1. Higher mental functions

• Level of consciousness: alert, drowsy, stupor, coma
• Orientation and attention
• Speech and language:
  • Aphasia: impaired naming, comprehension, repetition, reading/writing, usually dominant hemisphere stroke
  • Dysarthria: slurred articulation with intact language
• Neglect/inattention: ask the patient to identify stimuli on both sides or draw/copy a figure
• Memory may be impaired

2. Cranial nerve signs

• Gaze deviation toward the side of a large hemispheric lesion
• Visual-field defect, especially contralateral homonymous hemianopia
• Pupils and ocular movements: diplopia, internuclear ophthalmoplegia, gaze palsy, nystagmus may suggest posterior-circulation/brainstem stroke
• Upper motor neuron facial weakness: contralateral lower facial droop with forehead sparing
• Dysphagia, dysphonia, reduced palatal movement, weak cough, tongue deviation: especially brainstem stroke
• Test swallowing only when it is safe and according to local protocol. Keep the patient nil by mouth if dysphagia is suspected.

3. Motor examination

• Contralateral hemiparesis or hemiplegia
• Weakness of face, arm, and/or leg. Arm more than leg can suggest MCA territory; leg more than arm can suggest ACA territory.
• Pronator drift: arms outstretched, palms upward, eyes closed; the weak arm pronates and drifts down.
• Reduced fine finger movements
• Tone:
  • early acute stroke may cause flaccidity
  • later, increased tone and spasticity
• Abnormal posture or contractures in established stroke

4. Reflexes and plantar response

• Brisk deep-tendon reflexes on the affected side, commonly later in the course
• Extensor plantar response (Babinski sign) on the affected side
• Clonus may be present in spastic hemiparesis
• In very acute severe stroke, reflexes may initially be reduced rather than brisk.

5. Sensory examination

• Light touch and pinprick
• Temperature if needed
• Vibration and joint position sense
• Contralateral hemisensory loss or sensory neglect
• Cortical sensory deficits: astereognosis, agraphesthesia, impaired two-point discrimination, if the patient can cooperate

6. Coordination and cerebellar signs

• Finger-nose and heel-knee-shin tests
• Dysmetria, intention tremor, dysdiadochokinesia
• Truncal or gait ataxia, nystagmus, dysarthria
  These may point to cerebellar or posterior-circulation stroke. Do not force a patient with acute weakness or imbalance to walk.

7. Gait, stance, and balance

• Hemiplegic/spastic gait: circumduction of the affected leg, reduced arm swing
• Broad-based ataxic gait
• Romberg test only if the patient can stand safely

8. Other bedside signs

• Check for headache, vomiting, seizures, neck stiffness, and reduced consciousness, which may occur with intracranial hemorrhage or raised intracranial pressure.
• Examine pulse/rhythm for atrial fibrillation, blood pressure, carotid bruit, and cardiovascular status. A carotid bruit is not required for stroke and absence does not exclude carotid disease.

Quick exam presentation

“This patient has a focal neurological deficit characterized by [right/left] UMN facial weakness, [right/left] hemiparesis with pronator drift, increased tone/hyperreflexia and an extensor plantar response, with/without hemisensory loss, aphasia, visual-field defect, neglect, or cerebellar signs. These findings are consistent with a [hemispheric/brainstem/cerebellar] stroke syndrome.”

Step-by-step neurological examination in suspected stroke

1. General observation

• Conscious level, distress, vomiting, seizure activity
• Facial asymmetry
• Spontaneous movement or non-movement of one side
• Speech clarity and ability to engage
• Head or eye deviation
• Posture, tone, involuntary movement
• Any trauma, rash, anticoagulant alert bracelet, or medical devices

2. Consciousness and cognition

• Alertness: awake? needs voice or painful stimulus?
• Orientation: name, age/date, place
• Attention: ask them to follow a simple command, such as “close your eyes and open them”
• Observe for confusion, agitation, or reduced awareness

3. Speech, language, and neglect

• Dysarthria: slurred speech due to weak/incoordinated articulation. Language content and comprehension are relatively intact.
• Aphasia/dysphasia: language impairment, usually from the dominant hemisphere.
  • Ask: “What is your name?” and “Where are you?”
  • Ask them to name familiar objects, e.g. pen, watch.
  • Give commands: “Show me two fingers,” then “Touch your left ear with your right hand.”
  • Ask them to repeat: “No ifs, ands, or buts.”
• Neglect/inattention: stimulate or show fingers on both sides simultaneously. Extinction of one side suggests neglect, classically with a nondominant parietal stroke.

