Clinical Correlations

Depressed fracture

Fracture where a fragment of bone is depressed inward after a hard blow to the head, which then compresses and/or injures the brain

Comminuted fracture

Fracture when a bone is broken into multiple pieces

Linear calvarial fracture

Fracture that happens at the point of impact, with the fracture lines radiating away

Linear calvarial fracture

Most common type of skull fracture

Contrecoup (counterblow) fracture

Fracture that occurs on the opposite side instead of the point of impact, often from secondary impact due to displacement of head

Basilar fracture

Fractures to bones of the cranial base (such as occipital bone around foramen magnum, temporal and/or sphenoid bones, or roof of orbit)

CSF to leak into nose and ear or CN or blood vessel injury

What can basilar fractures cause?

Pterion fractures

Life-threatening fractures because they overly frontal branches of middle meningeal vessels

thin

The bones at the pterion are very...

epidural hematoma leading to increased pressure on cerebral cortex

Rupture of frontal branches of the pterion can result in a...

Subclavian vein (subclavian vein puncture)

Where is a central line usually placed?

Fluids, medication, nutrition, and to measure venous pressure

What is a central line for?

cisternal puncture

How is CSF obtained for diagnostic purposes?

posterior cerebellomedullary cistern

Where is CSF obtained during a cisternal puncture?

CSF otorrhea; external acoustic meatus

Fractures in floor of middle cranial fossa can cause ________________________, where CSF leaks out of the _________________________.

CSF rhinorrhea; nose

Fractures in anterior cranial fossa floor can cause ___________________________, where CSF leaks out of the _____________.

meningitis

CSF otorrhea and CSF rhinorrhea both increase chances of ______________________.

arterial blood

What kind of blood is involved in an extradural/epidural hematoma?

middle meningeal artery; periosteal dura; calvarium

In an extradural/epidural hematoma, blood from a torn _______________________ collects between ________________________ and ____________________.

concussion, followed by lucid period, then drowsiness and coma

symptoms of extradural/epidural hematoma

venous blood

What kind of blood is involved in a dural border hematoma (subdural hematoma)?

sinus; dura-arachnoid junction

In a dural border hematoma, blood from ____________ creates a space at __________________________.

trivial blow

What causes slow formation of a dural border hematoma?

typically arterial

What kind of blood is involved in a subarachnoid hemorrhage?

saccular; subarachnoid

In a subarachnoid hemorrhage, a _________________________ aneurysm ruptures into _______________________ space.

meningeal irritation, severe headache, stiff neck, loss of consciousness

symptoms of subarachnoid hemorrhage

Parkinson's disease

Degeneration of the substantia nigra is the initial step in ____________________ __________________.

Broca's aphasia

problems with production of language; speak in short phrases with difficulty

Wernicke's aphasia

produce fluent, nonsensical language; also difficulty understanding speech

strong lateral pterygoid contraction or blow to the chin with mouth open (more common)

What can cause dislocation of the mandible?

anterior; anterior tubercle

When strong lateral pterygoid contraction occurs, the head of the mandible moves ______________ to ________________ _________________.

side of impact; fracture

A blow to the chin with the mouth open dislocates the mandible on the ________________________, and can result in a ______________________ of the mandible.

facial and auriculotemporal

Which nerves could be injured during dislocation/surgery involving the TMJ

trigeminal neuralgia

sensory disorder of sensory order of CN V

sudden attacks of excruciating, lightning-like jabs of facial pain which can last for 15+ minutes

symptoms of trigeminal neuralgia

maxillary (V2), V3, V1

Which branches of trigeminal are involved in trigeminal neuralgia from most common to least common?

unknown

What is the cause of trigeminal neuralgia?

brain tumor compressing abducens nerve or increased intracranial pressure which causes weakness/paralysis of lateral rectus

What causes medial strabismus?

loss of all lower motor neurons to face from both sides (Bell's palsy)

If a facial nerve on one side is lesioned....

upper muscles still have innervation from other side of motor cortex so upper face muscles still function while lower muscles do not

If supra nuclear lesion occurs.....

