Idiopathic intracranial hypertension (previously termed benign intracranial hypertension or pseudotumour cerebri) is defined as raised intracranial pressure (> 20 mmHg) that is not associated with intracranial pathology. It is a rare but well-recognised syndrome that typically affects young to middle-aged overweight females, causing headache and visual disturbances. The aetiology is unclear and there are no focal neurological signs. In pregnancy, it is more common in the first two trimesters.
Problems and special considerations
General treatment is weight control and diuretics if necessary. In more severe cases, lumbar puncture and cerebrospinal fluid (CSF) removal maybe recommended. Insertion of lumboperitoneal shunts and optic nerve sheath decompression have been performed in very severe cases.
Headache and visual disturbances may also occur in pre-eclampsia and postdural puncture headache, possibly posing a diagnostic challenge.
Although CSF pressure is increased, dural puncture (deliberate or accidental) will not lead to coning in this group of patients, and it may even be temporarily beneficial in relieving CSF pressure.
Management options
Epidural and spinal analgesia/anaesthesia (single-shot or via an intrathecal catheter) have been successfully used for labour and caesarean section in this patient group. Concerns have been raised over the possibility of excessive increases in intracranial pressure with bolus injection of epidural solutions; slow administration or the use of infusions has been suggested. Spinal anaesthesia may be potentially difficult, as the CSF is under pressure, and some CSF may need to be withdrawn before injection of the local anaesthetic. Recent CSF drainage may precipitate a block level that is higher than expected.
Regional anaesthesia in women with lumboperitoneal shunts carries a potential risk of damage to the shunt catheter or dissipation of the injectate into the peritoneal cavity. Radiographic imaging may demonstrate the exact location of the shunt; if this is unavailable, epidural catheter insertion should be performed using a midline approach in the intervertebral space above or below the skin scar.
General anaesthesia is not contraindicated, but the technique must be modified to ensure the maintenance of adequate cerebral perfusion and the avoidance of factors that may cause a rise in intracranial pressure.
Key points
• Idiopathic intracranial hypertension may present with severe headache and visual disturbances.
• Regional analgesia and anaesthesia (including spinal block) are not contraindicated.
Further reading
Anson JA, Vaida S, Giampetro DM, McQuillan PM. Anesthetic management of labor and delivery in patients with elevated intracranial pressure. Int J Obstet Anesth 2015; 24: 147-60.
Hopkins AN, Alshaeri T, Akst SA, Berger JS. Neurologic disease with pregnancy and considerations for the obstetric anesthesiologist. Semin Perinatal 2014; 38: 359-69.