Head injuryFrom Wikipedia, the free encyclopediaJump to: navigation, search This article needs attention from an expert on the subject. The specific problem is: It contains a significant amount of unreferenced information that needs to be checked for accuracy. WikiProject Medicine or the Medicine Portal may be able to help recruit an expert. (April 2012) This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (April 2012) Head injury Classification and external resourcesICD-10 S00.0S09ICD-9 800-879eMedicine neuro/153MeSH D006259See also: Traumatic brain injuryHead injury refers to trauma of the head. This may or may not include injury to the brain.However, the terms traumatic brain injury and head injury are often used interchangeably inmedical literature.The incidence (number of new cases) of head injury is 300 of every 100,000 per year (0.3% ofthe population), with a mortality rate of 25 per 100,000 in North America and 9 per 100,000 inBritain. Head trauma is a common cause of childhood hospitalization.Contents[hide] 1 Classification o 1.1 Concussion o 1.2 Intracranial hemorrhage 1.2.1 Intra-axial hemorrhage 1.2.2 Extra-axial hemorrhage o 1.3 Cerebral contusion o 1.4 Diffuse axonal injury 2 Signs and symptoms 3 Causes 4 Diagnosis
5 Management 6 Prognosis 7 References 8 External links ClassificationHead injuries include both injuries to the brain and those to other parts of the head, such as thescalp and skull.Head injuriess may be closed or open. A closed (non-missile) head injury is where the duramater remains intact. The skull can be fractured, but not necessarily. A penetrating head injuryoccurs when an object pierces the skull and breaches the dura mater. Brain injuries may bediffuse, occurring over a wide area, or focal, located in a small, specific area.A head injury may cause skull fracture, which may or may not be associated with injury to thebrain. Some patients may have linear or depressed skull fractures.If intracranial hemorrhage occurs, a hematoma within the skull can put pressure on the brain.Types of intracranial hemorrage include subdural, subarachnoid, extradural, andintraparenchymal hematoma. Craniotomy surgeries are used in these cases to lessen the pressureby draining off blood.Brain injury can be at the site of impact, but can also be at the opposite side of the skull due to acontrecoup effect (the impact to the head can cause the brain to move within the skull, causingthe brain to impact the interior of the skull opposite the head-impact).If the impact causes the head to move, the injury may be worsened, because the brain mayricochet inside the skull causing additional impacts, or the brain may stay relatively still (due toinertia) but be hit by the moving skull (both are contrecoup injuries).Private Patrick Hughes, Co. K, 4th New York Volunteers, wounded at the battle of Antietam onSeptember 17, 1862.Specific problems after head injury can include:
Skull fracture Lacerations to the scalp and resulting hemorrhage of the skin Traumatic subdural hematoma, a bleeding below the dura mater which may develop slowly Traumatic extradural, or epidural hematoma, bleeding between the dura mater and the skull Traumatic subarachnoid hemorrhage Cerebral contusion, a bruise of the brain Concussion, a loss of function due to trauma Dementia pugilistica, or "punch-drunk syndrome", caused by repetitive head injuries, for example in boxing or other contact sports A severe injury may lead to a coma or death Shaken Baby Syndrome - a form of child abuse ConcussionMain article: ConcussionTraumatic brain injury (TBI) is an exchangeable word used for the word concussion. This termrefers to a mild brain injury. This injury is a result due to a blow to the head that could make theperson’s physical, cognitive, and emotional behaviors irregular.Symptoms may include: Clumsiness, Fatigue, Confusion, Nausea, Blurry Vision, Headaches, andothers.Mild concussions are associated with sequelae. Severity is measured using various concussiongrading systems.A slightly greater injury is associated with both anterograde and retrograde amnesia (inability toremember events before or after the injury). The amount of time that the amnesia is presentcorrelates with the severity of the injury. In all cases the patients develop postconcussionsyndrome, which includes memory problems, dizziness, tiredness, sickness and depression.Cerebral concussion is the most common head injury seen in children. Intracranial hemorrhageMain article: Intracranial hemorrhageTypes of intracranial hemorrhage are roughly grouped into intra-axial and extra-axial. Thehemorrhage is considered a focal brain injury; that is, it occurs in a localized spot rather thancausing diffuse damage over a wider area. Intra-axial hemorrhageMain article: cerebral hemorrhage
