Pathology I Flashcards
effects of lesion in frontal lobe
Disinhibition and problems with concentration, judgement
Reemergence of primitive reflexes
effects of lesion in frontal eye fields
If its a destructive lesions such as MCA stroke - eyes look towards side of lesion
If its an irritive lesion such as seizure - eyes look towards shaking limb
effects of lesion in paramedian pontine reticular formation
ipsilateral gaze palsy (cannot look toward the side of the lesion)
What is the paramedian pontine reticular formation
Brain region in the pons that coordinates eye movements - especially horizontal gaze/saccades
Coordinates the eyes looking in the same direction
What is the medial longitudinal fasciculus?
Links the nerves that control eye movements (CN III, CN IV, CN VI) and integrates eye movements with head movements
Findings with a lesion in the medial longitudinal fasciculus
Impaired adduction of eye on ipsilateral side and nystagmus of eye on contralateral side with abduction
effects of lesion in dominant parietal cortex
Agraphia, acalculia, finger agnosia, left-right disorientation (confusion of left and right limbs)
effects of lesion in nondominant parietal cortex
agnosia of the contralateral side of the world
a lesion in the dominant parietal cortex results in which syndrome?
Gestmann syndrome
a lesion in the nondominant parietal cortex results in which syndrome?
hemispatial neglect syndrome
effects of lesion in hippocampus (bilateral)
anteriograde amnesia
effects of lesion in basal ganglia
can result in tremor at rest, chorea, athetosis
effects of lesion in subthalamic nucleus
contralateral hemiballismus
effects of lesion in mammillary bodies
memory loss
An example of a lesion to the mammilary bodies is seen in which syndrome?
Wernicke-Korsakoff
Wernicke-korsakoffe presentation
confusion, ataxia, nystagmus, opthalmoplegia, memory loss, confabulation, personality changes
effects of lesion in amygdala (bilateral)
Results in Kluver-Busy syndrome - disinhibited behaviour - hyperphagia, hypersexuality, hyperorality
Viral cause of Kluver-Busy syndrome?
HSV-1 encephalitis
Lesion in dorsal midbrain causes which syndrome?
Parinaud syndrome
Parinaud syndrome presentation
vertical gaze palsy, pupillary light-near dissociation, lid retraction, convergence-retraction nystagmus
effects of lesion in reticular activating system
reduced levels of arousal and wakefulness (coma)
effects of lesion in cerebellar hemisphere
intention tremor, limb ataxia, loss of balance
IPSILATERAL deficits
effects of lesion in red nucleus (midbrain)
Decorticate posturing if lesion is above red nucleus
Decerebrate posturing if lesion is at or below red nucleus
effects of lesion in cerebellar vermis
truncal ataxia, nystagmus
Chronic alcohol use is associated with a lesion where?
cerebellar vermis
Which scan detects ischemic injury within 3-30 min?
MRI
Which scan detects ischemic injury within 6-24 hours?
CT
Histology of ischemic stroke at 12-24 hours
Eosinophilic cytoplasm + pyknotic nuclei (red neurons)
Histology of ischemic stroke at 24-72 hours
necrosis + neutrophils
Histology of ischemic stroke at 3-5 days
macrophages
Histology of ischemic stroke at 1-2 weeks
reactive gliosis (astrocytes) + vascular proliferation
Histology of ischemic stroke at >2weeks
glial scar
What is neonatal intravenricular hemorrhage
bleeding into the ventricles
which babies are at risk for intravenricular hemorrhage
premature and low-birth-weight infants
Where does the bleeding orginate in neonatal intravenricular hemorrhage?
germinal matrix (highly vascularized region within the subventricular zone)
how does neonatal intravenricular hemorrhage present?
altered consciousness, buldging fontanelle, hypotension, seizures, coma
Which artery is rupted in a epidural hematoma?
middle meningeal
presentation of epidural hematoma
loss of consciousness -> recovery (lucid interval) -> rapid deterioration due to hematoma expansion
what will a CT of an epidural hematoma look like
biconvex hyperdense blood collection that does not cross suture lines
What ruptures in a subdural hematoma?
bridging veins (venous bleed)
causes of a chronic subdural hematoma?
mild trauma, cerebral atrophy, elderly, alcoholism, shaken baby
what does a subdural hematoma look like on CT ?
crescent-shaped hemorrhage that crosses suture lines. May cause a midline shift.
