Blog C Miller Fisher epidural haematoma fixed dilated pupil Henri Duret History intracranial pressure conte Jonathan Hutchinson Richard Bright Special Feature

The dilated pupil and brain herniation | ACNR

The dilated pupil and brain herniation

Posted in Historical past,Particular Function on 7th Might 2019

JMS Pearce MD, FRCP Emeritus Advisor Neurologist, Department of Neurology, Hull Royal Infirmary, UK.
Correspondence to: J.M.S. Pearce, 304 Beverley Street Anlaby, East Yorks, HU10 7BG, UK. E mail: [email protected]

Battle of Interest assertion: None declared.
Date first submitted: three/9/18
Acceptance date: four/9/18
To cite: Pearce JMS, ACNR 2018;18(three);16-19.
Revealed online: 7/5/19


This paper recollects the descriptions and early concepts concerning the dilated pupil accom-panying raised intracranial strain ensuing from head injuries and space-occupying lesions. The remark of the ominous fastened, dilated pupils in those with increasing brain lesions dates to Richard Vibrant and Jonathan Hutchinson within the 19th century, however its significance and mechanisms have been solely debated within the early years of the 20th century. Compression or stretching of the oculomotor nerve have been thought-about attainable causes, but the related mechanisms of coning and the significance of lateral shift have been solely extra just lately realised.

FEW investigations of late years have excited extra interest than these which have been made into the connection of sure modifications within the eye with illnesses of the central nervous system, and into the additional technique of analysis which such modifications might afford.
Sir Thomas Clifford Allbutt ,1872

Not until the early 20th century was the importance of a hard and fast dilated pupil recognised as an ominous bodily sign. It turned a neurosurgical axiom that a fastened dilated pupil happens ipsilateral to a strain cone brought on by a space-occupying lesion with intracranial hypertension.2

Brain herniations are traditionally classed as: subfalcial, uncal (transtentorial), and cerebellar tonsillar. They will complicate head damage or another causes of a brain mass or swelling.three Central herniation, often preceded by uncal and cingulate herniation, is the downward movement of the brain by means of the tentorial notch. Clinically it’s manifested by stupor resulting in coma; small, reactive pupils turning into fastened and dilated; with irregular respiration, leading to decerebrate posture, and finally demise. With herniation, the ipsilateral posterior cerebral artery could also be compressed including to the ischaemia induced by brain oedema.

Observations of raised intracranial strain, and extra lately papilloedema (in early accounts described as ‘choked disc’, stauung-spapille, or optic neuritis) have been recorded more than a century in the past.1,4 However neither the mechanisms nor medical significance of the associated dilated pupil have been absolutely understood.

The redoubtable surgeon, Percivall Pott (1714-1788) detailed his Observations on the Nature and Penalties of those Accidents to which the Head is liable from exterior Violence5 and referred to the woodcuts of the surgeon Hans von Gersdorff (c.1455-c.1529). However Pott failed to say the ocular indicators in von Gersdorff’s historic woodcut, the work of Johannes [syn. Hans] Wechtlin, contained in his Feldbuch der Wundartzney (Fieldbook of wound drugs) 1517. This illustrated the elevation of a depressed cranium fracture. The affected person exhibits a slightly dilated proper pupil and the eye is abducted, suggesting a partial third nerve palsy (Figure 1 under). It has been stated that his remark was not repeated for an additional 300 years. Nevertheless, in this oft-cited instance6 there’s insufficient proof to wholly exclude an unrelated strabismus with a physiological asymmetry of the pupils of up to zero.four mm, present in about 20% of normal individuals.

John Cheyne (1777-1836), remembered for Cheyne-Stokes respiration, studied drugs at Edinburgh, where Alexander Monro secundus (1733-1817), who described the interventricular foramen, was one in every of his academics. In instances of apoplexy, Cheyne believed that cerebral anaemia is perhaps the cause; in an early case in 1812 he recorded the contraction and dilatation of the pupil and famous, ‘Thus we do not despair until the pupil ceases to contract.’7

Richard Shiny

Figure 2. Richard Brilliant (from http://blueplaquesguy.

