Neurology Flashcards
supraoptic nucleus of hypothalamus
ADH production
paraventricular nucleus of hypothalamus
oxytocin
lateral area of hypothalamus
hunger, destruction–>anorexia, failure to thrive (infants). Inhibited by leptin.
ventromedial area of hypothalamus
Satiety, destruction (eg craniopharnygioma)–>hyperphagia. Stimuated by leptin.
anterior hypothalamus
cooling, parasympathetic
posterior hypothalamus
heating, sympathetic
suprachiasmatic nucleus
circadium rhythms
Sleep cycle regulation
at night, nocturnal release of ACTH/prolactin/melatonin/NE: SCN–>NE release–>pineal gland–>melatonin
extraocular movement during REM are due to..
activity of PPRF (conjugate gaze center)
VPL of thalamus
input from spinothalamic and dorsal columns/medial lemniscus; pain/temp, pressure/touch, vibration/proprioception; transmits signals to primary somatosensory cortex
VPM of thalamus
input from trigeminal and gustatory pathway; face sensation and taste; primary somatosensory cortex
LGN of thalamus
input from CNII; vision; signals to calcarine sulcus
MGN of thalamus
input from superior olive and inferior colliculus of tectum; hearing; signs to auditory cortex of temporal lobe
VL of thalamus
input from basal ganglia, cerebellum; motor; signals to motor cortex
Lateral lesions of cerebellum
control voluntary movement; tendency to fall toward ipsilateral side
medial lesions of cerebellum
truncal ataxia, nystagmus, head tilting; wide based cerebellar gait; deficits in truncal coordination; bilateral motor deficits
lateral to medial deep nuclei of cerebellum
dentate, emboliform, globose, fastigial (don’t eat greasy foods)
MCP of cerebellum
receives input via contralateral cortex
ICP of cerebellem
receives ipsilateral proprioceptive information (spinal cord) via climbing and mossy fibers
SCP of cerebellum
output tract, purkinje cells–>deep nuclei–>contralateral cortex via SCP
Direct pathway of basal ganglia
D1 receptor; facilitates movement; cortex–>putamen–>GPi–>thalamus–>cortex
Indirect pathway of basal ganglia
D2 receptor; inhibits movement; cortex–>putamen–>GPe–>STN–>GPI–>thalamus–>motor cortex
excitation of GPe:
increase in movement via inhibition of STN and resultant decrease in inhibitory signals from GPi to thalamus
excitation of GPi:
decrease in movement via inhibition of thalamus and a resultant decrease in stimulatory signals to cortex
sudden, wild flailing of 1 arm +/- ipsilateral leg
hemiballismus; contralateral subthalamic nucleus (lacunar stroke)
sudden, jerky, purposeless movements
chorea; basal ganglia–huntingtons
slow, writhing movements; esp in fingers
athetosis; basal ganglia–huntingtons
sudden, brief, uncontrolled muscle contraction
myoclonus; jerks/hiccups common in metabolic abnormalities like renal/liver failure
sustained, involuntary muscle contractions
dystonia
action tremor, exacerbated by holding posture/limb position
essential tremor (postural tremor); genetic predisposition, patients often self medicate with EtOH; tx with B blockers and primidone
uncontrolled movement of distal appendages; tremor alleviated by intentional movement
resting tremor; parkinson disease (pill rolling) tremor
slow zigzag motion when point/extending toward target
intention tremor; cerebellar dysfunction
hyperorality, hypersexuality, disinhibited behavior
Kluver Bucy syndrome, bilateral amygdala lesion; associated with HSV-1
disinhibition and deficits in concentration, orietation, judgment, emergence of primitive reflexes
frontal lobe lesion
spatial neglect syndrome (agnosia of contralateral side of the world)
right parietal-temporal cortex
agraphia, acalculia, finger agnosia, left/right disorientation
left parietal temporal cortex; gerstmann syndrome
reduced levels of arousal and wakefulness (coma)
reticular activating system in midbrain
confusion, ataxia, nstagmus, memory loss (anterograde and retrograde amnesia), confabulation, personality changes
Wernicke Korsakoff, bilateray mammillary bodies
contralateral hemiballismus
subthalamic nucleus
anterograde amnesia
hippocampus, bilateral
eyes looking away from side of lesion
PPRF
eyes look toward lesion
frontal eye fields
nonfluent aphasia with intact comprehension
broca aphasia (brocas area–inferior frontal gyrus of frontal lobe)
fluent aphasia with impaired comprehension and repetition
Wernicke aphasia–superior temporal gyrus of temporal lobe
non fluent aphasia with impaired comprehension
global aphasia; both broca and wernicke lesioned
