Makindo Medical Notes

📖 About

• A congenital abnormality of neural tube closure affecting the CNS, most often in the lumbosacral region.
• Results from failure of the spinal column to fuse properly, leaving neural tissue vulnerable.
• May cause severe dysfunction of cauda equina roots or conus medullaris.

🧬 Aetiology

• Folate deficiency: Major modifiable risk factor.
• Genetic factors: Account for ~60–70% of cases.
• Drugs: Anticonvulsants (esp. valproate, carbamazepine) increase risk.
• Maternal conditions: Diabetes mellitus, obesity, hyperthermia.

🧠 Features

• The neural tube normally closes by day 28 post-conception.
• In spina bifida, failure of closure leaves neural elements exposed/damaged.
• Common associations: hydrocephalus, Chiari II malformation, neurogenic bladder, recurrent UTIs.

🔎 Types

• Myelomeningocele: Most severe. Sac contains spinal cord + damaged nerves → motor, sensory, sphincter deficits.
• Meningocele: Sac contains CSF and meninges only → little/no nerve damage.
• Spina bifida occulta: Mildest form. Small bony defect, often only visible as tuft of hair/dimple. Often asymptomatic.

💡 Classification: Open NTDs (myelomeningocele, meningocele) vs Closed (occulta).

🩺 Clinical Presentation

• At birth: Visible sac or defect in severe forms.
• Occulta: Subtle skin markers (dimple, hair tuft, lipoma).
• Neurological signs: leg weakness, absent reflexes, bladder/bowel incontinence.

🧪 Investigations

• Maternity screening: Raised maternal serum alpha-fetoprotein (AFP) at 15–16 weeks.
• Ultrasound: 18–20 week anomaly scan detects open NTDs.
• Amniotic fluid AChE: Diagnostic if ultrasound is equivocal.
• Postnatal: MRI spine/brain for associated malformations.

🖼️ Diagram

🛡️ Prevention

• Folic acid 400 mcg daily for all women from pre-conception until 12 weeks gestation.
• High risk women: 5 mg daily (epilepsy, diabetes, obesity, family history).
• Avoid teratogenic drugs (esp. valproate) if alternatives exist.

⚕️ Management

• Prenatal: In-utero surgical closure (improves motor outcomes vs postnatal repair) in selected cases; option of termination in severe cases.
• Postnatal: Early neurosurgical closure to prevent infection/meningitis.
• Hydrocephalus: May require ventriculoperitoneal shunt.
• Orthopaedic: Bracing, physiotherapy for mobility.
• Urological: CIC (clean intermittent catheterisation), anticholinergics, bladder augmentation for neurogenic bladder.
• Multidisciplinary care: Specialist nurses, physiotherapy, urology, orthopaedics, neurosurgery, psychology.

🌟 Summary: Spina bifida is a neural tube defect due to failure of closure by day 28. Risk reduced with folate supplementation. Management requires early neurosurgical repair and long-term multidisciplinary support for mobility, bladder, and bowel function.

Cases — Spina Bifida 🧠🦴

• Case 1 — Spina Bifida Occulta (Mildest Form) 🔍: A 12-year-old girl is found to have a small dimple with a tuft of hair over her lumbosacral spine during a routine exam. She has no neurological deficits and normal bladder function. Diagnosis: Spina bifida occulta. Management: Usually benign, but MRI spine to exclude tethered cord; reassure family; surgery only if symptomatic tethering develops.
• Case 2 — Meningocele 🎈: A newborn boy presents with a fluid-filled sac protruding from the lower back, covered by thin skin. Neuro exam: normal limb movements and bladder function. MRI: meningeal sac containing CSF, no spinal cord tissue. Diagnosis: Spina bifida with meningocele. Management: Surgical repair to prevent infection; long-term prognosis good if no cord involvement.
• Case 3 — Myelomeningocele (Most Severe) ⚠️: A term infant is born with an open defect in the lumbosacral region, with exposed spinal cord and meninges. Exam: flaccid paralysis of lower limbs, absent anal tone, urinary incontinence. Hydrocephalus noted on cranial ultrasound. Diagnosis: Spina bifida with myelomeningocele. Management: Urgent neurosurgical closure, antibiotics, ventriculoperitoneal shunt for hydrocephalus, long-term multidisciplinary care (urology, orthopaedics, physiotherapy).

Teaching Commentary 🧠

Spina bifida = failure of neural tube closure (usually lumbar/sacral). - Occulta: Hidden, no neuro deficit, only skin signs (dimple, hair tuft). - Meningocele: Protruding CSF sac, cord intact → usually no neuro deficits. - Myelomeningocele: Protruding sac containing cord + meninges → severe neurological impairment + bladder/bowel dysfunction. Prevention: Maternal folic acid supplementation before conception and in early pregnancy. Associations: Hydrocephalus (Chiari II malformation), orthopaedic deformities, neurogenic bladder.