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| {{SI}}
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| {{CMG}} | | {{Head injury}} |
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| ==Overview==
| | '''For patient information click [[{{PAGENAME}} (patient information)|here]]''' |
| Head injury is a [[Physical trauma|trauma]] to the [[head (anatomy)|head]], that may or may not include injury to the [[human brain|brain]] (see also [[brain injury]]).
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| The [[incidence (epidemiology)|incidence]] (number of new cases) of head injury is 300 per 100,000 per year (0.3% of the population), with a mortality of 25 per 100,000 in [[North America]] and 9 per 100,000 in [[United Kingdom|Britain]]. Head trauma is a common cause of childhood hospitalization.
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| ==Causes==
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| Common causes of head injury are [[motor vehicle accident|traffic accident]]s, home and occupational accidents, falls, and [[assault]]s. Bicycle accidents are also a common cause of head injury-related death and disability, especially among children.
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| <ref name="NSKC">{{cite web | url=http://www.preventinjury.org/PDFs/BICYCLE_INJURY.pdf
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| | title=Bicycle injury fact sheet| author=National Safe Kids Campaign (NSKC) | date=2004 | publisher=NSKC | accessdate=2006-12-19 }}</ref>
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| ==Classification==
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| Head injuries include both injuries to the brain and those to other parts of the head, such as the [[scalp]] and [[skull]].
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| Head injuries may be closed or open. A closed (non-missile) head injury is one in which the skull is not broken. A [[penetrating head injury]] occurs when an object pierces the skull and breaches the [[dura mater]]. Brain injuries may be [[diffuse brain injury|diffuse]], occurring over a wide area, or focal, located in a small, specific area.
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| A head injury may cause a [[skull fracture]], which may or may not be associated with injury to the brain. Some patients may have linear or depressed skull fractures.
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| If intracranial [[hemorrhage]], or [[intracranial hemorrhage|bleeding within the brain]] occurs, a [[hematoma]] within the skull can put pressure on the brain. Types of [[intracranial hematoma]] include [[subdural hemorrhage|subdural]], [[subarachnoid hemorrhage|subarachnoid]], [[extradural hematoma|extradural]], and [[intraparenchymal hematoma]]. [[Craniotomy]] surgeries are used in these cases to lessen the pressure by draining off blood.
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| [[Brain injury]] can be at the site of impact, but can also be at the opposite side of the skull due to a ''[[contrecoup]]'' effect (the impact to the head can cause the brain to move within the skull, causing the brain to impact the interior of the skull opposite the head-impact).
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| If the impact causes the head to move, the injury may be worsened, because the brain may ricochet inside the skull (causing additional impacts), or the brain may stay relatively still (due to inertia) but be hit by the moving skull.
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| Specific '''problems''' after head injury can include:
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| * Skull fracture
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| * [[Laceration]]s to the scalp and resulting [[hemorrhage]] of the skin
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| * Traumatic subdural hematoma, a bleeding below the [[dura mater]] which may develop slowly
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| * Traumatic extradural, or epidural hematoma, bleeding between the dura mater and the skull
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| * Traumatic subarachnoid hemorrhage
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| * [[Cerebral contusion]], a bruise of the brain
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| * [[Concussion]], a temporary loss of function due to trauma
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| * [[Dementia pugilistica]], or "punch-drunk syndrome", caused by repetitive head injuries, for example in boxing or other contact sports
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| * A severe injury may lead to a [[coma]] or [[death]]
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| === Concussion ===
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| Mild concussions are not associated with any [[sequelae]]. However, a slightly greater injury can be associated with both anterograde and retrograde [[amnesia]] (inability to remember events before or after the injury). The amount of time that the amnesia is present correlates with the severity of the injury. In some cases the patients may develop [[postconcussion syndrome]], which can include memory problems, dizziness, and [[major depression|depression]]. Cerebral [[concussion]] is the most common head injury seen in children.
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| === Epidural hematoma ===
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| Epidural hematoma (EDH) is a rapidly accumulating hematoma between the [[dura mater]] and the cranium. These patients have a history of head trauma with loss of consciousness, then a lucid period, followed by loss of consciousness. Clinical onset occurs over minutes to hours. Many of these injuries are associated with lacerations of the [[middle meningeal artery]]. A "lenticular", or convex, lens-shaped extracerebral hemorrhage will likely be visible on a [[CT scan]] of the head. Although death is a potential complication, the prognosis is good when this injury is recognized and treated.
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| === Subdural hematoma ===
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| [[Subdural hematoma]] occurs when there is tearing of the bridging vein between the cerebral cortex and a draining venous sinus. At times they may be caused by arterial lacerations on the brain surface. Patients may have a history of loss of consciousness but they recover and do not relapse. Clinical onset occurs over hours. A crescent shaped hemorrhage compressing the brain will be noted on CT of the head. Surgical evacuation is the treatment. Complications include [[uncal herniation]], focal neurologic deficits, and death. The prognosis is guarded.