poor reptition but fluent speech, intact comprehension
conduction aphasia; caused by damage to left superior temporal lobe and or left supramarginal gyrus
nonfluent aphasia with good comprehension and repetition
transcortical motor
poor comprehension with fluent speech and repetition
transcortical sensory
nonfluent speech, poor comprehension, good repetition
mixed transcortical
MCA stroke
motor cortex–upper limb/face; sensory cortex–upper limb and face; temporal lobe (Wernicke area); frontal lobe (Broca area)
ACA stroke
motor cortex–lower limb; sensory cortex–lower limb
lenticulostriate artery stroke
striatum, internal capsule; lacunar infarcts
ASA stroke
lateral corticospinal tract; medial lemniscus; caudal medulla–hypoglossal nerve
PICA stroke
lateral medulla–vestibular nuclei; lateral spinothalamic tract; spinal trigeminal nucleus; nucleus ambiguus, sympathetic fibers, inferior cerebellar peduncle
AICA stroke
lateral pons–cranial nerve nuclei; vestibular nuclei; facial nucleus; spinal trigeminal nucleus, cochlear nuclei, sympathetic fibers; middle and inferior cerebellar peduncles
PCA stroke
occipital cortex, visual cortex
basilary artery stroke
pons, medulla, lower midbrain, corticospinal and corticobulbar tracts, ocular cranial nerve nuclei, PPRF
ACOM stroke
can impinge CNII, ocular defects
PCOM stroke
CN III palsy (eye is down and out) with ptosis and mydriasis
contralateral paralysis–upper limb and face, contralateral loss of sensation–upper limbs and face; aphasia if in dominant hemisphere; hemineglect if in nondominal hemisphere
MCA stroke
contralateral paralysis–lower limb, contralateral loss of sensation–lower limb
ACA stroke
contralateral hemiparesis/hemiplegia
lenticulostriate artery strok; lacunar infarcts 2ndary to unmanaged HTN
contralateral hemiparesis–upper and lower limbs; decreased contralateral proprioception; ipsilateral hypoglossal dysfunction (tongue deviates towards lesion)
ASA stroke, medial medullary syndrome (infarct of paramedian branches of ASA and vertebral arteries)
vomiting, vertigo, nystagmus; decreased pain and temp sensation from ipsilateral face and contralateral body; dysphagia/hoarsness; decreased gag reflex; ipsilateral horner syndrome; ataxia/dysmetria
PICA stroke; lateral medullary syndrome (Wallenberg); nucleus ambiguus effects are specific to PICA lesions (dysphagia, hoarseness)
vomiting, vertigo, nystagmus, paralysis of face, decreased lacrimation, salivation, decreased taste from anterior 2/3 tongue, decreased corneal reflex; ipsilateral loss of hearing/Horner syndrome
AICA stroke; facial nucleus effects specific to AICA lesions
contralateral hemianopia with macular sparing
PCA
Poliomyelitis and spinal muscular atrophy (werdnig hoffman disease)
LMN lesions only due to destruction of anterior horns; flaccid paralysis
Multiple sclerosis
demyelination; affects posterior columns/ random white matter; scanning speech/intention tremor/nystagmus
amyotrophic lateral sclerosis
combined UMN/LMN deficits with no sensory, cognitive or oculomotor deficits
enzyme deficiency that can cause ALS?
superoxide dismutase I
tx for ALS?
riluzole; decreases presynaptic glutamate release
absence of DTRs and + romberg
tabes dorsalis–teritary syphilis affecting posterior columns
bilateral loss of pain/temp sensation usually C8-T1
syringomyelia; syrinx expands and damages anterior white commissure of spinothalamic tract (2nd order neurons)
ataxic gait, paresthesia, impaired position sense, vibration sense
subacute combined degeneration–demyelination of dorsal columns and lateral corticospinal tracts; VitB12 or E deficiency
Friedrich ataxia
AR; GAA repeat on chromosome 9 in gene that codes frataxin–mitochondrial functioning impairment; staggering gait, frequent falling, nystagmus, dysarthria, pes cavus, hammer toes, hypertrophic CM (cause of death); childhood kyphoscoliosis
Parinaud syndrome
paralysis of conjugate vertical gaze due to lesion in superior colliculi
Cribiform plate
CNI
middle cranial fossa–through sphenoid bone
CN 2-6
optic canal
CN2, opthalmic artery, central retinal vein
superior orbital fissue
CN 3, 4, V1, 6, opthalmic vein, sympathetic fibers
foramen rotundum
CN V2
foramen ovale
CN V3
foramen spinosum
middle meningeal artery
Posterior cranial fossa through temporal or occipital bone
CN 7-12
internal auditory meatus
CN 7, 8
jugular foramen
CN 9, 10, 11, jugular vein
hypoglossal canal
CN12
foramen magnum
spinal roots of CN9, brain stem, vertebral arteries