Stroke

1
Stroke

• Refer to Chapter 9 of
• Clinical Neurology Textbook

2
Stroke

• A syndrome characterized by the acute onset of
  neurological deficit that persists for at least
  24 hrs and is due to a disturbance is cerebral
  circulation resulting in focal involvement of the
  CNS.

3
Stroke

• Diagnosis
• History
• Onset
• Clinical Pearl Focal cerebral deficits that
  develop more slowly are more suggestive of tumor,
  inflammatory, or degenerative diseases.
• Duration
• Stroke
• TIAs (Trans-ischemic Attacks)
• RIND (Reversible Ischemic Neurological Deficit)
  AKA Minor Stroke

4
Stroke

• Diagnosis
• Physical Exam
• Location determined by -
• Nature of Symptoms
• Neurological Examination
• Special Imaging CT or MRI
• CT best to differentiate ischemic vs hemorrhagic
• MRI can detect an ischemic stroke earlier than
  CT preferred image of choice for identifying
  brainstem cerebellar infarcts

5
Stroke

• Focal Involvement
• Stroke produces focal s/s that correlate w/ the
  area of the brain supplied by the affected
  circulation

6
Stroke

• Types of Stroke
• Ischemic Stroke
• Cause
• Occlusion of cervicocranial vessels or
  hypoperfusion to the brain due to
• Atherothrombosis
• Embolism
• Neurological S/s
• Produces stereotyped pattern of deficits
• Pathophysiology

7
Stroke

• Ischemic Stroke
• Ischemia
• Energy Failure
• Depolarization
• Glutamate Release
• Na/Ca Influx
• Cellular Mitochondrial Free Radical Enzyme
• Swelling Injury Generation Activation
• Necrotic Cell Death Programmed Cell Death
• (Rapid) (Progressive)

8
Stroke

• Types of Stroke
• Hemorrhagic Stroke
• Neurological S/s
• Produce less predictable pattern of focal
  involvement
• Impair cerebral fcn via a variety of mechanisms
• Pathophsyiology

9
Stroke

• Types of Stroke
• Hemorrhagic Stroke
• Classification
• Intracerebral (ICH)
• Subarachnoid (SAH)
• Subdural or Epidural

10
Stroke

• Diseases Which Cause Ischemia
• Atherothrombotic Disease
• Thromobotic Process
• Overgrowth in the subintima formation of
  plaques that can encroach on the lumen.
• Adherence of platelets to the crevices in the
  plaques forming clots
• Two Different Types
• White-Clots
• Red-Clots

11
Stroke

• Diseases Which Cause Ischemia
• Atherothrombotic Disease
• Clinical Features
• Often develops during or just after sleep
• Assoc w/
• Occlusion or sever stenosis
• Absence of a distal embolus by angiography
• Infarct on CT or MRI
• Risk Factors HBP, diabetes, smoking
• S/s are dependent upon which vessels are
  involved and the regions of brain ischemia

12
Stroke

• Diseases Which Cause Ischemia
• Occlusive Disease - Small Penetrating Arteries
• Lipohyalinosis
• Destructive vasculopathy
• Lumenal size is not affected by an intimal
  process but by a thickening of the vessel wall
  itself
• Lacunes
• Clinical Features
• Affects MCAs, PCAs, Vertebral Basilar
  Arteries
• Affect Subcortical Structures
• S/s are less sever and involve only a few systems

13
Stroke

• Diseases Which Cause Ischemia
• Brain Embolism
• Three Major Sources
• Cardiogenic
• Intra-Arterial
• Paradoxical
• Risk Factors
• Arrhythmias
• Valvular Disease
• Heart Disease

14
Stroke

• Diseases Which Cause Ischemia
• Brain Embolism
• Pathophysiology
• Lodged Embolus
• Reperfusion injury hemorrhagic infarct
• Clinical Features
• Abrupt onset
• Fluctuations worsening of symptoms
• S/s more severe
• Occurs during
• Activity
• Sudden straining
• Coughing
• Sneezing

