Uncal herniation

Changed by Owen Kang, 9 Oct 2016

Updates to Article Attributes

Body was changed:

Show markup changes

Uncal herniation is a subtype of transtentorial downward brain ~~herniation~~ herniation, usually ~~related to~~ related to cerebral mass effect increasing the ~~intracranial~~ intracranial pressure.

Clinical presentation

Abnormal posture and poor GCS. There may be ~~pupillary~~ pupillary dilation and loss of light reflex due to direct compression of the oculomotor ~~nerve~~ nerve.

Pathology

In uncal herniation, the uncus and adjacent part of the temporal lobe glide downward across the tentorial ~~incisura compressing~~ incisura compressing the brainstem and the posterior cerebral arteries in the ambient cistern. Uncal herniation may be unilateral or bilateral^1,2.

Aetiology

Uncal herniation occurs secondary to large mass effect (that can occur from traumatic or non-traumatic haemorrhage, malignancy, etc.) that will lead to increased intracranial pressure and herniation.

Radiographic features

Uncal herniation can be suggested on CT CT, however ~~MRI~~ MRI is the gold standard. Mass effect and obliteration of the suprasellar cistern will be seen. The ~~midbrain~~ midbrain is displaced and effaced.

MRI

Unilateral transtentorial herniation:

more common
uncus and medial temporal lobe displaced medially causing effacement of the suprasellar cistern if if mild
hippocampus will obliterate the quadrigeminal cistern in moderate transtentorial ~~herniation~~ herniation

Bilateral transtentorial herniation:

occurs due to extensive mass effect or severe trauma, less common
both temporal lobes herniated into tentorial incisura
complete obliteration of suprasellar cistern
midbrain effaced and displaced inferiorly

Treatment and prognosis

Uncal herniation carries a bad prognosis ~~due~~ due to the direct compression of the vital midbrain centres. They often require emergency ~~neurosurgical~~ neurosurgical decompression.

Complications

extensive brainstem ischemia
Duret haemorrhage
contralateral midbrain compressed against tentorium, may causeKernohan phenomenon
compression of the ipsilateral posterior cerebral artery will result in ischemia of of the visual cortex with resultant homonymous hemianopsia

Practical points

if uncal herniation is diagnosed, the referring physician should be notified ~~immediately~~ immediately, because of its life-threatening nature

-<p><strong>Uncal herniation</strong> is a subtype of transtentorial downward <a href="/articles/brain-herniation">brain herniation</a>, usually related to cerebral mass effect increasing the intracranial pressure.</p><h4>Clinical presentation</h4><p>Abnormal posture and poor <a href="/articles/glasgow-coma-scale">GCS</a>. There may be pupillary dilation and loss of light reflex due to direct compression of the <a href="/articles/oculomotor-nerve">oculomotor nerve</a>. </p><h4>Pathology</h4><p>In uncal herniation, <a href="/articles/the-uncus">the</a><a href="/articles/the-uncus"> uncus</a> and adjacent part of the <a href="/articles/temporal-lobe">temporal lobe</a> glide downward across the tentorial incisura compressing the brainstem and the posterior cerebral arteries in the <a href="/articles/ambient-cistern">ambient cistern</a>. Uncal herniation may be unilateral or bilateral <sup>1,2</sup>.</p><h5>Aetiology</h5><p>Uncal herniation occurs secondary to large mass effect (that can occur from traumatic or non-traumatic haemorrhage, malignancy, etc.) that will lead to increased intracranial pressure and herniation.</p><h4>Radiographic features</h4><p>Uncal herniation can be suggested on CT, however MRI is the gold standard. Mass effect and obliteration of the suprasellar cistern will be seen. The midbrain is displaced and effaced. </p><h5>MRI</h5><p>Unilateral transtentorial herniation:</p><ul>
+<p><strong>Uncal herniation</strong> is a subtype of transtentorial downward <a href="/articles/brain-herniation">brain herniation</a>, usually related to cerebral mass effect increasing the intracranial pressure.</p><h4>Clinical presentation</h4><p>Abnormal posture and poor <a href="/articles/glasgow-coma-scale">GCS</a>. There may be pupillary dilation and loss of light reflex due to direct compression of the <a href="/articles/oculomotor-nerve">oculomotor nerve</a>. </p><h4>Pathology</h4><p>In uncal herniation, the <a title="Uncus" href="/articles/uncus">uncus</a> and adjacent part of the <a href="/articles/temporal-lobe">temporal lobe</a> glide downward across the tentorial incisura compressing the brainstem and the posterior cerebral arteries in the <a href="/articles/ambient-cistern">ambient cistern</a>. Uncal herniation may be unilateral or bilateral <sup>1,2</sup>.</p><h5>Aetiology</h5><p>Uncal herniation occurs secondary to large mass effect (that can occur from traumatic or non-traumatic haemorrhage, malignancy, etc.) that will lead to increased intracranial pressure and herniation.</p><h4>Radiographic features</h4><p>Uncal herniation can be suggested on CT, however MRI is the gold standard. Mass effect and obliteration of the suprasellar cistern will be seen. The midbrain is displaced and effaced. </p><h5>MRI</h5><p>Unilateral transtentorial herniation:</p><ul>
~~-<li>uncus and medial temporal lobe displaced medially causing effacement of the suprasellar cistern if mild</li>~~
~~-<li>hippocampus will obliterate the quadrigeminal cistern in moderate transtentorial herniation</li>~~
+<li>uncus and medial temporal lobe displaced medially causing effacement of the suprasellar cistern if mild</li>
+<li>hippocampus will obliterate the quadrigeminal cistern in moderate transtentorial herniation</li>
-</ul><h4>Treatment and prognosis</h4><p>Uncal herniation carries a bad prognosis due to the direct compression of the vital midbrain centres. They often require emergency neurosurgical decompression. </p><h5>Complications </h5><ul>
+</ul><h4>Treatment and prognosis</h4><p>Uncal herniation carries a bad prognosis due to the direct compression of the vital midbrain centres. They often require emergency neurosurgical decompression. </p><h5>Complications </h5><ul>
~~-<li>contralateral midbrain compressed against tentorium, may cause <a href="/articles/kernohan-phenomenon">Kernohan phenomenon</a>~~
+<li>contralateral midbrain compressed against tentorium, may cause <a href="/articles/kernohan-phenomenon">Kernohan phenomenon</a>
~~-<li>compression of the ipsilateral <a href="/articles/posterior-cerebral-artery">posterior cerebral artery</a> will result in ischemia of the visual cortex with resultant homonymous hemianopsia</li>~~
~~-</ul><h4>Practical points</h4><ul><li>if uncal herniation is diagnosed, the referring physician should be notified immediately, because of its life-threatening nature</li></ul>~~
+<li>compression of the ipsilateral <a href="/articles/posterior-cerebral-artery">posterior cerebral artery</a> will result in ischemia of the visual cortex with resultant homonymous hemianopsia</li>
+</ul><h4>Practical points</h4><ul><li>if uncal herniation is diagnosed, the referring physician should be notified immediately, because of its life-threatening nature</li></ul>

