, and peripheral vision loss. Many patients experience pulsatile tinnitus, a whooshing sound in the ears that synchronizes with the heartbeat. Other symptoms can include back pain, and radicular pain along the arms. Some patients report cognitive difficulties such as memory problems and trouble concentrating.

According to the study by 1, the combination of raised intracranial pressure, without hydrocephalus or mass lesion, normal cerebrospinal fluid (CSF) composition and where no underlying aetiology is found are accepted criteria for the diagnosis of IIH. The study by 1 also notes that headache is the principal morbidity in patients with IIHWOP, and that management of headache should be the same as typical IIH.

The study by 1 provides guidance statements for the investigation and management of adult IIH, and identifies three main principles: (1) to treat the underlying disease; (2) to protect the vision; and (3) to minimise the headache morbidity. The study by 1 notes that patients should be referred to a community weight management programme or a hospital-based weight programme, and that the amount of weight loss required to put the disease into remission is not known.

Key symptoms of benign intracranial hypertension include:

• Headache, which is usually worse in the morning or when lying down
• Visual disturbances, including transient visual obscurations, blurred vision, double vision, and peripheral vision loss
• Pulsatile tinnitus, a whooshing sound in the ears that synchronizes with the heartbeat
• Neck and shoulder pain
• Back pain
• Radicular pain along the arms
• Cognitive difficulties, such as memory problems and trouble concentrating.

The management of benign intracranial hypertension should focus on treating the underlying disease, protecting the vision, and minimising the headache morbidity, as noted in the study by 1. This can include weight management, as noted in the study by 1, as well as other treatments aimed at reducing intracranial pressure and alleviating symptoms.

From the Research

Benign Intracranial Hypertension Symptoms

• The symptoms of benign intracranial hypertension (BIH) include elevated intracranial pressure, headaches, and visual complaints such as blurred vision, double vision, and loss of visual field 2, 3.
• The disease is characterized by an increase in intracranial pressure without any evidence of a tumor or other intracranial process, and with normal cerebrospinal fluid (CSF) contents 2.
• The exact definition of BIH remains debated, and other terms such as "pseudotumor cerebri" or "idiopathic intracranial hypertension" are often used in the literature 2.

Diagnosis and Treatment

• The diagnosis of BIH is based on the presence of elevated intracranial pressure, normal CSF contents, and the absence of any intracranial process or tumor 2.
• The treatment of BIH depends on the severity of the symptoms and the presence of any underlying conditions that may be contributing to the disease 2, 4.
• Medical treatment with acetazolamide is often effective in reducing intracranial pressure and alleviating symptoms such as headaches and visual disturbances 4, 5.
• In some cases, surgical treatment such as optic nerve sheath fenestration or lumboperitoneal shunt may be necessary to relieve symptoms and prevent progressive visual loss 2, 3.

Pathophysiology

• The pathophysiology of BIH is complex and not fully understood, but it is thought to involve increased secretion or decreased absorption of CSF, as well as cerebral venous outflow obstruction due to venous sinus stenosis 3.
• Obesity is also thought to play a role in the development of BIH, given its high prevalence in patients with the disease 3.
• Carbonic anhydrase inhibitors such as acetazolamide have been shown to be effective in reducing intracranial pressure and alleviating symptoms of BIH, and are thought to work by inhibiting the production of CSF 5, 6.