The Cavum Vergae (CV) is a fluid-filled space located deep within the center of the brain. This structure represents the persistence of a normal cavity that forms during early fetal brain development. The fluid it contains is a filtrate of cerebrospinal fluid, but the CV does not communicate directly with the brain’s main ventricular system. The presence of a CV is a common finding, particularly in infants and children, and is largely considered a benign anatomical variation.
Anatomical Location and Developmental Timeline
The Cavum Vergae is situated in the midline of the brain, positioned above the third ventricle and below the corpus callosum. It is defined as the posterior extension of the more commonly known Cavum Septum Pellucidum (CSP). The boundary separating the CV from the CSP is an arbitrary vertical plane formed by the columns of the fornix, which are key structures in the limbic system.
The CV, the CSP, and the Cavum Veli Interpositi (CVI) are the three main midline cavities that can be found in this region. These cavities arise because the septum pellucidum, a thin, dual-layered membrane, forms from the medial walls of the cerebral hemispheres. The space between these two leaflets initially contains fluid.
Normal development involves the gradual fusion of the two leaflets of the septum pellucidum, which obliterates this fluid-filled space. This fusion process begins during gestation, typically starting from the back and moving forward. The obliteration of the CV, the posterior portion, is usually completed before or shortly after a full-term birth, occurring in an estimated 97% of babies by term.
If this fusion does not occur, the remnant cavity persists. While the CSP may persist into adulthood in about 15% of people, the persistence of the CV is less common because it is the first part to close. Due to this ordered closure, a persistent CV is nearly always accompanied by a persistent CSP, a condition sometimes termed Cavum Septum Pellucidum et Vergae.
Clinical Significance of Persistent Cavum Vergae
In the vast majority of cases, the persistence of the Cavum Vergae into childhood or adulthood is clinically silent and considered a benign anatomical variant. The finding of a CV on a brain scan does not cause symptoms or require medical intervention. Its presence reflects only a slight deviation from the typical developmental timeline.
The size of the cavity becomes a factor in rare instances of pathology. When the CV becomes significantly enlarged, it is classified as a Cavum Vergae cyst, a term often applied when the transverse diameter exceeds 10 millimeters. This abnormal enlargement can transform the structure from an incidental finding to a source of neurological symptoms.
The primary concern with an enlarged CV cyst is its potential to cause obstructive hydrocephalus, resulting in a buildup of cerebrospinal fluid. The expanding cyst can physically compress adjacent structures, such as the interventricular foramina, which are small channels necessary for normal fluid circulation. This compression leads to symptoms associated with increased intracranial pressure, including headaches, nausea, vomiting, or visual disturbances.
A persistent CV has also been studied regarding neurodevelopmental and psychiatric disorders. Because the CV is located near structures of the limbic system, its presence has been investigated as a possible marker of disturbed midline brain development. Some epidemiological studies have found a correlation between enlarged CV and certain psychiatric conditions, including schizophrenia and mood spectrum disorders, suggesting it may be an unspecific risk factor.
Establishing a direct cause-and-effect relationship between a persistent CV and psychiatric symptoms is difficult. The presence of the cavity may simply be a byproduct of a broader, underlying developmental issue affecting the brain’s midline structures. Symptomatic presentation of a CV is rare, and symptoms are most often linked to the physical mass effect of an enlarged cyst.
Detection and Management
The Cavum Vergae is typically identified incidentally during brain imaging performed for unrelated reasons. Both Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) scans clearly visualize the structure during a general neurological workup. Radiologists use the specific location and fluid-filled nature of the cavity to distinguish it from other midline fluid collections, such as the Cavum Veli Interpositi.
The diagnostic process involves assessing the cavity’s size and whether it communicates with the ventricular system. A finding within the expected range, often defined as a width of 1 to 4 millimeters, is considered a normal anatomical variation. When the CV is asymptomatic and not causing mass effect, no treatment or regular follow-up is necessary.
Management is only considered for rare cases where the CV has enlarged into a cyst and is causing symptoms, primarily due to hydrocephalus. For these symptomatic patients, the goal of treatment is to relieve the pressure caused by the cyst. Surgical intervention is the standard approach, most commonly involving neuroendoscopic fenestration.
Endoscopic fenestration is a procedure where a small opening is created in the cyst wall, allowing the trapped fluid to drain and communicate with the ventricular system. This technique is effective in resolving the mass effect and associated symptoms. In some instances, a surgical shunt may be required to divert fluid and manage pressure if fenestration is unsuccessful.