Brain herniation syndromes - Revision history

Danbot: Add evidence-based Disposition section

2026-03-22T10:03:11Z

Add evidence-based Disposition section

@@ Línea 54: / Línea 54: @@
 *Treat underlying cause (evacuate hematoma, treat [[cerebral edema]])
 *Avoid [[hyperthermia]], [[hyperglycemia]], [[seizures]]
 ==See Also==

Danbot: Expand with concise EM-focused content: background, types with clinical features, management

2026-03-21T01:13:36Z

Expand with concise EM-focused content: background, types with clinical features, management

← Revisión anterior		Revisión del 01:13 21 mar 2026
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			==Background==
			*Brain herniation occurs when increased [[intracranial pressure]] causes brain tissue to shift across rigid dural structures (falx, tentorium) or through the foramen magnum
			*Represents a life-threatening neurological emergency requiring immediate recognition and intervention
			*Most commonly caused by mass lesions ([[intracranial hemorrhage (main)\|intracranial hemorrhage]], [[brain tumor\|tumor]], [[brain abscess\|abscess]]) or diffuse cerebral edema

	==Types==		==Types==
	[[File:Brain herniation.png\|thumbnail\|Type of brain herniation]]		[[File:Brain herniation.png\|thumbnail\|Type of brain herniation]]
	#Uncal		===Uncal (Lateral Transtentorial)===
	#*~~Blown~~ pupil ([[third nerve palsy]], ~~compression from uncus into tentorium cerebelli~~		*Most common clinically significant herniation pattern
	#*[[weakness\|~~Hemiparesis~~]]~~/babinski~~ (75% ~~contralateral~~)		*Medial temporal lobe (uncus) herniates over the tentorial edge
	#Central Transtentorial		*'''Classic triad:''' ipsilateral blown pupil ([[third nerve palsy]]), contralateral [[weakness\|hemiparesis]], decreased consciousness
	#*~~Pinpoint → nonresponsive midpoint pupils~~		**Contralateral hemiparesis occurs ~75% of the time (ipsilateral ''Kernohan notch'' phenomenon in ~25%)
	#*~~Motor~~ [[~~weakness~~]] → increased tone ~~→ flexor~~, ~~then~~ extensor posturing		*May progress to bilateral fixed dilated pupils and posturing if untreated
	~~#Cerebellotonsilar~~ (~~posterior fossa pressure~~)
	#*Pinpoint pupils		===Central Transtentorial===
	#*Sudden [[respiratory failure\|respiratory]] and [[shock\|cardiovascular collapse]]		*Both cerebral hemispheres herniate downward through the tentorium
	#*Flaccid [[weakness\|quadriplegia]]		*Progressive rostral-to-caudal deterioration:
	#Upward Transtentorial		**Early: small reactive pupils, [[Cheyne-Stokes respiration]], increased tone
	#*Pinpoint pupils		**Late: midpoint fixed pupils, extensor posturing, loss of brainstem reflexes
	#*~~Downward conjugate gaze~~
	#Subfalcine herniation (~~cerebral mass lesion causes medial surface~~ of ~~affected hemisphere~~ to ~~push against rigid falx cerebri, then herniate underneath~~)		===Cerebellotonsillar (Tonsillar)===
	#*~~Cingulate gyrus most commonly affected~~		*Cerebellar tonsils herniate through foramen magnum → brainstem compression
	#*~~Often clinically silent~~		*Pinpoint pupils
			*Sudden [[respiratory failure\|respiratory]] and [[shock\|cardiovascular collapse]]
			*Flaccid [[weakness\|quadriplegia]]
			*'''Most rapidly fatal''' herniation pattern

			===Upward (Ascending) Transtentorial===
			*Posterior fossa mass pushes cerebellum upward through tentorial notch
			*Pinpoint pupils, downward conjugate gaze
			*Obstructive [[hydrocephalus]] may occur

			===Subfalcine===
			*Cingulate gyrus herniates under the falx cerebri
			*May compress anterior cerebral artery → contralateral leg weakness
			*Often clinically silent early but may progress to other herniation patterns

			==Clinical Features==
			*Decreasing [[Glasgow Coma Scale (GCS)\|GCS]]
			*Unilateral or bilateral pupil dilation and fixation
			*Abnormal posturing (decorticate → decerebrate)
			*[[Cushing reflex]]: [[hypertension]], [[bradycardia]], irregular respirations (late finding)
			*Loss of brainstem reflexes (corneal, gag, oculocephalic)
			*Respiratory pattern changes (Cheyne-Stokes → central neurogenic hyperventilation → ataxic → apnea)

