Neurological complications in Maxillofacial trauma

Dr. Amit T. SuryawanshiOral and Maxillofacial Surgeon

Pune, India

Contact details :Email ID - amitsuryawanshi999@gmail.com

Mobile No - 9405622455

Contents-

• Introduction• Initial assessment • Rapid initial assessment • Types of brain injuries• Neurological complications in Maxillofacial

trauma.• References

Introduction

• Trauma is the leading cause of death and in more than 75% of cases, head injury accounts for a notable portion of the morbidity.

• Despite recent medical advancements, physical and functional morbidity frequently follows traumatic brain injury (TBI) even in seemingly minor trauma.

• Fall, sport activities, motor vehicle accidents and assaults are the major causes of maxillofacial injuries which are commonly associated with cervical spine and intracranial injury.

• The principles of management of trauma are directed at stabilizing patient’s medical condition and providing safe reconstruction to maximize both functional and aesthetic rehabilitation.

Initial assessment and treatment

It includes1. Airway maintenance2. Breathing - Mechanical ventilation3. Circulatory stabilization4. Assessment of Disability / Definitive care5. Exposure

Rapid Initial Assessment

• Consciousness• Respiration and vital signs• Associated trauma • Neck

Cervical spine injury -Cervical spine must be immobilized Carotid injury

• Eyes – Pupils , movements , reflexes• Airway – Gag reflex• Limbs –Motor examination, reflexes, sensation

C

R

A

N

IAL

Cervical spine injury-

• Incidence – 2% in maxillofacial trauma

• One must assume that every head injury has an associated cervical spine injury until proven otherwise.

• Clinical features –1. Patient particularly complains of neck pain2. Paralysis or weakness of limbs depending on

extent of injury.3. If it is severe , there is loss of respiratory drive and

death.

Management -• Patients with unrestrained cervical spine must

be immobilized in a carefully placed hard cervical collar until cervical spine radiographs or CT obtained and examined.

Pupillary findings• Unilaterally dilated -Light response(Sluggish or fixed) -

Occulomotor nerve compression• • Bilaterally dilated -Light response (Sluggish or fixed) –Bilateral

Occulomotor nerve palsy

• Unilaterally dilated – Light response(cross reactive)- Optic nerve injury.

• Bilaterally constricted –Light response (difficult to determine )- Metabolic encephalopathy or pontic lesion.

• Unilaterally constricted – Light response (preserved ) Carotid sheath injury.

Extraoccular muscles

Examination of the movements of the extraoccularmuscles may reveal various nerve palsies • Unilateral lateral gaze palsy-

It can occur due to damage to the Abducens nerve by direct trauma to the clivus region or lateral orbital wall fracture.

• Paresis of Upward gaze – • This can occur with hemorrhage causing

compression of the midbrain tectum.• Common manifestations- Lack of light reflex &

convergence.

Complete opthalmoplegia –• It is the inability to move all the extraoccular

muscles, resulting in damage to occulomotor nerve, trochlear nerve, abducens nerve which is often accompanied by proptosis, ptosis, a fixed and dilated pupil, and loss of sensation of the forehead .

Motor examination

• Tone, strength and reflexes must be assessed.Tone & strength assessment –1. Increased tone –due to compression of

contralateral cerebral peduncle 2. Flaccid tone –implies either brainstem

infarction or spinal cord transection

• Deep tendon reflexes –

• Hyperreflexia – Usually occurs with compression lesions in contralateral cerebral peduncle.Extensor plantar reflex (positive babinski’s sign)

• Areflexia –Occurs in spinal cord trauma or transection.

Neurological complications in Maxillofacial trauma

Intracranial lesions -

Traumatic brain injury is divided into two distinctivecomponents 1. Primary brain injury –2. Secondary brain injury -

Primary brain injury –

Primary brain injury occurs immediatelyupon impact and results from rapidacceleration or the shearing and rotationaleffects of a blow to the head. This can lead toirreversible damage as a result of directmechanical cell disruption.

It is divided into 1. Focal injury 2. Diffuse injury

Focal injury - Focal injury is associated with blows to the head that produce cerebral contusion and hematoma.

Diffuse injury – It includes concussion which is temporary loss of consciousness with no permanent organic brain damage and diffuse axonal injury secondary to shearing of axons.

