Posterior Cerebral Artery Infarction from Vertebral Artery Dissection,

Presenting with Homonymous Hemianopia

Kristen Hudson, MD Valerie Biousse, MD

Abbreviations

• PCA: Posterior cerebral artery • ICA: Internal carotid artery • VA: Vertebral artery • MCA: Middle cerebral artery • ACA: Anterior cerebral artery • R: Right • L: Left • MRA: Magnetic resonance angiography

Clinical Presentation

• History – 49 y/o healthy man – Acute onset left upper and lower extremity

weakness and incoordination resulting in ground level fall

– Associated with dull headache

• Neurologic exam: – Left homonymous hemianopia – Left hemisensory (face, arm, and leg) loss – Mild left hemiparesis

Humphrey Visual Fields (HVF)

LEFT EYE RIGHT EYE

Complete Left Homonymous Hemianopia

Figure 1a Figure 1b

Brain MRI (8 hours after symptom onset) Diffusion Weighted Images (DWI) and Apparent Diffusion Coefficient (ADC)

DWI ADC

Note hyperintense (bright) areas on DWI (red arrows) with corresponding dark on ADC (green arrows) indicating acute infarction in right PCA territory (occipital and inferior temporal lobes)

Figure 2a Figure 2b

Axial images, progressing inferior to superior – 1 of 4

Brain MRI (8 hours after symptom onset) Diffusion Weighted Images (DWI) and Apparent Diffusion Coefficient (ADC)

DWI ADC

Figure 3a Figure 3b

Axial images, progressing inferior to superior – 2 of 4

Note bright on DWI (red arrows) and corresponding dark on ADC (green arrows) indicating acute infarction in right PCA territory (occipital and inferior temporal lobes)

Brain MRI (8 hours after symptom onset) Diffusion Weighted Images (DWI) and Apparent Diffusion Coefficient (ADC)

DWI ADC

Figure 4a Figure 4b

Axial images, progressing inferior to superior – 3 of 4

Note bright on DWI (red arrows) and corresponding dark on ADC (green arrows) indicating acute infarction in right occipital lobe and thalamus

Brain MRI (8 hours after symptom onset) Diffusion Weighted Images (DWI) and Apparent Diffusion Coefficient (ADC)

DWI ADC

Figure 5a Figure 5b

Axial images, progressing inferior to superior – 4 of 4

Note bright on DWI (red arrows) and corresponding dark on ADC (green arrows) indicating acute infarction in right occipital lobe and thalamus

MRA Head with contrast– Source Images Axial images, progressing inferior to superior – 1 of 2

Figure 6a

Figure 6b

Figure 6c

Lack of flow-related signal in left VA (green circle), with minimal signal visualized in only most proximal VA (green arrows) near vertebrobasilar junction. Normal flow-related signal in bilateral ICAs and right VA (red arrows).

R ICA

R ICA

L ICA

R ICA L ICA

L ICA

Axial images, progressing inferior to superior – 2 of 2

Note right PCA (red arrows) visualized to takeoff from basilar artery (yellow arrow) with initial flow-related signal, followed by loss of signal (red circle). Left PCA visualized on all slices for comparison (blue arrows).

Basilar Artery

Figure 7a

Figure 7b

Figure 7c

MRA Head with contrast– Source Images

R PCA

R PCA

L PCA

L PCA L PCA

Note lack of visualization of the left VA (green arrows) and right PCA (red arrow) compared to normal (dominant) right VA and left PCA (blue arrow).

ACAs

R MCA L MCA

ACAs

R MCA L MCA

R VA

Basilar A

L PCA

R ICA

L ICA

L ICA

R ICA

Figure 8a Figure 8b

R VA

MRA Head with contrast– 3D reconstructions

Rotation: view from above Rotation: view from the back

L VA

R PCA

L VA

Head CT without contrast (2.5 weeks later) Axial images, progressing inferior to superior

Hypodensity (red arrows) in right occipital and inferior temporal lobes corresponding to old infarction (2.5 weeks)

Figure 9b

Figure 9a

Figure 9d

Figure 9c

Summary

• Right posterior cerebral artery ischemic infarction due to post traumatic (martial arts) left vertebral artery dissection with resulting right PCA occlusion. Left homonymous hemianopia due to right occipital lobe infarction

• Left hemisensory loss due to right thalamic infarction