Intra-axial hemorrhage is bleeding within the brain itself, or cerebral hemorrhage. This categoryincludes intraparenchymal hemorrhage, or bleeding within the brain tissue, and intraventricularhemorrhage, bleeding within the brains ventricles (particularly of premature infants). Intra-axialhemorrhages are more dangerous and harder to treat than extra-axial bleeds. Subdural Hematoma v Epidural type t e Between the dura and the Location Between the skull and the dura arachnoid Temperoparietal locus (most likely) - Middle meningeal artery Involved Frontal locus - anterior ethmoidal artery Bridging veins vessel Occipital locus - transverse or sigmoid sinuses Vertex locus - superior sagittal sinus Gradually increasing headache Symptoms Lucid interval followed by unconsciousness and confusion CT Biconvex lens Crescent-shaped appearance Extra-axial hemorrhageExtra-axial hemorrhage, bleeding that occurs within the skull but outside of the brain tissue, fallsinto three subtypes: Epidural hemorrhage (extradural hemorrhage) which occur between the dura mater (the outermost meninx) and the skull, is caused by trauma. It may result from laceration of an artery, most commonly the middle meningeal artery. This is a very dangerous type of injury because the bleed is from a high-pressure system and deadly increases in intracranial pressure can result rapidly. However, it is the least common type of meningeal bleeding and is seen in 1% to 3% cases of head injury . o Patients have a loss of consciousness (LOC), then a lucid interval, then sudden deterioration (vomiting, restlessness, LOC) o Head CT shows lenticular (convex) deformity. Subdural hemorrhage results from tearing of the bridging veins in the subdural space between the dura and arachnoid mater. o Head CT shows crescent-shaped deformity Subarachnoid hemorrhage, which occur between the arachnoid and pia meningeal layers, like intraparenchymal hemorrhage, can result either from trauma or from ruptures of aneurysms or arteriovenous malformations. Blood is seen layering into the brain along
sulci and fissures, or filling cisterns (most often the suprasellar cistern because of the presence of the vessels of the circle of Willis and their branchpoints within that space). The classic presentation of subarachnoid hemorrhage is the sudden onset of a severe headache (a thunderclap headache). This can be a very dangerous entity, and requires emergent neurosurgical evaluation, and sometimes urgent intervention. Cerebral contusionMain article: Cerebral contusionCerebral contusion is bruising of the brain tissue. The majority of contusions occur in the frontaland temporal lobes. Complications may include cerebral edema and transtentorial herniation.The goal of treatment should be to treat the increased intracranial pressure. The prognosis isguarded. Diffuse axonal injuryMain article: Diffuse axonal injuryDiffuse axonal injury, or DAI, usually occurs as the result of an acceleration or decelerationmotion, not necessarily an impact. Axons are stretched and damaged when parts of the brain ofdiffering density slide over one another. Prognoses vary widely depending on the extent ofdamage. Signs and symptomsPresentation varies according to the injury. Some patients with head trauma stabilize and otherpatients deteriorate. A patient may present with or without neurologic deficit.Patients with concussion may have a history of seconds to minutes unconsciousness, then normalarousal. Disturbance of vision and equilibrium may also occur.Common symptoms of head injury include coma, confusion, drowsiness, personality change,seizures, nausea and vomiting, headache and a lucid interval, during which a patient appearsconscious only to deteriorate later.Symptoms of skull fracture can include: leaking cerebrospinal fluid (a clear fluid drainage from nose, mouth or ear) may be and is strongly indicative of basilar skull fracture and the tearing of sheaths surrounding the brain, which can lead to secondary brain infection. visible deformity or depression in the head or face; for example a sunken eye can indicate a maxillar fracture 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 wounds or bruises on the scalp or face.
