Atlanto-occipital assimilation

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Atlanto-occipital assimilation is the fusion of the atlas (C1) to the occiput and is one of the transitional vertebrae.

Epidemiology

Atlanto-occipital assimilation occurs in ~0approximately 0.5% (range 0.25-1%) of the population ^2-4.

Clinical presentation

Atlanto-occipital is typically asymptomatic but symptoms from nerve or vascular compression can occur.

Gross anatomy

Fusion of C1 to the occiput can be either ³:

complete: C1 not identifiable
incomplete: C1 partially identifiable

Associations

Atlanto-occipital assimilation is associated with ²:

fusion of C2 and C3 (occurs in 50% of cases)
basilar invagination
cleft palate
cervical ribs
urinary tract anomalies

-<p><strong>Atlanto-occipital assimilation</strong> is the fusion of the <a href="/articles/atlas">atlas</a> (C1) to the occiput and is one of the <a href="/articles/transitional-vertebra">transitional vertebrae</a>. </p><h4>Epidemiology</h4><p>Atlanto-occipital assimilation occurs in ~0.5% (range 0.25-1%) of the population <sup>2-4</sup>. </p><h4>Clinical presentation</h4><p>Atlanto-occipital is typically asymptomatic but symptoms from nerve or vascular compression can occur. </p><h4>Gross anatomy</h4><p>Fusion of C1 to the occiput can be either <sup>3</sup>:</p><ul>
+<p><strong>Atlanto-occipital assimilation</strong> is the fusion of the <a href="/articles/atlas">atlas</a> (C1) to the occiput and is one of the <a href="/articles/transitional-vertebra">transitional vertebrae</a>. </p><h4>Epidemiology</h4><p>Atlanto-occipital assimilation occurs in approximately 0.5% (range 0.25-1%) of the population <sup>2-4</sup>. </p><h4>Clinical presentation</h4><p>Atlanto-occipital is typically asymptomatic but symptoms from nerve or vascular compression can occur. </p><h4>Gross anatomy</h4><p>Fusion of C1 to the occiput can be either <sup>3</sup>:</p><ul>

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