A extra complete description is present in 1831, in Volume two* of Richard Shiny’s (1789-1858) (Determine 2) famous case reports8 devoted to neuropathology9 with 54 magnificent plates (Determine three). William Munk in his Roll was justifiably dazzled by Vibrant’s talents:

‘Dr. Bright showed the most sagacious observation, untiring industry, and wonderful powers of investigating truth, the end and aim of all his work.’10 Vibrant reported the ipsilateral dilated pupil in a person whose post-mortem confirmed an epidural haematoma with petechial haemorrhages in the brain after head damage (case 191).8,11 On the second day after a nicely described lucid interval the affected person was famous to be much less responsive and to have a sluggish pulse. Shiny noticed:

A 38-year-old man working at a big wharf under London bridge fell from a peak of 11 or 12 ft. The following day his language was incoherent and speech scarcely articulate, and he complained of ache within the head. He was bled, and on the third day he is in a state of stupor, however could also be roused to reply query. The muscle mass of the left aspect of the face are paralyzed… right pupil dilated. He died the sixth day and an autopsy was carried out. An epidural hematoma was discovered. Normally the pupils typically contracted, at different occasions dilated, and appearing quite irregularly underneath the stimulus of light.

Brilliant described one other case, a 20-year-old man with apoplexy whose pupils dilated, and didn’t contract when a candle was brought close to. He clearly recognised the significance of this very important medical sign; nevertheless, he advised no mechanism.

Figure 3. Shiny’s Reviews on Medical Instances (Vol 2).

Shiny’s salient statement might have prompted the experiments of Ernst Viktor von Leyden (1832-1910), which in 1866 confirmed that with increased intracranial strain, the pupils first turned slender, then dilated, but not all the time symmetrical, accompanied by coma with a sluggish pulse, impaired respiration and demise.12 Five years later, Alexander Pagenstecher (1828-79) studied consecutive reactions of the pupil with growing experimental strain, noting an preliminary constriction adopted by a dilated fastened pupil with stupor or coma.13,14 The controversial Guy’s hospital surgeon and anatomist Astley Paston Cooper (1768-1841) also experimented on canine, manually compressing the uncovered dura, making an attempt to differentiate compression from ‘simple concussion’. In people he defined the symptoms brought on by compression:15 (lecture XVII):

The respiration being stertorous, the heart beat sluggish, and the pupils dilated; …if you then discover a patient with the apoplectic stertor, sluggish pulse, dilated pupils, it can usually occur that the brain is compressed.

Hutchinson’s pupil

It remained for Jonathan Hutchinson (1828-1913)16 (Figure four) in 1867 to offer a more detailed report of his expertise with human head injuries and his observations of a dilated pupil on the aspect of a fatal traumatic epidural haematoma:17

…Unilateral dilatation of pupil after damage to the top. A man had died in whom this symptom was current, and in whom we found a big clot of blood between the dura mater and the bone pressing forwards upon the sphenoidal fissure, and little question compressing the trunk of the third nerve. …We will have little hesitation in assuming that the cause of demise was compression of the brain.

Fig 4. Sir Jonathan Hutchinson (from

Hutchinson also reported a boy, who was admitted on a Thursday, having been knocked down in the street and probably run over. He didn’t relate the dilated pupil to transtentorial shift, however invoked the mechanism of third nerve compression that impacts the ocular para-sympathetic causing the pupil to dilate, and to fail to constrict in response to mild:

From the position of the clot there could be little doubt that the third nerve is compressed and thus, the dilatation of the pupil is explained. These two instances, so exactly parallel, seem to provide us with a brand new and very helpful symptom indicative of effusion of blood on this state of affairs. … You will notice that beyond the signs which often attend instances of extreme concussion of the brain (accompanied as they often are by kind of of contusion additionally), we had had none excepting the dilatation of the suitable pupil. The boy had been acutely aware up to within about half an hour of his demise; he had had a speedy pulse and great restlessness all through; he had had no observable paralysis.17

The Man’s hospital surgeon, WHA Jacobson (1847-1924) recommended in 1886, that this phenomenon ought to be named ‘Hutchinson pupil’.18 He might have neglected Shiny’s earlier account.

William Macewen (1848–1924) in 1887 thought-about pupillary dilatation to be an indication of oculomotor nerve irritation, paralysis or vascular modifications in reference to a middle cranial fossa clot.19

Duret Haemorrhage

Henri Duret (1849–1921) a surgeon, who educated with Charcot and Vulpian,20 reported that blows on the top in animals elevated intracranial strain. He noticed loss of consciousness, rigidity, sluggish then quicker respiration, and mid-dilated pupils; days later the pupils constricted and the animal died. Along with the cerebral injury at autopsy he noticed ‘haemorrhagic lesions in the superior part of the bulbar base’, which proved ‘that the blows to the skull may have a considerable effect on the bulbus’:21,22

A dotted line of haemorrhages on the floor of the medulla’s thickness and around the central canal… that is explained by the truth that at the time of influence, the fluid in the ventricles has an impact on the cerebral aqueduct, the fourth ventricle and, especially, the spine’s central canal.

