Presenting History
When evaluating an infant or young child with progressive head enlargement or a spinal swelling (Neural Tube Defect / Meningomyelocele), obtain an exhaustive chronological account of symptoms differentiating communicating from non-communicating (obstructive) hydrocephalus, and assessing associated spinal cord tethering and lower limb paralysis.
- Head Enlargement & Inability to Hold Neck: Inquire about the onset and rate of head circumference expansion. Ask if the infant has difficulty lifting or holding the head upright due to excessive craniocervical weight.
- Signs of Raised Intracranial Pressure (Age-Dependent):
- Infants (<2 years, open sutures): Bulging, tense, non-pulsatile anterior fontanelle, splayed cranial sutures, shiny scalp with prominent engorged veins, irritability, high-pitched "cerebral cry", and poor feeding.
- Children (>2 years, closed sutures): Morning headaches, projectile vomiting without preceding nausea, lethargy, diplopia, and failing school performance.
- Ocular & Cranial Nerve Manifestations:
- Inquire about downward deviation of the eyes where the sclera is visible above the iris (Sunset Sign / Setting Sun Phenomenon due to tectal compression of the periaqueductal gray).
- Inquire about inward eye turning (CN VI palsy) or blindness.
- Spinal Lesion & Lower Extremity Deficits (in Meningomyelocele / Spina Bifida):
- Inquire about the location, size, and fluid leakage from the spinal cystic swelling.
- Inquire about flaccid or spastic weakness of the lower limbs, foot deformities (clubfoot / talipes equinovarus), and loss of sensation in the perineum.
- Sphincter & Autonomic Dysfunction: Inquire about continuous dribbling of urine (overflow incontinence due to neurogenic bladder), lax anal sphincter, constant soiling, or severe constipation.
Negative History (3C 1D Framework)
| Category | Pertinent Negative Question | Rationale / Significance |
|---|---|---|
| Causes (Etiology) | History of maternal periconceptional folic acid deficiency, fever with rash (TORCH), or valproate use? | Folic acid deficiency and valproate/carbamazepine use are major causes of Neural Tube Defects (NTDs); intrauterine CMV/Toxoplasmosis causes congenital aqueductal stenosis. |
| Causes | History of neonatal meningitis, prolonged NICU stay, or intraventricular hemorrhage (IVH)? | Post-hemorrhagic (in preterms) and post-meningitic (fibrosing basal arachnoiditis) are the leading acquired causes of communicating hydrocephalus. |
| Causes | History of male maternal relatives with large heads, adducted thumbs, and spasticity? | Points to Bickers-Adams Syndrome (X-Linked Aqueductal Stenosis - L1CAM mutation) with clasped/adducted thumbs. |
| Complaints (Chiari II) | History of inspiratory stridor, apnea, hoarse cry, or swallowing difficulty? | Detects Arnold-Chiari Malformation Type II (herniation of cerebellar vermis and medulla through the foramen magnum, causing brainstem compression). |
| Complications | History of shunt malfunction (fever, redness along shunt tract, abdominal pain, drowsiness)? | Identifies Ventriculoperitoneal (VP) Shunt blockage, shunt tract infection, or pseudocyst formation. |
| Differentials (Mimics) | History of large head with loss of attained milestones (neuroregression), startle, or cherry-red spot? | Distinguishes hydrocephalus from Megalencephaly in Neurodegenerative / Storage Disorders (Alexander disease, Canavan disease, Tay-Sachs disease). |
| Differentials | History of prominent familial large head in parents with completely normal milestones and imaging? | Suggests Benign Familial Megalencephaly (autosomal dominant benign condition with normal ventricles). |
Other Relevant History
- Antenatal & Birth History: Antenatal ultrasound detection of ventriculomegaly or lemon/banana sign (spina bifida/Chiari II), mode of delivery (elective cesarean to prevent rupture of meningomyelocele sac), gestational age, and birth weight.
- Developmental History: Detailed assessment across all four domains; weak neck holding is common due to mechanical head weight, but true global delay reflects cerebral mantle thinning.
- Immunization & Nutrition: Document complete immunization and calorie/protein intake.
History Summary
"I would like to summarize the history of this Age in months old Male / Female infant, Birth Order order child born to a Consanguineous / Non-consanguineous couple from Geographic Location, who presented with progressive enlargement of head size since Age at onset, bulging anterior fontanelle, downward deviation of the eyes (sunset sign), and failure to achieve neck holding, with Presence / Absence of a lumbosacral cystic swelling (meningomyelocele), lower limb weakness, and urinary dribbling.
In view of the progressive macrocephaly, dilated scalp veins, setting-sun phenomenon, and Congenital / Post-infectious / NTD-associated etiology, I would like to consider a clinical diagnosis of Hydrocephalus, clinically consistent with Non-Communicating (Aqueductal Stenosis) / Communicating / Chiari Type II Malformation associated with Lumbar Meningomyelocele, with No active signs of acute decompensated brainstem herniation."