4. Cranial nerves

Pupils

• Inspect size, equality, and response to light.
• Marked anisocoria or an abnormal pupil may point to a third-nerve problem or herniation, not simply an uncomplicated hemispheric stroke.

Visual fields

• Ask the patient to look at your nose.
• Present moving fingers in each quadrant and ask which side they see.
• Look for a homonymous hemianopia, meaning loss of the same side of the visual field in both eyes.

Eye position and movements

• Observe for resting eye deviation.
• Ask the patient to follow your finger horizontally and vertically.
• Look for gaze palsy, nystagmus, diplopia, or internuclear ophthalmoplegia.
• A large hemispheric stroke may cause gaze deviation toward the side of the lesion.

Facial movement

• Inspect the face at rest.
• Ask the patient to raise eyebrows, close eyes tightly, show teeth, and puff cheeks.
• UMN facial weakness: contralateral lower facial weakness with forehead sparing.
• Check for dysarthria while they speak.

Palate, tongue, and bulbar function

• Listen for hoarse or wet voice.
• Ask the patient to say “ah” and look for palatal asymmetry.
• Ask them to protrude the tongue and note deviation.
• Ask about choking, coughing with fluids, or swallowing difficulty.
• Do not give food or water until a validated swallow screen is passed.

5. Motor examination

Inspect

• Compare bulk, posture, and involuntary movements.
• Look for flaccidity or spastic posture.

Pronator drift

1. Ask the patient to stretch both arms forward at shoulder level.
2. Palms face upward.
3. Ask them to close their eyes for 10 seconds.
4. Observe for downward drift and pronation of one arm.

Tone

• Shoulder, elbow, wrist
• Hip, knee, ankle

• Reduced tone/flaccidity in very acute stroke
• Spasticity/increased tone in established UMN weakness

Power

• Shoulder abduction
• Elbow flexion and extension
• Wrist extension
• Finger abduction
• Grip strength

• Hip flexion
• Knee extension and flexion
• Ankle dorsiflexion and plantarflexion

• Face and arm more affected than leg: often MCA territory
• Leg more affected than arm: often ACA territory
• Pure motor weakness without cortical signs can occur in a lacunar stroke

6. Reflexes

• Biceps
• Triceps
• Supinator
• Knee jerk
• Ankle jerk

• Stroke the lateral sole from heel to little toe, then across the forefoot.
• Extensor plantar response (Babinski sign) supports an UMN lesion.

7. Sensory examination

• Light touch over face, arm, trunk, and leg
• Pinprick if needed
• Vibration at distal bony points, if time allows
• Joint position at the great toe or finger, if needed

• Contralateral hemisensory loss
• Sensory extinction on double simultaneous stimulation
• A sensory level, which suggests a spinal rather than cerebral lesion

8. Coordination and cerebellar testing

• Finger-nose-finger: dysmetria, intention tremor
• Heel-knee-shin
• Rapid alternating movements: dysdiadochokinesia
• Look for nystagmus and scanning dysarthria

9. Gait and balance

• Observe sitting balance first.
• Assess ability to stand and walk with assistance.
• Look for hemiplegic gait, circumduction, reduced arm swing, or broad-based ataxic gait.
• Avoid making an acutely weak, dizzy, or unstable patient walk.

10. Screen for a stroke mimic and examine relevant systems

• Bedside capillary glucose immediately
• Temperature
• Blood pressure and oxygen saturation
• Pulse rate and rhythm, especially atrial fibrillation
• Cardiac examination for murmurs
• Carotid bruits if appropriate, but do not press or repeatedly manipulate the carotids
• Consider seizure, migraine, hypoglycemia, infection, drug toxicity, and functional neurological disorder as possible mimics

Quick acute-stroke sequence: NIHSS domains

1. Level of consciousness
2. LOC questions
3. LOC commands
4. Best gaze
5. Visual fields
6. Facial palsy
7. Left arm motor function
8. Right arm motor function
9. Left leg motor function
10. Right leg motor function
11. Limb ataxia
12. Sensory loss
13. Best language
14. Dysarthria
15. Extinction/inattention

Example of a concise examination summary

“The patient is alert but has expressive aphasia. There is right lower facial weakness with forehead sparing, right pronator drift, reduced power in the right arm and leg, brisk right-sided reflexes, and an extensor right plantar response. There is reduced right-sided sensation and a right homonymous hemianopia. This is a left hemispheric cortical stroke syndrome, likely in the left MCA territory.”