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| === Cerebral contusion ===
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| [[Cerebral contusion]] is bruising of the brain tissue. The majority of contusions occur in the [[frontal lobe|frontal]] and [[temporal lobe]]s. Complications may include cerebral [[edema]] and transtentorial herniation. The goal of treatment should be to treat the increased [[intracranial pressure]]. The prognosis is guarded.
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| === Diffuse axonal injury === | | ==[[Head injury overview|Overview]]== |
| [[Diffuse axonal injury]], or DAI, usually occurs as the result of an [[acceleration]] or deceleration motion, not necessarily an impact. [[Axon]]s are stretched and damaged when parts of the brain of differing density slide over one another. Prognoses vary widely depending on the extent of damage. | |
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| ==Symptoms== | | ==[[Head injury historical perspective|Historical Perspective]]== |
| Presentation varies according to the injury. Some patients with head trauma stabilize and other patients deteriorate. A patient may present with or without [[neurologic deficit]].
| | ==[[Head injury classification|Classification]]== |
| | ==[[Head injury pathophysiology|Pathophysiology]]== |
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| Patients with concussion may have a history of seconds to minutes unconsciousness, then normal arousal. Disturbance of vision and equilibrium may also occur.
| | ==[[Head injury causes|Causes]]== |
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| Common symptoms of head injury include those indicative of traumatic brain injury:
| | ==[[Head injury differential diagnosis|Differentiating a Head Injury from other Conditions]]== |
| *[[coma|loss of consciousness]],
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| *confusion,
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| *drowsiness,
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| *personality change,
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| *[[seizure]]s,
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| *[[nausea]] and [[vomiting]],
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| *[[headache]],
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| *a [[lucid interval]], during which a patient appears conscious only to deteriorate later
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| Symptoms of skull fracture can include:
| | ==[[Head injury epidemiology and demographics|Epidemiology and Demographics]]== |
| *leaking [[cerebrospinal fluid]] (a clear fluid drainage from [[nose]], [[mouth]] or [[ear]]) may be and is strongly indicative of [[skull fracture|basilar skull fracture]] and the tearing of sheaths surrounding the brain, which can lead to secondary brain [[infection]].
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| *visible deformity or depression in the head or face; for example a sunken eye can indicate a [[maxilla]]r fracture
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| *an eye that cannot move or is deviated to one side can indicate that a broken facial bone is pinching a [[nerve]] that innervates eye muscles
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| *[[wound]]s or bruises on the scalp or face.
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| *[[Basilar skull fracture]]s, those that occur at the base of the [[skull]], are associated with [[Battle's sign]], a [[subcutaneous]] bleed over the [[mastoid]], [[hemotympanum]], and [[cerebrospinal fluid]] [[rhinorrhea]] and [[otorrhea]].
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| Because brain injuries can be life threatening, even people with apparently slight injuries, with no noticeable signs or complaints, require close observation. The caretakers of those patients with mild trauma who are released from the hospital are frequently advised to rouse the patient several times during the next 12 to 24 hours to assess for worsening symptoms.
| | ==[[Head injury risk factors|Risk Factors]]== |
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| The [[Glasgow Coma Scale]] is a tool for measuring degree of unconsciousness and is thus a useful tool for determining severity of injury. The [[Pediatric Glasgow Coma Scale]] is used in young children.
| | ==[[Head injury natural history, complications and prognosis|Natural History, Complications and Prognosis]]== |
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| == Diagnosis and prognosis == | | ==Diagnosis== |
| Head injury may be associated with a neck injury. Bruises on the back or neck, back pain, pain radiating to the arms is a sign of cervical spine injury meriting [[spinal immobilization]] and application of a [[cervical collar]]. It is common for head trauma patients to have drowsiness but to be easily aroused, headaches, and vomiting after injury. If exam and consciousness are preserved, this is of no concern. But if these symptoms persist > 1 or 2 days, a CT of the head is needed. In some cases transient neurologic disturbance may occur, lasting minutes to hours and causing [[occipital blindness]] and a state of confusion. Malignant post traumatic cerebral swelling can develop unexpectedly in stable patients after an injury, as can post traumatic [[seizure]]s. Recovery in children with neurologic deficits will vary. Children with neurologic deficits who improve daily are more likely to recover. Children who are vegetative for months are less likely to improve. Most patients without deficits have full recovery. However, persons who sustain head trauma resulting in unconsciousness for an hour or more have twice the risk of developing Alzheimer's disease later in life.<ref>{{cite journal | last = Small | | [[Head injury history and symptoms|History and Symptoms]] | [[Head injury physical examination|Physical Examination]] | [[Head injury laboratory findings|Laboratory Findings]] | [[Head injury x ray|X Ray]] | [[Head injury CT|CT]] | [[Head injury MRI|MRI]] | [[Head injury other imaging findings|Other Imaging Findings]] | [[Head injury other diagnostic studies|Other Diagnostic Studies]] |
| | first = Gary W | title = What we need to know about age related memory loss | journal = British Medical Journal | pages = 1502-1507 | date = [[2002-06-22]] | url = http://bmj.bmjjournals.com/cgi/content/full/324/7352/1502#B21 | accessdate = 2006-11-05}}</ref>
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| ==Management== | | ==Treatment== |
| Unfortunately, once the brain has been damaged by trauma, there is no quick fix. However, there are some steps that can be taken to prevent secondary damage. If left untreated many patients with head injury will rapidly develop complications which may lead to death or permanent disability. Prompt medical treatment may prevent the worsening of symptoms and lead to a better outcome.