ADVERTISEMENT: Supporters see fewer/no ads

{"current_user":null,"inclusions":[{"imageId":23046545,"studyId":49865,"caseSlug":"brain-herniation-types","caption":"Figure 1: herniation types","thumbnail":"https://prod-images-static.radiopaedia.org/images/23046545/07e301f939d34615566b841eeacd0d_big_gallery.jpeg","isStack":false,"diagnosticCertainty":"not_applicable"},{"imageId":55968199,"studyId":111536,"caseSlug":"meningioma-frontotemporal","caption":"Case 1","thumbnail":"https://prod-images-static.radiopaedia.org/images/55968199/IM0035_big_gallery.jpeg","isStack":true,"diagnosticCertainty":"confirmed_unsubstantiated"},{"imageId":9220386,"studyId":33331,"caseSlug":"subdural-haematoma-uncal-herniation-and-duret-brainstem-haemorrhage-1","caption":"Case 2: with Duret hemorrhage","thumbnail":"https://prod-images-static.radiopaedia.org/images/9220386/027a76f6962ca57286592bbee852fa_big_gallery.jpg","isStack":true,"diagnosticCertainty":"confirmed_substantiated"},{"imageId":552037,"studyId":11385,"caseSlug":"kernohan-phenomenon","caption":"Case 3","thumbnail":"https://prod-images-static.radiopaedia.org/images/552037/4f309e2de89de637f0b88b5cf033c8_big_gallery.jpg","isStack":true,"diagnosticCertainty":"confirmed_substantiated"},{"imageId":24501,"studyId":7601,"caseSlug":"cerebral-oedema","caption":"Case 4: bilateral ","thumbnail":"https://prod-images-static.radiopaedia.org/images/24501/a38458737abf6fce8a26d02ed4531c_big_gallery.jpeg","isStack":true,"diagnosticCertainty":"confirmed_substantiated"},{"imageId":16434900,"studyId":42609,"caseSlug":"posterior-cerebral-artery-territory-infarct-due-to-subdural-haematoma-and-uncal-herniation","caption":"Case 5: with PCA infarct","thumbnail":"https://prod-images-static.radiopaedia.org/images/16434900/88a8297893772e1569e7949d16fa23_big_gallery.jpeg","isStack":true,"diagnosticCertainty":"confirmed_substantiated"},{"imageId":52898686,"studyId":91676,"caseSlug":"cystic-glioblastoma","caption":"Case 6: cystic glioblastoma","thumbnail":"https://prod-images-static.radiopaedia.org/images/52898686/c6896a5bee87f91819057d17599482_big_gallery.jpeg","isStack":true,"diagnosticCertainty":"confirmed_substantiated"},{"imageId":9230997,"studyId":33341,"caseSlug":"uncal-herniation-with-kernohan-phenomenon","caption":"Case 7","thumbnail":"https://prod-images-static.radiopaedia.org/images/9230997/41de85716ecc1a9435aadca101ec65_big_gallery.jpg","isStack":true,"diagnosticCertainty":"confirmed_substantiated"}],"ddx_inclusions":[],"lang":"us"}