Hydrocephalus in Children and Adults

Shikher ShresthaNINAS

History

Most commonly encountered clinical diagnoses in neurosurgery

Orginin Gk. Hydro- “water” and Kefale “head” – recognized >2000 years

Build up of CSF within intracranial compartments raised ICP

Can develop anytime from fetal period to adulthoood

Grossly the different causes..

Myriad of conditions leading to hydrocephalus:

congenital defectsperinatal insultsacquired conditions – infection, tumor,

traumatic and non traumatic hemorrahage

CSF overproduction rarely

Problem statement..

Sipek et. Al – Czech national registry 1961-2000mean incidence of congenital HCP – 6.35 per 10,000 live

births

Fernell and Hagberg (Sweden)1970s – 6.99 per 10001980s – 25.37 per 10001990s – 13.69 per 1000

Increase trend – increased survival of very preterm infantsIncidence in developing countries may even be higher

History.. Landmark periods..

Recognition dates back to antiquity

5th century BC – Hippocrates – water accumulation within the headGalen – choroid plexus and relationship of CSF to the brain (physiology lacking)17th century – Willis – secretion of CSF by choroid plexus and absorption in the venous system (pathways described was less accurate)1701 – Pacchioni – arachnoid granulations (misidentified as site of production)19th century – current accepted physiology clarified

History contd.. Evolution of Rx – 3 stages

First stage – Renaissancepoor medical understanding of CSF dynamics and

pathologynonsurgical and surgical treatment largely

useless

Second stage (19th and mid 20th century)CSF physiology and pathology elucidatedtreatment option in their infancy

Second stage in the evolution of HCP Rx

1891 – Quincke – lumbar puncture as a diagnostic modality and mean for treating HCP

Keen – drained cerebral ventricles through a temporal approach

Cushing – treated hydrocephalus by a lumbar peritoneal connection with encouraging result

1910 – Lespinnase – choroid plexus coagulation by using endoscope (cystoscope) for cannulation of cerebral ventricles.

1922 – Dandy –Third ventriculostomy via subfrontal approach

1923 – Mixter – first endoscopic third ventriculostomy for non communicating hydrocephalus using Urethroscope

1939 – Torkildsen – valveless rubber catheter to connect the lateral ventricles with the cisterna magna for non communicating hydrocephalus

Third stage of evolution..

1950 - Development of silicon shunts with unidirectional valves

Nulsen and Spitz – stainless steel unidirectional ball valve connected to rubber catheter to divert ventricular CSF to jugular vein

Variations and improvement of valve over the years

VP shunt – standard surgical treatment (though historically and in current practice, various sites described and identified)

Resurgence of endoscopy and third ventriculostomy for non communicating hydrocephalus obviating the inherent complication of foreign material in the body

Cerebrospinal Fluid and Pathophysiology of HCP

Clear, colorless fluid

Produced mostly by – choroid plexus of lateral, third and fourth ventricles

<20% - interstitial space and ependymal lining

Dura of nerve root sleeves – in spinal compartment

95% of production by ventricular choroid plexus – lateral ventricles

CSF

Infant – 50 ml (total volume)Adult – 150 ml (total volume)

Distribution – 50% cranial cavity and 50% spinal cavity

Rate of production:newborns – 25 ml/dayadult – 500 ml/day (0.3-0.35 ml/minute)

ICP – newborn – 9-12 mm Hg; adult – 18-20 mm Hg

Rate of CSF production NOT dependent on ICP

CSF absorption in arachnoid villi (close proximity to dural venous sinuses) – dependent on ICP

Monro-Kellie Doctrine – within the rigid container of the skull, the sum of intracranial contents, including CSF, blood and brain, is constant.Exception: children less than 2-3 yrs where fontanelle is not closed

CSF flow

N.B. dysregulation in production, absorption, or circulation of CSF can lead to symptomatic hydrocephalus

