Blood supply of the brain

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Amr Hassan, M.D. Associate professor of Neurology - Cairo

University

BLOOD SUPPLY OF

THE BRAIN

The blood reaches brain through two systems of blood vessels:

The carotid system

The vertebral system

BLOOD SUPPLY OF BRAIN

The Carotid system:

Carotid and vertebral arteries

The Carotid system:

The circle of Willis

Areas supplied by MCA

MC

A p

ath

way

Branches of MCA:

Capsular

lenticulostriate

Cortical:

1. Frontal

2. Pareital

3. Temporal

Internal capsule:

3/9/2017 Neurology for physiotherapist by Prof.Dr Ahmed Aboumousa

21

The middle cerebral artery (MCA) occlusion

Capsular branch occlusion: (lenticulo striate artery)

Contralateral complete hemiplegia: affecting the upper and lower limbs to the same extent.

Contralateral hemihyposthesia

Contralateral hemianopia: may occur.

No loss of consciousness or aphasia.

Frontal branches

occlusion:

1. Facio-brachial

monoplegia

2. Motor aphasia and

agraphia in doninant

hemispheres

Parietal branches occlusion:

1. Cortical sensory loss

In U.L

2. Lower quadrantic

homonymous

hemianopia

3. In dominant

hemisphere:

• Sensory aphasia

• Alexia

• Apraxia

Temporal branches

occlusion:

1. Upper quadrantic

homonymous

hemianopia

2. Auditory agnosia

The middle cerebral artery (MCA) occlusion

Main artery occlusion( =1+2):

Coma at the onset.

Contralateral hemiplegia affecting U.L. more than L.L.

Contralateral hemihyposthesia with cortical sensory loss in U.L.

Contralateral homonymous hemianopia.

Aphasia and agraphia in left sided lesions.

Branches of ACA:

Capsular

Heubner’s artery

Cortical

1. Frontal

2. Paracentral

3. Callosal

AC

A p

ath

way

Areas supplied by ACA

Internal capsule:

Association fibres

Pyramidal fibres

Sensory fibres

Auditory radiation

Visual radiation

The ant cerebral artery (ACA) occlusion

Capsular branch occlusion (Heubner Arterv):

Facio-brachial monoplegia

Cortical branches occlusion

Frontal branches occlusion:

1. Severe behavior

disturbance (apathy or

“abulia,akinetic mutism)

2. Perseveration

3. Grasp reflexes, and diffuse

rigidity—“gegenhalten”)

Cortical branches occlusion

Paracentral branches occlusion:

1. Contralateral hemiparesis in L.L

2. Contralateral sensory loss in L.L

3. Urinary incontinence

Cortical branches occlusion

Callosal branches occlusion:

Apraxia of the left side

The ant cerebral artery (ACA) occlusion

Main artery occlusion( =1+2):

Contralateral hemiplegia affecting L.L. more than U.L.

Contralateral cortical sensory loss in the lower limb.

Incontinence of urine.

Mentality and personality changes.

Forced grasp reflex.

Apraxia of the left side.

Vertebrobasilar system

Vertebrobasilar system

Int.aud.

Vertebrobasilar system

Brain stem branches ( Paramedian branches) occlusion

= brain stem syndromes (revise P.53)

Sup. Cerebellar A.

(SCA occlusion)

Ant. Inf. Cerebellar A.

(AICA occlusion)

Post. Inf. Cerebellar A.

(PICA occlusion)

Ipsilateral cerebellar

ataxia

Ipsilateral Horner's

syndrome √ √ √

Ipsilateral deafness. √ X X

Contralateral

hemihyposthesia. √ √ √

Other features X Ipsilateral 5th, 6th and 7th

cranial nerve paralysis

Bulbar palsy

Ipsilateral loss of pain and

temperature sensations over

the face.

Acute onset associated with

syncope, hiccup, vomiting and

vertigo.

Basilar artery

Partial occlusion (insufficiency) Complete occlusion (usually fatal)

- Syncope, diplopia and

ophthalmoplegia.

- Vertigo or tinnitus.

- Bulbar palsy

- Hemiparesis, hemianaesthesia

- Ataxia.

- Deep coma.

- Complete quadriplegia with

decerebrate rigidity.

- Bulbar paralysis.

- Respiratory embarrassment.

.1Basilar artery (main vessel )occlusion

Clinical features of partial and complete occlusion of basilar artery.

The posterior cerebral artery

It gives the following branches:

Capsular branch supplying the ventral half of the posterior limb of the internal capsule, the thalamus and the geniculate bodies (Thalamogeniculate artery).

Cortical branches to the occipital lobe.

Posterior communicating artery.

Areas supplied by PCA

Posterior cerebral artery occlusion

thalamoqeniculatebranch: ( Ganalionicartery) occlusion= thalamic syndrome:

Thalamic pain i.e. constant burning severe pain in the hemianaesthetic side.

Complete contralateral hemianaesthesia to all types of sensations.

Reflex dystrophy of the shoulder girdle and arm, secondary to the pain.

Choreo-athetosis or hemiballismus due to ischaemia of the basal ganglia and/or subthalamus.

Cortical branches occlusion:

Contralateral homonymous hemianopia with macular sparing.

Visual agnosia in left sided lesions.

Internal capsule:

Association fibres

Pyramidal fibres

Sensory fibres

Auditory radiation

Visual radiation

Posterior cerebral artery occlusion

thalamoqeniculatebranch: ( Ganalionicartery) occlusion= thalamic syndrome:

Thalamic pain i.e. constant burning severe pain in the hemianaesthetic side.

Complete contralateral hemianaesthesia to all types of sensations.

Reflex dystrophy of the shoulder girdle and arm, secondary to the pain.

Choreo-athetosis or hemiballismus due to ischaemia of the basal ganglia and/or subthalamus.

Cortical branches occlusion:

Contralateral homonymous hemianopia with macular sparing.

Visual agnosia in left sided lesions.

Posterior cerebral artery occlusion

):2+1Main vessel occlusion ( =

Thalamic syndrome

Contralateral homonymous hemianopia with macular sparing as the macula has double blood supply.

Visual agnosia in left sided lesions.

Walllenberg Syndrome

LEFT

Ipsi pyramidal

Contra Ipsi Contra LEFT

Ataxia SENSORY

Contra

Ipsi

Ipsi

Ipsi

Internal capsule:

Association fibres

Pyramidal fibres

Sensory fibres

Auditory radiation

Visual radiation

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