Posterior inferior cerebellar artery
Disclosures
- updated 11 May 2022:
Nothing to disclose
Updates to Article Attributes
Body
was changed:
Posterior inferior cerebellar artery (PICA) is one of the three vessels that provide arterial supply to the cerebellum. It is the most variable and tortuous cerebellar artery.
Gross anatomy
Origin
The PICA is a paired artery that originates from the vertebral artery V4 segment.
However, its origin is highly variable:
~20% arise extracranially, inferior to the foramen magnum
10% arise from the basilar rather than vertebral artery
2% bilaterally absent
occasionally arises from a common origin with the anterior inferior cerebellar artery
Segments
The segmental anatomy was defined microsurgically by Lister et al. 6,7:
-
anterior medullary (p1) segment
courses along the front of the medulla at the level of the inferior olive
-
lateral medullary (p2) segment
-
tonsillomedullary (p3; TM) segment
courses along the posterolateral surface of the medulla and inferior cerebellar tonsil
contains the caudal loop, a downward convex loop that mostly remain superior to the foramen magnum but occasionally extend below it
marks the transition between the proximal (medulla-supplying) and distal (cerebellum-supplying) parts of the posterior inferior cerebellar artery
-
telovelotonsillar (p4; TVT) segment
courses in the cleft between the tela choroidea, inferior medullary velum rostrally, and superior pole of the cerebellar tonsil caudally
contains the cranial loop, also known as the choroid point or choroid arch, an upward convex loop that has a constant relation to the 4th ventricle and gives rise to choroidal arteries
-
cortical (p5) segment
supplies branches to the cerebellar surface
Branches
The main trunk of the posterior inferior cerebellar artery usually bifurcates somewhere along the margin of the cerebellar tonsil into
-
medial trunk
supplies the vermis and adjacent hemisphere
-
lateral trunk
supplies the tonsil and hemisphere
The posterior inferior cerebellar artery gives off the following arteries:
perforating (medullary) arteries
choroidal arteries
cortical arteries
Note: occasionally, a small vertebral artery will terminate into a common AICA-PICA complex.
Supply
It has a variable territory depending on the size of the AICA (AICA-PICA dominance). Typically it supplies:
-
posteroinferior cerebellar hemispheres (up to the great horizontal fissure)
cerebellar tonsils: 85% of the time
biventral lobule: 80%
nucleus gracilis: 85%
superior semilunar lobule: 50%
inferior portion of the vermis
lower part of the medulla: 50%
Variant anatomy
course may loop around the cerebellar tonsil
rarely a single unpaired PICA will supply the PICA territory bilaterally 8
Related pathology
-<p><strong>Posterior inferior cerebellar artery (PICA)</strong> is one of the three vessels that provide arterial supply to the <a href="/articles/cerebellum">cerebellum</a>. It is the most variable and tortuous cerebellar artery.</p><h4>Gross anatomy</h4><h5>Origin</h5><p>The PICA is a paired artery that originates from the <a href="/articles/vertebral-artery" title="Vertebral artery">vertebral artery</a> V4 segment.</p><p>However, its origin is highly variable:</p><ul>-<li><p>~20% arise extracranially, inferior to the <a href="/articles/foramen-magnum">foramen magnum</a></p></li>-<li><p>10% arise from the basilar rather than vertebral artery</p></li>-<li><p>2% bilaterally absent</p></li>-<li><p>occasionally arises from a common origin with the <a href="/articles/anterior-inferior-cerebellar-artery" title="Anterior inferior cerebellar artery">anterior inferior cerebellar artery</a></p></li>-</ul><h5>Segments</h5><p>The segmental anatomy was defined microsurgically by Lister et al. <sup>6,7</sup>:</p><ol>-<li>-<p>anterior medullary (p1) segment</p>-<ul><li><p>courses along the front of the medulla at the level of the <a href="/articles/inferior-olivary-nucleus">inferior olive</a></p></li></ul>-</li>-<li>-<p>lateral medullary (p2) segment</p>-<ul><li><p>variably courses (ascending or descending) along the side of the medulla near or between the origins of the <a href="/articles/glossopharyngeal-nerve">9<sup>th</sup></a>, <a