Mistakenly, he thought-about:

the sudden cessation or suppression of brain perform subsequent to an impression to the skull is produced by the use of the cerebrospinal fluid, which transmits the damaging motion to regions of the brain able to producing all the noticed phenomena.

This mechanism he termed choc céphalo-rachidien (cephalospinal shock). He distinguished two levels, first, pupil constriction by bulbar lesions as a consequence of choc céphalo-rachidien, secondly, dilatation from the buildup of blood across the oculomotor nerve. Theodor Kocher (1841–1917), a Swiss surgeon then used the eponym ‘Duret haemorrhages’ in his complete assessment of brain injuries.23

Later investigations

The German surgeon, Ernst von Bergmann (1836–1907), a keen advocate of Lister’s aseptic methods, described fastened dilated pupils in his textual content on brain accidents.24 He observed that the ipsilateral pupil turned narrower at first and then, with increased pres-sure leading to coma, it dilated.

In 1904 James Collier observed both the cerebellar strain cone and ‘false localising signs’ in instances of intracranial tumour examined clinically and pathologically.25 He distinguished this from the dilated pupil of uncal herniation.26 He commented:27

In lots of instances of intracranial tumour of long period, it was discovered autopsy that the posterior inferior part of the cerebellum had been pushed down and backwards into the foramen magnum and the medulla itself considerably caudally displaced, the 2 buildings together forming a cone-shaped plug tightly filling up the foramen magnum.

Adolf Meyer (1866-1950) associated the strain on the third nerve to herniation of the uncus into the incisura angularis.28 Equally, Sir Geoffrey Jefferson (1886-1961) described in 4 instances the mechanism of temporal lobe herniation: a strain cone shaped by uncal herniation on the crus cerebri, with ensuing impingement on the oculomotor nerve.three

Later accounts of Kernohan-Woltman’s notch of the crus cerebri causing ipsilateral hemiplegia29 have been followed by the newer concept that melancholy of alertness corresponded to distortion of the brain by horizontal fairly than vertical displacement.

Holman and Scott pointed out that though a dilated pupil was beneficial in locating the location of damage, there were just a few descriptions within the literature of patients who deteriorated and lapsed into coma.

The mechanism of its look just isn’t apparent, but it is assumed that the intracranial course of the third nerve, because it lies towards the bony wall of the cranium, lends itself peculiarly nicely to compression from a strain utilized lateral and superior to it.30

This mirrored Hutchinson’s cautionary remark:

This case adds another to a substantial collection which we’ve got just lately had displaying that the orthodox signs of compression of the brain, absolute insensibility, stertor, sluggish, laboured pulse, and scorching surface, will not be by any means all the time met with…17

Holman and Scott echoed Horsley’s earlier report4 of the results of this sign for surgical procedure:

‘[We] place reliance on the unilateral dilatation and fixation of the pupil as a sign of unilateral cerebral compression, due extra notably to haemorrhage…Unilateral dilatation and fixa-tion of the pupil is a worthwhile assist in figuring out the situation of the intracranial damage and haemorrhage following head accidents. When one pupil was dilated the operation must be on the ipsilateral aspect.‘30

Miller Fisher

With attribute shrewdness, in 1995 Miller Fisher (1913-2012) investigated transtentorial herniation with computed tomography: descent by means of the tentorial opening could not be documented. Stressing the significance of lateral displacement, he warned that bilateral brain stem compression in acute bilateral instances have to be distinguished from herniation:

Upward cerebellar herniation is simply the signal of an overfull posterior fossa. …Subfalcial herniation is tolerated until lateral displacement is excessive…Combining medical, pathologic, computed tomography and magnetic resonance imaging knowledge, it’s concluded that temporal lobe herniation is just not the means by which the midbrain sustains irreversible injury in acute instances, however slightly lateral displacement of the brain at the tentorium is the prime mover and herniation a innocent accompaniment.31 The dilated pupil is attributed to midbrain distortion as an alternative of uncal herniation.


It is scarcely essential to conclude that on this context the mechanisms of abnormal pupils remain debatable since many elementary questions nonetheless await answer. The unilaterally dilated pupil might be explained by stretching of the oculomotor nerve over the clivus or by its compression by a bulging hemispheric mass or haemorrhage. It appears that melancholy of consciousness is especially related to a lateral brain shift at the tentorium. The false-localising impaired pupil reaction on the other aspect is attributed to midbrain injury because of distortion and compression.32,25


1. Allbutt TC. On the causation and significance of the choked disc in intracranial illnesses. Br. Med. J. 1872;1:443–445.