Etiology

HCP due to overproduction:Choroid plexus tumors

occurs more commonly in children younger than 2 yrs

account for <1% of intracranial tumorsChoroid plexus villous hypertrophy – treated with

coagulation

Due to obstruction Obstruction of foramina of Monro – congenital

atresia, membranes or gliosis after hemorrhage – Unilateral ventriculomegaly

Etiology

Obstructive causes:cysts and tumors in third ventriclethird ventricular colloid cysts (anterosuperior

part of third ventricle) - <2% of intracranial tumors – acute or chronic hydrocephalus

Rx – stereotactic aspiration, endoscopic resection or open microsurgery

arachnoid and ependymal cysts/ dermoid cysts (rarely)

craniopharyngiomasgliomas (hypothalamic astrocytomas and SEGA)

Hydrocephalus may persist after resection of tumor due to operative hemorrhage and scarring after surgery

Obstruction at sylvian aqueductneonate (0.2 -0.5 mm size) – therefore more risks of

obstructioncongenital malformation (stenosis, forking, septum formation

and subependymal gliosis)true luminal obstruction uncommonAVM and periaqueductal tumors – tectal glioma and pineal

tumorNewer methods of Rx – endoscopic aqueductoplasty + stenting

Fourth ventricular or basal foramina obstructionDandy Walker Malformation

large posterior fossa cyst with cerebellar vermian hypoplasia

cerebellar atrophyTumor of posterior fossa and 4th ventricle

adult- mets, glioma, meningioma, neuroma, hemangioblastoma

pediatric – medulloblastoma, ependymomas, cerebellar

astrocytoma and brainstem glioma

Obstruction around base of skull – Chiari Malformation

Obstruction at the level of arachnoid granulation – idiopathicinfectionsubarachnoid hemorrhagetraumatumor

Properties of surrounding parenchyma ie., compressibility is important

If brain parenchyma attenuates the increase in intraventricular pressure overall ICP does not rise above the normal levels in the setting of abnormal transventricular pressure gradient NPH

It is not clear if parenchymal damage play primary or secondary role in the development of NPH

Classification of HCP

Gower (1888) classification

Acute or chronicacute – rapid decompensation due to raised ICPchronic – idiopathic or secondary to known

pathological conditionlower or normal ICP

Primary or secondary

secondary – tumors, hemorrhage, trauma, infection

Etiology and Clinical presentation

InfantsPost Hemorrhagic Hydrocephalus (PHH)

due to intraventricular or germinal matrix hemorrhage

intraventricular blood fibrosing arachnoiditis, meningeal fibrosis and subependymal gliosis alteration of CSF flow

congenital malformations – Aqueductal stenosis, Dandy walker etc

Intrauterine infectionsOlder children – tumor, trauma and infection

Symptomatology

Apnea and bradycardiaBulging anterior fontanelleHead circumference (increases rapidly - 0.5 cm to 2 cm per week)Parinaud’s sign – lateral rectus and vertical gaze palsyPoor feeding, vomiting, irritabilityMacrocephaly (normal head circumference in full term – 33-36cm)Bulging fontanelleSplaying of cranial suturesFrontal bossing, Prominent scalp veins, sunsetting sign; Collier’s sign

Older children with neoplasm and trauma

headache (dull, typically upon awakening)vision changes (blurry or double vision)lethargy, vomiting, decreased food intakebehavioral disturbances, poor school performanceendocrinopathies (short stature, precocious puberty)

O/E – papilledema, lateral rectus palsy, hyperreflexia, clonus, Cushing’s triad

IN adults..

