Common related conditions

There are several conditions that commonly occur alongside Hydrocephalus.

 

Spina Bifida and Hydrocephalus

Most babies born with spina bifida have hydrocephalus. In addition to the lesion in the spinal cord, structural abnormalities in parts of the brain can develop before birth. This prevents proper drainage of the CSF which increases the pressure and can compress the brain further.

Open spina bifida is strongly associated with hydrocephalus. Although the baby may not have enlarged ventricles before birth, once the surgery to close the spina bifida lesion is carried out, the CSF may have nowhere to go. It accumulates in the ventricles, resulting in hydrocephalus. Checking the baby’s head circumference in the early days after back surgery usually picks this up, so the baby can be treated.

Some babies with spina bifida develop hydrocephalus in the womb, as the Chiari II (a problem with the cerebellum associated with open spina bifida) disrupts the CSF flow.

 

Longstanding overt ventriculomegaly in adults (LOVA)

LOVA is a term used to describe forms of chronic hydrocephalus, present since birth or early infancy, but which don’t cause symptoms for many years. Arrested hydrocephalus, decompensating hydrocephalus and chronic congenital hydrocephalus are terms associated with LOVA which you may have heard.

It is thought that a process which is present at birth such as aqueduct stenosis (a narrowing of the channel between the third and fourth ventricles), blocks the flow of CSF inside the lateral and third ventricles.(1) The ventricles enlarge, and because the bones of the skull are not yet fused, the head circumference increases without causing the pressure inside the head to increase enough to cause symptoms. At some point, the aqueduct opens the blockage clears, and CSF flows freely again, leaving large ventricles and a larger-than-typical head circumference. This stable state continues into adulthood, when the CSF begins to build up, and lead to symptoms of raised pressure (a process known as decompensation).

These symptoms may start in early adult life, but more commonly begin in the middle or later decades. They may begin gradually and progress slowly, over the course of months, but for other people, the onset and progression are quite rapid, over days or weeks. 

The most common signs and symptoms are:

  • gait ataxia (difficulty coordinating the movements of walking, using wide-based, staggering steps)  
  • cognitive decline  
  • urinary problems (frequency, urgency, leakage)  
  • headache  
  • nausea/vomiting  
  • papilloedema  

The symptoms of LOVA can be similar to those of Normal Pressure Hydrocephalus (NPH), especially in older people. 

The enlarged ventricles may be found as an incidental finding on scans before symptoms begin, or through MRI to investigate the symptoms. The signs that would point to LOVA include large lateral and third ventricles, with a large head circumference (see scan illustration below), and damaged sella turcica (a bony structure of the skull that may be flattened by hydrocephalus in infancy, shown in red in the 3D picture of the skull below).  

Image credit: BodyParts3D via Wikimedia Commons. Licensed under the Creative Commons Attribution-Share Alike 2.1 Japan license. 

Treatment is either by ETV (endoscopic third ventriculostomy) or by a VP shunt. A literature review of treatment for LOVA reported 81.8% of people treated with ETV found their symptoms improved, and 86.7% improved with a shunt. However, the complication rate for ETV (4.6%) was far lower than for a shunt (27.1%) (2). The ventricles don’t become smaller after treatment.  

It can be unsettling to find you had a condition since birth without being aware, and some people find they become angry, anxious or depressed.  Do reach out to your GP if this is something you’ve noticed. Shine’s Health Team are also on hand to support you and answer your questions.  

  1. Palandri G, Carretta A, La Corte E, Mazzatenta D, and Conti A. Longstanding overt ventriculomegaly in adults (LOVA) with patent aqueduct: surgical outcome and etiopathogenesis of a possibly distinct form of chronic hydrocephalus. Acta Neurochir (Wien). 2021 Dec; 163(12): 3343-3352.  doi: 10.1007/s00701-021-04983-0.   
      
  2. Gillespie CS, Fang WYS, Lee KS, Clynch AL, Alam AM, McMahon CJ. Long-Standing Overt Ventriculomegaly in Adults: A Systematic Review and Meta-Analysis of Endoscopic Third Ventriculostomy Versus Ventriculoperitoneal Shunt as First-Line Treatment. World Neurosurg. 2023 Jun; 174: 213-220.e2. doi: 10.1016/j.wneu.2023.03.064.  
 

Ventriculomegaly

Ventriculomegaly is a word used to describe the enlargement of the ventricles of the brain.   

  • Ventriculomegaly occurs in around 2% of all pregnancies and can be detected during antenatal scans. If an underlying genetic cause is suspected, genetic counselling may be recommended for future pregnancies. 
  • If there is no other developmental issue detected, the term Mild Isolated Ventriculomegaly is used. This often resolves spontaneously before or shortly after birth. It seems unlikely to cause problems, but research is needed to see how the condition affects children long term. 
  • If there are no symptoms and scans do not show signs of raised pressure or increasing ventricle size, children do not usually require further medical intervention. Treatment and long-term monitoring are only needed if a baby/child shows signs of developing hydrocephalus. 
  • Developmental delay is rarely associated with mild ventriculomegaly, and when it does occur, it is usually due to an underlying condition rather than the ventriculomegaly.  

External hydrocephalus

External hydrocephalus is a benign, self-limiting condition with an increase in the volume of the space around the brain and no change or only slightly raised volume in the chambers of the brain known as the lateral ventricles. 

  • External hydrocephalus is sometimes referred to as benign external hydrocephalus of infancy, pseudohydrocephalus, extraventricular hydrocephalus, subdural hygroma, and benign enlargement of the subarachnoid space.  
  • The cause is not known but some different theories have been put forward about how the brain develops. It is also thought that in some babies, the cells that absorb CSF are slow to mature and during this time, CSF builds up. Most cases are associated with a strong family history of larger head size (benign familial macrocephaly).  
  • In most cases, the external hydrocephalus resolves spontaneously by the time the child reaches two years old. For some children, it may be a predictor for autism.  

Hydrocephalus ex vacuo 

Hydrocephalus ex vacuo describes a state where brain tissue has shrunk, and the space left has filled with CSF. This sign is found in conditions where the brain is damaged, such as in stroke, or where the volume of the brain is reduced, such as in Alzheimer’s Disease. The flow of CSF is not affected, and the pressure inside the head is normal.