658 - Correlation between Initial Sarnat exam, brain injury and Prechtl examinations in neonates with Hypoxic-Ischemic Encephalopathy

Publication Number: 658.4309

Daniel Sprehe, St. Louis Children's Hospital, St. Louis, MO, United States; Nathalie ElTers, Saint Louis University School of Medicine, St. Louis, MO, United States; Amit Mathur, Saint Louis University School of Medicine, Chesterfield, MO, United States; Rakesh Rao, Washington University in St. Louis School of Medicine, St. Louis, MO, United States

Background: Therapeutic hypothermia (TH) initiated within 6 hours of birth in infants with Hypoxic-ischemic encephalopathy (HIE) improves survival and neurodevelopmental outcomes. Serial neurologic examination using the modified Sarnat exam is used to assess moderate or severe HIE to determine eligibility for TH. Brain magnetic resonance imaging (MRI) after rewarming establish site and severity of injury and are useful for prognosis. Prechtl’s Assessment of General Movements (Prechtl) is used as screening and diagnostic tool for functional assessment at 40-60 weeks post-menstrual age. The relationship between Sarnat exam, MRI injury and Prechtl exams are unclear.

Objective: To evaluate the association between the initial Sarnat exam, brain injury on MRI, and General Movement assessment using the Prechtl exam.

Design/Methods: Infants ≥ 35 weeks gestation assessed for HIE by one or more Sarnat exams within 6 hours of age. Sarnat exam data in all 6 categories (level of consciousness, spontaneous activity, muscle tone, posture, primitive reflexes, autonomic responses) were collected. Brain MRIs were obtained following TH. Prechtl exams were conducted at either 0-2 months or at 2-5 months to assess for writhing or fidgety movements respectively. Data were analyzed using Chi-square and student t-tests.

Results: 45 infants had initial Sarnat exam, brain MRI and Prechtl exams. 20 (44%) were female. The mean (SD) gestational age was 37 (2.0) weeks and birth weight was 3062g (671.7) grams. Median [IQR] Apgar were 1 [1, 2.5] and 5 [3, 6] at 1 and 5-minutes respectively.
MRIs were evaluated at median 5 [5,6] and 11 [11,11] days. On initial Sarnat exam, autonomic changes (heart rate) were associated with deep nuclear gray injury (DNGM, p=0.04) and subdural/epidural hemorrhage (p=0.04); abnormal primitive reflexes with white matter injury (WMI, p=0.03) and muscle tone correlated with severe intra-ventricular hemorrhage (p=0.018) on the first MRI.
25 infants (56%) were examined by Prechtl at 0-2 months post-term age and 20 infants (44%) were examined at 2-5 months post-term age. Abnormalities in spontaneous activity on the Sarnat exam (consciousness) correlated with decreased writhing movements (p = 0.007) while abnormalities in posture correlated with decreased fidgety movements (p = 0.001). DNGM injury on 2nd MRI correlated with decreased fidgety movements (P = 0.044).

Conclusion(s): Sarnat exam correlates with brain injury on first MRI and Prechtl examination after discharge. The study also confirms the association between DNGM injury and decreased fidgety movements, an early marker for cerebral palsy (CP).