href="/articles/vagus-nerve">10<sup>th</sup></a>, and <a href="/articles/accessory-nerve-1">11<sup>th</sup></a> cranial nerve roots</p></li></ul>-</li>-<li>-<p>tonsillomedullary (p3; TM) segment</p>-<ul>-<li><p>courses along the posterolateral surface of the medulla and inferior <a href="/articles/cerebellar-tonsils">cerebellar tonsil</a></p></li>-<li><p>contains the caudal loop, a downward convex loop that mostly remain superior to the <a href="/articles/foramen-magnum">foramen magnum</a> but occasionally extend below it</p></li>-<li><p>marks the transition between the proximal (medulla-supplying) and distal (cerebellum-supplying) parts of the posterior inferior cerebellar artery</p></li>-</ul>-</li>-<li>-<p>telovelotonsillar (p4; TVT) segment</p>-<ul>-<li><p>courses in the cleft between the <a href="/articles/tela-choroidea">tela choroidea</a>, <a href="/articles/inferior-medullary-velum">inferior medullary velum</a> rostrally, and superior pole of the cerebellar tonsil caudally</p></li>-<li><p>contains the cranial loop, also known as the choroid point or choroid arch, an upward convex loop that has a constant relation to the 4<sup>th</sup> ventricle and gives rise to choroidal arteries</p></li>-</ul>-</li>-<li>-<p>cortical (p5) segment</p>-<ul><li><p>supplies branches to the cerebellar surface</p></li></ul>-</li>-</ol><h5>Branches</h5><p>The main trunk of the posterior inferior cerebellar artery usually bifurcates somewhere along the margin of the cerebellar tonsil into</p><ul>-<li>-<p>medial trunk</p>-<ul><li><p>supplies the <a href="/articles/vermis">vermis</a> and adjacent hemisphere</p></li></ul>-</li>-<li>-<p>lateral trunk</p>-<ul><li><p>supplies the <a href="/articles/cerebellar-tonsils">tonsil</a> and hemisphere</p></li></ul>-</li>-</ul><p>The posterior inferior cerebellar artery gives off the following arteries:</p><ul>-<li><p>perforating (medullary) arteries</p></li>-<li><p>choroidal arteries</p></li>-<li><p>cortical arteries</p></li>-</ul><p>Note: occasionally, a small vertebral artery will terminate into a common AICA-PICA complex.</p><h4>Supply</h4><p>It has a variable territory depending on the size of the <a href="/articles/anterior-inferior-cerebellar-artery">AICA</a> (<a href="/articles/aica-pica-dominance-1">AICA-PICA dominance</a>). Typically it supplies:</p><ul>-<li>-<p>posteroinferior <a href="/articles/cerebellum">cerebellar </a>hemispheres (up to the great horizontal fissure)</p>-<ul>-<li><p>cerebellar tonsils: 85% of the time</p></li>-<li><p>biventral lobule: 80%</p></li>-<li><p>nucleus gracilis: 85%</p></li>-<li><p>superior semilunar lobule: 50%</p></li>-</ul>-</li>-<li><p>inferior portion of the vermis</p></li>-<li><p>lower part of the medulla: 50%</p></li>-<li><p><a href="/articles/inferior-cerebellar-peduncle-1">inferior cerebellar peduncles</a></p></li>-</ul><h4>Variant anatomy</h4><ul>-<li><p>course may loop around the cerebellar tonsil</p></li>-<li><p>rarely a single unpaired PICA will supply the PICA territory bilaterally <sup>8</sup></p></li>- +<p><strong>Posterior inferior cerebellar artery (PICA)</strong> is one of the three vessels that provide arterial supply to the <a href="/articles/cerebellum">cerebellum</a>. It is the most variable and tortuous cerebellar artery.</p><h4>Gross anatomy</h4><h5>Origin</h5><p>The PICA is a paired artery that originates from the <a href="/articles/vertebral-artery" title="Vertebral artery">vertebral artery</a> V4 segment.</p><p>However, its origin is highly variable:</p><ul>
- +<li><p>~20% arise extracranially, inferior to the <a href="/articles/foramen-magnum">foramen magnum</a></p></li>
- +<li><p>10% arise from the basilar rather than vertebral artery</p></li>
- +<li><p>2% bilaterally absent</p></li>
- +<li><p>occasionally arises from a common origin with the <a href="/articles/anterior-inferior-cerebellar-artery" title="Anterior inferior cerebellar artery">anterior inferior cerebellar artery</a></p></li>
- +</ul><h5>Segments</h5><p>The segmental anatomy was defined microsurgically by Lister et al. <sup>6,7</sup>:</p><ol>
- +<li>
- +<p>anterior medullary (p1) segment</p>
- +<ul><li><p>courses along the front of the medulla at the level of the <a href="/articles/inferior-olivary-nucleus">inferior olive</a></p></li></ul>
