Hydrocephalus in children and adults by Dr. Shikher Shrestha, FCPS, NEUROSURGERY , NINAS, Nepal
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Transcript of Hydrocephalus in children and adults by Dr. Shikher Shrestha, FCPS, NEUROSURGERY , NINAS, Nepal
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!!!