General & Head-to-Toe Examination
Pre-Examination Child Behavioral State
- Child State: Infant is quiet, non-crying, lying comfortably in mother's lap (Prechtl State 3: quiet wakefulness).
Cranial & Skull Examination (Pathognomonic Semiology)
- Head Circumference (HC): Measure fronto-occipital circumference across the widest prominence. Classify as Macrocephaly if HC $> +2\text{ to }+3\text{ SD}$ above the mean for age/sex.
- Cranial Shape & Proportions:
- Craniofacial Disproportion: Small triangular facies dwarfed by a huge, globular, ballooned calvarium.
- Frontal Bossing: Prominent, overhanging forehead with depressed nasal bridge.
- Occipital Prominence: Prominent shelf-like occiput (seen in Dandy-Walker malformation with posterior fossa cyst).
- Fontanelles & Sutures:
- Anterior Fontanelle: Markedly widened, tense, bulging, non-pulsatile.
- Splayed cranial sutures: Sagittal, coronal, and metopic sutures are widely separated ($>0.5\text{–}1.0\text{ cm}$).
- Scalp Semiology:
- Dilated Scalp Veins: Engorged, distended, tortuous collateral scalp veins radiating from the forehead to the occiput (due to compression of the sagittal sinus).
- Scalp skin appears thin, stretched, and shiny.
- Percussion & Transillumination:
- Macewen's Sign ("Cracked Pot Sound"): Percussion over the junction of the frontal, parietal, and temporal bones produces a resonant cracked-pot sound due to suture diastasis and ventricular dilatation.
- Transillumination Test: In a dark room with a cold light source, transillumination halo $>2.5\text{ cm}$ indicates severe cerebral mantle thinning ($<1\text{ cm}$) or hydranencephaly.
Ocular Signs
- Setting Sun Sign (Sunset Phenomenon): Forced downward deviation of both globes, exposing the white sclera between the upper eyelid and the limbus of the cornea (caused by pressure of the dilated third ventricle and suprapineal recess on the midbrain tectum / periaqueductal gray).
- Fundoscopy: Papilledema (in older children with closed sutures) or pale optic disc (optic atrophy secondary to chronic raised ICP or chiasmatic stretching).
Spine & Perineal Examination (in Spina Bifida / Meningomyelocele)
- Spinal Defect: Document location (cervical, thoracic, lumbar, sacral), size, epithelial covering, cerebrospinal fluid leakage, or ulceration.
- Lower Limb Neurological Status: Lower motor neuron flaccid paralysis (paraplegia), loss of deep tendon reflexes, and associated bilateral Talipes Equinovarus (Clubfoot).
- Sphincters: Patulous, lax anal sphincter; absence of anal wink reflex on pinprick stimulation of the S4–S5 dermatome; full bladder with expressible urinary dribbling (neurogenic bladder).
Systemic Examination: Central Nervous System
1. Motor System Examination
- Upper Limbs: Bulk, power (5/5), and tone usually preserved.
- Lower Limbs:
- In Pure Supratentorial Hydrocephalus: Periventricular pyramidal tract stretching produces Spastic Paraparesis or Quadriparesis (clasp-knife hypertonia, adductor spasm, brisk knee/ankle jerks, sustained clonus, extensor plantars).
- In Lumbosacral Meningomyelocele: Lower motor neuron Flaccid Paraplegia with hypotonia, absent reflexes, and wasting below the spinal defect level.
2. Cranial Nerves
- CN II: Sluggish pupillary light reaction; visual impairment.
- CN VI: Unilateral or bilateral lateral rectus palsy (convergent strabismus).
- CN IX, X, XII: Bulbar signs (stridor, vocal cord palsy, apnea in Chiari II).
Final Summary & Diagnosis
"On examination of this Age in months old Male / Female infant, cranial examination reveals macrocephaly with a head circumference of Observed HC in cm (>+3 SD), craniofacial disproportion, bulging tense anterior fontanelle, splayed cranial sutures, dilated scalp veins, positive Macewen's sign, bilateral setting-sun eye phenomenon, and Presence / Absence of a lumbosacral meningomyelocele with Lower motor neuron flaccid paraplegia / Pyramidal spastic paraparesis and neurogenic bladder.
Final Diagnosis: I formulate my diagnosis as a case of Congenital / Acquired Hydrocephalus, clinically consistent with Non-communicating Aqueductal Stenosis / Communicating Hydrocephalus / Chiari Malformation Type II with Lumbosacral Meningomyelocele, with Spastic Diplegia / Flaccid Paraplegia, and No signs of active shunt infection or ascending ventriculitis."