compression and temporary paralysis

Inflammation of the facial nerve can cause ____________________ and __________________________.

location

Depending on __________________ of compression, can also affect taste, tear and mucus secretion, deafness

Ramsay Hunt

Syndrome caused by the shingles virus which can compress the facial nerve and cause facial paralysis, ear pain, and a rash

gag

Lack of a ________ reflex can indicate an issue with the glossopharyngeal nerve (CN XII)

vasovagal syncope

response to a trigger or specific stimulus

decreases; decreasing

Vagus ________________ heart rate and BP thus ______________________ cerebral blood flow.

fainting and brain fog

symptoms of vasovagal syncope from insufficient blood flow to the brain

vagal nerve stimulator

treatment for vasovagal syncope where the vagus nerve is stimulated to modulate seizure activity or response to trigger

jugular foramen syndrome

compression on the nerves running in the jugular foramen which causes difficulty swallowing, hoarseness, and weakness in shoulder muscles

CNs IX, X, XI

Which nerves run through the jugular foramen?

tumors (most common), infections, trauma

What are some causes of jugular foramen syndrome?

spinal accessory nerve (CN XI) testing

have pt shrug their shoulders --> depression of one shoulder indicates paralyzed trapezius

have pt turn their head to the right or left --> checks innervation of sternocleidomastoid

hypoglossal nerve testing

have pt stick their tongue out --> deviation to one side indicates nerve damage

fasciculations and atrophy

other signs of hypoglossal nerve damage

demyelination diseases

can occur in the CNS and impact the optic nerve

blindness of ipsilateral eye

What is the result of damage to CN II?

loss of temporal (lateral) visual field bilaterally (tunnel vision)

What is the result of damage to the middle of the optic chiasm?

loss of nasal (medial) visual field in ipsilateral eye

What is the result of damage to a lateral portion of optic chiasm?

visual loss in the same side of field of each eye

What is the result of damage to the optic tract?

lens becomes harder and flatter with age which reduces focusing power

presbyopia

loss of transparency of lens

cataracts

lens

can be extracted and replaced with artificial one within capsule

glaucoma

reduction in the ability to drain aqueous humor at the rate it is produced which increases intraocular pressure

blindness due to damage to retina and retinal arteries

What results from glaucoma?

CN III palsy

affects most of the extraocular muscles

superior eyelid droops, pupil is fully dilated, pupil fully abducted and depressed

symptoms of CN III palsy

CN VI palsy

only affects lateral rectus so the pupil cannot be abducted on affected side but is fully adducted

central retinal artery blockage

results in instant and total blindness (usually unilateral and in the elderly)

central retinal vein blockage

slow, painless loss of vision

otitis media

middle ear infection caused by pus or fluid in middle ear (often secondary to upper respiratory infections)

earache, building red tympanic membrane, inflammation/swelling of mucous membrane, possible hearing loss

symptoms of otitis media

tympanic membrane perforation

"ruptured eardrum"

otitis media, foreign bodies, trauma, excessive pressure

What are some causes of tympanic membrane perforation?

injury to CN XII

paralyzes ipsilateral half of tongue and causes gradual atrophy --> when protruded, the apex of the tongue deviates toward the paralyzed side

paralysis of genioglossus

tongue shifts posteriorly, obstructing the airway

trauma; Kiesselbach

In most cases of epistaxis, the cause is ________________ which results in bleeding from the _______________________ area.

mild; veins

______________ epistaxis can result from nose picking, which tears ___________ in the vestibule.

infections, hypertension

What are some other causes of epistaxis?

deviated nasal septum

nasal septum is deviated to one side; can be severe and obstruct breathing or exacerbate snoring

birth injury, developmental abnormality, or trauma

What are some causes of a deviated septum?

1. root could be fractured

2. root could be forced into maxillary sinus

3. infection can spread from oral cavity to maxillary sinus

What are some complications of extraction of the maxillary molars?

danger; thorax

Infections in the _______________ space can spread to the _____________.

deep cervical

_____________________ fascia layers help prevent spread of abscesses.

abscess, difficulty swallowing and speaking, mediastinitis

signs/symptoms of infection in retropharyngeal space