Hypoxic Ischaemic Encephalopathy

A 1-day-old female neonate born via emergency lower-segment caesarean section for suspected placental abruption is admitted to your NICU. Delivery was traumatic; Apgar scores were 2 at 1 minute and 4 at 5 minutes. The infant required intubation and mechanical ventilation for 12 minutes. On day 1, she is lethargic, has absent Moro reflex, and exhibits severe hypertonia with opisthotonus. Serum lactate is 8.2 mmol/L (normal < 2), and CSF analysis shows xanthochromia with RBC 2500/µL. Brain MRI at 18 hours shows extensive T2 hyperintensity in the cortex, white matter, and basal ganglia with restricted diffusion. The attending asks you to prognosticate. Which of the following findings is most predictive of severe neurodevelopmental disability or death in this case?

According to Sarnat and Sarnat staging, which clinical sign is characteristic of Stage 2 (moderate) hypoxic-ischaemic encephalopathy in neonates?