neonatal head pathology
ventriculomegally/ hydrocephalus
- refers to the dilatation of the csf venticular system.
- it can be communicating or non-communicating.
- the ventricular index (ratio of ts lateral ventrical:hemispheric diameter) has been shown to be less sensitive than the diagonal venticular diameter in early detection of hydrocephalus.
ref:1: journal of paediatric child health. 2003 apr;39(3):186-90. links ultrasound grading of cerebral ventricular dilatation in preterm neonates.grasby dc, esterman a, marshall p. department of paediatrics and child health, flinders medical centre, bedford park, adelaide, south australia, australia. degras@arcom.com.au.
a coronal view through the anterior fontanelle demonstrating ways to measure / quantify the venticulomegally.
ultrasound image- a coronal view using a linear high frequency probe.
demonstrating dilated lateral and 3rd ventricles, and the foramina of munro.
ultrasound image- marked hydrocephalus.
coronal anterior.
ultrasound image- marked hydrocephalus.
coronal mid-posterior.
ultrasound image-marked hydrocephalus.
axial view.
ultrasound image-marked hydrocephalus.
sagittal view.
ultrasound image- mild ventriculomegally.
para-sagittal view.
ultrasound image- this slightly oblique view shows the dilated 3rd ventricle under the dilated lateral ventricle. part of the foramen of munro is visible thinly joining the two.
ultrasound image- coronal view of ventriculomegally and a likely meningioma in the 3rd ventricle.
- most common in premature infants due to their poor auto-regulatory system.
- beyond 32weeks, the risk of haemorrhage is far less likely due to maturity of the germinal matrix(in the subependymal region).
grading:
i. subependymal.
ii. intra-ventricular extension.
iii. with venticulomegally
iv. with intra-parenchymal extension.
subependymal haemorrhage
- an isolated haemorrhage, or extension of a haemorrhage, into the cerebral parenchyma.
intraventicular haemorrhage
- an isolated haemorrhage, or extension of a haemorrhage, into the cerebral parenchyma.
intracerebral haemorrhage
- an isolated haemorrhage, or extension of a haemorrhage, into the cerebral parenchyma.
porencephalic cyst
- these are the common sequelae to cerebral haemorrhage in the neonate.
- they are the reulting encephalomalacia after the area of clot retracts, leaving a void where the haemorrhage was.
- their size and subsequent prognosis vary proportional to the size of the initial bleed.
ultrasound image- coronal view of a subependymal hemorrhage at the floor of the anterior horn of the right lateral venticle.
ultrasound image- parasagittal view of a subependymal hemorrhage (red).
the blue indicates the small porencephalic cyst.
periventricular leukomalaicia (pvl)
- is the most common ishaemic brain injury of neonates.
- the prognosis is poor. many surviving infants will have cerebral palsy.
- occurs when there is a loss of arterial flow at the watershed point in the peri-ventricular white matter.
begins with increased echogenicity of the parenchyma superior to the lateral ventricles (=/> choroid plexus). the increased echogenicity corresponds with inflammation. if ischaemia ensues. this will become more echogenic and subsequently degenerate into small cystic areas.
grading of pvl
- grade l – periventricular flares more than 1 week old
- grade il – small periventricular cysts
- grade ill – defined as extensive periventricular cysts
- grade lv – multicystic leukomalacia in the periventricular and subcortical region
ref:de vries ls, eken p, dubowitz lm. “the spectrum of leukomalacia using cranial ultrasound.” behav brain res. jul 31 1992;49(1):1-6.
mri is usually required to provide longer term follow-up and prognostics.
sub-dural haemorrhage
- between the dura mater and the arachnoid mater.
- usually traumatic or surgical
the red arrows indicate the subdural haematoma.
this is actually an adult who had presented post craniotomy after excision of a meningioma.
the patient had no pain, however there was an increase in swelling for investigation.
a subcutaneous haematoma had developed with an underlying sub-dural haematoma.
ultrasound image- debris associated with the meningitis is visible between the arachnoid and the cerebrum.
the overlying subdural fluid is evident.
subarachnoid space
look for evidence of widening of the subarachnoid space.
may be the result of gross hydrocephalus, haemorrhage or infection.
ultrasound image- widening of the subarachnoid space in communicating hydrocephalus.
ultrasound image- the fine, complex fluid inan acute subarchnoid haemorhage.
tuberous sclerosis
- is a rare(only approximately 1/10000), genetic (1/3) disorder causing benign (‘tubers’) to grow in the brain (and other organs).
- as seen in this case, ependymal lesions may be the first manifestation in the neonate or infant.
- clinical signs may include seizures and white patches on the skin.
- most will have learning dificulties.
ultrasound image- tuberous sclerosis tuber impressing on the underside of the anterior horn of the lateral ventricle.
ultrasound image- the blue arrow indicates indendation of the floor of the lateral ventricle, differentiating the echogenic material from haemorrhage.