What are the effects and signs?
The clinical features vary depending upon the age of the child and the severity of the hydrocephalus.
In infants, the initial symptoms and signs include an unusually large head or increasing head circumference, a bulging fontanelle (a gap in the bones of the skull which usually fuse together during infancy) poor feeding, vomiting, drowsiness, irritability and fits. A late sign is downward deviation of the eyes known as “sunsetting.”
In older children, the initial symptoms and signs include headache, nausea and vomiting, lethargy, drowsiness, irritability, changes in personality and cognition including memory loss, blurred and double vision, problems with balance, coordination and gait, urinary incontinence, developmental delay and precocious (early) puberty.
Long term problems associated with hydrocephalus include -:
- Learning disability (low IQ <70)
- Cognitive problems including difficulties with learning, memory and executive function (the ability to organise, set priorities, manage time and make decisions)
- Speech and language problems
- Behavioural problems
- Autism
- ADHD
- Cerebral palsy
- Other motor deficits (delay or deficiency in attaining motor milestones), for example difficulty walking and problems with gross and fine motor control and balance. Motor deficits may worsen after a certain age due to factors such as the effect of growth and ageing and the effect on the musculoskeletal system. The age at which this deterioration occurs is very variable.
- Epilepsy
- Visual problems and squint
- Hearing problems
- Shunt related problems -:
- Mechanical - either obstruction or fracture/destruction of the shunt tube
- Infection - usually occuring within six months of insertion
- Over drainage - which can result in sub-dural haematomas (blood clots under the skull overlying the brain due to tearing of blood vessels) or collapse of the ventricles (slit ventricles) resulting in obstruction
- “Shuntalgia” - discomfort at the shunt valve or along the route of the catheter in the neck.
- Accumulation of cerebrospinal fluid (CSF) at the site of drainage, for example abdominal swelling or hydroceles (fluid surrounding the testicles usually only in infants less than 12 months of age) in ventriculoperitoneal shunts.
Children with myelomeningocele and hydrocephalus
Children with myelomeningocele and hydrocephalus have similar clinical features to those with hydrocephalus alone. However, children with myelomeningocele and hydrocephalus are less likely to have learning disability and epilepsy and are extremely unlikely to have cerebral palsy. Children with myelomeningocele are more likely to have a severe functional loss with regard to mobility and physical dependence and are likely to have a problem with social integration as well.
Factors associated with more severe disability include -:
- Gestational age
Term infants are those born after 36 weeks of gestation (pregnancy). Preterm infants are those born between 32 and 36 weeks of gestation. Very pre-term infants are those born before 32 weeks of gestation.
There is a correlation between lower gestational age at birth and the number of neuro-impairments (learning disability, cerebral palsy or epilepsy) present. There is also a correlation with poor motor function and higher total handicap scores.
- Cause of hydrocephalus
Associated impairments are more likely in children in whom the cause of their hydrocephalus is perinatal or postnatal rather than prenatal. Children who develop hydrocephalus after intraventricular haemorrhage or infection are much more likely to develop cognitive problems than those who have a prenatal cause for their hydrocephalus.
- Number of shunt failures
There is a correlation between the number of shunt failures and poor fine motor control and the number of neuro-impairments.
- Ventricular size at follow up
Additional neuro-impairments, especially learning disability, are more likely in children who have enlarged or collapsed (slit) ventricles at follow up. Slit ventricle syndrome usually only occurs if the shunt has been in place for more than 5 years.