15
Stroke

• Circulation Involved
• Anterior Circulation (Fig 9-2)
• Supplies most of the cerebral cortex
  subcortical white matter, basal ganglia,
  internal capsule
• Consists of
• Internal Carotid branches
• Ant Choroidal
• Ant Cerebral
• Middle Cerebral
• S/s indicate hemispheric dysfunction
• Aphasia
• Apraxia (purposive movement)
• Agnosia (comprehension of sensory input)

16
Stroke

• Circulation Involved
• Posterior Circulation (Fig 9-2)
• Supplies the brainstem, cerebellum, thalamus, and
  portions of the occipital temporal lobes
• Consists of
• Vertebral Arteries
• Basilar Artery
• S/s indicate brainstem dysfunction

17
Stroke

• Clinical Anatomical Correlation
• To determine the location of the ischemia, one
  must be able to identify the clinical deficits on
  a neuro-anatomic basis

18
Stroke

• Clinical Anatomical Correlation
• Anterior Cerebral Artery
• Supplies portions of motor sensory cortex
• Controls contralateral leg micturition center
• Clinical Presentation
• Contralateral leg paralysis
• Contralateral leg sensory loss
• Loss of voluntary control of micturition
  incontinence

19
Stroke

• Clinical Anatomical Correlation
• Middle Cerebral Artery
• Supplies 3 Branches
• Superior Div
• Inferior Div
• Lenticulostriate
• Clinical Presentation
• Superior Div
• Contralateral hemiparesis
• Contralateral hemisensory deficit
• Brocas Aphasia if dominate hemisphere is
  involved

20
Stroke

• Clinical Anatomical Correlation
• Middle Cerebral Artery
• Clinical Presentation
• Inferior Div
• Contralateral homonymous hemianopia
• Marked impairment of cortical sensory fcs of the
  contralateral body
• Disorders of spatial thought
• Wernickes Aphasia if dominant hemisphere is
  involved
• Acute confusional state if non-dominate
  hemisphere is involved

21
Stroke

• Clinical Anatomical Correlation
• Middle Cerebral Artery
• Clinical Presentation
• Occlusion _at_ the Bifurcation or Trifurcation of
  the MCA Combined clinical features of both the
  superior inferior divisions
• Contralateral hemiparesis hemisensory deficit
  of face arm
• Homonymous hemianopia
• Global aphasia if dominant hemisphere is
  involved

22
Stroke

• Clinical Anatomical Correlation
• Middle Cerebral Artery
• Clinical Presentation
• Occlusion of the stem of the MCA similar
  clinical presentation as w/ occlusion _at_ the
  trifurcation except
• Contralateral hemiplegia
• Sensory loss affecting all face, hand, arm,
  leg

23
Stroke

• Clinical Anatomical Correlation
• Internal Carotid Artery
• Arises from the common carotid artery
• 3 Branches
• Ant Cerebral already discussed
• Middle Cerebral already discussed
• Ophthalmic supplies the retina
• Clinical Presentation
• May be asymptomatic
• If s/s present, then similar presentation as w/
  the middle cerebral artery
• Accounts for 1/5 of ischemic strokes

24
Stroke

• Clinical Anatomical Correlation
• Posterior Cerebral Artery
• Arises from the tip of the apex of the basilar
  artery and is paired
• Supplies
• Occipital, medial temporal, thalamus, rostral
  midbrain
• Clinical Presentation
• Single Posterior Artery
• Homonymous hemianopia of contralateral field
• Macular vision may be spared d/t dual supply

25
Stroke

• Clinical Anatomical Correlation
• Posterior Cerebral Artery
• Clinical Presentation
• Occlusion _at_ the origin of PCA ocular
  abnormalities
• Vertical gaze palsy
• CN III palsy
• Internuclear opthamoplegia
• Occlusion affecting Occipital lobe of dominant
  hemisphere
• Anomic aphasia
• Alexia w/o agraphia
• Visual agnosia
• Bilateral Occclusion
• Cortical Blindness
• Memory impairment
• Prosopagnosia

