General Review Flashcards
Cingulate herniation under falx cerebri
compresses?
ACA
Downward transtentorial herniation (central)
compresses?
Sx?
Brainstem, can cause impaired vertical gaze, bilateral miosis, –> coma/ death
Classical uncal herniation can cause?
ipsilateral CN IIII palsy
contra/ipsi hemiparesis
Cerebellar tonisillar herniation thru foramen magnum can cause?
respiratory depression
brain tumor - adults
GFAP+
Butterfly glioma, crosses corpus callosum
Glioblastoma Multiform
Brain tumor
Arise from arachnoid cells, usually benign, resectable, spindle cells in a whirled pattern w/ calcifications, = psommoma bodies
Meningioma
Brain tumor
S100+, a/wNF-2
presents w/ hearing loss/ tinnitis, ataxia, dizziness
Schwannomas
Brain tumor
Frontal lobes, rare, slow growing
Chicken wire capillaries, fried egg cells, often calcified
Oligodendroglioma
MC locations for pediatric brain tumors?
cerebellum and brainstem
Infratentorial > supratentorial > midline
Infratentorial tumors cause ICP because?
compression of 4rth ventricle
MC childhood brain tumor most in the posterior fossa hyalinization of blood vessels BRAF: cerebellar V600E: extra-cerebellar
pilocytic astrocytoma
Highly malignant childhood brain tumor Primitive neuroectoderm can compress 4rth ventricle > increasing ICP can send drop mets Homer Write rosettes
Medulloblastoma
Perivascular pseudorossettes int he 4rth ventricle
Rod shaped plepharaplasts
Poor prognosis
Ependymoma
cerebellar tumor
a/w VHL, retinal angiomas
Can produce EPO
Foamy cells, high vascularity
Hemangioblastoma
Rathke’s pouch, calcification
MC supratentorial tumor
Craniopharynioma
Pain transmission in migraine:
CN?
Nucleus?
Release of what causes what?
CN V1 - innervates dura, meninges, cerebral arteries/ veins
CN VII: Superior Salivatory Nucleus: vasodilation’
Increase in CGRP acts on CRL receptor causing mast cell degranulation and vasodilation
Extreme severe headache over one eye, conjunctival injection, rhinorrhea, non-pulsing
Acute tx: oxygen, sumatriptan (blocks CRGP release)
cluster headache
Bandlike/ occipital, steady, no photo/phono phobia
Tension
Light inhibits the retinal ganglion cells w/ melanopsin
Darkness stimulates the retinal ganglion cells which signal the?
suprachiasmatic nucleus (Master clock)
Master clock signals?
Paraventrcular nucleus –> SNS in superior cervical ganglion –> pineal gland to release melatonin into the brainstem
Awake brain activity
alpha and beta
stage 1 & 2 sleep
theta, sleep spindles
Stage 3 & 4 sleep
delta, increased amplidude
frequency > 13 Hz
Beta (cholinergic)
frequency 8-13 Hz
Alpha
frequency 4-7
Theta
frequency <4
Delta
REM sleep components
Beta and Theta
increases in frequency & duration toward the morning
lost as we age
Cholinergic neurons in the PPT and LDT
Active?
Inactive?
Active in wakefulness and REM sleep
Not active in NREM
Beta waves
Noradrenergic: Locus cereleus
Neurons most active in wakefulness, some in NREM sleep, none in REM sleep
DA neurons
Active during wakefulness
SIlent during REM
Seratonergic neurons from raphe nucleus:
Wake: highest activity
NREM: some
REM: none
Histaminergic
Tuberomamillary nucleus
Wake: highest
NREM: some
REM: none
Orexin/ Hypocretn
Lateral hypothalamus
Suprachiasmatic/ paraventricular nucleus (light/dark)
excitatory, increases wakefulness
Narcopleptics have decreased orexin
Role of VPLO?
Inhibits nuclei that promote arousal
Lesions of the VPLO > insomnia
