Survival Guide Flashcards
C5 myotome (motor, reflex, sensory)
Motor - Deltoid (shoulder abduction)
Reflex - Bicep tendon
Sensory - Lateral upper arm
C6 myotome (motor, reflex, sensory)
Motor - Bicep, extensor carpi ulnaris
Reflex - Brachioradialis
Sensory - Radial forearm, thumb and index finger
C7 myotome (motor, reflex, sensory)
Motor - Triceps, flexor carpi ulnaris/radialis
Reflex - Trcieps
Sensory - Middle finger
C8 myotome (motor, reflex, sensory)
Motor - Finger flexion (grip)
Reflex - None
Sensory - Ulnar forearm, ring and little finger
T1 myotome (motor, reflex, sensory)
Motor - Interossei (finger abduction)
Reflex - None
Sensory - Upper medial forearm and medial arm
L2 myotome (motor, reflex, sensory)
Motor - Psoas
Reflex - None
Sensory - Anterio-med thigh
L3 myotome (motor, reflex, sensory)
Motor - Quads
Reflex - None
Sensory - Medial thigh around knee
L4 myotome (motor, reflex, sensory)
Motor - Tibialis anterior (dorsiflex and foot inversion)
Reflex - Patellar
Sensory - Medial foot
L5 myotome (motor, reflex, sensory)
Motor - EHL
Reflex - None
Sensory - Dorsum foot
S1 myotome (motor, reflex, sensory)
Motor - Gastrocnemius, peroneus longus and brevis (foot eversion)
Reflex - Achilles
Sensory - Lateral foot
S2,3,4 myotome (motor, reflex, sensory)
Motor - External bladder sphincter
Reflex - Bulbocavernosus
Sensory - Perianal area
P1 ICP waveform
Percussion wave, arterial systolic pressure wave
P2 ICP waveform
Tidal wave, reflects brain compliance, vasomotor paralysis, brain swelling or edema
Normally about 80% of P1
Elevated with poor compliance
P3 ICP waveform
Dicrotic wave, aortic valve closure
Increased and becomes one with venous ‘A’ wave in increased ICP
Lundberg A waves
AKA plateau waves are mean waves > 50mmHg lasting 5-20 minutes which then returns to slightly elevated baseline
Reflects maximally dilated vessels d/t low CPP triggering brainstem response and increased MAP
Reflects ischemia
Lundberg B waves
AKA pressure wave
Lower peaks pressure 20-50 mmHg, lasting between 30 seconds to 3 minutes
Due to respiratory changes and changes in CBF
Lundberg C waves
Preterminal waves, mean wave
Normal PbO2 values
Normal is around 30 mmHg (when treating, keep above 20-30 mmHg)
PbO2 values indicating ischemia
Less than 15
Frazier’s point location
6 cm up from the inion, 3-4 cm off midline
Frazier’s point trajectory
Aim catheter toward contralateral medial canthus, hard pass to 5 cm, if getting CSF soft pass to 10 cm
Keen’s point location
Measure 3 cm above and 3 cm behind the top of the pinna
Keen’s point trajectory
Pass the catheter perpendicular to the cortex in a slightly cephalic trajectory
Will hit CSF around 5 cm
Paine’s point location
2.5 cm above lateral orbital roof and 4.5 cm anterior to Sylvain fissure
Paine’s point trajectory
Pass the catheter perpendicular to the brain, CSF should be reached at about 5 cm
MR spec - NAA
Neuronal integrity marker
Decreases with tumor, stroke, epilepsy
MR spec - creatine
Energy source, most stable peak
Increased in hypo-metabolic states
Decreased in hyper-metabolic states
MR spec - choline
Precursor of Ach
Increased from increased cell proliferation or increased number of cells (tumors)
MR spec - lactate
Metabolic - if present, think badness
Necrosis from infection or high grade tumor
MR spec - characteristics seen with malignancy
Decreased NAA as it destroys neurons, and creatine as it depletes energy stores
Increased choline (cell turnover), lactate (necrosis from outgrowing blood supply), and lipid (d/t necrotic center in higher grade neoplasms)
Normal Hunter’s angle
The direction of Hunter’s angle is upward to the right in the normal WM
MR spec characteristics of lymphoma
++choline, - NAA, absent creatine
MR spec characteristics of GBM/mets
+choline, - NAA, - creatine, +++lactate
MR spec characteristics of abscesses
absent choline, absent NAA, absent creatine, +++lactate
Typical location of intraventricular colloid cyst
Foramen of Monro/third ventricle
Typical location of intraventricular meningioma
Trigone of lateral ventricle
Typical location of intraventricular choroid
Fourth ventricle
Typical location of intraventricular ependymoma
Lateral ventricle (more common in children) and 4th ventricle
Typical location of intraventricular neurocytoma
Lateral ventricle (involving septum pellucidum)
Typical location of intraventricular mets
Lateral ventricle, ependyma, and choroid plexus
Typical imaging features of sellar/parasellar pituitary macroadenoma
Enlarged sella turcica, strong enhancement, sometimes hemorrhagic (apoplexy)
Typical imaging features of sellar/parasellar meningioma
Broad dural base with tail, enhancement along planum sphenoidale, hyperostosis
Typical imaging features of sellar/parasellar Schwannoma
T1-hypo and T2-hyperintense, strong enhancement (CN V most common)
Typical imaging features of sellar/parasellar chordoma
Bone destruction on CT, heterogenous signal and enhancement on MRI, respects dura
Typical imaging features of sellar/parasellar chondrosarcoma
Bone destruction and calcification on CT, T2-hyperintense on MRI
Typical imaging features of sellar/parasellar Rathke’s cleft cyst
T1-hyperintense, smooth peripheral enhancement
Typical imaging features of sellar/parasellar dermoid
Hypodense on CT and T1-hyperintense on MRI
Typical imaging features of sellar/parasellar epidermoid
Isodense to CSF on CT and MRI T1 and T2 imaging, brighter than CSF on FLAIR and DWI
Typical imaging features of sellar/parasellar optic glioma
Thickening of chiasm, spread along optic pathways
Typical imaging features of sellar/parasellar germ cell tumor
Located in midline, intense enhancement, often with pineal germinomas
Commonly calcified lesions
Oligodendrogliomas (90%), choroid plexus tumors (papillomas), ependymoma, central neurocytoma, meningioma, craniopharyngioma, teratoma, chordoma
Commonly hemorrhagic lesions
GBM, oligodendrogliomas, mets (melanoma, lung, breast)