Neurology Mike-Mehlman Flashcards
Stroke risk factors ?
- HTN=Carotid arteries=Endothelial damage =Atherosclerotic plaque=Carotid stenosis
2.Atrial fibrillation=Turbulence and Stasis =Left atrial mural thrombus
“How do most strokes occur?” à
“Oh, well the patient will usually have c
Circle of willis affect of STROKE ?
- ACA= Motor/sensory abnormalities of LEG
2.MCA=Motor/sensory abnormalities of ARM & FACE
=Dominant MCA stroke—-Wernick & Broca aphasia
=Non dominant MCA stroke — Hemispatial neglect
3.PCA=Contralateral Homonymous Hemianopsia
=Prosopagnosia (inability to recognize faces)
Stroke syndromes?
- Lateral medullary
syndrome
2.Medial medullary
syndrome
3.Lateral pontine
syndrome
4.Weber syndrome
5.Locked-in syndrome
6.Gerstmann
syndrome
7.Hemiballismus
Lateral medullary
syndrome?
Wallenberg syndrome
- Dysphagia=Posterior inferiror cerebral artery /Vertebral artery stroke
- Horner syndrome=Miosis+Ptosis+Anhidrosis
dysphagia + ipsilateral Horner syndrome after a stroke.
Medial medullary
syndrome ?
ipsilateral tongue deviation
=stroke Anterior spinal artery
Lateral pontine
syndrome?
- ipsilateral Bells palsy after a stroke.
- stroke of anterior inferior cerebellar artery (AICA)
Weber syndrome ?
- Midbrain stroke.
- The answer for ipsilateral CN III palsy (i.e., down and out eye) + contralateral
spastic hemiparesis (weakness).
Locked-in syndrome ?
- Basilar artery stroke.
- The answer for inability to move entire body except for eyes
Gerstmann
syndrome ?
- Stroke=Angular gyrus of parietal lobe
- Tetrad
=Agraphia
=Acalculia
=Finger agnosia
=Left right disassociation
Hemiballismus ?
Stroke of subthalamic nucleus
=- Causes “ballistic” flailing of contralateral arm and/or leg.
For example, if they say patient has
random flailing of left arm follow
Lenticulostriate strokes ?
HTN causing lipohyalinosis of these small, penetrating vessels =Small lenticulostriate arteries deep within the brain
The USMLE doesn’t give a fuck about the specific types of lacunar
defic
Charcot-Bouchard
microaneurysms ?
e tiny (<1mm) aneurysms can form within
lenticulostriate arteries that can bleed an cause hemorrhagic strokes /
intraparenchymal (intracerebral) bleeds.
which Necrosis in nervous sytem ?
Liquefactive necrosis
What wiil be seen in Ischemic infraction of the CNS ?
“Red neurons”
=This refers to their strong eosinophilic (pink) staining with H&E.
“Red neurons”
Macrophage of brain ??
Microglia are the resident macrophages of the CNS. They phagocytose necrotic brain/spinal tissue.
Scar formation of CNS which cell ?
Astrocytes are the glial cells (non-neuronal cells of CNS/PNS) that proliferate and become a glial scar
(gliosis).
Wallerian degeneration ?
Wallerian degeneration is a term that refers to degradation of an axon/myelin sheath distal to the site of injury.Both PNS and CNS neurons undergo Wallerian
degeneration
regeneration occurs within the PNS, not CNS. WHY ?
This is because PNS Schwann cells can
regenerate myelin, whereas CNS oligodendrocytes do not effectively regenerate myelin post-injury.
why degeneration
of the optic nerve results in permanent blindness ???
The optic nerve is considered an extension of the CNS and is myelinated by oligodendrocytes; the other
cranial nerves are part of the PNS and are myelinated by Schwann cells. This distinction is why degeneration
of the optic nerve results in permanent blindness, whereas other facial nerves (e.g., CN VII for Bell’s palsy)
have better regenerative potential.
Other vascular DDx causing neuro Sx ?
- Subclavian steal syndrome
- Vertebral artery stenosis
- Vertebral artery dissection
Subclavian steal syndrome ?
Suclavian artery=1st branch=Vertebral artery
Narrow in branch point of vertebral artey =Low pressure in VA =Backflow of blood = DIZZINESS
Blood pressure is different between the two arms.
Subclavian steal syndrome ?
USMLE question pattern
2 pattern ………………….
- they’ll give you dizziness in
someone who has BP different between the arms and then ask for merely
“subclavian steal syndrome,” or “backflow in a vertebral artery” as the
answer
2.they’ll give you BP in one of the arms + give you dizziness,
then the answer will be, “Check blood pressure in other arm.”
- Next best step in Dx is CT or MR angiography
- I should point out that probably ¾ questions on USMLE where blood
pressure is different between the arms, this refers to aortic dissection. But
¼ is subclavian steal syndrome. As per my observation.
Vertebral artery stenosis ?
=Unexplained dizziness
=But no pressure difference in both hands
=ATHEROSCLEROSIS
“Vertebrobasilar insufficiency” is a broader term that refers to patient
“Vertebrobasilar insufficiency” is a broader term that refers to patients
who have either subclavian steal syndrome or vertebral artery stenosis.
Vertebral artery dissection ?
1.False lumen =By dissection of VA =stasis and clot formation =Embolize brain & cause STROKE
VA Dissection DRUG ?
- NBME can mention recent visit to a chiropractor (neck manipulation is
known cause). - The answer on the NBME is [ heparin ] for patients who have experienced
posterior stroke due to vertebral artery dissection. Sounds weird because
it’s arterial, but it’s what USMLE wants. Take it up with them if you think
it’s weird
Aphasia types ??
- Wenicke
- Broca
- Conductive
- Global
- Transcortical sensory
- Transcortical motor
Wernicke Aphasia ??
- Can make word=But meaningLess
- Comprehension Impaired
- Repitition impaired
- Temporal lobe=MCA Infarct
Broca aphasia ?
- Repitation impaired
- Frontal lobe=MCA
- NON-FLUENT Aphasia
patient has “telegraphic speech”), where there is frustration in
not being able to communicate despite comprehending normally, akin to trying to
communicate in a second language.