Head injuries and orbital fractures Flashcards
what are the bones that make up the skull
Occipital
* Parietal
* Temporal
* Frontal
* Sphenoid
* Ethmoid
Nasal
* Lacrimal
* Maxilla
* Zygomatic * Mandible
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what are the bones that make up the orbit
frontal
ethmoid
paletine
sphenoid - lesser and frontal
zygomatic
maxilla
lacrimal
what are the bones of the orbital rim
superior orbital rim and upper medial rim on the frontal bone
lateral orbital rim on the zygomatic bone
inferior and lower medial rims on the maxilla
orbital floor on the upper border of the maxillary sinus
medial rim separating the orbit from the nose - lacrimal bone
medial wall and part of the posterior wall - ethmoid
rest of the posterior orbit - 2 wings of the sphenoid bone , the continuation of the lacrimal bone from the medial wall and the orbital process of the palatine bone
where are the sinuses located
maxillary sinuses on the cheeks
frontal sinuses above eyebrows
ethmoidal sinus
on the outer bridges of nose / inner part of eye
what are the main structures within the orbit
Optic foramen
* Superior orbital
fissure
* Inferior orbital
fissure
* Infraorbital foramen
* Infraorbital notch * Trochlear notch
* Supraorbital notch
* Optic nerve * Ophthalmic
artery
medial rectus muscle
lateral rectus muscle
inferior rectus muscle
superior rectus muscle
inferior and superior oblique muscles
levator palpabele superiors
lacrimal nerve
frontal nerve
ocular motor nerve
trochlear nerve
nasocillary nerve
abducens nerve
tedious ring
what is the cribifrom plate
part of the ethmoid bone
midline bones - part of the orbit , cranium and nose
transmits the olfactory nerves which allows for a sense of smell
a fracture to the cribriform plate can lead to css leaking into the nasal cavity and a loss of sense of smell
what are the three types of head injury
open head injury , closed head injury, coup and contrecoup injuries
what is a open head injury
This may also be called a ‘penetrating head injury’ as it is caused by an object breaking the skull and entering the brain. This injury is often focal - affecting a specific area of the brain. There may be an obvious compound fracture of the skull or a more subtle fracture of the cribriform plate, paranasal air sinuses and / or the middle ear. Whilst other fractures may be initially less obvious, they are not less serious.
what is a closed head injury
Caused by a blow to the skull, but where the skull remains closed or intact. Damage to the brain can be large areas of bruising, tearing and bleeding or can be more localised to areas of bony prominences within the skull (i.e. the sphenoid ridges)
what are coup and countercoup injuries
Coup and contrecoup injuries are associated with closed head trauma. The coup injury occurs at the area of impact (direct blow) and the contrecoup injury occurs on the opposite side of the impacted area (counter-blow). They may occur individually or together. Coup and contrecoup injuries are associated with cerebral contusion (bruising of the brain) and both are focal brain injuries, rather than diffuse injuries, which occur over a more widespread area.
what diagnoses are important to consider after a head injury
neurogenic palsy
damage to the eom- myogenic
Orbital fracture
Accommodation insufficiency / paralysis
Convergence insufficiency / paralysis
Loss of / weakened suppression
Loss of / weakened fusion
Visual field defect – especially if visual cortex or visual pathways involved Damage to the optic nerve
Damage to the peri-ocular structures
Damage to the globe
Supra nuclear palsy and a skew deviation
what ocular problems can head injuries cause
A head injury may be sufficient to cause concussion. There may also be an abnormality in local blood flow, haemorrhage, cell destruction or damage to the white matter. Cranial nerve palsies are more common than a weakness or pareses of an individual extraocular muscle. Fusion may be weakened or completely lost following a head injury (called central fusion disruption). Convergence and/or accommodation may be affected, causing a range of problems from paralysis to insufficiency. Convergence & divergence paralysis has been reported to co-exist after head injury (Nashold & Seaber, 1972)
what ocular problems can be caused by whiplash
A range of ocular problems have been described following whiplash including blurred vision (most common), diplopia, seeing spots in front of the eyes, objects receding, CI (Burke and Orton, 1993) and reduced accommodation and ‘pupil cycle time’ (Brown, 1991).