			==Management==
			*'''ABCs''' — secure airway early; avoid hypoxia and hypotension
			*'''Elevate head of bed''' 30 degrees, keep head midline
			*'''Hyperosmolar therapy:'''
			**[[Mannitol]] 1-1.5 g/kg IV bolus
			**[[Hypertonic saline]] (23.4%) 30 mL IV over 10-20 min via central line (or 3% saline 250-500 mL via peripheral line)
			*'''Hyperventilation''' to PaCO2 30-35 mmHg (temporary bridge — effect lasts 15-20 min)
			*Emergent [[neurosurgery]] consult for surgical decompression or EVD placement
			*Treat underlying cause (evacuate hematoma, treat [[cerebral edema]])
			*Avoid [[hyperthermia]], [[hyperglycemia]], [[seizures]]

	==See Also==		==See Also==
Línea 22:		Línea 59:
	*[[Head trauma (main)]]		*[[Head trauma (main)]]
	*[[Intracranial hemorrhage (main)]]		*[[Intracranial hemorrhage (main)]]
			*[[Glasgow Coma Scale (GCS)]]

	==References==		==References==

ClaireLewis at 23:44, 1 October 2019

2019-10-01T23:44:58Z

← Revisión anterior		Revisión del 23:44 1 oct 2019
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	#Uncal		#Uncal
	#*Blown pupil ([[third nerve palsy]], compression from uncus into tentorium cerebelli		#*Blown pupil ([[third nerve palsy]], compression from uncus into tentorium cerebelli
	#*Hemiparesis/babinski (75% contralateral)		#*[[weakness\|Hemiparesis]]/babinski (75% contralateral)
	#Central Transtentorial		#Central Transtentorial
	#*Pinpoint → nonresponsive midpoint pupils		#*Pinpoint → nonresponsive midpoint pupils
	#*Motor weakness → increased tone → flexor, then extensor posturing		#*Motor [[weakness]] → increased tone → flexor, then extensor posturing
	#Cerebellotonsilar (posterior fossa pressure)		#Cerebellotonsilar (posterior fossa pressure)
	#*Pinpoint pupils		#*Pinpoint pupils
	#*Sudden respiratory and cardiovascular collapse		#*Sudden [[respiratory failure\|respiratory]] and [[shock\|cardiovascular collapse]]
	#*Flaccid quadriplegia		#*Flaccid [[weakness\|quadriplegia]]
	#Upward Transtentorial		#Upward Transtentorial
	#*Pinpoint pupils		#*Pinpoint pupils

Kxl328: /* Types */

2018-10-13T19:56:46Z

Types

← Revisión anterior		Revisión del 19:56 13 oct 2018
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	#*Pinpoint pupils		#*Pinpoint pupils
	#*Downward conjugate gaze		#*Downward conjugate gaze

	#Subfalcine herniation (cerebral mass lesion causes medial surface of affected hemisphere to push against rigid falx cerebri, then herniate underneath)		#Subfalcine herniation (cerebral mass lesion causes medial surface of affected hemisphere to push against rigid falx cerebri, then herniate underneath)

	#*Cingulate gyrus most commonly affected		#*Cingulate gyrus most commonly affected
	#*Often clinically silent		#*Often clinically silent

Kxl328: /* Types */

2018-10-13T19:56:32Z

Types

← Revisión anterior		Revisión del 19:56 13 oct 2018
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	[[File:Brain herniation.png\|thumbnail\|Type of brain herniation]]		[[File:Brain herniation.png\|thumbnail\|Type of brain herniation]]
	#Uncal		#Uncal
	#*~~blown~~ pupil		#*Blown pupil ([[third nerve palsy]], compression from uncus into tentorium cerebelli
	#*~~hemiparesis~~/babinski (75% contralateral)		#*Hemiparesis/babinski (75% contralateral)
	#Central Transtentorial		#Central Transtentorial
	#*~~pinpoint~~ → nonresponsive midpoint pupils		#*Pinpoint → nonresponsive midpoint pupils
	#*~~motor~~ weakness → increased tone → flexor, then extensor posturing		#*Motor weakness → increased tone → flexor, then extensor posturing
	#Cerebellotonsilar		#Cerebellotonsilar (posterior fossa pressure)
	#*~~pinpoint~~ pupils		#*Pinpoint pupils
	#*~~sudden~~ respiratory and cardiovascular collapse		#*Sudden respiratory and cardiovascular collapse
	#*~~flaccid~~ quadriplegia		#*Flaccid quadriplegia
	#Upward Transtentorial		#Upward Transtentorial
	#* ~~pinpoint~~ pupils		#*Pinpoint pupils
	#*~~downward~~ conjugate gaze		#*Downward conjugate gaze

