| Acute Stroke Assessment (ROSIER&NIHSS)
| Atrial Fibrillation
| Atrial Myxoma
| Causes of Stroke
| Ischaemic Stroke
| Cancer and Stroke
| Cardioembolic stroke
| CT Basics for Stroke
| Endocarditis and Stroke
| Haemorrhagic Stroke
| Stroke Thrombolysis
| Hyperacute Stroke Care
Interesting as most vascular supply respects the midline. This is a single vessel that supplies bilateral structures.
- The artery of Percheron was first described in 1973 by French Neurologist Gerard Percheron.
- It is interesting as it is an artery that provides vascular to two paramedian structures as most brain end arteries respect the midline and do not supply bilateral structures.
- It can produce a classical clinical presentation as seen below.
- 30% have a single artery supplying bilateral paramedian thalamus
- This is a single vessel that supplies bilateral structures.
- Usually there are bilateral medial thalamic infarcts and perhaps the involvement of the midbrain
- May have altered mental status, vertical gaze palsy, and memory impairment
- Reduced awareness and coma likely as thalamus is the top of the reticular activating system
- Usually there is an artery on either side supplying the right and left medial thalamus.
- Note there is an error in the graphic so read Posterior cerebral artery and not the posterior communicating artery.
- Acute Artery of Percheron infarcts represent 0.1 to 2% of total ischaemic stroke
- A typical stroke centre with 1000 strokes per annum may see 1-2 cases per annum
- The arterial supply of the thalamus and midbrain is complex and is provided by perforating branches from the posterior cerebral artery and the posterior communicating artery.
- Many numbers of significant variations in the vascular supply of thalami and mesencephalon are seen. The Artery of Percheron is a vascular variant in which a single dominant thalamo-perforating artery arises from one P1/2 segment of PCA and bifurcates to supply both paramedian thalami.
- Occlusion of this vessel results in a characteristic pattern of bilateral paramedian thalamic infarcts with or without mesencephalic infarctions.
- Aetiology is likely cardioembolic or artery to artery from the aorta or vertebral
- Result of bilateral damage patient is unresponsiveness and acute coma.
- Somnolescence - patient is unresponsive but may roll over and pull up bed clothes as if sleeping.
- Coma in others even needing intubation.
- Pinpoint pupils may be seen unless IIIrd nerve involved
- Long term when awakens memory and cognition often affected
- Midbrain involvement - may have hemiplegia, IIIrd nerve deficits
Differentials in Comatose patient with normal initial CT
- Opiates or other sedatives
- Pontine strokes
- Post ictal
- Post concussion
- FBC, U&E, LFTs. CRP. ESR. Cholesterol
- ECG/24 hr tape for AF / PAF
- Echo for cardioembolic causes
- CT: usually normal but may show bilateral thalamic hypodensity with time
- MRI: classical bilateral "butterfly" medial thalamic infarcts and may show some midbrain involvement. There may be the V sign of hyperintense signal intensity on axial FLAIR and DWI images along the pial surface of the midbrain in the interpeduncular fossa in 67% in cases of AOP infarction with midbrain involvement.
- CTA/MRA to look for vertebral dissection can be useful as a cause
- LP may be normal mildly elevated protein but may help exclude infective process if suspected
- ABC, support acutely. Often delayed diagnosis as stroke as other non-stroke diagnoses need exclusion
- Consider thrombolysis and /or thrombectomy if appropriate. However often the presentation is difficult, and diagnosis delayed and beyond the window for thrombolysis.
- Uncertainty means that one may give antibiotics, antivirals initially as ?? Meningitis/Encephalitis. LP may be normal or mildly elevated protein.
- Can make a good recovery. But there may remain memory and cognitive issues.
- Manage as other ischaemic strokes. Look for embolic sources.
- Standard Care: Antiplatelets, BP medications, Statin
- Neurorehabilitation: cognitive issues may predominate so involve Neuropsychology