| | [[Head injury medical therapy|Medical Therapy]] | [[Head injury surgery|Surgery]] | [[Head injury primary prevention|Primary Prevention]] | [[Head injury secondary prevention|Secondary Prevention]] | [[Head injury cost-effectiveness of therapy|Cost-Effectiveness of Therapy]] | [[Head injury future or investigational therapies|Future or Investigational Therapies]] |
| Medical treatment should begin at the scene of the trauma. Paramedics will generally immobilize the patient to insure no further damage to the spine or nervous system, insert an airway to insure uninterrupted breathing, and perform endotracheal intubation if indicated. One or more IVs will be inserted to maintain perfusion status. In some cases medications may be administered to sedate or paralyze the patient to prevent additional movement which may worsen the brain injury. | |
| The patient should be delivered promptly to a hospital with neurosurgical capabilities. The management of brain injury requires the involvement of subspecialists who are generally available only at larger hospitals. Primary treatment involves controlling elevated intracranial pressure. This can include sedation, paralytics, cerebrospinal fluid diversion. Second line alternatives include decompressive craniectomy (Jagannathan et al. found a net 65% favorable outcomes rate in pediatric patients), barbiturate coma, hypertonic saline and hypothermia. Although all of these methods have potential benefits, there has been no randomized study that has shown unequivocal benefit.
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| ==References== | | == Case Studies == |
| <references/>
| | [[Head injury case study one|Case #1]] |
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| ==External links==
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| * [http://www.birf.info The Brain Injury Resource Foundation] The Brain Injury Resource Foundation
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| *[http://www.neuroskills.com/ TBI Resource Guide] Central source of information, services and products relating to brain injury, brain injury recovery, and post-acute rehabilitation
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| *[http://www.seattlechildrens.org/child_health_safety/health_advice/head_injury.asp What to do if your child has a head injury] from Seattle Children's Hospital
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| *[http://www.braininjury.org.au/ Information on head injury, effects and strategies for survivors and their families]
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| *[http://www.ii.bham.ac.uk/clinicalimmunology/Neuroimmunology/Tau.htm Neuroimmunology, The Medical School, Birmingham University]
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| * [http://www.informaworld.com/smpp/title~db=all~content=t713394000~tab=summary Brain Injury] The official research journal of the [http://www.internationalbrain.org/ International Brain Injury Association (IBIA)]
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| * [http://www.sciencedaily.com/news/mind_brain/brain_injury/ Research News on Brain Injury from ScienceDaily] Research news and archives
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| * [http://www.bikeroute.com/AwakeAgain Awake Again, All the way back from head injury]
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| == Related Chapters == | | == Related Chapters == |
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| * [[Skull fracture]] | | * [[Brain contusion]] |
| * [[Brain injury]] | | * [[Brain injury]] |
| * [[Traumatic brain injury]]
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| * [[Coma]] | | * [[Coma]] |
| * [[Unconsciousness]]
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| * [[Concussion of the brain]] | | * [[Concussion of the brain]] |
| * [[Diffuse axonal injury]] | | * [[Diffuse axonal injury]] |
| * [[Brain contusion]] | | * [[Epidural hematoma]] |
| * [[Intracranial hemorrhage]] | | * [[Extra-axial hemorrhage]] |
| * [[Hematoma]] | | * [[Hematoma]] |
| * [[Intra-axial hemorrhage]] | | * [[Intra-axial hemorrhage]] |
| | * [[Intracranial hemorrhage]] |
| * [[Intraparenchymal hemorrhage]] | | * [[Intraparenchymal hemorrhage]] |
| * [[Intraventricular hemorrhage]] | | * [[Intraventricular hemorrhage]] |
| * [[Extra-axial hemorrhage]] | | * [[Skull fracture]] |
| | * [[Subarachnoid hemorrhage]] |
| * [[Subdural hematoma]] | | * [[Subdural hematoma]] |
| * [[Epidural hematoma]] | | * [[Traumatic brain injury]] |
| * [[Subarachnoid hemorrhage]] | | * [[Unconsciousness]] |
| {{Injuries, other than fractures, dislocations, sprains and strains}} | | {{Injuries, other than fractures, dislocations, sprains and strains}} |
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| [[Category:Neurotrauma]] | | [[Category:Neurotrauma]] |
| [[Category:Injuries]] | | [[Category:Injuries]] |
| [[Category:Primary care]]
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| [[de:Schädel-Hirn-Trauma]]
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| [[nl:Hersenschudding]]
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| [[no:Hodeskade]]
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