Stroke syndromesof posterior circulations

Done By: Dana Marafie

Posterior Circulation

Posterior circulation

Arteries & structures they supply

• PCA: temopral & occipital lobes, parts of thalamus & midbrain

• SCA: midbrain &superior cerebellum

• AICA: pons & cerebellum• PICA: medulla & cerebellum• Basilar: pons , other braches• Vertebral: • Anterior spinal : upper 2/3 of ant.

Surface of spinal cord

Specific supply

• Occipital lobe: PCA• Temporal lobe: MCA (suerpior lateral ) &PCA

( rest)• Midbrain: PCA( ant surface), SCA ( post surface)• Pons: Basilar ( mainly), AICA• Medulla: ant. Spinal , Vertebral & PICA . Small

region by ( post spinal)• Thalamus: branches from PCA• Cerebellum : SCA, AICA & PICA

Posterior circulation strokes• Form 20% of all ischemic strokes• Mortalility is around 4% except for basilar artery occlusion where

it can be up to 90% !• However, outcome is not very good• Usually cause bilateral involvement• severe headache, vomiting & Nausea are more common in posterior

circulation strokes• Vertigo, Nystagmus , hemiplagia or quadriplegia, ocular eye

movements, ataxia & change in level of consciousness are also seem

• When to expect Post circulation stroke in a patient?• 1- different symptoms & different functions or str. Affected in a way

that can not be explained by a cortical region (many tracts or cranial nerves involved)????

• 2- when patient is presented with vomiting ,Nystagmus, Nausea, ocular movement disorders or vertigo along with the other symptoms

Arteries & Syndromes!

From SUPERIOR TO INFERIOR :• PCA Occlusion : • Basilar Artery Occlusion: Locked-in Syndrome

Branches;• AICA Occlusion :• PICA Occlusion : Wallenberg’s Syndrome• Vertebral Occlusion :• Anterior Spinal Artery Occlusion:

These Syndrome can be produced by occlusion of not just

mentioned artery but the other arteries as ,long as the same str involved: However, there are commonly seen in

case of occlusion of the mentioned artery

PCA occlusion

Lateral surface Medial surface

PCA Occlusion• contralateral

hemianopia ( with macular sparing)

• memory deficit : damage in hippocampal formation

(disconnection syndrome )

• Bilateral PCA occlusion = Blindness + inability to form new memories

Picture as seen inLeft homonymous hemianopia ( with macular

sparing)

PCA occlusion

T1 MRI of PCA infart

PCA ( al level of branches to midbrain)(Weber’s syndrome)

• at level of midbrain ,

• specifically the BASEX

PCA ( al level of branches to midbrain)(Weber’s syndrome)

• Manifestations: : at level of midbrain

• Motor Weakness – contralateral hemiplegia (upper and lower extremity) : Corticospinal tract

• corticobulbar fibers in the cerebral peduncle

• Ipsilateral Lateral gaze weakness & diplopia :CN 3 fibers (LMN)

PE eye movements: patient is inable to move eye up,down, or medially in the epsilateral side

• pupillary dilitation: if Edinger-Westphal nucleus are involved

CASE!• A 55 year old African woman had abdominal

surgery 2 weeks before suddenly remarking to her husband that she was seeing double. She also felt a weakness in her left arm and leg. Her husband noticed that her right eyelid was drooping.

• PE: Her general physical condition was good. EYES: : right eyelid does not open fully. right eye was deviated to the right

(laterally). When asked to converge the eyes only

the left eye adducted showed pupillary constriction ( right is dilated).

MOTOR SYSTEM: Motor strength was normal on the right but was reduced on the left, especially in the arm where there was an increased biceps reflex and resistance to passive stretch.

Basilar artery occlusion(Locked-in Syndrome)

Basilar artery occlusion(Locked-in Syndrome)

•Manifestation :at the Level of the Pons•Weakness of both upper and lower extremity (Quadriplegia): bilateral cortical spinal tracts•Weakness of face - entire side :Bilateral corticobulbar tracts•If lesion is big,Horizonal gaze weakness: Bilateral fascicles of CN VI ( ONLY vertical gaze is possible!)•Dysarthria: Bilateral corticobulbar tracts•Death from respiratory failure is common•PATEINT are alert, conscoius with normal cognitive fuction • IF VERY SEVERE, the only way to communication may be blinking

Patient is LOCKED-IN their bodies : Quadriplegic, with dysarthria& facial weekness!