			#Subfalcine herniation (cerebral mass lesion causes medial surface of affected hemisphere to push against rigid falx cerebri, then herniate underneath)

			#*Cingulate gyrus most commonly affected
			#*Often clinically silent

	==See Also==		==See Also==

Lisayee25 at 15:59, 8 July 2017

2017-07-08T15:59:44Z

← Revisión anterior		Revisión del 15:59 8 jul 2017
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	#Uncal		#Uncal
	#*blown pupil		#*blown pupil
	#*hemiparesis/babinski (75% ~~contralat~~)		#*hemiparesis/babinski (75% contralateral)
	#Central Transtentorial		#Central Transtentorial
	#*B pinpoint → nonresponsive midpoint		#*pinpoint → nonresponsive midpoint pupils
	#*B motor weakness~~/inc~~ tone		#*motor weakness → increased tone → flexor, then extensor posturing
	#Cerebellotonsilar		#Cerebellotonsilar
	#*B pinpoint		#*pinpoint pupils
	#*sudden ~~cario/resp colapse~~		#*sudden respiratory and cardiovascular collapse
	#*~~flacid quadraplegia~~		#*flaccid quadriplegia
	#Upward Transtentorial		#Upward Transtentorial
	#*B pinpoint		#* pinpoint pupils
	#*downward conjugate gaze		#*downward conjugate gaze

	==See Also==		==See Also==
			*[[Elevated intracranial pressure]]
			*[[Head trauma (main)]]
	*[[Intracranial hemorrhage (main)]]		*[[Intracranial hemorrhage (main)]]

Mholtz: Text replacement - "-->" to "→"

2017-02-08T23:04:40Z

Text replacement - "-->" to "→"

← Revisión anterior		Revisión del 23:04 8 feb 2017
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	#*hemiparesis/babinski (75% contralat)		#*hemiparesis/babinski (75% contralat)
	#Central Transtentorial		#Central Transtentorial
	#*B pinpoint ~~-->~~ nonresponsive midpoint		#*B pinpoint → nonresponsive midpoint
	#*B motor weakness/inc tone		#*B motor weakness/inc tone
	#Cerebellotonsilar		#Cerebellotonsilar

Alvarez13: Picture

2016-08-16T13:48:46Z

Picture

← Revisión anterior		Revisión del 13:48 16 ago 2016
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	==Types==		==Types==
			[[File:Brain herniation.png\|thumbnail\|Type of brain herniation]]
	#Uncal		#Uncal
	#*blown pupil		#*blown pupil

Neil.m.young: Text replacement - "# " to "#"

2016-07-08T13:32:10Z

Text replacement - "# " to "#"

← Revisión anterior		Revisión del 13:32 8 jul 2016
Línea 1:		Línea 1:
	==Types==		==Types==
	# Uncal		#Uncal
	#*blown pupil		#*blown pupil
	#*hemiparesis/babinski (75% contralat)		#*hemiparesis/babinski (75% contralat)
	# Central Transtentorial		#Central Transtentorial
	#*B pinpoint --> nonresponsive midpoint		#*B pinpoint --> nonresponsive midpoint
	#*B motor weakness/inc tone		#*B motor weakness/inc tone
	# Cerebellotonsilar		#Cerebellotonsilar
	#*B pinpoint		#*B pinpoint
	#*sudden cario/resp colapse		#*sudden cario/resp colapse
	#*flacid quadraplegia		#*flacid quadraplegia
	# Upward Transtentorial		#Upward Transtentorial
	#*B pinpoint		#*B pinpoint
	#*downward conjugate gaze		#*downward conjugate gaze

Neil.m.young: Text replacement - "==Source==" to "==References== "

2016-06-26T04:17:12Z

Text replacement - "==Source==" to "==References== <references/>"

← Revisión anterior		Revisión del 04:17 26 jun 2016
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	*[[Intracranial hemorrhage (main)]]		*[[Intracranial hemorrhage (main)]]

	==~~Source~~==		==References==
			<references/>

	[[Category:Neurology]]		[[Category:Neurology]]