- +</li>
- +<li>
- +<p>lateral medullary (p2) segment</p>
- +<ul><li><p>variably courses (ascending or descending) along the side of the medulla near or between the origins of the <a href="/articles/glossopharyngeal-nerve">9<sup>th</sup></a>, <a href="/articles/vagus-nerve">10<sup>th</sup></a>, and <a href="/articles/accessory-nerve-1">11<sup>th</sup></a> cranial nerve roots</p></li></ul>
- +</li>
- +<li>
- +<p>tonsillomedullary (p3; TM) segment</p>
- +<ul>
- +<li><p>courses along the posterolateral surface of the medulla and inferior <a href="/articles/cerebellar-tonsils">cerebellar tonsil</a></p></li>
- +<li><p>contains the caudal loop, a downward convex loop that mostly remain superior to the <a href="/articles/foramen-magnum">foramen magnum</a> but occasionally extend below it</p></li>
- +<li><p>marks the transition between the proximal (medulla-supplying) and distal (cerebellum-supplying) parts of the posterior inferior cerebellar artery</p></li>
- +</ul>
- +</li>
- +<li>
- +<p>telovelotonsillar (p4; TVT) segment</p>
- +<ul>
- +<li><p>courses in the cleft between the <a href="/articles/tela-choroidea">tela choroidea</a>, <a href="/articles/inferior-medullary-velum">inferior medullary velum</a> rostrally, and superior pole of the cerebellar tonsil caudally</p></li>
- +<li><p>contains the cranial loop, also known as the choroid point or choroid arch, an upward convex loop that has a constant relation to the 4<sup>th</sup> ventricle and gives rise to choroidal arteries</p></li>
- +</ul>
- +</li>
- +<li>
- +<p>cortical (p5) segment</p>
- +<ul><li><p>supplies branches to the cerebellar surface</p></li></ul>
- +</li>
- +</ol><h5>Branches</h5><p>The main trunk of the posterior inferior cerebellar artery usually bifurcates somewhere along the margin of the cerebellar tonsil into</p><ul>
- +<li>
- +<p>medial trunk</p>
- +<ul><li><p>supplies the <a href="/articles/vermis">vermis</a> and adjacent hemisphere</p></li></ul>
- +</li>
- +<li>
- +<p>lateral trunk</p>
- +<ul><li><p>supplies the <a href="/articles/cerebellar-tonsils">tonsil</a> and hemisphere</p></li></ul>
- +</li>
- +</ul><p>The posterior inferior cerebellar artery gives off the following arteries:</p><ul>
- +<li><p>perforating (medullary) arteries</p></li>
- +<li><p>choroidal arteries</p></li>
- +<li><p>cortical arteries</p></li>
- +</ul><p>Note: occasionally, a small vertebral artery will terminate into a common AICA-PICA complex.</p><h4>Supply</h4><p>It has a variable territory depending on the size of the <a href="/articles/anterior-inferior-cerebellar-artery">AICA</a> (<a href="/articles/aica-pica-dominance-1">AICA-PICA dominance</a>). Typically it supplies:</p><ul>
- +<li>
- +<p>posteroinferior <a href="/articles/cerebellum">cerebellar </a>hemispheres (up to the great horizontal fissure)</p>
- +<ul>
- +<li><p>cerebellar tonsils: 85% of the time</p></li>
- +<li><p>biventral lobule: 80%</p></li>
- +<li><p>nucleus gracilis: 85%</p></li>
- +<li><p>superior semilunar lobule: 50%</p></li>
- +</ul>
- +</li>
- +<li><p>inferior portion of the vermis</p></li>
- +<li><p>lower part of the medulla: 50%</p></li>
- +<li><p><a href="/articles/inferior-cerebellar-peduncle-1">inferior cerebellar peduncles</a></p></li>
- +</ul><h4>Variant anatomy</h4><ul>
- +<li><p>course may loop around the cerebellar tonsil</p></li>
- +<li><p>rarely a single unpaired PICA will supply the PICA territory bilaterally <sup>8</sup></p></li>
Images Changes:
Image 2 Annotated image (Axial) ( update )
Position
changed from 3 to 2.
Image 3 Annotated image (Axial) ( update )
Position
changed from 5 to 3.
Image 4 Annotated image ( update )
Position
changed from 7 to 4.
Image 5 Annotated image ( update )
Position
changed from 8 to 5.
Image 6 Diagram ( update )
Position
changed from 9 to 6.
Image 7 Diagram (Arterial territories) ( update )
Position
changed from 10 to 7.
Image 8 CT (non-contrast) ( update )
Position
changed from 2 to 8.
Image 9 DSA (angiography) (Left vertebral artery) ( update )
Position
changed from 6 to 10.
Image 10 MRI (DWI) ( update )
Position
changed from 4 to 9.
Unable to process the form. Check for errors and try again.