Highlighted content lectures 2.1 & 2.2 Flashcards
If a patient has a gaze toward the side of the lesion, what kind of stroke may they have had?
MCA (middle cerebral artery)
What causes a watershed zone?
When the blood supply to 2 adjacent cerebral arteries is compromised
What are two causes of two adjacent cerebral arteries being compromised? [and thus causing watershed infarction]
1) Sudden occlusion of the internal carotid or
2) A drop in BP in setting of carotid stenosis
What are the 3 main somatosensory and motor pathways? List what each does
1) Lateral corticospinal tract: Motor
2) Anterolateral columns: Sensory; pain, temperature & crude touch
3) Posterolateral columns: Sensory; vibration, fine touch, proprioception
1) Where is the primary motor cortex?
2) Where is the primary somatosensory cortex?
1) Primary motor = precentral
2) Primary somatosensory = postcentral
1) What is the most important descending motor pathway of the nervous system?
2) What does it do?
1) Lateral corticospinal tract
2) Controls the movement of extremities
1) What forms the anterior spinal artery?
2) What supplies most of the cord?
3) What forms the posterior spinal artery?
1) Vertebral arteries
2) Anterior spinal artery
3) Vertebral arteries
Where is venous return for the spinal cord?
Epidural space
Where does pyramidal decussation occur?
At medulla/spinal cord junction
Where does the corticospinal tract go?
Posterior limb
Is the ANS afferent, efferent, or both?
Only efferent pathways
What are the two ANS divisions?
Sympathetic and parasympathetic divisions
1) What do sympathetic neurons release to end organs?
2) What about parasympathetic?
1) Sympathetic: norepinephrine to the end organs
2) Parasympathetic: acetylcholine
What 3 things control the ANS?
Hypothalamus, brainstem nuclei, and the amygdala
What are the 3 long tracts of the spinal cord?
1) Posterior column-medial leminiscal system
2) Anterolateral systems
3) Corticospinal tract
1) What does the Posterior column-medial leminiscal pathway convey?
2) Where does it decussate?
1) Proprioception, vibration sense, and fine touch
2) In lower medulla
What pathway’s nerves cross over at the same level?
Anterolateral pathway **
What can vitamin B12 deficiency affect?
Posterior cord
Anterior cord syndrome damage causes what?
Loss of pain and temperature sensation below the level of the lesion
**anterior spinal artery infarct is a common cause
What are the 4 dermatomes we need to know?
T4 – nipple line
T10 – umbilicus
C6 – thumb (6 shooter)
S5 - perianal
What is the biggest cause of radiculopathy?
Diabetes
1) What can cauda equina syndrome cause?
2) What can this then cause?
1) Saddle anesthesia (sensory loss in S2-5, numbness in inguinal area)
2) Bladder disfunction, constipation, fecal incontinence and loss of erections
Almost all pathways projecting into the cerebral cortex, relay through the thalamus; which one doesn’t?
Olfactory
1) What supply anterior hemispheres?
2) What about posterior hemispheres?
3) What forms the basilar artery?
4) What forms the Circle of Willis?
1) Internal carotid arteries
2) Vertebral arteries
3) Vertebral arteries
4) The anterior and posterior blood supplies form the anastomotic ring
1) What come off the aorta?
2) What does the common carotid arteries split into?
3) List the arteries that supply the cerebral hemispheres
1) Common carotid arteries
2) Internal and external carotid arteries
3) Anterior, middle and posterior cerebral arteries (ACA, MCA, PCA)
What are the anterior and middle cerebral arteries (ACA & MCA)?
The termination of the internal carotids
What supply the Wernicke’s and Broca’s areas?
Middle cerebral artery
What supply the basal ganglia and the internal capsule?
Branches of the MCA
What can cause lacunar infarctions?
HTN
What is the watershed?
The region in-between the 2 adjacent compromised vessels
What are watershed infarcts?
2 adjacent cerebral arteries are compromised
1) What type of stroke is caused by lack of adequate blood supply to the brain for long enough to cause cell death?
2) What can cause it?
1) Ischemic stroke
2) Can be caused by embolus or thrombus
1) What links the anterior cerebral arteries together?
2) What do the posterior communicating arteries do? Be specific
1) The anterior communicating artery
2) Link anterior and posterior circulations; specifically they join the internal carotids and the posterior cerebrals
1) Where does the anterior cerebral artery (ACA) go?
2) What does it supply?
1) Travels forward, splits into 2 main branches, then turns back over the corpus collosum
2) The cortex on the anterior medial surface of the brain from frontal to anterior parietal lobe.
-Includes the medial sensorimotor cortex.
1) Where does the middle cerebral artery (MCA) go?
2) What does it supply?
1) Enters Sylvian Fissure and then splits into 2-4 main branches, which form loops.
2) The cortex above and below the Sylvian Fissure; including the lateral temporal lobe and parts of the parietal lobe.
-Also includes thalamus and posterior limb of the internal capsule
1) Where does the posterior cerebral artery (PCA) go?
2) What does it supply?
1) Curves back off the basilar artery
2) Through its many branches supplies: the inferior and medial temporal lobes and the medial occipital cortex.
1) What artery supplies the medial sensorimotor cortex?
2) What supplies the the inferior and medial temporal lobes?
3) What supplies the lateral temporal lobes?
1) ACA
2) PCA
3) MCA
1) What supplies blood to the thalamus and posterior limb of the internal capsule?
2) What could a lacunar infarction in this area cause?
1) Small branches of the MCA
2) Contralateral hemiparesis
1) What is lacunar infarct syndrome?
2) What is it characterized by?
3) Give examples
1) The clinical manifestations of a lacunar infarct
2) Pure motor hemiparesis.
3) Contra/Unilateral face, arm and leg weakness.
-Location ex/posterior limb of internal capsule.
1) What strokes are most common, MCA, ACA, or PCA?
2) What is its unique symptom?
1) MCA
2) Patients often have a gaze toward the side of the lesion
What two things can watershed infarctions cause?
1) Sudden occlusion of the internal carotid
2) Drop in BP in setting of carotid stenosis
1) How long does a TIA last?
2) Give 4 common causes
1) <24 hours (usually closer to 10 minutes)
2) Migraines, seizures, arrhythmias and hypoglycemia
_____% of patients with TIAs with have a stroke within ___ months and most of those within the next _____ hours
10%; 3 months; 48 hours
What is leading cause of significant disability?
Strokes
1) What are the two main types of strokes?
2) What type of stroke is caused by a thrombus or embolus?
1) Ischemic and hemorrhagic
2) Ischemic
What is the biggest difference between a thrombus and embolus?
1) Embolus: travels
2) Thrombus: doesn’t travel
1) What type of stroke is usually caused by an embolus, large vessel or small vessel?
2) What are small vessel strokes also called?
1) Large vessel
2) Lacunar infarcts
1) What are emboli most often made of?
2) Where do they commonly come from?
1) Most often blood clots.
2) The heart
Define dissection [in the context of strokes]
Tear on the inner surface of an artery
1) What do cortical signs come from?
2) What are they?
1) Lobar strokes
2) Aphasia, neglect, homonymous visual field defects, apraxia, hemiparesis, and sensory loss
What sometimes causes headaches with ischemic strokes?
Innervation of the blood vessels and meninges
What is usually the cause of strokes in younger patients?
Dissection/trauma
What do the internal jugular veins do?
Drain the dural sinuses (which is where the veins that drain the brain go)