Types of primary brain injury

• Cerebral Concussion • Cerebral Contusion • Epidural Hematoma • Subdural hematoma

Concussion

• Incidence –6 % of all head injuries

• A concussion is a mild brain injury in which consciousness is preserved but there is a noticeable degree of temporary neurologic dysfunction.

.

Cause -

• Signs and symptoms –• Headache, confusion, disorientation, dizziness,

vomiting, nausea, lack of motor coordination difficulty in balancing, blurred vision, double vision, tinnitus, difficulty with reasoning,

concentrating and performing daily activities.

• A slightly greater injury causes confusion with both retrograde and anterograde amnesia

Cerebral Contusion

• Incidence - 20–30% of all head injuries

Cause -Cerebral contusion can be caused by multiple microhemorrhages into brain tissue following injury.

• Signs and symptoms –

Headache, confusion, dizziness, loss of consciousness; nausea and vomiting; seizures;Hemiparesis, aphasia and difficulty with coordination, movement, vision, speech, hearing and thinking.

Epidural hematoma

Causes – It occurs due to haemorrhage between inner table of skull and dura mater.

• It is caused by fracture across grooves of frontal, temporal and occipital bone. Hematoma rapidly increases in size and compresses cerebral cortex.

• Signs and symptoms–1. Unconsciousness for a brief period2. LUCID INTERVAL after regaining

consciousness .3. After lucid interval gradual deterioration of

consciousness that progresses to coma and death if hematoma is not evacuated.

Subdural hematoma

• More common than epidural hematoma( 30%)

• Caused due to tear of veins bridging cerebral cortex to venous sinuses or intracerebral hematoma extends into subdural space.

• Patient’s outcome depends upon injury caused by force of impact rather than pressure of the bleed.

• Signs and symptoms –• Irritability• Seizures• Pain• Numbness• Headache• Dizziness• Disorientation• Amnesia• Weakness• Nausea• vomiting

Secondary brain injury

• It occurs after the initial trauma. Damage to neurons is caused by systemic physiologic response to initial injury. It may be within minutes, hours, or days after initial injury.It can lead to further damage and permanent dysfunction.

• Hypotension and hypoxia following injury are major causes of secondary brain injury.

Intra-cranial complications

• Facial bones absorb much of the impact of trauma associated with frontal violence, the majority of patients with severe facial injuries should be considered as having sustained concomitant head injuries, with or without fractures of the base of the skull.

• Morbidity and mortality due to complications such as intracranial haemorrhage and infection are high.

General consideration of diagnosis and care

• Many potential fatal complications can occur at any time during first 2 weeks following injury or even later, so high standard experienced nursing care and medical supervision is important.

• It is important to remember that the level of consciousness or responsiveness is the most useful indicator of any change for better or worse in patient’s condition.

Glasgow Coma Scale

Early complications

These are early complications of head injury occurswithin few hours or so

1. Unconsciousness2. Cerebrospinal fluid leaks 3. Meningism4. Skull fractures

Unconsciousness

• Unconscious patient may be admitted (Witnesses should be questioned)

1. Unconscious, having previously been conscious since the injury -

There may have been lucid interval followed by acute rise in intracranial pressure leading to unconsciousness.

2. Never have been conscious since the injury – Here, patients are more likely to have cerebralcontusions, but it does not preclude thedevelopment of other intracranial complications.

Cerebrospinal fluid leaks

• Fractures of the facial skeleton frequently involve the floor of anterior cranial fossa, usually in the region of posterior wall of frontal sinus or cribriform plate.

• These injuries are associated with a communication between the meninges and nose or paranasal sinuses leading to cause csf rhinorrhoea or otorrhoea from an associated dural laceration.

• In early hours following injury, leakage will be blood stained but later persists as a clear watery discharge from the nostrils, ears or associated laceratons.

• Patient in reclined position is more like to have flow down the posterior pharyngeal wall.

Meningism

• Sometimes signs of meningism are present shortly after injury, although they may take several hours to develop, and are usually due to traumatic subarachnoid haemorrhage.

• Photophobia, headache, neck stiffness and positive kernig’s sign should be sought in initial examination.