2. Marshman LAG, Polkey CE, C. Penney CC. Unilateral Fastened Dilation of the Pupil as a False-localizing Sign with Intracranial Hemorrhage: Case Report and Literature Evaluation. Neurosurgery 2001;49:1251-6.

3. Jefferson G: The tentorial strain cone. Arch Neurol Psychiatry 1938;40:857–876.

four. Horsley V. “Optic Neuritis,” or ” Papilloedema.” Remedy, Localizing Worth, and Pathology. Br. Med. J. 1910;1:553-558.

5. Pott P. Observations on the Nature and Consequences of these Accidents to which the Head is liable from external Violence, London. L. Hawes, W. Clarke, & R. Collins 1768.

6. Flamm ES. The dilated pupil and head trauma 1517-1867. Med Hist 1972;16:194-199.

7. Cheyne J. Instances of Apoplexy and Lethargy: With Observations Upon the Comatose Illnesses. London: Underwood, 1812. casesofapoplexyl00chey_djvu.txt

eight. Brilliant R. Stories on Medical Instances selected with a View of illustrating the Symptoms and Remedy of Illnesses by a Reference to Morbid Anat. Vol 2. London, Longman, 1831.

9. Pearce JMS. Richard Shiny and His Neurological Research. Eur Neurol 2009;61:250–254.

10. Munk’s Roll. Lives of the Fellows RCP London. Richard Vibrant. Quantity III, web page 155.

11. Pearce JMS. Observations on Concussion. Eur Neurol 2008;59:113–119

12. Von Leyden E. Beitrage und Untersuchungen zur physiologie und pathologie des gehirns. Virchow’s archives 1866;37:519- 59. Cited by Eelco FM Wijdicks In: Well-known First Papers for the Neurointensivist. New York: Springer, 2013.12-16

13. Pagenstecher F: Experimente und Studien über Gehirndruck. Heidelberg: Winter, 1871 Cited by Koehler PJ and Wijdicks EFM. Ref 14

14. Koehler PJ, Wijdicks EFM. In: Fastened and dilated: the history of a basic pupil abnormality. J Neurosurg 2015;122:453–463.

15. Cooper A. The Rules and Follow of Surgical procedure. Lee A, ed. London: E Cox, 1836. Pp. 160-161.

16. Pearce JMS. Sir Jonathan Hutchinson and sarcoidosis: A quick history. Ann R Coll Surg Engl 2010;92(eight)280–82.

17. Hutchinson J. 4 lectures on compression of the brain, Medical Lectures and Reviews of the London Hospital. 1867- 1868,4,10-55.

18. Jacobson,W.H.A. On middle meningeal haemorrhage. Guy’s Hospital Reviews 1885;(6)43:147-308

19. Macewen W. The pupil in its semiological points. Am J Med Sci 1887;94:123–146.

20. Walusinski O, Courrivaud P. Henry Duret (1849–1921): A Surgeon and Forgotten Neurologist. Eur Neurol 2014;72:193– 202

21. Duret H. Etudes expérimentales sur les trau- matismes cérébraux. Thèse, Paris, 1878, n° 64, Versailles, Imprimerie Cerf, 1878, p 339.

22. Duret H. On the position of the dura mater in cerebral traumatism. Brain 1878;1:29–47.

23. Kocher T. Hirnerschütterung, Hirndruck und chirurgische Eingriffe bei Hirnkrankheiten. Specielle Pathologie und Therapie. Ed, Nothnagel H. Vienna: Hölder, 1901; Vol 9.

24. Von Bergmann E.Die Chirurgische Behandlung der Hirnkrankheiten (1888; “The Surgical Treatment of Brain Disorders”).

25. Larner AJ. False localising signs Journal of Neurology. Neurosurgery & Psychiatry 2003;74:415-418.

26. Pearce JMS. James Collier (1870–1935) and uncal herniation. J Neurol Neurosurg Psychiatry. 2006; 77(7): 883–884.

27. Collier J. The false localizing signs of intracranial tumour. Brain 190427490–508.

28. Meyer A. Herniation of the brain. Arch Neurol Psychiatry 1920;4:387–400.

29. Kernohan J, Woltman H. “Incisura of the crus due to contralateral brain tumour”. Arch Neurol Psychiatry. 1929;21: 274–287.

30. Holman E, Scott WMJ. Significance of unilateral dilatation and fixation of pupil in extreme skull injuries. JAMA. 1925;84:1329–32.

31. Fisher CM. Brain Herniation: A Revision of Classical Ideas. Can. J. Neurol. Sci. 1995; 22: 83-91.

32. Ropper AH. The reverse pupil in herniation. Neurology 1990;40:1707-9.

Obtain this