Monday 7 November 2011

Periventricular leukomalacia MRI

A 12 yo male with delayed mile stones.
Birth history significant, term non hospital delivery, delayed cry, was in NICU for 1month after birth.
MRI Axial FLAIR images of brain show:
Bilateral mild ex vacuo dilatation of lateral ventricles, undulating walls with band of sub ependymal Gliosis implies to Gliosis and paucity of peri ventricular white matter.

Imaging diagnosis : Peri ventricular leukomalacia

Periventricular Leukomalacia (PVL)

A type of brain damage that involves the periventricular white matter of the brain.
Damage to white matter results in the death and decay of injured cells, giving rise to areas of Gliosis or leaving empty areas which fill with fluid called as leukomalacia.

The brain primarily consists of white matter and gray matter. Gray matter has neural cell bodies, which can initiate nerve impulses, while white matter transports impulses between gray matter cells.
The periventricular white matter that surrounds two horseshoe shaped cavities in the brain is primarily responsible for the transmission of nerve impulses that control motor function.
Damage in this area can result in spasticity and intellectual impairment.
Myelin is an integral component of white matter that coats and essentially insulates cell pathways, promoting speedy transmission of nerve impulses.
Damage to myelin slows and impedes nerve transmission, possibly impairing brain function.

Approximately 60-100% of infants with periventricular leukomalacia are diagnosed with cerebral palsy.
4 to 26% of premature infants placed in neonatal intensive care units have cerebral palsy.
In severe cases, postmortem examinations have discovered that 75% of premature infants who died shortly after birth had periventricular leukomalacia.
Intrauterine infections are also believed to be the underlying factor for periventricular leukomalacia. Membranes around the fetus are affected by the release of toxins, which travel through amniotic fluid to selectively injure areas of the developing brain. These toxins can also cause premature rupture of the membranes and premature birth.

Damage can occur at any time but fetus is particularly vulnerable to periventricular leukomalacia somewhere between 26 weeks and 34 weeks of gestation.
Premature birth is a high risk factor for periventricular leukomalacia.
PVL is most common in infants born prior to 32 weeks and with a birth weight below 3.3 lbs.

Risk Factors and Causes: 
Decreased blood flow or cell damage to periventricular tissue is an underlying cause of periventricular leukomalacia.
Infants who are born before 32 weeks of gestation and are mechanically ventilated are at greatest risk for periventricular leukomalacia.
Hypotension, hypoxemia, acidosis, and hypocarbia in ventilated premature infants can cause periventricular leukomalacia.
Intrauterine infection, abnormal bacteria can infect the amniotic fluid, is one factor; infection around the time of delivery also increases likelihood. This is more common during premature delivery.
Other risk factors associated with periventricular leukomalacia include Placental blood vessel conditions, known as placental vascular anastomoses, Twin gestation, Vaginal bleeding during pregnancy, known as antepartum hemorrhage, Inflammation of fetal membranes due to a bacterial infection, known as chorioamnionitis, Inflammation of the umbilical cord connective tissue, known as funisitis, severe illness in which the bloodstream is overwhelmed by bacteria, known as sepsis, Maternal cocaine use

Clinical presentation: 
Periventricular leukomalacia is difficult to detect in newborns, as very young infants typically do not show signs of impairment. Periventricular leukomalacia can resemble other conditions, and all cases are different. Intellectual impairment, developmental impairment, visual dysfunction, hearing impairment, and problematic coordination are common with periventricular leukomalacia.
Cerebral palsy - Spastic diplegia (tight muscles and limbs that do not bend easily) is the most common type of cerebral palsy caused by periventricular leukomalacia; quadriplegia is the most severe.

Cranial ultrasounds, CT and MRI.
Early ultrasounds may not reveal periventricular leukomalacia — it can take four to eight weeks for the condition to become detectable on cranial Usg.
MRI is investigation of choice due to its high sensitivity and specificity compared to CT, lacks radiation.

Focused on managing symptoms.
Massage therapy, physical therapy, speech therapy and treatment for visual dysfunction.

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