Clinical Conditions Flashcards
What is an extradural/epidural haematoma? Which blood vessel is usually involved? What type of fracture/injury causes this?
Blood from ant. branch of middle meningeal artery collects between the external periosteum layer of the dura mater and the calvaria (i.e. above the dura mater)
Extravasated blood strips the dura mater from the cranium
(normally no space exists apart from at the region of the dural venous sinuses)
Middle meningeal artery is a branch of the maxillary artery, which enters the cranium via the foramen spinosum (just behind the pterion)
Linear skull vault fracture causes skull to bend inwards (depressed fracture)
Typical injury: head strike (e.g. sports, RTC) +/- transient loss of consciousness followed by lucid interval, ongoing severe headache, rapid deterioration
Pterion overlying the middle meningeal artery is very weak
What is the classical appearance of an extradural haematoma on an MRI?
Lens-shape/centric shape
List some of the different types of skull fracture.
Simple = no damage to skin
Compound = break in/loss of skin & splintering of bone
Depressed = fragment of bone compresses/injures underlying brain
Trauma to vault = radiating linear fractures (away from point of impact in more than two directions) without splintering/depressing/distorting bone
Countercoup fracture = fracture occurs on opposite side of cranium to site of impact
note: base of skull is strong but can be fractured as it is attached to a lot of force (the body)
What are some of the signs and symptoms of head injuries?
- draining of CSF from ears/nose
- bleeding from wound/ears/nose/around eyes
- bruising
- swelling
- confusion
- convulsions
- difficulty with balance
- drowsiness
- headache
- visual disturbance
- slurred speech
- nausea/vomiting
- stiff neck
Give some examples of weak points in the skull.
Cribiform plate of ethmoid bone & roof of orbits (anterior cranial fossa)
Squamous temporal & parietal bones over temples & sphenoid bone
Foramen magnum & inner parts of sphenoid wing (skull base)
Middle cranial fossa (thin bones & multiple foramina)
Posterior cranial fossa (areas between mastoid & dural sinuses)
Pterion
Describe some common facial fractures.
Most common cause = automobile accidents, fist fights, falls
Most commonly involve nasal bones (due to prominence)
Blow to lower jaw —> fractured neck & body of mandible (+ dislocation of temporomandibular joint)
Trauma to supracillary arches (around eyebrows) —> laceration of skin & profuse bleeding —> “black eye” (skin bruising around orbit as tissue fluid and blood accumulates in the surrounding connective tissue)
Describe some common features of cervical vertebral fractures.
Most fatal at C1/C2
Most common C2 & C6/C7
Fall on head —> fracture of dens (displacement of which may injure spinal cord —> quadriplegia/death)
Narrowing of intervertebral discs (age) —> narrowing of intervertebral foramina —> compression of nerve roots —> neck pain
HYPERFLEXION (head-on collision) = rupture of lower cervical IV discs (C5-C7) —> compression of spinal roots C6 & C7 —> neck, shoulder, arm, hand pain
HYPEREXTENSION (whiplash) = tearing of anterior & posterior longitudinal ligaments, fracture of cervical spinous processes, disc rupture, neck muscles & blood vessel injury
note: “broken neck” refers to compression of cervical spine against scapula, causing fractured cervical vertebrae
What is the cause of pain in osteoarthritis?
Osteophyte formation of zygopophyseal joints (vertebral arches) —> pain along distribution patterns of dermatomes of related spinal & spasm of muscles derived from associated myotomes
What are some of the differential diagnoses for a neck mass?
Diffuse, enlarged thyroid gland (more likely if between 20-40yrs)
Under 20yrs:
- thyroglossal cyst (mass in midline)
- enlarged tonsillar lymph nodes/congenital mass
Goitre —> superficial venous distension
Associated pain = acute infection
Duration:
- few days = inflammatory
- months = tumour (no change inside for long period = congenital/benign)
Blockage of salivary glands may produce mass that changes in size as the patient eats
Location:
- midline = benign/dermoid cyst
- lateral = freq. neoplastic: lateral upper = metastatic lesions from head & neck tumours, lateral lower = metastases from breast/lung/stomach
Neoplasms compress recurrent laryngeal nerve —> hoarseness
Give some examples for causes of neck stiffness.
Spasm of cervical muscles due to:
- tension headaches
- meningeal irritation (sudden onset + fever + headache)
What is Bell’s palsy? What does someone with Bell’s palsy look like?
Paralysis of facial nerve causes weakness of one side of the face
Most commonly caused by a viral infection causing inflammation of the facial nerve near its exit from the cranium at the stylomastoid foramen
Ask patient to smile —> one side of face will remain expressionless
Inability to close eye due to loss of tone in orbicularis oculi —> inferior eyelid falls —> risk of damaging the cornea
What is the pattern of pain in parotid gland disease, and why?
Facial nerve passes through parotid gland
Pain in auricle of ear, external acoustic meatus, temporal regions, and temporomandibular joint
Areas supplied by facial nerve? CHECK
What is the difference between proptosis and exompthalmos? Give some examples of causes.
PROPTOSIS = bulging of eyeballs due to displacement forwards
- unilateral = retrobulbar haemorrhage, swelling of soft tissues of the orbit
- bilateral = Graves’ disease (not just hyperthyroidism)
EXOMPTHALMOS = protrusion of eyeballs within socket
note: often used interchangeably; lost meaning
What is Horner’s syndrome?
Injury to sympathetic trunk or ganglia in neck/upper thorax
Affected side:
- miosis (constricted pupil)
- ptosis (drooping of upper eyelid)
- flushing of face
- anhydrosis (lack of sweating)
What is foetal alcohol syndrome?
note: foetal alcohol syndrome + alcohol-related neurodevelopmental delay = 1/100 births
Condition of newborn babies that results from the toxic effects of maternal alcohol abuse on the foetus (greater amount of alcohol, the more severe the abnormalities)
note: no known “safe” level of alcohol consumption during pregnancy
Neural crest migration/brain development extremely sensitive to alcohol (passes through the placenta)
Typical appearance:
- small head
- low nasal bridge
- short nose
- epicanthal folds
- underdeveloped jaw
- thin upper lip
- flat midface
