Cerebrospinal+Fluid

ventricles C shape with extension frontal horn, body, occipital horn, temporal horn 3rd ventricle aaqueduct of sylvius 4th ventricle

choroid plexus in lateral ventricle, 3rd ventricle some in 4th entricle

purupose is to produce CSF...about 80% of CSF part of blood-brain barrier choroidal epithelium--tight junctions CSF production is CP and BP independent production over physiologic ranges arbonic Anhydrase dependent in part

cartoon.... interstitial space... epithelium ventricular space....

to develop concentration gradient, expel bicarbonate into insterstitial space carbonate/chloride exchange pump on basal membrane

20% CSF ceerebral vasculature penedyma pia, arachnoid layer clinically-choroid plexectomy... dpoes not eliminate hydroceplaus because of extra-choroidal cSf production

CSF composition 25% protein (vs 7000 mg/l in plsma) glucose 60 vs 90 mg/dl pH 7.33 vs 7.41 p)2 43 vs 104 K 2.8 vs 4.5 Cl- 119 vs 102 Na_++ 138 vs 138

magendie largely pulsatile as the brain fills wth blood... pulsatile rather than laminar

rachnoid space rubarachnoid space has abroptive proterties

movement of CSF back and forth into CSF itself soe extrecellular CSF movement CSF can moe through ependyma

some debate about how it can be reasrobed olfactory lynphatics periascular spaces other than sagittal sinus dural root sleeves if have treatment for hydrocephalus and fails... shows up wtih stuffy nose...

role of spinal nerve root sleeves

neonate: 25 ml/day, volume 5-10 ml dult: 450 mlday, volume 150 ml
 * remember**

increased intracranial pressure compliane of brain tiself intracranial pressure will depend on size of ventricles and ressponse of brain to compression

the greater the compliance of the brain, the more the symptoms will relate to stretching of fibers

CSF functins protect bain from injury...buoyancy buffer hnages in volume... brain, blood harmonic resonance may allow non-pulsatile capillary blood flow > may be way of translating pulse from one way to other side of capillary role in nutrient/waste managemment---ECM extension

movement of CSF across ependyma CSF flow... opposite arterial pathway

how CSF is relevant... alternative explanations: not completely nderstood......

chiari I and hydrocephalus

chiari malformation... below level of foramen magnum

instead, cerebellum going to have to move forces fluid into middle of spinal fcrd inadequate post fossa volue tonsillar herniation

csf production exceeds CSF reabsorption

hydrocephalus can be divided into obstructive, and communicating

relatively rare... different levels...different patterns... lateral ventricles enlarged...

communicating hydrocelphauls... all ventricles enlarged adult & pediatric

external hydrocephalus..usually benign/self/limiting

normal pressure hydrcephals treatable cause of dementia-elderly

pseydotumor cerebri idiopathic intracranial hyerpension

normal pressure hydrocephalus-> massively compliant normal presure... remember: gait distrubance, dementia, incontinance

Psuedoteumor cerebri classic: obse female headaches visual field loss papilledema normal ventiular size icp...> 25-30 mmHg pathophysiolgoy unknown presumed outflow obstruction low compliance...brain resistess compression

CSF shunt optic nerve sheath venestration optic nerve sheath decomprless optic nerves much more common as treatment options

reverse of normal pressure hydrocephalus

dandy walker variant cyst exposure to intrauterine environment

most hemorrhages occur within 24h of birth 90% within 72 h of brith acute symptoms/signsfotanelle tense apnea/breadychardia posturing seizure drop in hemtocrit or hypotension progressive mcrocephaly

other aquired hypdrocephalus... infection meningitis neurocystericosis mass lesion tumor blocking carcinomatous meningits sarcoidosis

tumor infiltrating role of growth factors....TGFbeta vascular

often related to other underlying disease \symptoms generally dpedent on age, rate of onset

general presentation... overt parinaud's syndrome: sunset eyes coma lethary/sleepiness nausea/vomiting headache

insidious deteriorating intellect visual deterioation

vomiting hydrocephalus adults: ataxia, gait disturbance incontinence dementia imaging: t/mri entricular size teanrependyal CSF flow etiology \ plain films.. split sutures copper beaten skull empty sella diff diag ventriuclar size apnea/bradycardia sutures might not split Apnea/bradiycardia not always rpesent fontanel might not be that tense look for combo of symptos, signs

work out other causes of dementia might be able to treat gait changes first symptom early is most predictive walking problems most dramatic test principle... 70% response rate to CSF shunting

actute: > rapid progression f symptoms 3arly deatth/disability progressive > typically used in newborns surigcal treatment: CSF shunt ttreatment entdoscopic third ventriculostoy CSF shunt

venous pressure generally lower CSF move down one way shunt... making series of incisions creating a tunnel feeding catheter system inserting first into ventricles shunt looks like reseroir to puncture stops fluid goign backwards regulate how much comes out four parts catheter, ventricle rickha reservoir distal tubing punchture through up front

other measure... spirtal staircase... rotating affects cam arm... affects pressure

relatively easy to place, surgically small risk of injury but! problem in keeping devices working

shunt failure after first shunt placement 34% fail at one year 40-65% at two years 3-6^ late ETV failure

management of shunt failure ventriuclar system recogntion

10 yo headache ausea, and vomiting multiple other sick contacts oversesas vacation startst omorrow