Clinical localisation of stroke

1. Is it cortical, subcortical, brainstem, or cerebellar?
2. Which side is involved?
3. Which vascular territory fits: MCA, ACA, PCA, vertebrobasilar, or lacunar?
4. Confirm with urgent CT/CTA and often MRI. Clinical localisation guides urgency but does not replace imaging.

1. First decide: anterior or posterior circulation?

Anterior circulation: carotid, ACA, MCA

• Contralateral face/arm/leg weakness or sensory loss
• Aphasia
• Neglect
• Gaze deviation
• Homonymous visual-field loss
• Cortical sensory signs

Posterior circulation: vertebral, basilar, PCA, cerebellar arteries

• Vertigo, vomiting, severe imbalance
• Diplopia, nystagmus, dysarthria, dysphagia
• Cranial nerve signs
• Ataxia
• Reduced consciousness
• “Crossed” signs: ipsilateral cranial nerve deficit with contralateral limb weakness or sensory loss

2. Decide the side

Hemispheric lesions

• Right face/arm/leg weakness → usually left hemisphere
• Left face/arm/leg weakness → usually right hemisphere

• Aphasia → dominant hemisphere, usually left MCA
• Left-sided neglect → usually right, nondominant parietal MCA
• Right homonymous hemianopia → left retrochiasmal visual pathway, commonly left PCA or posterior MCA
• Left homonymous hemianopia → right PCA or posterior MCA

Brainstem lesions

• Left facial palsy or left palate weakness + right hemiparesis → left brainstem
• This is called a crossed neurological deficit.

Cerebellar lesions

• Left limb dysmetria, left-sided falling, left ataxia → left cerebellar hemisphere

3. Localise by vascular territory

4. High-yield patterns to memorise

MCA stroke

• Contralateral lower facial weakness
• Contralateral arm weakness and sensory loss
• Contralateral homonymous hemianopia
• Eyes may deviate toward the lesion
• Dominant hemisphere: aphasia
• Nondominant hemisphere: neglect

ACA stroke

• Contralateral leg-predominant weakness and sensory loss
• Difficulty initiating walking
• Abulia/apathy, reduced spontaneous speech
• Urinary urgency or incontinence in larger bilateral/medial frontal lesions

PCA stroke

• Contralateral homonymous hemianopia
• May have visual neglect or visual hallucinations
• Dominant occipital plus splenial involvement: alexia without agraphia
• Thalamic involvement: contralateral sensory loss or pain

Lacunar stroke

• Posterior limb of internal capsule
• Corona radiata
• Thalamus
• Pons

• Pure motor hemiparesis
• Pure sensory stroke
• Sensorimotor stroke
• Ataxic hemiparesis
• Dysarthria-clumsy hand syndrome

5. Brainstem localisation: practical approach

1. Cranial nerve signs: diplopia, facial weakness, impaired facial sensation, dysphagia, dysphonia, tongue weakness
2. Long-tract signs: contralateral weakness, sensory loss, hyperreflexia, Babinski response
3. Cerebellar signs: ipsilateral limb ataxia, nystagmus, vertigo

Rule

Cranial nerve deficit on one side + weakness/sensory loss on the opposite side = brainstem stroke until proven otherwise.

• Ipsilateral facial weakness + contralateral hemiparesis → pontine lesion
• Ipsilateral palate weakness/hoarseness + contralateral body pain-temperature loss, with ipsilateral facial pain-temperature loss and ataxia → lateral medullary pattern
• Diplopia, dysarthria, quadriparesis, or reduced consciousness → consider basilar artery occlusion urgently

6. Cerebellar stroke

• Severe vertigo and vomiting
• Gait or truncal ataxia
• Ipsilateral dysmetria
• Nystagmus
• Dysarthria
• Inability to sit unsupported or walk

7. A simple bedside localisation algorithm

Exam-style summary format

“The patient has a left hemispheric cortical syndrome, with right lower facial weakness, right arm-predominant hemiparesis, right hemisensory loss, expressive aphasia, and right homonymous hemianopia. This localises to the left MCA territory.”

“The patient has a posterior-circulation syndrome with left facial weakness and impaired palatal movement, right-sided body weakness, dysarthria, and ataxia. The crossed signs localise to the left brainstem.”

The core idea

What brain function is lost, where is that function located, and which artery supplies that location?

