Chapter 122: Nervous System Disorders

Cranium & extracranial hemorrhages · Traumatic head injuries · IVH & PVL · Hypoxic-ischemic encephalopathy (HIE) · Spine & peripheral nerve injuries
🧠 Key topics: Germinal matrix IVH grading · MOMS trial for MMC · Therapeutic hypothermia · EEG/aEEG prognostication

🧠 Neonatal Neurocritical Care: Core Concepts

🩸 Intracranial hemorrhage (IVH)
Grades I-IV (germinal matrix). Highest risk <30 wk. Antenatal steroids reduce severe IVH. Post-hemorrhagic hydrocephalus may require shunt.
⚪ Periventricular leukomalacia (PVL)
Cystic or diffuse white matter injury. Risk: prematurity, hypoxia, inflammation. Predicts cerebral palsy (spastic diplegia).
❄️ Hypoxic-ischemic encephalopathy (HIE)
Therapeutic hypothermia (33.5°C for 72h) reduces death/disability. Moderate-severe HIE. MRI (DWI) best for early injury.
🧬 Myelomeningocele (MMC)
MOMS trial: prenatal repair <26 wk reduces VP shunt (40% vs 82%) and improves motor outcomes.
💪 Brachial plexus injury
Erb palsy (C5-C6): waiter's tip. Klumpke (C8-T1): hand weakness + Horner. Most recover spontaneously.
📊 EEG prognostication
Burst suppression, low voltage, or isoelectric background in HIE predicts poor outcome. aEEG used for hypothermia candidates.
📌 HIE predictors of poor outcome: Apgar 0-3 at 10 min, severe acidosis (pH<6.7), need for CPR, seizures onset <12h, severe BG/thalamic injury on MRI.

🔍 Approach to neonatal neurologic emergencies

1
Seizures – Stabilize ABCs, bedside glucose, Ca, Mg, electrolytes. Load phenobarbital (20 mg/kg). Video-EEG to confirm and quantify.
2
Suspected HIE – Assess eligibility for therapeutic hypothermia (≥36 wk, <6h age, moderate-severe encephalopathy, +/- aEEG abnormality).
3
Bulging fontanel + hypotension in preterm – Cranial ultrasound STAT to rule out severe IVH or post-hemorrhagic hydrocephalus.
4
Asymmetric arm weakness after delivery – Examine for Erb palsy (shoulder adduction, internal rotation, forearm pronation). X-ray to exclude clavicle fracture.
5
Hypotonia + poor feeding + cryptorchidism – Consider Prader-Willi, myotonic dystrophy, or spinal muscular atrophy (SMA). Genetic testing.

📋 Stepwise management: HIE, IVH, and MMC

1
Therapeutic hypothermia for HIE – Initiate within 6h of birth. Target rectal/esophageal temp 33.5°C for 72h, then slow rewarming (0.5°C/h). Monitor for bradycardia, thrombocytopenia, fat necrosis.
2
IVH prevention – Antenatal steroids, delayed cord clamping, avoid hyperoxia/hypocarbia, maintain cerebral perfusion pressure, head midline.
3
Post-hemorrhagic hydrocephalus – Serial lumbar punctures if progressive. Neurosurgical evaluation for ventricular reservoir or shunt when ventricle index >97th percentile with tension.
4
Prenatal MMC repair – Candidates: <26 wk, isolated MMC, normal karyotype, no severe kyphosis. Reduces need for VP shunt and improves motor outcomes (MOMS trial).
5
Brachial plexus palsy management – Conservative: passive range of motion, splinting. If no improvement by 3 months, consider neurosurgical exploration.
🧪 HIE biomarkers: MRI diffusion-weighted imaging (DWI) within 3-5 days best detects acute injury; basal ganglia/thalamic involvement predicts poor outcome.

🧠 Rapid reflex prompts – Neonatal neurology

📌 Grades of IVH?
I: germinal matrix only; II: IVH without ventricular dilation; III: IVH with dilation; IV: periventricular hemorrhagic infarction (PVHI).
📌 Imaging modality for early HIE?
MRI with DWI (within 3-5 days) most sensitive. Cranial US for IVH/PVL.
📌 When to start therapeutic hypothermia?
Within 6 hours of birth, ≥36 weeks, moderate-severe encephalopathy.
📌 Which finding on aEEG predicts poor outcome in HIE?
Burst suppression, continuous low voltage, or isoelectric tracing.
📌 Most common neonatal brachial plexus injury?
Erb-Duchenne palsy (C5-C6) – waiter's tip position.
📌 MOMS trial main outcome?
Prenatal MMC repair reduced VP shunt requirement (40% vs 82%) and improved motor outcomes at 30 months.