Chapter 22: Neurology

Neural tube defects · Hydrocephalus · Neurocutaneous diseases (NF1, tuberous sclerosis, Sturge-Weber, ataxia-telangiectasia)
🧠 Key concepts: Spina bifida management, Chiari malformations, VP shunt complications, cutaneous markers of neurofibromatosis (café-au-lait spots), tuberous sclerosis (ash-leaf spots, subependymal nodules), and seizures.

📖 Neural tube defects, hydrocephalus & neurocutaneous syndromes

🧬 Neural tube defects (NTD)
Open defects: myelomeningocele (most severe), meningocele, anencephaly. Closed: lipomeningocele, tethered cord. Prenatal folic acid (5mg) reduces recurrence.
💧 Hydrocephalus
Communicating (post-haemorrhagic, meningitis) vs non-communicating (aqueduct stenosis, Chiari, Dandy-Walker). VP shunt complications: blockage, infection, overdrainage, slit ventricles.
🫘 Neurofibromatosis type 1 (NF1)
Diagnostic criteria: ≥6 café-au-lait spots, axillary/inguinal freckling, Lisch nodules, optic glioma, bone dysplasia, first-degree relative. NF2: bilateral vestibular schwannomas.
⚡ Tuberous sclerosis complex (TSC)
Cardinal features: hypopigmented ash-leaf spots, facial angiofibromas, subependymal nodules, cardiac rhabdomyomas, seizures (infantile spasms). TSC1/TSC2 genes.
🧩 Sturge-Weber & ataxia-telangiectasia
Sturge-Weber: facial port-wine stain (V1), ipsilateral leptomeningeal angioma, glaucoma, seizures. Ataxia-telangiectasia: telangiectasias, cerebellar ataxia, immunodeficiency, high AFP.
⚠️ Key red flags in neurocutaneous disorders: New-onset seizures in infant with hypopigmented macules → Wood’s lamp exam; progressive ataxia + telangiectasia → IgA deficiency, AFP; facial port-wine stain + contralateral hemiparesis → neuroimaging.

🩺 Clinical approach: neural tube defects & neurocutaneous signs

1
Antenatal diagnosis of NTD – Elevated maternal serum AFP, ultrasound (spinal defect, lemon sign, banana sign). Folic acid 5 mg preconception for high-risk mothers.
2
Newborn with myelomeningocele – Cover defect with sterile saline-soaked gauze, avoid trauma, start IV antibiotics (to prevent meningitis), head ultrasound for hydrocephalus, early neurosurgical closure (24–48h).
3
VP shunt failure: presentation – Headache, vomiting, sunsetting eyes, increasing head circumference, drowsiness, bulging fontanelle. Shunt series X-ray (disconnection), CT (ventricular enlargement), shunt tap (infection/block).
4
Neurocutaneous red flags on skin exam – Wood’s lamp for ash-leaf spots (TSC); >5 café-au-lait >0.5cm (prepubertal) suggests NF1; port-wine stain (V1) + ipsilateral glaucoma/ seizures → Sturge-Weber.
5
Evaluation of suspected neurofibromatosis – Ophthalmology (Lisch nodules, optic glioma), MRI brain/orbits, BP monitoring (renal artery stenosis), developmental assessment, genetic counselling.
📌 Clinical pearl: Any infant with a sacral dimple or hair tuft over spine → ultrasound/spinal MRI to rule out tethered cord or diastematomyelia. Atypical dimple: >5mm, off-midline, deep, associated skin lesion.

📋 Management algorithms: NTD, hydrocephalus & neurocutaneous diseases

1
Hydrocephalus (newly diagnosed) – Urgent neurosurgical referral. Temporary CSF diversion if severe (external ventricular drain). Definitive: VP shunt (most common) or endoscopic third ventriculostomy (ETV) for obstructive hydrocephalus.
2
Shunt infection management – Most common <6 months post-op: Staphylococcus epidermidis. Externalisation of shunt, IV antibiotics (vancomycin + ceftazidime), then new shunt after sterile CSF.
3
Tuberous sclerosis: infantile spasms – Urgent EEG. First-line: vigabatrin (especially if TSC-related) or high-dose prednisolone. Early treatment improves developmental outcome. Seizure control with everolimus for subependymal giant cell astrocytoma (SEGA).
4
NF1 complications surveillance – Annual ophthalmology (optic pathway glioma), MRI if proptosis/vision loss; monitor blood pressure (pheochromocytoma/renal artery stenosis); scoliosis surveillance; cognitive/behavioural support.
5
Sturge-Weber: seizure and glaucoma management – Low-dose aspirin to reduce stroke-like episodes? Controversial. Antiepileptic drugs (oxcarbazepine, levetiracetam). Glaucoma treatment (topical medication, surgery). Laser for port-wine stain.
🚨 Shunt emergency: signs of increased ICP – If child is obtunded or has signs of herniation, urgent neurosurgical intervention. CT + immediate shunt tap (rule out block/infection).

🧠 Neurology reflex prompts: NTD, hydrocephalus & neurocutaneous syndromes

🧬 A newborn with a lumbosacral myelomeningocele. Immediate next step?
Sterile saline dressing, antibiotics (ampicillin+gentamicin/cefotaxime), head ultrasound to rule out hydrocephalus, neurosurgical closure within 48h.
💧 A 6-month-old with VP shunt presents with vomiting, sunsetting eyes, and bulging fontanelle. Most likely cause?
Shunt obstruction (proximal or distal). Emergency: CT head, shunt series X-ray, neurosurgery referral. Shunt tap to assess function.
☕ A 4-year-old with 8 café-au-lait spots (>1cm), axillary freckling, and Lisch nodules. Diagnosis?
Neurofibromatosis type 1 (NF1). Also monitor for optic glioma, bone dysplasia, hypertension.
⚪ An infant with infantile spasms, Wood’s lamp shows hypopigmented ash-leaf spots. Diagnosis?
Tuberous sclerosis complex. Brain MRI: subependymal nodules, cortical tubers. Vigabatrin first-line.
🍷 A neonate with extensive port-wine stain in V1 distribution. What complication must be screened?
Glaucoma (ipsilateral) and leptomeningeal angioma → Sturge-Weber syndrome. MRI brain with contrast, ophthalmology assessment.
🧬 Recurrence risk of neural tube defect after one affected child?
2–3% risk; folic acid 5 mg daily preconception reduces recurrence by 70%.
🧪 What is the most common organism causing VP shunt infection in children?
Coagulase-negative staphylococci (Staphylococcus epidermidis). Late infection: Propionibacterium acnes.
🧬 A child with ataxia, oculocutaneous telangiectasia, and recurrent sinopulmonary infections. Likely diagnosis?
Ataxia-telangiectasia (ATM gene). High AFP, IgA deficiency, lymphoma risk.
🩺 A newborn with a sacral dimple, hair tuft, and normal neurological exam. Investigation?
Spinal ultrasound (or MRI) to exclude tethered cord, diastematomyelia, or dermal sinus tract.
🧠 What is the most common type of hydrocephalus in children?
Aqueductal stenosis (congenital or acquired). Non-communicating → ETV effective.