brain - part 3 Flashcards
intracranial pathologies? (9)
Intracranial Hemorrhage - ICH Hydrocephalus Cerebellar Hemorrhage Periventricular Leukomalacia – PVL Agenesis of Corpus Callosum Dandy-Walker complex Chiari Malformation Holoprosencephaly Intracranial Infections
what is Hydrocephalus?
- progressive dialation of ventricular system
3 mechanisms of Hydrocephalus?
- obstruction to CSF outflow
- decreased CSF absorption
- CSF overproduction
what can cause Hydrocephalus?
hemorrhage grade 3 and 4
Hydrocephalus clinical signs?
- increasing head size
- bulging of the anterior frontanelle
- separation of cranial sutures
why are serial u/s required to monitor the progression of Hydrocephalus?
because bradycardia, apnea, and increased ICP appear days or weeks later
post hemorrhagic hydrocephalus
- shows grade III hemorrhage
- hydrocephalus with clot in lateral and 3rd ventricle
- ependymal lining of ventricles in increased in echogenicity consistent with ependymitis
what is ependymitis caused by?
- blood products/ chemical ventriculitis
Infants with progressive hydrocephalus and increased ICP may require ?
placement of a shunt
Hydrocephalus u/s scan?
- Doppler used to identify infants with increased ICP
- Compression of anterior fontanelle with transducer while obtaining a spectral Doppler from pericallosal artery (anterior cerebral a.)
- Compress gently for 3 – 5 sec
- Do not compress if you see reversal of flow without compression
- Stop compression if heart rate goes down.
Cerebellar hemorrhage clinically?
- may be silent and found on routine cranial U/S
Cerebellar hemorrhage approach?
- mastoid frontanelle approach is used
- cerebellum is in far field in anterior frontanelle scan
- highly echogenic tentorium is avoided
posterior fossa
Normal posterior fossa structures obtained via the mastoid fontanelle
Coronal sonogram shows a normal
- 4th ventricle (4)
- cerebellar hemispheres (*)
- midline vermis (V)
- cisterna magna (CM).
Coronal image shows large echogenic hemorrhage in the right cerebellar hemisphere (arrows).
Coronal scan shows clot (c) in dilated fourth ventricle (4).
Periventricular Leukomalacia (PVL)?
- Hypoxic-ischemic brain injury
- Hypoxia – lack of O2
- Ischemia – lack of adequate blood flow
- Leukomalacia – softening of white matter
common sites for Periventricular Leukomalacia (PVL)?
- White matter adjacent to peritrigonal area of lateral ventricles
- Frontal cerebral white matter anterolateral to frontal horns
Periventricular Leukomalacia (PVL) on u/s?
SONO – not very reliable
Increased echogenicity in affected area
Bilateral and symmetric
Echogenicity should not be > choroid plexus
Difficult to differentiate from periventricular blush
Later changes to PVL
Formation of cysts as a result of necrosis and cavitation
Periventricular Leukomalacia (PVL) long term affects?
cerebral palsy
developmental abnormalities
intellectual and visual impairment