Stroke
Factors in
Rehabilitation
Anthony Munson, M.D.
Medical Director,
Christiana Care Stroke Program
Outline
Stroke Basics
Neuroanatomy
Neuroimaging
Stroke symptoms
Stroke syndromes
Subacute complications
Ischemic Stroke
Two subtypes by general mechanism:
– Thrombotic
More common
Current theory: Atherosclerotic plaque “cracks”, exposing an
inner, thrombogenic surface that then triggers clot formation
– Embolic
Material from elsewhere that travels to the cerebral
circulation and blocks a vessel supplying blood to an area of
brain
Can be thrombus, fat, infectious material, foreign objects, or
even air
Hemorrhagic Stroke
Intraparenchymal
– Most commonly the basal ganglia, thalamus, brain
stem, and cerebellum
Intraventricular (extension)
– Possibility of obstructive hydrocephalus
– Can require neurosurgical intervention
Stroke Risk Factors
Ischemic
–
–
–
–
–
–
–
–
Smoking
Hypertension
Atrial fibrillation
Elevated cholesterol
Clotting disorders
Endocarditis
Diabetes mellitus
Drug abuse
Hemorrhagic
–
–
–
–
–
–
–
Hypertension
Amyloidosis
Vascular malformation
Trauma
Drug abuse
Ischemic stroke
Metastatic disease
NEUROANATOMY
Anatomy and Physiology
Vascular tree
– Anterior circulation
CCA
ICA
ACA
MCA
– Posterior circulation
Vertebral
PICA
Basilar
SCA
AICA
PCA
Imaging (MRA)
Vascular Territories
The Brain
Homunculus
NEUROIMAGING
Non-enhanced CT (NECT)
Advantages
Fast!
Sensitive for acute
hemorrhage
Widely available
Less Expensive
Disadvantages
Radiation dose
Not sensitive for acute
ischemia
Less sensitive for
subacute or chronic
hemorrhage
Non-enhanced CT (NCET)
CT Angiogram
Advantages
Allows visualization of the
actual vessels
More sensitive for arterial
dissection
Can identify aneurysms
or other vascular
malformations
Disadvantages
Radiation dose is much
higher than NECT
Contrast required
Requires 18g or larger IV
in the arm
CT Angiogram
Non-enhanced MRI
Advantages
More detailed scan of the
brain parenchyma
Able to differentiate
conditions that mimic
stroke
Able to identify smaller
lesions and infarcts
DWI exquisitely sensitive
for acute ischemia
Disadvantages
Longer study
Limitations due to
magnetic field (no
pacemakers)
More difficult for patients
to tolerate
Less forgiving of patient
motion
Less readily available
Non-enhanced MRI
DWI
ADC
MRA / MRV
Advantages
Allows visualization of the
actual vessels
Can identify aneurysms
or other vascular
malformations
Disadvantages
Same as non-enhanced
MRI
Additional time in the
scanner
Neuroimaging - Stroke
CT
DWI
T2 - FLAIR
MRA
STROKE SYMPTOMS
Motor Deficits - Weakness
Various terms (weakness,
plegia, paresis, palsy) all
describe loss of strength
Vascular anatomy
determines the deficits
– ACA = leg weakness >> arm
or face
– Cortical MCA = face and arm
> leg
– Deep MCA = all three equally
affected
Motor Symptoms
Spasticity
– Velocity-dependent increase in tone
– Seen with many types of upper motor neuron
dysfunction (cortex to spinal cord)
– Abnormal regulation of stretch reflex
Apraxia (actually cognitive)
– Inability to perform a previously learned task despite
preserved strength, vision, and coordination
– Caused primarily by injury to the motor planning
areas (MCA territory) in the dominant hemisphere
Other motor symptoms
Myoclonus
– Seen most often with large strokes or diffuse brain
injury (hypoxia), as well as metabolic syndromes
Tremor
– Ventral intermediate nucleus of thalamus
Hemiballismus
– Subthalamic nucleus
Chorea / Athetosis
Sensory Symptoms
Usually described by modality
–
–