Acute (generally high pressure)

tumor, posterior fossa infarcts, SAH, infectionHCP closely follows the causative diseasegeneralized headaches worse on lying downnausea, vomiting, vision changes (blurring,

diplopia), papilledemalateral rectus palsies, ataxia and mental status

change

Chronic HCP:

insiduous symptoms; apparent over weeks, months or years

idiopathic or secondary to known pathological process

cognitive dysfunction including dementia, intellectual and behavioral changes, urinary incontinence, motor difficulties

vision changesskull changes – thinning and widening of suture

lineEg. Tumors obstructing CSF pathways

Pseudotumor cerebri/ IIH

Non hydrocephalic clinical entity with raised ICP Both pediatric and adult group affected Ventricles are not enlarged and are usually small Diagnosis of exclusion Overweight women Unclear pathophysiology but venous stasis and

effects of hormone leptin implicated Symptoms of headache and papilledema 25% develop visual deterioration due to optic nerve

atrophy

Dandy 1937, original criteria

Smith’s modification, 1985

Diagnosis of HCP

In utero diagnosis – USG and fetal MRI

CT scan – current standard imaging for diagnosistransependymal edemasigns of raised ICP – sulcal/gyri effacementobliteration of subarchnoid spaceEvan’s ratio: Frontal horn width to maximal biparietal diameter

– if >0.3 then indicative of HCP

Cisternography/ Ventriculography (in select case) – shows compartmentalization of cyst and its communication with CSF (Dandy walker and trapped fourth ventricle)

Transfontanelle USG

MRI – for the cause like tumor

MRI CSF flow study

Invasive ICP monitoring in certain settings when symptoms and imaging do not correlate

Dutch NPH study (Boon et al) – positive predictors of outcome from shunting were observed in patients whose CSF was about 18 mm Hg/ ml/min

Eide and Stanisic (Norway) – suggested CSF pulsatility determined by ICP wave amplitude can help identify clincal responders to shunting

Eide and Sorteberg –

93% of those with increase CSF pulsatility (ICP waveform >4mm Hg amplitude on average) showed response to shunting as opposed to 10% of those without increased pulsatility.

Normal Pressure Hydrocephalus

Much studied and debated topic since the initial seminal work from the Massachusetts General Hospital in 1964

60-80 yrs – affected age group

Classic triad – gait disturbance, urinary incontinence, dementia (Hakim’s/Adam’s)

Gait – apraxic or magnetic gait – first symptom notedSlow, wide base shuffling walking pattern

Urinary frequency and urgency progress to incontinence owing to bladder hyperactivity

Dementia is subcortical in nature (c/f vascular and neurodenerative disorders like alzheimer’s, Lewy body dementia are cortical)

apathy, psychomotor retardation, inattention presentapraxia, aphasia and agnosia are NOT seen

CT/MRI findings – ventriculomegaly with no evidence of extrinsic obstruction to CSF flow; Transependymal flow seen occasionally only

Management:Miller Fischer test - 40-50 ml CSF withdrawn in conjunction

with detailed examination before and after the procedure to document clinical response to CSF removal in terms of intellectual function, memory, gait and continence

Symptomatic improvement – shunt responsive (PPV – 73% -100%)

Prolonged external CSF drainage of 300ml CSF – higher sensitivity and higher positive predictive value (PPV) – 80-100%

more invasive and higher complications

Treatment of Hydrocephalus

Non surgical

Surgical

Nonsurgical..

Medications to decrease CSF productionAcetazolamide (100mg/kg/d)

carbonic anhydrase inhibitorFurosemide (1mg/kg/d)

loop diuretic• Especially studied in infants with posthemorrhagic hydrocephalus• International Posthemorrhagic Ventricular Dilatation Trial Group

studied their use study stopped prematurely as the data showed increased neurological sequelae and increased shunt placement

• Side effects like metabolic acidosis, electrolyte imbalance and diarrhea

Medication to promote CSF absorption – Hyaluronidase

Medication to decrease ICPosmotic diuretic- mannitol, urea and glycerol

Other non surgical means – head wrapping and intermittent CSF removalHead wrapping – creates a constant force high enough to promote increased CSF absorption in infants with unfused skulls not a common practice due to complications including raised ICP

Surgical Management

Non shunting Vs CSF shunting options

Non shuntingEndoscopic Third VentriculostomyResection of obstructing lesion causing

hydrocephalusChoroid plexus ablation

CSF shunting option..

