Congenital Hydrocephalus (Aqueductal Stenosis) in a Very Low Birth Weight Preterm baby with Failure to thrive

by kh-ima-admin | July 11, 2023 6:05 am

MAA Kauvery Paediatric Intensive Care Team

Paediatric Intensive Care is one of the challenging and fast growing fields of medicine. We handle kids up to the age of 18 years who are critically ill. Apart from General Paediatric Critical care it has branched into Cardiac critical care, Transplant and Onco critical care. It’s mentally and emotionally difficult to see little kids suffering. But we work day and night with these little lives and help them to recover from the critical illness. Apart from continuously acquiring the knowledge and skills to handle these sickest kids, it’s utmost important to be empathetic and supportive to the parents who really go through a tough time when their lovable little one’s get critically ill. Many times it’s really stressful and tiring as a paediatric Intensivist, but when we see a kid coming back with an innocent smile, we tell ourselves, it’s all worth it. Rightly said “Pure happiness is found in nothing but in the innocent smile of a baby” which keeps us motivating.


3 months old male, very low birth weight (1.4 Kg on presentation and 650 gms at birth) preterm baby (Gestation age on admission 37 weeks and at birth 25 weeks) was brought by parents with history of gradual increase in head size for last 3 weeks , difficulty in feeding, loss of weight and lethargy.

Birth history: Baby is a 2nd twin (1st twin died in NICU at 1 week age) delivered through preterm labour to a primi mother with no significant antenatal morbidity. Postnatal period, baby was on mechanical ventilator support (1 dose surfactant given) for 2 days followed by high flow oxygen support (8 weeks of NICU stay and discharged). No history or evidence suggestive of birth asphyxia, Intracranial haemorrhage, seizures, meningitis.

After discharge Parents have shown the baby to their Paediatrician for the complaint of increasing head size, who has asked for a CT brain which suggested Obstructive hydrocephalus required neurosurgical intervention. But it was denied considering the low birth weight and failure to thrive.

On admission, the baby was severely dehydrated (HR-180, pulse + , RR- 42, no distress, SPO2 – 96%), Skin turgor increased,lethargic) with sunset sign and Macrocephaly (HC- 37.5 cm , > 97th percentile as per Fentons chart).There were no neurocutaneous markers or any other significant systemic examination findings and the spine was normal. Initial lab reports showed severe hyponatremia (S.Na- 111.3 mEq/L), Hyperkalemia (5.83 mEq/L), Metabolic acidosis, elevated CRP, Urine pus cells (10-12/hpf) and normal renal function. Child was resuscitated with volume bolus and was started with IV antibiotics, NG feeds (Expressed Breast Milk + Human Milk fortifier) and other supportive medications (Caffeine, Domstal, Iron, calcium and vitamin supplements). Hyponatremia of prematurity was slowly corrected over next 4 days by adding 3%NS (2-4 meq/kg/day) in NG feed by maintaining Osmolarity of the feed. Neurosurgery team did a percutaneous CSF aspiration to decrease the raised ICP, through Rt.Coronal suture (45 ml of clear CSF aspirated). CSF study showed 20 cells (60% N, 40% L) with Glucose- 30 mg/dl (blood glucose – 92), Protein- 256 mg/dl. Endoscopic third ventriculostomy was planned after correction of Electrolyte abnormalities and adequate management of sepsis. Oral acetazolamide and low dose Lasix was started after correction of electrolyte and metabolic derangements. IV antibiotics were continued for 14 days, meanwhile overall nutritional status of the baby improved (Weight -1.83 kg) with HC remained constant. MRI brain with spine showed gross dilatation of the bilateral lateral and 3rd ventricles with relatively normal sized fourth ventricle – likely aqueductal stenosis. Blood, urine and CSF cultures did not show any growth. PRBC transfusion was given in view of anaemia (Hb-7.5).

After 14 days, Endoscopic third ventriculostomy with choroid plexus fulguration was done under GA. Postoperative period was uneventful and the antibiotics were continued for a total of 21 days. On discharge the baby was on spoon feeds and direct breastfeeds trials with consistent weight gain (1.9 Kg). ROP screening was done, which showed Bilateral zone 1 recurrent ROP with plus disease and right eye lifted retinal vessels with Neo vascularisation. Laser therapy was started by Pediatric Ophthalmologist. BERA was done after discharge which was found to be normal.