–
–
–
Light touch
Pinprick
Proprioception (position sense)
Vibration
Temperature
Most sensation areas in the brain are mixed
modality, as opposed to the spinal cord where
they are separated into two different tracts
Sensory deficits and rehabilitation
Light touch, pinprick, temperature
– Need training regarding safety
Proprioception
– Significant gait deficits
Wide base, decreased stride length, foot slap
– Loss of ability to type, operate devices without
visual input
Aphasia
Broca’s / Motor / Expressive
Wernicke’s / Sensory / Receptive
Transcortical
– Same as above but repetition is spared
Anomia
Global
STROKE SYNDROMES
Stroke Syndromes - ACA
Contralateral motor and sensory deficits
– Primarily involves the leg, although occasionally arm and rarely
face
Apraxia
Personality changes
Ipsilateral eye deviation
Abulia (inability to make decisions)
Bowel and bladder dysfunction
Tendency to speak in whispers
Distractibility
Lack of spontaneity
Akinetic Mutism
Stroke Syndromes - MCA
Complete occlusion (either side)
–
–
–
–
Contralateral hemiplegia
Contralateral hemianesthesia/hyperesthesia
Homonymous hemianopsia
Deviation of the head and eyes toward the side of the
lesion
Stroke Syndromes - MCA
Dominant hemisphere
– Receptive aphasia (Wernicke’s area)
– Expressive aphasia (Broca’s area)
– Apraxia
Inability to perform a previously learned task despite
preserved strength, vision, and coordination
– Gerstmann’s syndrome
asomatognosia (right-left confusion)
dyscalculia
finger agnosia
dysgraphia
Stroke Syndromes - MCA
Non-dominant hemisphere
–
–
–
–
–
–
–
–
–
Amorphosynthesis
Anosognosia
Hemi-neglect
Extinction
Topographic memory deficit
Confabulation
Constructional apraxia
Allesthesia
Aprosody, lack of intonation in speech, and affective
agnosia
Stroke Syndromes - MCA
Non-dominant hemisphere (testing)
–
–
–
–
Clock drawing test
Famous people flash cards
Puzzle pictures
“Cookie theft” picture
Stroke Syndromes - MCA
Stroke Syndromes - PCA
Contralateral homonymous hemianopsia
Dominant hemisphere
– dyslexia
– color anomia
– alexia without agraphia
Non-dominant hemisphere
– prosopagnosia
Anton’s syndrome
Lacunar / Brainstem syndromes
Pure motor hemiplegia
Pure sensory syndrome
Sensorimotor syndrome
Ataxia hemiparesis
Dysarthria - clumsy hand syndrome
Wallenberg syndrome
Brain Stem / Cerebellar
Brain Stem
– Symptoms vary widely, due to significant function packed into a
small volume
– One of the few places that can cause loss of consciousness or
sudden death from stroke
– Locked-in syndrome
Cerebellar
– Ataxia
– Vertigo
– Dysmetria
– Dysdiadochokinesia
– Speech abnormalities
Alien Hand syndrome
Frontal version
– Reaching, grasping and other purposeful movements
in the contralateral hand
– Trouble releasing objects once grasped
Parietal / Occipital version
– “parietal hand” – avoidance of palmar contact
– Hand often levitates in the air on that side with fingers
extended
Callosal version
– Non-dominant hand performs “purposeful”, often
oppositional movements
Other stroke syndromes
Balint syndrome
– Asimultagnosia
– Optic ataxia
– Loss of voluntary eye movement
Foreign Accent syndrome
Acalculia
Kluver-Bucy syndrome
SUBACUTE COMPLICATIONS
Post-Stroke Depression
Incidence of 5 - 60%, depending on study (most
common statistic seems to be 40%).
The strongest predictors of PSD were:
– history of depression,
– increased severity of stroke
– post-stroke physical or cognitive impairment.
Under-appreciated in the caregivers of stroke
patients as well.