Pupil cycle time involves using a slit lamp light to induce pupil constriction and timing how many regular oscillations of pupil construction and relaxation occur using a stop watch. Evidence from pharmacological testing suggests that pupil cycle time is a sensitive measure of dysfunction of the parasympathetic efferent limb of the pupillary light reflex. It has been suggested that whiplash associated with defective accommodation may be caused by interruption of the sympathetic innervation to the eye (Brown, 2003).
how is optic atrophy related to a head injury
Direct optic neuropathy is caused by direct damage to the optic nerve (e.g. in a penetrating head injury). Indirect optic neuropathy is an injury to the optic nerve due to the non-penetrating effects of trauma (e.g. haemorrhage, oedema). Both direct and indirect optic neuropathy may result in optic atrophy. In optic atrophy the patient will have a severe reduction in VA, a pale optic disc and an RAPD. This may be unilateral or bilateral. Subtle optic atrophy should be considered if no other cause is found in a case of loss of previously good VA. There are limited treatment options; usually observation for spontaneous improvement is recommended (Steinsapir & Goldberg, 2011).
how are patients with head injuries orthoptically managed
In all cases of head injury (recent onset or longstanding) your orthoptic management may be complicated by…
Loss of / weakened suppression Loss of / weakened fusion
Incomitance
Visual field defect
Insuperable torsion
VA
Weakness / paralysis of convergence / divergence
Exophthalmos
- enopthalmos
how are patients conservatively managed
- fresnel prisms
- advice on using an abnormal head posture or head movements
orthoptic exercises
monocular occlusion - total or sector
bangerter foils , occlusive tape (blender/ leukosilk)
refractive correction - consider near ADD
what type of orbital injuries can be caused
eyelid injuries - lacerations to the eyelids that may involve the lid margins , result in tissue loss
canaliculi and lacrimal glands may be involved - may need to protect the cornea with artificial tears or taping of the lids
ptosis may be caused by swelling of the upper lid or damage to the lps
peri- orbital oedema - welling and/or haemorrhage (see soft tissue injury V orbital fracture). If the oedema is significant – you will need to carefully examine whether the patient can open their eye to test their VA. Need to ensure globe is intact and functioning.
Retrobulbar haemorrhage - this is a serious problem that may cause proptosis, limitation of eye movement and pain. The threat to vision is a medical emergency.
Direct damage to the extra-ocular muscles – this may be a muscle laceration or an avulsion. Need to carefully look for globe damage and how far back damage extends. If recent onset damage – there may be swelling, whereas if damage acquired some time ago – there may be scar tissue.
what are the type of globe injuries
May result from blunt or sharp trauma and can cause devastating damage. A globe injury is usually an ophthalmic emergency and may require urgent surgical repair
Corneal abrasion - mild
Subconjunctival haemorrhage
Hyphaema (blood in anterior chamber)
Penetrating injury (ophthalmic emergency ?foreign body)
Lens damage and/or dislocation
Retinal detachment, haemorrhage, contusion
Choroidal ruptures
Optic nerve damage (direct or indirect optic neuropathy)
what are the type of globe injuries
May result from blunt or sharp trauma and can cause devastating damage. A globe injury is usually an ophthalmic emergency and may require urgent surgical repair
Corneal abrasion - mild
Subconjunctival haemorrhage
Hyphaema (blood in anterior chamber)
Penetrating injury (ophthalmic emergency ?foreign body)
Lens damage and/or dislocation
Retinal detachment, haemorrhage, contusion
Choroidal ruptures
Optic nerve damage (direct or indirect optic neuropathy)
what are the types of orbital fractures
Orbital fractures can vary hugely in severity, from a minimally displaced fracture of an isolated part of the orbit requiring no surgery, to complex fractures of multiple orbital bones that require surgery and reconstruction by maxillofacial surgeons.