Discussion:

In our patient, in the background of hydrocephalus, managing hyponatremia of prematurity with failure to thrive was challenging, as the fortified feeds along with 3% Sodium chloride increased the osmolarity of feeds and caused frequent feed intolerance.

Hydrocephalus is defined as an increase in the fluid containing spaces of the brain at increased pressure, resulting from impaired circulation and/or absorption of CSF or, in rare circumstances, from increased production of CSF by a choroid plexus papilloma.

Epidemiology: Incidence in newborn ranges from 0.3 to 4 per 1000 live births. Occurring as a single congenital disorder, the incidence has been reported as 0.9 to 1.5 per 1000 births. The incidence of paediatric hydrocephalus has declined in many developed countries as a result of antenatal screening, genetic testing, early pregnancy termination and better perinatal management of preterm babies.

Etiology & Pathophysiology: Hydrocephalus is usually classified as Non-communicating (Obstructive- resulting from obstruction within the ventricular system) and Communicating (absorptive-resulting from obliteration of the subarachnoid cisterns or malfunction of the arachnoid villi). Congenital hydrocephalus is present at birth and often associated with developmental defects, whereas acquired hydrocephalus (post IVH, post meningitis, tumour) occurs after the development of the brain and ventricle. The various subtypes of foetal hydrocephalus are classified according to the mechanism of obstruction to the flow of CSF. These include: primary or simple hydrocephalus with a single point of obstruction to flow; dysgenetic hydrocephalus with complex abnormalities of the CNS, such as the Arnold–Chiari malformation; and secondary hydrocephalus from tumour or bleeding.

Approximately 55% of all cases of hydrocephalus are congenital. Primary aqueductal stenosis, accounts for 5% and aqueductal stenosis secondary to neoplasm, infection, or haemorrhage accounts for another 5%.  Occlusion of the aqueduct of Sylvius results in enlargement of the lateral and third ventricles (proximal to the aqueduct), with relative normalcy of the fourth ventricle (distal to the aqueduct).

Clinical features: Infancy upto 2 years: Accelerated rate of enlargement of head, wide open & bulging AF, Setting sun eye sign (impingement of the dilated suprapineal recess on the brain stem testimony), Irritability, lethargy, vomiting, and failure to thrive.

Children (older than 2 years): Change in personality, Learning problems, headache, vomiting, gait changes, ataxia, Long tract signs (brisk DTR, spasticity, clonus, Babinski sign), papilledema, impaired upward or lateral gaze.

Neuro imaging:

Neurosonogram – Most convenient and cheapest method to demonstrate ventricular enlargement in infants with an open fontanel, particularly for posthemorrhagic hydrocephalus in premature infants and as serial imaging in follow-up. It may not visualise posterior fossa well and not always establish etiological diagnosis.

CT – demonstrates ventricular size and morphology and periventricular lucency, and can reveal underlying pathologies, such as hemorrhage or posterior fossa tumors. Can be used for followup after surgery. Exposure to radiation is the limitation.

MRI – it provides better morphologic and etiological diagnosis.Cine MRI is a technique to measure CSF stroke volume in the cerebral aqueduct and can be used for demonstrating patency of third ventriculostomy fenestration.

Management: Therapy for hydrocephalus depends on the cause.

Medical management (acetazolamide and furosemide) can only provide temporary relief by reducing the rate of CSF production. Surgical – Endoscopic third ventriculostomy (sometimes this procedure might need to be repeated to be effective), ventriculo-peritoneal shunt. The major complication of shunt is, occlusion and bacterial infection.

Prognosis: Prognosis depends on the cause of the dilated ventricles and not on the size of the cortical mantle at the time of operative intervention, except in cases in which the cortical mantle has been severely compressed and stretched. Associated conditions, such as IVH, CNS infection, and hypoxia, may dictate the ultimate prognosis more than the hydrocephalus. Normal intellectual function is present in 40% to 65% of patients who received appropriate treatment. The probability of normal intelligence is enhanced if shunts are placed early and proper function is maintained.

Dr. D. Sivaraman
Associate Consultant – Paediatrics & Intensive Care Specialist
Kauvery Hospital Chennai

Source URL: https://www.kauveryhospital.com/ima-journal/ima-journal-july-2023/congenital-hydrocephalus-aqueductal-stenosis-in-a-very-low-birth-weight-preterm-baby-with-failure-to-thrive/