Causes of a subarachnoid hemorhage?
bleeding due to trauma, ruupture of an aneurysm, arteriovenous malformation
What will be seen on a lumbar puncture of someone with a subarachnoid haemorrhage?
bloody or yellow lumbar puncture
What is a common complication of someone with a subarachnoid hemorrhage?
Vasospasm or rebleed 3-10 days laters
Increased risk of communicating/obstructive hydrocephalus
How to prevent vasopspasm/rebleed in a patient who has had a subarachnoid hemorrhage?
nimodipine
What is the most common cause of an intraparenchymal haemorrhage?
systemic hypertension
What is amyloid angiopathy associated with?
Intraparenchymal hemorrhage
Where do intraparynchemal hemorrhages commonly occur?
putamen/internal capsule
Complication of intraparenchymal hemorrhage
Contralateral hemiparesis and hemisensory loss
Which areas of the brain may be effected with a MCA stroke?
motor and sensory cortexes --- upper limb and face Temporal lobe (wernickes), frontal lobe (brocas)
What areas of the brain may be effected with a ACA stroke?
motor and sensory cortexes of the lower limb
Which areas may be effected with a stroek in the lenticulostriate-artery?
striatum, internal capsule
How will a patient who has had a stroke in the lenticulostriate artery present?
Contralateral paralysis without cortical signs (aphasia, visual loss, etc).
presentatin of a patient who has had a MCA stroke?
contralateral paralysis and sensory loss —- face and upper limb
If in dominant hemisphere -aphasia
If in nondominant hemisphere - hemineglect
Which areas will be affected in a patient with an anterior spinal artery stroke?
Lateral corticospinal tract
Medial lemniscus
caudal medulla (hypoglossal nerve)
Medial medullary syndrome cause
infarct of the paramedian branches of the ASA and or vertebral arteries
areas effected in someone with a posterior inferior cerebellar artery stroke
Lateral medulla (nucleus ambiguus CN IX, X, XI)
Vestibular nuclei
Lateral spinothalamic tract, spinal trigeminal nucleus
Sympathetic fibers
Inferior cerebellar peduncle
Presentation of someone with an ASA stroke
Tongue deviated towards side of lesion (ipsilateral)
Contralateral paralysis of upper and lower limbs
Decreased contralateral proprioception
Presentation of someone with a PICA stroke
Dysphagia, hoarseness, decreased gag reflex, hiccups
Vomiting, vertigo, nystagmus
Decreased pain and temp sensation from contrateral body and ipsilateral face
Ipsilateral horner syndrome, ipsilateral ataxia
What is the name of the syndrome seen in someone with a PICA stroke?
Lateral medullary (Wallenburg) syndrome
Areas effected in someone with an AICA stroke
Lateral pons (facial nucleus)
Vestibular nuclei
Spinothalamic tract, spinal trigeminal nucleus
Sympathetic fibers,
middle and inferior cerebellar peduncles
Labyrinthe artery
Presentation of someone with an AICA stroke?
paralysis of the face - decreased lacrimation, decreased salivation, decreased taste from anterior tongue
vomiting, vertigo, nystagmus, decreased pain and temp sensation from controlateral body and ipsilateral face
Ipsilateral horner syndrome
Ipsilateral ataxia, dysmetric
Ipsilateral sensorineural deafness/vertigo
What is the name of the syndrome seen in someone with an AICA stroke?
Lateral pontine syndrome
Areas effected in someone with a basilar artery stroke?
pons, medulla, lower midbrain
Corticopsinal and corticobulbar tracts
Ocular cranial nerve nuclei, paramedian pontine reticular formation
Presentation of someone with a basilar artery stroke?
RAS spared so there is preserved consciousness
Quadriplegia: loss of voluntary facial mouth and tongue movements
Loss of horizontal but not verticle eye movements
What is the name of the syndrome seen in someone who has had a basilar artery stroke?
Locked in syndrome
What area is affected in someone who has had a posterior cerebral artery stroke?
occipital lobe
Presentation of someone who has had a PCA stroke?
contralateral hemianopia with macular sparing
Alexia without agraphia
What is central poststroke pain syndrome?
neuropathic pain due to thalamic lesoins
Initial parasthesias followed by allodynia
(10% of stroke patients)
What causes diffuse axonal injury?
traumatic shearing forces during rapid acceleration/decceleration
Presentation of patient with diffuse axonal injury
coma or persistant vegetative state
MRI findings of patient with diffuse axonal injury
multiple lesions (punctate hemorrhages) involving the white matter tracts