Post on 14-Jan-2016
The Head Lecture 18
Bones of the Skull
the skull is primarily composed of flat bones that interlock at immovable joints called sutures
the skull often referred to as the cranium protects the brain
8 cranial bones and 14 facial bones
The Scalp is composed of three layers
i) the skinii) subcutaneous tissueiii) pericranium
the protective function these tissues is enhanced by the hair and the looseness of the scalp
this enables some dissipation of force when the head sustains a glancing blow
the scalp and face have extensive blood supply , hence lacerations to the face and scalp tend to bleed profusely
Scalp Injuries
the scalp is highly vascular and bleeds freely
primary concern is to control bleeding and to prevent contamination
must check for skull fracture apply mild pressure , clean wound and
refer to physician for suturing
The Brain
the brain has four major regions which are the i) cerebral
hemispheresii)
diencephaloniii) brainstem iv) cerebellum
the entire brain and spinal cord are enclosed in three layers of protective tissue known as the cerebral meniges
the outer layer – dura mater, which is thick fibrous tissue connective tissue that is a protective membrane to the brain,highly vascular containing both arteries and veins
the arachnoid mater ( middle) is a thin membrane separated from the dura mater by the subdural space
beneath the arachnoid mater is the subarachnoid space , which is filled with Cerebral Spinal Fluid ( CSF) which purpose is to cushion the brain from external forces
the third layer ( inner) pia mater is a very thin and delicate membrane that is physically attached to the brain tissue and serves to provide the framework for extensive vasculature that supplies the brain
Twelve Cranial Nerves
Pairs of nerves with motor, sensory or both functions
Prevention of Injuries
the most important protective measure for the head is the use of helmets
the proper use of protective equipment can protect the head from accidental or routine injuries
Cranial Injury Mechanisms the extent of the injury to the head
depends on the material properties of the skull , thickness of the skull , magnitude and direction and size ( area) of the impact
on direct impact the bone deforms and bends inwards placing the inner border of the skull under tensile strain, where the outer is compressed
if sufficient magnitude and if the skull is thin in that region , a skull fracture will occur at the site of impact
however if the skull is thick and dense enough it may withstand the inward bending without a fracture
a fracture may then occur somewhere away from the impact site where the skull is thinner
on impact shock waves travel through the skull to the brain causing acceleration
this acceleration may lead to shear, tensile and compression strains with in the brain
shear is the most serious
Coup – is a direct blow
Countrecoup - is an injury that occurs away from the actual injury site due to axial rotation and acceleration
Focal injuries – this involves only localized damage ( usually due to high velocity –low mass forces)Or
Diffuse injuries – widespread disruption and damage to function or structure of the brain ( usually due to low velocity high mass for
Skull Fractures
Skull fractures may be : linear (in a line) communited (multiple
pieces) depressed (fragments
driven internally toward the brain)
basilar ( involving base of skull)
If there is a break in the underlying dura mater, there is a high risk of bacterial infection into the intracranial cavity , which may result in septic meningitis
Signs and Symptoms
discolouration around eyes ( racoon eyes) blood or CSF may leak from nose or ears vision problems discoloration behind the ear that appears
within minutes ( battle’s sign ) a suspect skull fracture requires
immediate attention – EAP
cover open wounds with a steril dressing – but do not apply pressure
monitor vital signs – treat for shock – protect for neck injury as well
transport ASAP
Cerebral Hematomas
hematoma is a collection of blood in a localized area
with in the skull there is no room for additional accumulation of blood
any additional matter with in the cranial cavity increases pressure on the brain
leading to significant alterations in neurologic functions
type of hematoma depends on location of the accumulated blood
Majority of intercranial injuries result from blunt trauma to the head.
Epidural Hematoma
Usually an arterial bleed into the epidural space ( blood usually emerges from the middle meningeal artery between the dura mater and the cranial bones)
the athlete will have a initial loss of consciousness at the time of injury followed by a lucid interval in which they feel fine – however with in 10 to 20 minute a decline in mental status will occur very rapidly
S/S headache , blurred vision, speech changes, mental
confusion, a decreased level of consciousness , and dizziness
Rx- immediate surgery is required to decrease pressure and control bleeding
Subdural Hematoma these occur at approximately
three time the rate of epidural hematomas
haemorrhaging occurs below the dura mater and involves bleeding from a cerebral vein rather than an artery ( low pressure venous bleeding that clots slowly)
Onset of s/s may be more gradual in some cases 24- 72 hours
S/S Patient may be conscious with out any s/s because of the delay in S/S this is the most
prevalent cause of death from a trauma in sports hence all head injuries must be monitored for
delayed complications ,they will get progressively worse
S/S to watch out for ; persistent headache or increasing headache nausea and or vomiting restless and irritable , or drastic changes in
personality increasing mental confusion dizziness difficulty speaking or slurring of speech progressive or sudden impairment of
consciousness
Rx- immediate emergency response -- surgical drainage with in less than 4 hours of the injury
Concussions A concussion is a type of traumatic
brain injury that interferes with normal function of the brain.
