Localising a Stroke

LOCALISING A STROKE

WE ALREADY HAVE A BRIEF IDEA OF ARTERIAL SUPPLY TO THE BRAIN

THE SUPPLY IS DIVIDED INTO ZONES OF CIRCULATION ANTERIOR TERRITORY

POSTERIOR TERRITORY

VERTEBRO-BASILAR TERRITORY

WHAT CAN GO WRONG These systems of circulation supply

specific regions of the brain Therefore if there is a interruption to the

specific blood supply, characteristic symptoms are experienced.

This is particularly useful in the clinical scene to locate exactly the position of a lesion or the offending supply.

ANTERIOR TERRITORY

Interior Carotid Artery

Middle Cerebral Artery

Anterior Cerebral Artery

POSTERIOR TERRITORY Posterior Cerebral Artery

Vertebral arteries

Basilar Artery

ANTERIOR

POSTERIOR

1

2

3

4

ANTERIOR CEREBRAL ARTERY Frontal lobe behavioural abnormalities

Loss of motivation Disinhibition

Grasp reflex

Leg Weakness

Leg loss of sensation

Contralateral neglect

MIDDLE CEREBRAL ARTERY Contralateral

hemiplegia

Contralateral hemiparesis

Contralateral hemisensory loss

Contralateral Hemianopia

Dysphasia

Visual/sensory neglect/inattention

Visual Field deficit

In deep supply (Lenticulostriate arteries): Pure Motor and/or Sensory loss, Dysarthria, Dyspahasia

POSTERIOR CEREBRAL ARTERY Contralateral

homonymous hemianopia.

Contralateral hemiparesis

Contralateral hemisensory loss.

Alexia without agraphia.

Dysphasia

Dysphagia

Dysarthria

Cerebellar ataxia

Cortical blindness

Impaired consciousness

Locked-in syndrome

‘Long tract’ motor & sensory signs

VERTEBRO-BASILAR SYSTEM Cranial nerve

abnormalities

Dysdiadokokinesia

Tremor,

Cerebellar ataxia

Vertigo

Locked-in syndrome

Nausea and vomiting

Nystagmus

Impaired consciousness

Respiratory arrest

Autonomic instability

Contralateral sensory and motor loss

Dysarthria

Dysphagia

‘Long tract’ motor & sensory signs

BAMFORD CLASSIFICATION OF STROKE1. Total Anterior Circulation Stroke –

TACS

2. Partial Anterior Circulation Stroke – PACS

3. Lacunar Stroke - LACS

4. Posterior Circulation Stroke – POCS

TOTAL ANTERIOR CIRCULATION STROKEAll of:1. New higher cerebral dysfunction in the

affected hemisphere (e.g. Dysphasia, inattention, neglect, dyspraxia , Visual field defect)

2. Contralateral hemiplegia and hemiparesis. Motor and / or sensory deficit of at least two areas out of face, arm and leg.

3. Contralateral hemianopia

*If drowsy with unilateral weakness, last two factors are assumed

PARTIAL ANTERIOR CIRCULATION STROKEAny of: No Drowsiness 2 out of 3 criteria of TACSOR• Isolated Higher cerebral dysfunction

alone (eg dysphasia)OR• Motor/sensory deficit more restricted

than those classified as LAC (eg confined to one limb)(Monoplaegia)

LACUNAR STROKE SYNDROMESNO visual field defectNO disturbance of language or other higher cortical functionNO evidence of brainstem dysfunction

Types:1. Pure Motor Stroke(most common). Complete or incomplete

weakness of 1 side, involving the whole of 2 of 3 of the body areas of face, arm and leg).

2. Pure Sensory Stroke. Sensory symptoms and/or signs, same distribution as above.

3. Ataxic Hemiparesis (inc. dysarthria-clumsy hand) . Hemiparesis with ipsilateral cerebellar ataxia

4. Sensorimotor Stroke. Combination of the above. Includes dysarthria (“clumsy hand syndrome”) and dysphasia

POSTERIOR CIRCULATION STROKE

Any of Dysfunctions of the brainstem, cerebellar

or occipital lobes(cortical blindness) Ipsilateral cranial nerve palsy with

contralateral motor and / or sensory deficit Bilateral motor and / or sensory deficit. Disorder of conjugate eye movement Isolated homonymous visual field defect Cerebellar dysfunction without ipsilateral

long tract signs (ataxia)

REFERENCES Robin Smithuis. Brain Ischemia - Vascular

territories. The Radiology Assistant, 24-11-2008[online]. http://www.radiologyassistant.nl/en/484b8328cb6b2. Accessed 04/05/2012

Iain Wilkinson and Graham Lennox. Essential Neurology© 2005 by Blackwell Publishing Ltd.

BLUMENFELD, H. Neuroanatomy Through Clinical Cases 1st edition. © 2002 by Sinauer Associates.

Seminar: Stroke by Dr Paul Worth. 3rd May 2012. 1100hrs CD ANNEX 0.01 Norwich Medical School.