CSF shunts entail using silicone polymer silastic tube

Diverts CSF from ventricles to body cavities where it can be reabsorbed (peritoneum, cardiac atrium, pleura)

Shunting systems have 3 componentsproximal catheter that drains the intracranial ventriclesone-way valve systemdistal tubing that diverts CSF to its final body cavity destinationoccasionally anti-siphon devices also included to prevent

overdraining

Different types of valves used..

Pressure-dependentmost commonly usedallows CSF flow across the valve when the pressure

differential exceeds its preset opening pressure

Flow controlledallows constant flow of CSF across different pressure

gradients with different patient positionsDrake et. Al. 344 pts shunted with different valve systems (pressure/valve with antisiphon device/flow controlled) compared no difference in failure rate

Pressure programmable valvesthe preset pressure can be changed by extrinsic

devices without requiring surgery to change the valve itself

Studies show both programmable and conventional valves have similar safety and efficacy profiles

programming device work through magnetic field interaction; hence the valve settings should be evaluated and reprogrammed appropriately each time after the patient undergoes MRI

VP Shunt..

Involves ventricular cannulation and tunneling of a distal subcutaneous catheter to the peritoneal cavity

Ventricular cannulation can be done through frontal, occipital or parietal catheter

Frontal horn through Kocher’s point, occipital horn through Frazier’s point and the trigone through a parietal approach at Keen’s point

Frameless stereotactic guidance and endoscope assisted ventricular catheter placement are gaining popularity when ventricles are difficult to cannulate

Other sites for drainage

If peritoneum not an option – peritonitis

Alternative sites – cardiac atrium or pleura

VA shunt- open cervical approach to cannulate the internal jugular vein or common facial veinmodified Seldinger’s technique for percutaneous insertion of the

distal tube through the subclavian vein via peel away catheter into the rt. Atrium

Complications – migration out of atrium, cardiac embolism and immune mediated glomerulonephritis

V-pleural shuntsecond intercostal space accessed on the superior aspect

of the rib to prevent injury to the neurovascular bundle

pleura opened at the end of expiration and the catheter inserted under direct visualization

wound irrigated while the patient is ventilated

not practical for children <4 yrs due to associated pleural effusion and respiratory compromise

Lumboperitoneal shuntdifficult ventricular cannulation as in slit ventricle syndrome

L4-L5 interspace accessed and subarachnoid space cannulated via Tuohy needle

Catheter tunneled to the peritoneal cavity and secured in lumbar fascia

Complications: overdrainage, which are more difficult to assess and control, difficulty in pressure regulation, lumbar nerve root irritation, progressive cerebellar tonsillar herniation, arachnoiditis and arachnoid adhesion

Other distal sites of CSF drainage if problems with diverting to the common locations (peritonitis, subacute bacterial endocarditis, pleural adhesions/effusions)

Gallbladderureterurinary bladder

Post op follow up of shunted patient

Postoperative CTbaseline evaluation of ventricular systemcatheter position

Radiograph programmable valve to confirm the valve settingVA shunt – to look for pneumothorax

Complications of Hydrocephalus treatment

Shunt infections

Rate: 5-15%>70% infections – develop within 1 month90% - within 6 months

Presentation:low grade fevers, headaches, malaise, elevation of

inflammatory markers (ESR, CRP), erythema along the shunt tract, symptoms of malfunction (obstruction)

severe – bacteremia, peritonitis, ventriculitis, bacterial endocarditis, pleural empyema, peritoneal pseudocyst (USG/CT abdomen)

Most common organism – coagulase negative Staphylococcus aureus

Other organisms (less common) – gram positive (streptococci, enterococci), gram negative and anaerobic (Proprionibacterium acnes)