May be caused by direct blow to the head, face, or elsewhere on the body with any force transmitted to the head
Basically any force that is transmitted to the head that causes the brain to bounce or twist around in the skull
Concussion Typically results in the rapid onset of short lived impairment
of neurological function that resolves spontaneously May result in neuropathological changes , but acute clinical
symptoms largely reflect a functional disturbance rather than a structural injury
May or may not involve loss of consciousness ( only approximately 10 % result in LOC)
Concussions are typically associated with normal structural neuroimaging studies ( CAT and or MRI’s)
Concussion Effects
Concussions effect four areas of functionality
The way the person feels How they think Changes in emotions How they sleep
Signs to watch for in athletes Appears dazed or stunned Confused about assignments Forgets plays Unsure of game score or opponent Moves clumsily Answers questions slowly Behaviour or personality changes Can’t recall events prior to or after injury LOC
Symptoms to watch for in Athletes Headache Nausea Balance problems /dizziness Double or blurry vision Sensitivity to light or noise Feeling sluggish , foggy Concentration or memory problems confusion
SCAT
See handout
Second Impact Syndrome this occurs when an athlete (generally
seen in children under 18) has sustained a head injury – usually a concussion and then sustains a second concussion before the symptoms associated with the first injury have totally resolved
the athlete may receive a relatively minor second blow to the head – the athlete often continues to compete and may be able to function fine for a short period of time
however the cranium becomes engorged with blood increasing the pressure on the brain
the athlete collapses , slips into a comatose state and respiratory failure ensues
the usual time from second impact to brainstem failure is rapid , 2 to 5 minute
Hence it is imperative any athlete who complains of headache, light headiness, visual disturbances or other neurologic symptoms should not be allowed to participate in any athletic event until they are totally asymptomatic
“When in doubt sit them out”
Assessment of Cranial Injuries head traumas demand immediate
assessment for life threatening conditions be aware that head injuries may also cause
neck and or spinal injuries , stabilize the head and neck
never use ammonia capsules to arouse the person , as they may jerk the head and neck leading to serious complications
observe vital signs determine level of consciousness
History Mechanism of injury - what happened,
what position at impact Loss of consciousness- how long? unresponsive, confused , disoriented do they respond to painful stimuli Amnesia - confusion loss of memory of events after injury
(posttraumatic amnesia)
loss of memory prior to injury ( retrograde amnesia)
Pupil abnormalities- note pupil size and accommodation to light - both should be equal (PEARL)
one side dilated pupil may indicate a subdural or epidural hematoma
bilateral dilated pupils indicates a severe cranial injury
vision problems - blurred, double , seeing stars
Headache - does the individual have one progressive headaches indicates
increasing pressure Nausea or Vomiting - intracranial
pressure can stimulate the reflex and cause vomiting or nausea
Associated neck injury- pain ,numbness or weakness in the extremities ,grip strength , sensations sharp or dull
Observations
1) Leakage of Cerebrospinal fluid - CSF is clear, colorless fluid that protects the brain and spinal cord
2) Signs of Trauma - discolouration around the eyes, behind the ears
- bleeding , depressions , lacerations or hematomas
3) Skin colour - note skin colour and presence of moisture
- watch for signs of shock 4) Loss of emotional control - irritability,
aggressive behaviour , uncontrolled crying - refer to Physician
Palpation
Palpations can help to pinpoint possible skull fractures. Palpate for points of tenderness, crepitus , depressions, swelling , blood or changes in skin temperature.
Special Tests
Special tests assess brain function through co-ordination, balance, depth perception and logical thought process
1) 100 minus 7 - test's ones ability to concentrate.
Individual starts at at 100 and subtract 7 , then 7 again and so on.
Month backwards
2) Finger to nose test - tests depth perception and ability to focus on an object
Hold a finger out front of the individual and ask them to reach out and touch it, alternate between left and right hand , can move finger around. A variation is to have the individual to touch their nose between touches.
3) Rhomberg's test - balance test - individual stands with feet together arms at side and eyes closed while maintaining their balance.
Variations include raising arms to 90 degrees , standing on toes or touching nose with eyes closed.
4) Stork stand - with eyes closed have individual stand on one leg
5) Heel /toe walking - ask individual to walk on toes and then on heels - note swaying or inability to walk in a straight line
Determination of Findings If the individual is not in a crisis situation ,
vital signs and special tests should be completed every 5 to 7 minutes to determine progress of condition.
The recommendation with all concussions is the athletes should not return to play on the same day , should be reassessed and return to play guidelines followed ( see SCAT )
If S/S linger but appear minor an individual close to the injured person should be informed of the injury and told to watch for changes in behaviour, unsteady gait , slurred speech , progressive headache or nausea, restlessness , mental confusion or drowsiness.
These danger signs should be documented on a sheet to give out and given to the individual watching the injured person. If any S/S worsen then the injured person should be taken to the emergency room ASAP.
Must be checked by medical personal at some time
Must never be sent alone to the bus ,locker room, home etc.
When to call the ambulance ?A player with a witnessed LOC of any duration
A player who exhibits the one or more of the following symptoms
Decrease level of consciousness
Unusual drowsiness or the inability to be awakened
Difficulty getting attention
Breathing difficulty
Severe or worsening headaches
Vomiting
Seizures
Rest for a player with a concussion at home Sleep often Limit brain stimulation
phone ,computer, texting, tv
gaming
Cognitive and Physical rest
Rest for a player with a concussion at school Stay at home or attend half days Take naps , need rest time Extended time for assignments or tests Written instructions for assignments Repeat and present new information
slowly