From the Research
Ex vacuo hydrocephalus is a condition characterized by the enlargement of the brain's ventricles due to the loss of brain tissue, rather than increased cerebrospinal fluid (CSF) pressure, as noted in a study published in 2021 1. This condition occurs when brain atrophy or tissue loss creates extra space that becomes filled with CSF, and it is commonly associated with neurodegenerative diseases, stroke, traumatic brain injury, or aging processes that cause brain volume reduction. The key distinction is that in ex vacuo hydrocephalus, CSF pressure remains normal, and the ventricle enlargement is compensatory rather than pathological. Some of the key radiological parameters that can be used to discriminate ex vacuo hydrocephalus from other forms of hydrocephalus include a small callosal angle, the Sylvian fissure dilatation, and absence of narrowing of superior parietal sulci, as identified in a study published in 2021 1. Treatment typically focuses on addressing the underlying cause of brain tissue loss rather than CSF diversion procedures like shunting, which are standard for pressure-related hydrocephalus. Patients may not experience the typical symptoms of increased intracranial pressure seen in other forms of hydrocephalus, such as headaches, vomiting, or visual disturbances. Diagnosis usually involves brain imaging (CT or MRI) along with clinical evaluation to differentiate it from other forms of hydrocephalus that require different management approaches, as discussed in a study published in 2017 2. The term "ex vacuo" was first proposed in a study published in 1976 3 to describe abnormal collections of CSF replacing brain tissue that is absent or has disappeared as a result of various factors. Some of the main points to consider when diagnosing and managing ex vacuo hydrocephalus include:
- The condition is characterized by the loss of brain tissue, rather than increased CSF pressure
- Radiological parameters such as callosal angle, Sylvian fissure dilatation, and narrowing of superior parietal sulci can be used to discriminate ex vacuo hydrocephalus from other forms of hydrocephalus
- Treatment focuses on addressing the underlying cause of brain tissue loss, rather than CSF diversion procedures
- Patients may not experience typical symptoms of increased intracranial pressure
- Diagnosis involves brain imaging and clinical evaluation to differentiate it from other forms of hydrocephalus.