1. Each hemisphere controls the opposite side of the body
2. The motor/sensory body map has leg on the inner surface, face and arm on the outer surface
3. The left hemisphere is usually language dominant
4. The back of the brain is mainly vision and balance/coordination

1. Why are stroke deficits on the opposite side?

• Left cerebral hemisphere controls the right face, arm, and leg.
• Right cerebral hemisphere controls the left face, arm, and leg.

Right hemiplegia usually means a left cerebral hemispheric stroke.

2. The homunculus: why MCA is face-arm and ACA is leg

Inner (medial) surface                 Outer (lateral) surface

        LEG / FOOT  |  TRUNK  |  ARM / HAND / FACE

          ACA
   supplies the INNER surface
      ↓
      LEG and FOOT area


          MCA
   supplies the OUTER surface
      ↓
      FACE, ARM and HAND area

• ACA infarct damages the medial leg area.
  • Therefore: opposite leg weakness and sensory loss more than arm
• MCA infarct damages the lateral face-arm area.
  • Therefore: opposite face and arm weakness/sensory loss more than leg

Easy memory image

• The legs are on the inside, near the midline, so ACA supplies them.
• The face and arms are on the outside, so MCA supplies them.

ACA = Along the midline = leg
MCA = Most of the side surface = face and arm

3. Why do MCA strokes cause aphasia or neglect?

Left MCA: language

• Frontal language output area: speech becomes nonfluent or effortful
• Temporal language comprehension area: speech may be fluent but meaningless, with poor comprehension
• Larger lesion: both affected, causing global aphasia

Right weakness + aphasia = left MCA until proven otherwise.

Right MCA: neglect

• Left-sided neglect
• Failure to attend to the left side of body or room
• Extinction on double simultaneous stimulation
• Sometimes denial of deficit

Left weakness + left neglect = right MCA.

4. Why does MCA stroke cause visual-field loss?

• Left occipital or posterior temporal/parietal lesion → right homonymous hemianopia
• Right occipital or posterior temporal/parietal lesion → left homonymous hemianopia

5. PCA stroke: why is it mainly visual?

PCA = posterior = picture/vision

• Contralateral homonymous hemianopia
• Often relatively preserved limb strength
• Possible visual hallucinations or impaired visual recognition

Sudden inability to see objects on the right side, with normal power and speech
→ left PCA/left occipital stroke

6. Why does ACA stroke cause apathy and incontinence?

• Initiation and motivation
• Voluntary movement, especially of the leg
• Frontal control of bladder function

Medial frontal cortex damaged
        ↓
Leg area damaged      Frontal initiation impaired     Bladder control impaired
        ↓                     ↓                         ↓
Leg weakness       Abulia/apathy, reduced speech     Urinary incontinence

ACA = leg + lack of initiation + loss of bladder control

7. Why does a lacunar stroke have weakness but no aphasia or neglect?

• Internal capsule
• Thalamus
• Pons
• Corona radiata

Cortex
  ↓
Motor fibers converge tightly
  ↓
Internal capsule = small lesion can hit all fibers
  ↓
Contralateral face + arm + leg weakness

• No aphasia
• No neglect
• No gaze deviation
• No clear visual-field defect
• No seizure at onset due to cortical irritation

Pure motor hemiparesis, with no aphasia/neglect/field defect, suggests a lacunar internal-capsule or pontine stroke.

8. Brainstem: why are signs “crossed”?

1. Cranial nerve nuclei/fibers, which usually supply the same side of the face
2. Long motor and sensory tracts, which affect the opposite side of the body at many brainstem levels

Lesion on LEFT side of brainstem

Left cranial nerve signs     +      Right body signs
(face, eye, palate, tongue)         (arm/leg weakness or sensory loss)

Left facial weakness or left palate weakness + right arm and leg weakness
→ left brainstem stroke

Face and body affected on opposite sides = brainstem.

9. Cerebellum: why is there ataxia on the same side?

• Left cerebellar lesion → left limb dysmetria and left-sided falling
• Right cerebellar lesion → right limb dysmetria and right-sided falling

• Sudden severe vertigo
• Vomiting
• Nystagmus
• Dysarthria
• Limb dysmetria
• Severe gait/truncal ataxia
• Falling toward the lesion

Severe sudden inability to sit or walk, even with normal strength, is a posterior-circulation red flag.

The reasoning algorithm at the bedside

Question 1: Is there a cortical sign?

• Aphasia
• Neglect
• Gaze deviation
• Homonymous hemianopia
• Seizure at onset
• Cortical sensory loss

Question 2: Which side of the body is weak?

• Right body signs → left cerebral hemisphere
• Left body signs → right cerebral hemisphere

Question 3: Which body part is worst?