Basilar skull fractures, those that occur at the base of the skull, are associated with Battles sign, a subcutaneous bleed over the mastoid, hemotympanum, and cerebrospinal fluid rhinorrhea and otorrhea.Because brain injuries can be life threatening, even people with apparently slight injuries, withno noticeable signs or complaints, require close observation; They have a chance for severesymptoms later on. The caretakers of those patients with mild trauma who are released from thehospital are frequently advised to rouse the patient several times during the next 12 to 24 hoursto assess for worsening symptoms.The Glasgow Coma Scale is a tool for measuring degree of unconsciousness and is thus a usefultool for determining severity of injury. The Pediatric Glasgow Coma Scale is used in youngchildren. CausesCommon causes of head injury are motor vehicle traffic collisions, home and occupationalaccidents, falls, and assaults. Bicycle accidents are also a cause of head injury-related death anddisability, especially among children. Wilsons disease has also been indicative of head injury.  DiagnosisSee also: Head injury criterionThe need for imaging in patients who have suffered a minor head injury is debated. A non-contrast CT of the head should be performed immediately in all those who have suffered amoderate or severe head injury,an MRI is also an option.http://www.jpmsonline.com/jpms-vol1-issue3-pages78-82-oa.html ManagementSee also: Traumatic_brain_injury#TreatmentMost head injuries are of a benign nature and require no treatment beyond analgesics and closemonitoring for potential complications such as intracranial bleeding. If the brain has beenseverely damaged by trauma, neurosurgical evaluation may be useful. Treatments may involvecontrolling elevated intracranial pressure. This can include sedation, paralytics, cerebrospinalfluid diversion. Second line alternatives include decompressive craniectomy (Jagannathan et al.found a net 65% favorable outcomes rate in pediatric patients), barbiturate coma, hypertonicsaline and hypothermia. Although all of these methods have potential benefits, there has been norandomized study that has shown unequivocal benefit. Prognosis
In children with uncomplicated minor head injuries the risk of intra cranial bleeding over thenext year is rare at 2 cases per 1 million.In some cases transient neurological disturbances may occur, lasting minutes to hours. Malignantpost traumatic cerebral swelling can develop unexpectedly in stable patients after an injury, ascan post traumatic seizures. Recovery in children with neurologic deficits will vary. Childrenwith neurologic deficits who improve daily are more likely to recover, while those who arevegetative for months are less likely to improve. Most patients without deficits have fullrecovery. However, persons who sustain head trauma resulting in unconsciousness for an hour ormore have twice the risk of developing Alzheimers disease later in life.Head injury may be associated with a neck injury. Bruises on the back or neck, neck pain, orpain radiating to the arms are signs of cervical spine injury and merit spinal immobilization viaapplication of a cervical collar and possibly a long board.If the neurological exam is normal this is reassuring. Reassessment is needed if there is aworsening headache, seizure, one sided weakness, or has persistent vomiting. References 1. ^ Anderson T, Heitger M, and Macleod AD (2006). "Concussion and Mild Head Injury". Practical Neurology 6 (6): 342–357. DOI:10.1136/jnnp.2006.106583. http://pn.bmj.com/cgi/content/extract/6/6/342. Retrieved 2008-01-23. 2. ^ McCaffrey RJ (1997). "Special Issues in the Evaluation of Mild Traumatic Brain Injury". The Practice of Forensic Neuropsychology: Meeting Challenges in the Courtroom. New York: Plenum Press. pp. 71–75. ISBN 0-306-45256-1. 3. ^ Seidenwurm DI (2007). "Introduction to brain imaging". In Brant WE, Helms CA. Fundamentals of Diagnostic Radiology. Philadelphia: Lippincott, Williams & Wilkins. pp. 53. ISBN 0-7817-6135-2. http://books.google.com/?id=Sossht2t5XwC&pg=PA53&lpg=PA53&dq=extra- axial+intra-axial. Retrieved 2008-11-17. 4. ^ "Head Injury: Description". Seattle Childrens Hospital. http://www.seattlechildrens.org/child_health_safety/health_advice/head_injury.asp. Retrieved 2008-01-07. 5. ^ National Safe Kids Campaign (NSKC) (2004). "Bicycle injury fact sheet" (pdf). NSKC. http://www.preventinjury.org/PDFs/BICYCLE_INJURY.pdf. Retrieved 2006-12- 19. 6. ^ "www.nice.org.uk" (PDF). NHS. http://www.nice.org.uk/nicemedia/pdf/CG56NICEGuideline.pdf. Retrieved December 12, 2008. Computed tomography (CT) has become the diagnostic modality of choice for head trauma due to its accuracy, reliability, safety, and wide availability. The changes in microcirculation, impaired auto-regulation, cerebral edema, and axonal injury start as soon as head injury occurs and manifest as clinical, biochemical, and radiological changes.
7. ^ Hamilton M, Mrazik M, Johnson DW (July 2010). "Incidence of delayed intracranial hemorrhage in children after uncomplicated minor head injuries". Pediatrics 126 (1): e33–9. DOI:10.1542/peds.2009-0692. PMID 20566618.8. ^ Small, Gary W (2002-06-22). "What we need to know about age related memory loss". British Medical Journal 324 (7352): 1502–1507. DOI:10.1136/bmj.324.7352.1502. PMC 1123445. PMID 12077041. http://bmj.bmjjournals.com/cgi/content/full/324/7352/1502#B21. Retrieved 2008-11-13.