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CNS [Meth 1]

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alkathryn's version from 2016-11-08 01:23

Brain Anatomy

Question Answer
brain tumors most commonly involvenuroglia
Cerebrum is thelargest portion
Two hemispheres are connected bycorpus callosum
How many brain lobesfour
Where do we inject for lumbar puncturesL5
Cerebellum is thesecond largest portion
Cerebellum is separated from cerebrum bytransverse fissure
Cerebellum functioncontrols skeletal muscle contraction for movements, coordination, posture, and balance
Cerebellum locationInf/post portion of cranial cavity, posterior to medulla and pons
How much O2 is consumed by the brain20%
The brain's principle source of energyglucose
Dural sinuses drain blood intojugular veins
Ventricles areCSF-filled cavitie within the brain
CSF is found insubarachnoid space
CSF is produced bychoroid plexus
CSF functionprotection :: removes waste from the brain and spinal cord, and delivers nutritive substances
CSF volume~150 mL
BBB function*prevents harmful substances from entering brain tissues
BBB allowsnutrients essential to brain tissue to cross the barrier
Movement of substances across the BBB is controlled byeither active transport or degree of lipophilicity of the cells
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Pathology

Question Answer
Alzheimers *** is due to atrophy of the ____ lobesfrontal and temporal
Parkinson's is a neurodegenerative disorder of the CNS
Parkinson's producesmovement disorders and changes in cognition and mood
Subdural hematoma locatedbetween dura mater and arachnoid
Subdural hematoma caused bytrauma
Intracerebral hematoma is caused byhead trauma or nontraumatic forms
Stroke is whenblood flow to the brain is disrupted and brain cells lose their blood supply of nutrients
Stroke risk factorscarotid stenosis, HTN, obesity, smoking, high cholesterol
Stroke symptomssudden weakness and loss of vision, difficulty speaking
2 types of stroke areischemic and hemorrhagic
Ischemic stroke ismore common
Hemorrhagic stroke isless common but more deadly
Transient Ischemic Attacks aretemporary with no permanent damage
TIAs caused bytemporarily blocked artery to the brain
TIA symptomsblurry vision, weakness or numbness in arm or hand, slurred speech
Aneurysms arethin-walled dilation off of an artery
Aneursms develop wherean artery branches and the wall is weak
Aneurysm symptomsblurred vision, double vision, headache
Treatment for aneurysmclip
Two types of brain tumorsgliomas, meningiomas
Gliomas aremalignant
Meningiomas arebenign
Gliaoms arise fromglial cells
Meningiomas arise frommeniges
50% of all brain tumors aremetastatic disease from a malignant tumor
Hydrocephalus is anaccumulation of excessive amounts of CSF within the ventricles of the brain
Types of hydrocephalusnormal pressure, communicating & non-communicating
Hydrocephalus treatmentCSF shunt from the ventricles of the brain to the peritoneal cavity
Otorrhea isleakage of CSF from the external auditory canal (ears)
Otorrhea usually results fromprior ear surgery or trauma to the skull
Rhinorrhea isdischarge of spinal fluid from the nose
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Brain Imaging SPECT