• These findings alone are not indications for performing lumbar puncture unless there is risk brain stem compression

• Bacterial meningitis may be suspected from the development of pyrexia and changes in blood picture. Use of antibiotics or sulphonamides are advised rather than early diagnostic lumbar puncture.

Skull fractures

• Although it is not necessarily important for neurosurgeon to treat all skull fractures, it is desirable that they are diagnosed early so that complications may be anticipated and definitive treatment is planned.

• Accordingly radiological examination should be made for cervical spine injuries which may limit manipulation of the head.

Intermediate complications

• Intermediate complications may occur at any time up to several days or even later .These are

1. Increasing intracranial pressure 2. Meningitis 3. Persistent or recurrent CSF leaks 4. Intracranial air

Increasing intracranial pressure

• This very serious complication may occur at any time up to several days , or even later , following head injury.

• Causes –contusion, oedema , extradural, subdural or intracerebral haemorrhage or combination of these.

• General signs are –1. Deterioration in the level of consciousness 2. Restlessness 3. Vomiting 4. Hypertension 5. Headache & photophobia 6. Papilloedema.

• Examination of pupils is of vital importance • A dilating pupil which becomes less responsive to

light in the eye(direct) or opposite eye in the presence of deterioration in the level of responsiveness is the classical sign of developing ipsilateral intracranial hematoma.

• Developing motor weakness on one side may indicate contralateral hematoma in the region of motor cortex. There may be developing aphasia.

• If diagnosed , then steps can be taken to avoid serious problems of midbrain distortion & haemorrhage, cerebral compression, infarction, particularly of temporal and occipital lobes.

Meningitis

• Although this is relatively uncommon complication of maxillofacial injuries.

• All cases where there is Le Fort –II or III or naso –ethmoidal fracture , should be given prophylactic penicillin and sulphonamides IM, along with adequate fluid intake.

• The diagnosis of bacterial meningitis requiring intrathecal treatment is the only indication for lumbar puncture following head injury.

Persistent or recurrent CSF leaks

• In patients with maxillary fracture, the average duration of CSF rhinorrhoea is 4-5 days with or without reduction of fracture.

• Most neurosrgeons agree that CSF rhinorrhoea lasts for 14 days after reduction and immobilisation of facial fractures.

Diagnostic method –1. Tc cisternogram 2. CT scan for the site of leak

Intracranial air

• The finding of intracranial air is usually associated with a cerebrospinal fluid leak at some age following injury.

• Subdural or subarachnoid collections of air are often seen on the radiographs taken within the 1st day or so but are usually absorbed instantaneously.

• The development of aerocoel may coincide with recurrence of CSF rhinorrhoea indicating a breakdown of healing dural fistula

Symptoms – Headache, nausea, personality disturbance, hemiparesis

• Most significant danger of aerocoel is infection with the development of cerebral abcess.

Late complications

• Late complications of head injury pass unnoticed at the time of injury but occurs within few weeks. These are

1. Cranial nerve damage.2. Epilepsy. 3. Accident or compensation neurosis.

Cranial nerve damage

• Damage to cranial nerves may pass unnoticed at the time of injury. It is important that any sensory or motor neurological deficit is documented soon after injury, in order that the impairment may be properly ascribed either to the injury or to the subsequent events for both prognosis and medicolegal purpose.

Trigeminal nerve

• Sensory disturbances in the distribution of terminal branches of trigeminal nerve are common after facial injuries, and are due to stretching, compression or division of nerves.Examples – Inferior alveolar nerve in mandibular fractures and infraorbital nerve in maxillary and zygomatic fractures

• When nerve is contused but intact (Neurapraxia), the sensory disturbances referred to usually respond to reduction and immobilization of fractures. Recovery takes places within days or weeks.

• When nerve has been divided(neurotmesis),loss of function is absolute and may never recover.

• However, assuming the divided nerve has been resutured or its bony canal re-aligned,adequate time should be allowed for wallerian degeneration and regeneration to take place Example – In angle of mandible, it will take 12- 18 moths.

• During follow-ups, if there is no improvement in reduced sensation, paraethesia(altered sensation) and increased sensation(hyperaesthesia), it is often important to explore the nerve close to the site of injury in an attempt to decompress it, particularly in the region of infraorbital foramen or mental foramen.

• Because, in these sites it is sometimes possible to either refracture and reposition the fragment or to enlarge the foramen.