Treatment of shunt infection

Broad spectrum antibiotics initially then tailored to the specific

offending organism once isolated in culture

Intrathecal antibiotics

Externalization or removal of shunt

External ventricular drainage

Considerable variation as for the duration of antibiotic therapy

and how long to keep EVD

CSF cultures to be sterile at least 72 hrs before replacing shunt

Antibiotic impregnated shunt catheters

Recent retrospective study of 353 shunt placements – 2.4 fold decrease in infection rate with antibiotic impregnated catheters

other series – modest effect

Shunt Malfunction

Underdrainagedue to obstruction or disconnectionpresentation – symptoms of raised ICP

Proximal obstructioncatheters migrating towards choroid plexusmigration to brain parenchyma or subependymal space – continued

head growth in children or ventricular collapseDistal obstructiondisconnection due to movement and growth spurtsmultiple tubing connectors – risk for disconnectioncalcification of distal tubing leading to shunt fracturedislodgement from peritoneum in children with growth spurt if

inadequate length

Evaluation of patient with shunt obstruction

CT headevaluation of ventricles comparing it with

previous scansthose with altered ventricular complaince – no

change in size even with functioning shunt

Shunt Seriesradiograph of skull and body along the peripheral

shunt tractallows for evaluation of the continuity of the

distal tubing

Radionuclide scansrequires injection of a tracer into the reservoir

Valve examination at the bedsidecompressed against skullif depresses and does not refill – obstruction

reservoir accessed percutaneously with 23-25 gz butterfly – good flow indicates proximal part is patent

Management - obstruction

Prompt operative revision

Most malfunctions – secondary to occlusion of ventricular catheter

If resistance to removing of obstructed catheterstylet inserted and monopolar cautery used along

the stylet to free it from the tethering tissue (choroid plexus adhesions)

or new catheter inserted

Shunt malfunction from overdrainage

Presentation – low pressure headache

Pudnez and Foltz review – 10-12% incidence; usually within 6.5 yrs from the time of initial placement

complications: sudural hematomas [ipsilateral (more common)/ contralateral/both]

intracranial hypotensioncraniosynostosis and microcephalyslit ventricle syndrome

Valve pressure upgrades and addition of antisiphoning device may help

Slit Ventricle Syndrome

headaches lasting from 10-90 minutes

imaging studies showing small ventricles and slow refill of pumping devices

Uncommon complications..

Treatment Outcomes

Depends on underlying pathology, response to shunting and overall neurological comorbid factors

Casey et. Al 155 shunted children; 10 yrs follow up59% - goes to school44% - did not require revisionmost common complication – infection and

obstruction (most in 1 yr)11% mortality during 10 yrs

Billard et alIQ – 75% patients have IQ > 70many children – marked decrease in visual spatial

skills

lower IQ in patients with hydrocephalus due to infection as opposed to other causes

Endoscopic Treatment of Hydrocephalus

More likely to be successful in patients with acquired or late occlusion of the sylvian aqueduct

The results of ETV in young children are not as good as those in older children or adults

Technique

Patient supine with the brow up

Coronal burr hole just medial to the midpupillary line

Lateral ventricle entered and the endsoscope passed through the foramen of Monro into the third ventricle

Fenestration performed anterior to the mamillary body and posterior to the infundibular recess, through thinned tuber cinereum using blunt probe

Fenestration enlarged using balloon catheter; Image guidance can be used to facilitate the trajectory

Outcome after ETV

Sacko et al (France) – 368 casesoverall success 68.5%

Factors related to increased failure of ventriculostomyage < 6 mohemorrhage related or idiopathic hydrocephalus

Morbidity 10%; 97% failure within 2 months

Various success rates quoted 70-80% in different studies

Most successful - >10yrs age; aqueductal stenosis and those with no previous shunt

Other roles of neuroendoscopy

treatment of multiloculated hydrocephalusendoscopic cyst fenestrationfenestration of septum pellucidum

Recent studies have suggested a role for ETV for communicating hydrocephalus as well

Thank you!!!