Neonatal Head - Hydrocephalus (水腦）

 Dandy-Walker variant with prenatally detected hydrocephalus in a 34-week-old infant. US image obtained through the mastoid fontanelle shows dilatation of all the ventricles. The frontal horns (F [, left]), foramen of Monro (), third ventricle (3), aqueduct (), fourth ventricle (4), and temporal horns (T [, bottom right]) are clearly depicted. The inferior vermis (* [, top right]) is hypoplastic, resulting in enlargement of the vallecula.

Baby head study is commonly applied on premature newborn for r/o  intraventricular hemorrhage(IVH), or on slow developed babies with bigger heads for r/o hydrocephalus.  Hydrocephalus is a disease that caused by unbalance of CSF circulation; CSF which goes into cephalic ventricles is more than the fluid which exits the ventricals.



There are two types of hydrocephalus:

1. Communicating hydrocephalus : CSF still flows between ventricles and pathway reminds open.
2. Non-communicating/obstructive hydrocephalus: the flow of CSF is blocked because narrowing pathway between ventricles. 

The hydrocephalus can also be happened on adult. They mainly are hydrocephalus ex-vacuo (caused by traumatic injury) and normal pressure hydrocephalus (caused by age and may be primary to elder dementia) .

 Ethology

The causes of hydrocephalus is not will known. It may result form genetic (e.g.aqueductal stenosis) or developmental disorders (e.g. neural tube defects including spina bifida and encephalocele). Premature birth babies has higher chances to have intraventricular hemorrhage or subarachnoid hemorrhage and block the exit form the ventricles to the cisterns.  

Clinical finding

The symptoms are different from every person, and the best way to make sure is to have ventricular imaging study. 

1.  Infant: The main finding is  rapid increase in head circumference or an unusually large head size; the infant skull can expand to torrent the build up of CSF because the head joint have not close yet.  Other symptoms may include vomiting, sleepiness, irritability, downward deviation of the eyes (also called "sunsetting"), and seizures.

1. Older children and adult:  headache followed by vomiting, nausea, papilledema (swelling of the optic disk which is part of the optic nerve), blurred vision, diplopia (double vision), sunsetting of the eyes, problems with balance, poor coordination, gait disturbance, urinary incontinence, slowing or loss of development, lethargy, drowsiness, irritability, or other changes in personality or cognition including memory loss.

Tool of diagnosis: 

 CT, MRI (fetus > 18wk), Ultrasound (fetus: 12, 22, 32 wks & baby with open only),  Nuclear tracer

Ultrasound Images:(usually for follow up)

 Drawing illustrates the neonatal skull (lateral view) with the major sutures as well as the posterior () and anterior () fontanelles. A US transducer is positioned over the mastoid fontanelle.

 Normal and Pathology images: please view:
Ultrasound of the Natal Head . Ultrasoundpaedia. USA. 
http://www.ultrasoundpaedia.com/USP%20neonatal%20heads%20winner.html


Reference:

1. Vincent Iannelli. Hydrocephalus in Children. Types and Causes of Hydrocephalus. About.com Guide. Dec., 06, 2003. USA. http://pediatrics.about.com/cs/conditions/a/hydrocephalus.htm

2. 台北榮民總醫院神經醫學中心. 兒童水腦症. Taiwan. http://homepage.vghtpe.gov.tw/~nc/contents/2-4-4d-2.htm (Traditional Chinese)

All presented images in this article:
 Donald N. Di Salvo. A New View of the Neonatal Brain: Clinical Utility of Supplemental Neurologic US Imaging Windows. RadioGraphics. July 2001 RadioGraphics, 21, 943-955. http://radiographics.rsna.org/content/21/4/943.full


Outreach images resource:

Ultrasound of the Natal Head . Ultrasoundpaedia. USA. 
http://www.ultrasoundpaedia.com/USP%20neonatal%20heads%20winner.html