• Rarely, injury to sensory nerve leads to intactable neuralgic pain, termed as causalgia.Treatment includes, carbamazepine , alcohol injections or division of nerve.

Facial nerve

• Motor disturbances are less common than sensory disturbances in maxillofacial trauma and usually result from the damage to the facial nerve which may occur at any point in its course.

• Example- Lower motor neuron facial palsy in zygomatic bone fracture .

• Most frequently, damage is the result of a laceration.Example – Fracture of neck of condyle of mandible resulting into lower motor neuron facial palsy.

Early administration of corticosteroids orsurgical decompression improves the prognosisof these injuries.

Auriculotemporal nerve

• Damage to auriculotemporal nerve in the region of mandibular condyle can produce phenomenon of gustatory sweating of the skin in the temporal region, known as von Frey’s syndrome.

• The syndrome is probably caused by the inappropriate regeneration of autonomic nerve fibers along the distribution of the sensory part of the nerve, with vasodilation and sweating.In troublesome, nerve may be avulsed.

• Anosmia is a frequent sequel to high- level maxillary fractures in which the olfactory nerves may be severed at the level of cribriform plates.

• Anosmia may be associated with the oedema around the fracture site in the base of the skull but recovery can be anticipated.

• Positional vertigo may result form damage to the vestibular apparatus, in which nystagmus and distress are elicited by sudden lowering of rotated head to 30 degree below the horizontal plane.

Epilepsy

• Incidence – 5 % of all head injuries within 1st week. while its 1% for late epilepsy (after a week)

• Risk of epilepsy is more in those where there has been a dural laceration, intracranial hematoma, or post-traumatic amnesia of more than 24 hrs duration.

• Treatment –• Phenobarbitone 30mg BD

Accident or compensation neurosis

• Many patients will experience protracted symptoms of headaches, visual disturbances, loss of concentration & irritability following head injury.

• These symptoms frequently persists and don’t improve with the passage of time.

Maxillofacial injuries

• Nasal fracturesIsolated nasal fractures are the most commonly seen fractures in facial trauma. However, nasal injuries may be associated with severe mid-facial trauma involving the naso-orbito-ethmoidal (NOE) complex, the frontal sinuses and the orbito-zygomatic complex.

Nasal fractures

Neurological complication -

• CSF rhinorrhoea may be present if the fractures of the NOE complex involve the base of the skull and a dural breach.

Zygomatico-maxillary complex fractures (ZMC)

• Diplopia secondary to extraocular muscle dysfunction.

• Paraesthesia of the infraorbital nerve distribution (cheek, lateral nose, upper lip, upper anterior teeth and gingiva)

• Tenderness and diastasis at the fronto-zygomatic suture.

• Lower motor neuron facial palsy.

Neurological complication -

Retrobulbar haemorrhage

• The development of proptosis of the globe, reduced or lost vision and severe orbital pain, are features of retrobulbar haemorrhage. This is an emergency with the potential for permanent blindness and requires urgent surgical intervention.

Maxillary fractures

• Infraorbital paraesthesia.• Tenderness at the fronto-zygomatic sutures .• CSF rhinorrhoea due to dural tear and fracture

of the anterior cranial fossa

Neurological complication -

Frontal bone fractures

• Fractures of the frontal bone may occur:In association with extensive facial injuries orin isolation, as a result of direct blunt trauma to the forehead in an MVA, sporting collision or assault.

Frontal bone fractures

• CSF rhinorrhoea may be present when involved with nasal fractures and NOE.

Neurological complication -

Mandibular fractures

• Mandibular fractures occur in all age groups. Fractures of the condyle and subcondylar regions, are the most common due to trauma to the chin from falls.

Mandibular fractures

• Paraesthesia in distribution of inferior alveolar nerve (lower lip and chin)

• Frey’s syndrome in case of damage to auriculotemporal nerve in fracture of neck of condyle.

• References :

1. Text book of Oral and Maxillofacial trauma, third edition- Fonseca

2. Text book of oral and maxillofacial surgery Petersons

3. Maxillofacial injuries .Row & williams vol. 1& 24. ACS Committee on Trauma. Student Course

Manual 8th ed. American College of Surgeons Chicago, Illinois, 2009.

•Thank you