26
Stroke

• Clinical Anatomical Correlation
• Basilar Artery
• Arises from the jcn of paired vertebral arteries
• Supplies
• Occipital lobe
• Medial temporal lobe
• Medial thalamus
• Post limb of internal capsule
• Entire brainstem cerebellum

27
Stroke

• Clinical Anatomical Correlation
• Basilar Artery
• Clinical Presentation
• Thrombolitic Occlusion
• Often results in death
• Bilateral neurological signs
• Subclavian Steal Syndrome
• Mc site is proximal portion which supplies the
  pons

28
Stroke

• Clinical Anatomical Correlation
• Basilar Artery
• Clinical Presentation
• Thrombolitic Occlusion involving the
  dorsal/tegmentum portion of the pons
• Uni or bilateral CN VI palsy
• Vertical nystagmus
• Pupils constricted but are reactive to light
• Hemi or quadroplegia
• Coma - common

29
Stroke

• Clinical Anatomical Correlation
• Basilar Artery
• Clinical Presentation
• Thrombolitic Occlusion involving the ventral
  portion of the pons
• Remains conscious
• Quadriplegic
• Locked-In Syndrome

30
Stroke

• Clinical Anatomical Correlation
• Basilar Artery
• Clinical Presentation
• Embolitic Occlusion
• Mc at the apex
• Top of the Basilar Syndrome

31
Stroke

• Intracerebral Hemorrhage
• Hypertensive Hemorrhage
• Pathophysiology
• Autoregulation of Cerebral Blood Flow
• Normaotensive Individuals
• Hypertensive Individuals
• Clinical Relevance

32
Stroke

• Intracerebral Hemorrhage
• Hypertensive Hemorrhage
• Pathophysiology
• Chronic Hypertension
• Massive cerebral hemorrhages usually follow
  rupture of Charcot-Bouchard aneurysms or
  lipohyalinotic segment
• Pathology
• Hypertensive hemorrhages occur in certain areas
  of predilection

33
Stroke

• Intracerebral Hemorrhage
• Hypertensive Hemorrhage
• Mc cause
• Clinical Presentation
• Occur w/o warning while awake
• HA in 50 of pts
• Vomiting
• Inc BP after hemorrhage
• gt 50 yoa

34
Stroke

• Intracerebral Hemorrhage
• Clinical Features Correlated w/ Site of
  Hemorrhage (Table 9-5)
• Deep Cerebral Hemorrhage
• 2 mc sites Putamen Thalamus
• Putamen
• Severe motor deficits
• Persistant Homonymous Hemianopia
• Thalamus
• Marked Sensory deficits
• Transient Homonymous Hemianopia
• Eyes deviate downward

35
Stroke

• Intracerebral Hemorrhage
• Clinical Features Correlated w/ Site of
  Hemorrhage (Table 9-5)
• Lobar Hemorrhage
• Hemorrhage in subcortical white matter underlying
  the frontal, parietal, temporal, occipital
  lobes
• s/s vary
• HA
• Vomitting
• Hemiparesis
• Hemisensory Deficit
• Aphasia
• Seizures more frequent than w/ other hemorrhages
• Coma less common

36
Stroke

• Intracerebral Hemorrhage
• Clinical Features Correlated w/ Site of
  Hemorrhage (Table 9-5)
• Pontine Hemorrhage
• Coma w/I sec to min
• Death w/I 48 hrs
• Ocular Findings
• Quadriparetic w/ decerebrate posturing
• Usually ruptures into the 4th ventricle

37
Stroke

• Intracerebral Hemorrhage
• Clinical Features Correlated w/ Site of
  Hemorrhage (Table 9-5)
• Cerebellar Hemorrhage
• Distinctive s/s begin suddenly w/I minutes of
  onset
• Coma
• Ocular Findings
• Ipsilateral facial weakness
• Limb strength is normal
• Plantar reflexes normal initially but become
  abnormal w/ time