Locked-in SyndomeA 62-year old woman with a history of hypertension for 35 years developed left-sided hemiparesis. One

week later she became tetraplegic and unable to speak. However, she was able to communicate by

blinking. She died three months after the onset of her neurological symptoms.

MRI after 19 days in hospital MRA after 19 days in hospital

After autopsy

locked-in syndrome

A quadriplegic patient with locked-in syndrome who managed to survive ( less

severe case)

Labyrinthine Artery Syndrome

• labyrinthine or internal auditory artery usually takes its origin from AICA, but it can also take origin from PICA or the basilar artery.

• It supplies the inner ear• Occlusion of this artery can lead

to sudden tinnitus, vertigo or even unilateral ipsilateral deafness !!!

Labrinthine Artery

PICA Occlusion(Lateral Medullary syndrome Of Wallenberg )

At the level of dorso-lateral part of medulla & Cerebellum

PICA Occlusion(Lateral Medullary syndrome Of Wallenberg )

• The commonest of brainstem strokes!

• Manifestation: At the level of dorso-lateral medulla & Cerebellum

• Ipsilateral Sensory loss of face - pain and • Temperature CN 5 spinal N• Ipsilateral Facial pain CN 5 spinal N• Ipsilateral Ataxia - arm and l Restiform body,

Ipsilateral cerebellum• Ipsilateral Gait ataxia Restiform body,

cerebellum• Ipsilateral Nystagmus Vestibular nucleus• Ipsilateral Nausea / vomiting Vestibular nucleus• Ipsilateral Vertigo Vestibular nucleus• Ipsilateral Horseness Nucleus ambiguus• Ipsilateral Dysphagia Nucleus ambiguus• Ipsilateral Horner syndrome-Descending sympathetics• Contralateral Hemisensory loss - pain and Temperature Spinothalamic tract• Hiccups  ( whatever you do, it does not go !!!)

Prognosis is generally quite good with full or near full recovery expected at 6 months.

CTscan showing lesion in Medulla & Cerebellum

in Wallenberg Syndrome

Vertebral artery occlusion

• Can also give Wallenberg’s syndrome

Thalamic infarction(Dejerine-Roussy syndrome or central pain

synrome)

• Very sad syndrome• Manifestation : pure sensory

loss without weakness : due to lesion of (CONTRLATERAL: WHY? Crossing below thalamus)

- Hemilateral sensory loss of all modalities

- Hemilateral pain ( hypersensitivity) : if you touch their affected side, they

will shout !

PCA

PCA Pentrating branches to thalamus

After death, autopsy

MRI of the patient I day afterMRI of the patient I day after

Anterior Spinal Artery Occlusion ( Anterior Spinal Artery syndrome)

• Complete sensory & motor loss below the level of occlusion except for proprioception

Anterior Spinal Artery syndrome• Manifestations:• Loss of motor function below level of

damage : due to damage of corticospinal tracts ( ant & post)

• Bilateral anesthesia ( loss of sensation below the level of damage )

: damage of spinothalamic• Loss of bladder & bowel control :

damage of descending autonomic tracts;

• Proprioception is intact due to sparing of dorsal system

• motor & sensory function in face can be intact

Note• Keep in mind that these are not the only

syndromes we see in posterior circulation• There are many other syndrome that are seen in

infartions affecting other regions of brain stem• EG of other syndromes of :• Midbain :Claude, Benedict ,Nothnagel,Parinaud

Syndromes• Pons: Millard-Gubler and Raymond-Foville • Medulla: Medial medullary syndrome

Quiz !

Alia :Overall mortality for posterior circulation strokes is:

a.       5%b.      20%c.       40%d.      70%e.       90%

• Wadha :1- Locked-in Syndrome consists of:  a. Coma with quadriplegia b. Bilateral upper extremity weakness

greater than lower extremity weaknessc. Quadriplegia, bilateral facial and

oropharyngeal palsy but preservation of cortical function and vertical gaze

d. Cranial nerve findings contralateral to motor and sensory findings

• Lastly, Sulaiman :In Weber Syndome:

a .Ipsilatral 3rd nerve palsy & hemiplgia

b. Ipsilateral hearing loss

c. vertigo, vomiting , ipsilateral ataxia & facial sensory loss & contralateral sensery loss of limbs

d.Ipsilatral 3rd nerve palsy & crossed hemiplgia