Question Answer
Indicationseval of blood flow, cerebrovascular diseases, neuropsychiatric disorders, cerebral ischemia, convulsive disorders, hematoma/tumors/lesions/abscesses, AVM (arteriovenous malformation)
Contraindicationspatients too agitated to cooperate
Patient prepbe able to lie still for study, inject in quiet low-lit room
Hydrophilic rphxspertechnetate, Tc-99m DTPA
Lipophilic rphxsHMPAO Ceretec, ECD neurolite
ECD akabicisate, neurolite
HMPAO akaceretec, hexamethylpropyleneamine oxime
HMPAO/ECD dose20-30 mCi
HMPAO/ECD MOLpassive diffusion
Patient positioning for flowsupine AP chin tucked down
When to image for SPECT30 mins to 3 hours post-inj
Which cross the BBBlipophilic Ceretec and Neurolite
Flow phasesarterial, capillary, venous
Arterial phasesubclavian, carotid, cerebral arteries
Capillary phasesymmetric diffuse activity in both cerebral hemispheres
Venous phasesagittal sinus seen
Blood poolsoft tissue activity seen
Normal delays increased activity incerebral cortex, sagittal, transverse and occipital sinus and salivary glands
Normal SPECTsymmetric uptake
Abnormalsareas of increased activity, lack of uptake or diminished flow
Abnormal flow/poolfocal areas of increased or decreased uptake
Abnormal delaysfocal areas of increased or decreased uptake
Abnormal SPECTasymmetrical areas of increased or decreased activity
Abnormal SPECT Alzheimers presents ASdecreased perfusion in PARIETAL & TEMPORAL lobes of both hemispheres
Abnormal SPECT Acute Cerebral Infarction presents asabsence of activity related to cereal artery affected by the stroke
Abnormal SPECT in Ictal state presents asincreased activity
Ictal isseizing
Inter-Ictal isnon-seizing
Inter-Ictal presents asnormal or decreased activity
Artifactsmovement, metal plates (attenuation), TIA can fill back in between attacks, uncooperative patients
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Diamox Imaging

Question Answer
Diamox akaacetazolamide
Diamox is acerebral vasodilator, diuretic, anticonvulsant, glaucoma pressure reducer, ventilation stimulant
Diamox is used todifferentiate between areas of brain supplied by normal vessels and those supplied by diseased vessels
Diamox indicationsto determine areas of the brain at risk of infarct in patients with TIA, stroke, or carotid artery disease
Diamox contraindicationsallergies to sulfa drugs
Two part demux test procedureday one with chemical, day two without
Diamox dose1 gram injected over 2 minutes
Imaging time after diamox injection20 minutes
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Brain Death

Question Answer
Brain death dose15-30 mCi
Brain death procedureanterior, bolus flow, blood pool A, P, Lats
Brain death normal/negativecortical perfusion and uptake, cerebral dural sinuses activity, middle and anterior cerebral arteries seen, sagittal sinus seen
Brain death abnormal/positiveabsent cortical perfusion and uptake, no intracerebral perfusion, no dural or sagittal sinus activity
Hot nose ___ indicate brain deathdoes not
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Radionuclide Cisternogram

Question Answer
Indicationseval of CSF flow, hydrocephalus, CSF leak, shunt patency
Patient preplumbar puncture, return times specified, instruct pt not to sit up for 2 hours post-inj, leak placement of pledgets
RphxIn-111 DTPA
Dose500 uCi - 1 mCi
MOLCompartmental
Injection is performed asslow intrathecal inj in L5 into the subarachnoid space of the lumbar spine
Procedure notespt prone, check for extravasation
Imaging times1-2 hours post-inj, delays at 4-6, 24, 48 hours
Imaging acquisitionsAP head, RL Lats
CSF leak positionwhere leak is made worse
CSF leak imaging times2, 4, 6, hours
CSF leak remove pledgets at6 hours
Draw 10 mL blood at6 hours
CSF leak normal 1-2 hoursactivity in spinal CSF space
CSF leak normal 2-4 hoursbasal cisterns fill
CSF leak normal 6 hoursViking helmet
CSF leak normal 24-48 hoursrphx in longitudinal fissure to the subarachnoid space, activity cleared from basal cisterns
CSF leak abnormalsactivity in lateral ventricles
CSF leak hydrocephalus appears asincrease in CSF volume cased by overproduction, decreased absorption, blockage of flow or cerebral atrophy
CSF leak otorrhea or rhinorrhea appears asactivity >3-4 times that of blood
Otorrhealeak from ears
Rhinorrhealeak from nose
Shouldn't see kidneys until24 hours
If you see kidneys immediately, this is indicative ofCSF leak
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