• Face and arm > leg → MCA
• Leg > arm/face → ACA
• No clear motor deficit but field defect → PCA
• Face, arm, leg equally affected, no cortical signs → lacunar/internal capsule

Question 4: Is there a cranial nerve sign on one side and body weakness on the other?

• Yes → brainstem.

Question 5: Is the major problem balance/coordination rather than power?

• Yes → cerebellum or posterior circulation.

Build the diagnosis from examples

Example 1

• Right body signs → left hemisphere
• Face-arm > leg → MCA
• Aphasia → dominant hemisphere, usually left

Example 2

• Left side deficit → right hemisphere
• Leg > arm → ACA
• Apathy and incontinence → medial frontal lobe, also ACA territory

Example 3

• Right visual field is represented in left occipital cortex
• Occipital cortex is supplied mainly by PCA

Example 4

• Face on left, body on right = crossed signs
• Crossed signs = brainstem
• Cranial nerve features support posterior circulation

Example 5

• No cortical signs
• Dense motor deficit can arise where motor fibers are packed together
• Internal capsule or pons are likely sites

The shortest memory framework

MCA = Mouth, Manual work, Meaning
      Face-arm weakness + aphasia/neglect

ACA = Ankles and Apathy
      Leg weakness + abulia/incontinence

PCA = Pictures
      Visual-field loss

Lacune = Little deep lesion, no cortical signs
      Pure motor or pure sensory syndrome

Brainstem = Crossed face-body signs

Cerebellum = Coordination, same-side ataxia

How to check gaze deviation in a stroke patient

Step 1: Observe at rest

• Are both eyes looking in the same horizontal direction?
• Is the head also turned that way?
• Does the patient spontaneously look toward you when you speak from either side?

“There is conjugate left gaze deviation.”

Step 2: Test voluntary horizontal gaze

“Keep your head still and follow my finger with your eyes.”

1. To the right
2. Back to midline
3. To the left
4. Back to midline

• Can both eyes move fully to both sides?
• Is movement reduced to one side?
• Does one eye fail to abduct or adduct?
• Can the eyes return to the midline?
• Is there double vision or nystagmus?

Step 3: Distinguish partial gaze palsy from forced deviation

Normal gaze

• Both eyes move fully right and left.
• No sustained deviation at rest.

Partial gaze palsy

• Eyes can look toward the affected side, but movement in the other direction is limited.
• Or the patient has a mild resting deviation but can overcome it when asked.

The patient’s eyes rest slightly leftward but can voluntarily look right.

Forced gaze deviation

• Both eyes are held toward one side.
• The patient cannot voluntarily bring them to the midline or move them to the opposite side.
• Usually associated with a large hemispheric stroke.

Both eyes are forced to the left and cannot look right.

How to localise it

Cortical hemispheric stroke: eyes look toward the lesion

Left frontal eye field pushes eyes to the RIGHT
Right frontal eye field pushes eyes to the LEFT

Left MCA/frontal eye field stroke
        ↓
Eyes deviate LEFT, toward the lesion
        ↓
Body weakness is RIGHT, opposite the lesion

High-yield rule

In an acute hemispheric stroke, eyes look toward the lesion and away from the weak side.

Seizure: eyes often look away from the seizure focus

Left frontal seizure
        ↓
Excess activation pushes eyes RIGHT

Stroke: eyes look toward the lesion.
Seizure: eyes often look away from the focus.

What about brainstem gaze palsy?

Left pontine gaze center lesion
        ↓
Cannot look LEFT
        ↓
Eyes may rest deviated RIGHT

• Inability to look left
• Eyes deviated right, which is away from a left pontine lesion
• Often other brainstem signs: diplopia, facial weakness, dysarthria, dysphagia, or crossed motor/sensory deficits

If the patient cannot cooperate

1. Hold the eyelids open.
2. Gently rotate the head horizontally.
3. In an intact brainstem, the eyes move in the direction opposite to head rotation, like doll’s eyes.

How to document it

• “Extraocular movements are full. No gaze deviation.”
• “There is a partial left gaze palsy. The patient has reduced ability to look left but can cross the midline.”
• “There is conjugate forced left gaze deviation. The patient cannot voluntarily move the eyes to the right.”
• “Left gaze deviation with right hemiparesis suggests a left hemispheric, likely left MCA, stroke.”

One-line memory aid

Cortex stroke: eyes look at the lesion.
Weak body: opposite the lesion.
Pons lesion: eyes may look away from the lesion.