Nervous System Disorders Flashcards
Major neuropathology lesions associated with VLBW infants
1) IVH 2) Periventricular leukomalacia
Where does IVH occur in premature infants
Gelatinous subependymal germinal matrix (site of origin for embryonal neurons and fetal glial cells)
IVH Grading by CT scan
Gr I - Subependymal area, Gr II - Within ventricle w/o evidence of dilatation, Gr III - IVH with dilatation, Gr IV - intraventricular and parenchymal
IVH Grading by Ultrasound
Gr I - confined to the germinal matrix-subependymal region or to less than 10% of the ventricle, Gr II - 10-50% of ventricle, Gr III >50% of the ventricle with dilatation
Ventriculomegaly spectrum
Mild - 0.5-1cm, Moderate - less than 1.5cm but more than 1cm, Severe - >1.5cm
Routine real-time CUTZ is recommended in
Premature infants less than 32 weeks AOG
All at risk infants should undergo ff up CUTZ at ___ to evaluate adequately for PVL
36-40 weeks PMA
20-30% of infants with HIE die within
Neonatal period
___ of HIE survivors are left with permanent neurodevelopment abnormalities
~33-50%
The initial circulatory response of the fetus in cases of HIE is
Increased shunting through the ductus venous, ductus aretriosus, and foramen ovale
Organs of priority blood flow in cases of shock
Brain, heart adrenals
May be the first indication of fetal hypoxia
IUGR with increased vascular resistance
Stages of HIE in term infants: Level of consciousness
St 1 Hyperalert, St 2 Lethargic, St 3 Stuporous/coma
Stages of HIE in term infants: Muscle tone
St 1 Normal, St 2 Hypotonic, St 3 Flaccid
Stages of HIE in term infants: Posture
St 1 Normal, St 2 Flexion, St 3 Decerebrate
Stages of HIE in term infants: Tendon reflexes/clonus
St 1 Hyperalert, St 2 Hyperactive, St 3 Absent
Stages of HIE in term infants: Myoclonus
St 1 Present, St 2 Present, St 3 Absent
Stages of HIE in term infants: Moro reflex
St 1 Strong, St 2 Weak, St 3 Absent
Stages of HIE in term infants: Pupils
St 1 Mydriasis, St 2 Miosis, St 3 Unequal, poor light reflex
Stages of HIE in term infants: Seizures
St 1 None, St 2 Common, St 3 Decerebrate
Stages of HIE in term infants: EEG
St 1 Normal, St 2 Low voltage changing to seizure activity, St 3 Burst suppression to isoelectric
Stages of HIE in term infants: Duration
St 1 Less than 24h if progresses, otherwise may return to normal; St 2 24h-14 days; St 3 Days to weeks
Stages of HIE in term infants: Outcome
St 1 Good, St 2 Variable, St 3 Death, severe deficits
Preferred imagine modality in neonates with HIE because of its high sensitivity and specificity early in the process and its ability to outline topography of the lesion
Diffusion-weighted MRI
Has limited utility in the evaluation of TERM INFANTS, but is the preferred modality in the evaluation of preterm infants with HIE
UTZ
May help determine which infants are at highest risk for long-term brain injury
Amplitude-integrated EEG
Mechanisms by which hypothermia benefits neonates with HIE
1) Decreases rate of apoptosis 2) Suppresses production of mediators known to be neurotoxic, including glutamate, free radicals, NO, and lactate (Downregulation of secondary mediators of injury resulting from edema, accumulation of cytokines, and seizures)
Poor predictor values of HIE
1) pH less than 6.7 2) APGAR 0-3 at 5 min 3) High base deficit (>20-25 mmol/L) 4) Decerebrate posture 5) Lack of spontaneous activity
Clinical criteria for brain death after neonatal HIE
1) Coma 2) Apnea with pCO2 rising from 40 to >60 mmHg without ventilator support 3) Absence of brainstem reflexes - Persistence of these 3 criteria for 2 days in term infants and 3 days in preterm infants predicts brain death