Direct trauma – an injury which results from a direct impact, e.g. a blow to the face
Indirect trauma – an injury which does not result from direct impact, e.g. whiplash
Any part of the orbit can fracture. In the case of direct trauma, the location of the orbital fracture will depend on which area of the face sustains the impact and the mechanism of the injury. Impact to the upper third of the skull will be more likely to result in a supra-orbital fracture (roof of orbit and superior orbital rim), whereas an impact to the middle third of the skull will be more likely to result in a fracture of the zygoma (which can also be displaced), nasal bones, or orbital bones (orbital floor, medial wall, lateral wall
what are le fort facial fractures
Classification of facial fractures into 3 types (Le Fort I, II and III) which are essentially commonly occurring lines of facial fracture.
Le Fort I fracture
▪ No ophthalmic significance, involves the nasal septum and travels laterally ▪ Also known as Guerin fracture or ‘floating palate’
Le Fort II fracture
▪ Occurs following a blow to the mid or lower maxilla
▪ Pyramid shaped fracture, relevant ophthalmically
▪ Associated with serious intracranial injury and increased mortality (Bellamy et al, 2013)
▪ Involves orbital rim and the floor of the orbit
▪ Extends from the nasal bridge, through frontal processes of the maxilla, inferolaterally across lacrimal bone, along floor of orbit to zygomatic suture, then along infraorbital foramen, across the maxilla and ending in the pterygo-maxillary fissure
Le Fort III fracture
▪ This is the most ophthalmically relevant of the Le Fort fractures, as it extensively involves the orbit
▪ Associated with serious intracranial injury (Bellamy et al, 2013)
▪ Occurs following an impact to the nasal bridge or upper maxilla
▪ Starts at nasofrontal & frontomaxillary sutures, extends along medial orbital wall, through the nasolacrimal groove & ethmoid bones. The thicker sphenoid bone posteriorly usually prevents continuation of the fracture into the optic canal. The fracture continues along orbital floor along the inferior orbital fissure, superolaterally through lateral orbital wall, through zygomaticofrontal junction and zygomatic arch. A branch of fracture extends through ethmoid, through the vomer, and through interface of the pterygoid plates to the base of the sphenoid
▪ This type of fracture predisposes the patient to CSF rhinorrhea more commonly than the other types
how likely are children to develop paediatric orbital fractures
Children are less likely to sustain an orbital fracture as they have a relatively small face compared to prominent cranium and have more cheek fat. They are therefore more likely to sustain a fracture to the upper face & skull. Superior orbital fractures have been found to be more likely in children
Due to the physiology of their bones greenstick fractures are more likely. In orbital fractures, an adult fracture is more likely to be comminuted (shatter), whereas a paediatric fracture would be more likely to be a clean ‘linear’ fracture. Paediatric patients are also more prone to ‘trap door fractures’, with increasing risk of them in younger patients (Gerber et al, 2013).
Dr Gemma Arblaster – Year 2 2022
Dr Gemma Arblaster – Year 2 2022
Mean age of orbital fracture in childhood = 12.5 years and 92% were male (Hatton et al, 2001). The most common aetiology for a childhood orbital fracture is a sports injury
what is a supra orbital fracture
A fracture of the roof of the orbit and/or superior orbital rim. Uncommon in both adults and children, although children are at increased risk of supraorbital fractures due to relative prominence of the cranium and a lack of frontal sinus pneumatisation (Patel & Brauer, 1998).
Mechanism: can occur due to a direct blow to the frontal region or an indirect blow to the base of the skull which radiates to the roof of the orbit (contre-coup effect).
Characteristics:
Superior orbital swelling and haemorrhage
Oedema of upper lid – may have ptosis ?traumatic ptosis
Supra-orbital anaesthesia/hypo-anaesthesia
Superior rectus or superior oblique damage / palsy
Dislocation /damage to trochlear
Depression of supra-orbital rim – exophthalmos and displacement of the globe
Retrobulbar haemorrhage – generalised limitation of movement
Emphysema
Leakage of CSF – may indicate a fracture of the cribriform plate
Infection
where are the superior orbital fissure and orbital apex located
The superior orbital fissure is a cleft, lying between greater & lesser wings of the sphenoid bone. It contains 4th, 6th & superior & inferior divisions of the 3rd cranial nerves; also the lacrimal, frontal and nasociliary branches of the ophthalmic division of the trigeminal nerve (V1). The orbital apex is the posterior narrow part of the orbit.