Anterior circulation clinical syndromes

Question 1

Ophthalmic artery syndrome

Answer 1

Cause: emboli from internal carotid stenosis

Deficit:
- Uniocular loss of vision
> Transient: amaurosis fugax
> Permanent

• Glaring or flashing white lights
  (tight carotid stenosis with haemodynamic compromise)

Question 2

ACA syndrome

Answer 2

Deficit:
- Contralateral hemiparesis (leg and trunk) with relative sparing of face
> Rarely both ACAs arise from single ICA -> bilateral lower limb and gait weakness
- Sensory disturbance of same distribution
- Abulia (reduced spontaneous speech and activity)
- Excessive or inappropriate emotions (crying, laughing)
- Callosal disconnection
- Perseveration

Question 3

Why does ACA syndrome shows such deficits?

Answer 3

ACA supplies:
1. Frontal lobe
- Premotor and motor cortex - homonculus
> Predominant lower limb weakness
> Minimal sensory disturbances

• Prefrontal cortex - higher cognitive function - planning, memory, speech control, emotion expression
  > Decreased spontaneous speech and activitity
  > Disinhibition of emotions
  > Stuck in thoughts (perseveration)

2. Olfactory lobe
3. Corpus callosum, head of caudate
   - Impared interhemispheric transfer of information
   > Callosal disconnection syndrome

Question 4

MCA syndrome

Answer 4

Deficit:

Contralateral
- Contralateral hemiplegia
- Movement disorder: chorea, dystonia
- Contralateral hemiamopia
- Contralateral hemianaesthesia
- Neglect
- Aphasia (in dominant hemisphere)
- Anosagnosia (in non-dominant hemisphere)

Ipsilateral
- Eye deviation towards side of infarct (disruption of frontal eye fields)

Question 5

Why does MCA syndrome show such deficits?

Answer 5

MCA supplies:
1. Parietal lobe

2. Temporal lobe
3. Basal ganglia - motor movement, learning, eye movement, cognition, emotion
4. Internal capsule
   - corticospinal tract, corticobulbar tract
   - fibres connecting caudate nucleus to putamen
   > Movement disorder: chorea, dystonia
5. Thalamus
   - relays sensorimotor signals to cortex
   - consciousness, sleep
6. Broca’s area
   - speech production
   > expressive aphasia