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91 Cards in this Set
- Front
- Back
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sports account for what percent of head injuries
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17%, second only to Motor vehicle accidents
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medullar oblongata (lower brainstem)
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vital functions
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leading cause of death ages 1-30 is
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accidents
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500000 people suffer
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head injurys each year
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ethanol involved in 1/3 to 1/2 of
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all TBI's
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4:1 ratio of males to females invovled in
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TBI's
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1/2 of all tramua related deaths are
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TBI's
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brain injury costs, on average
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100,000 dollars in acute medical care and rehabilitation
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pathomechanism of head injuries are
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forces placed on neurons, specifically axon and cell bodies (shear and straining)
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tensile strength of axon is
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resistence to longitudinal stress, measured by minimal amount of stress required to rupture axon
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retrograde degeneration
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tearing of axon causing degeneration down to cell body
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anterograde degeneration
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rupture of a cell body can lead to axon fiber degeneration which can cause domino effect by metabolic changes in post-synaptid neuron
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shearing effect most noticable at
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the junction between gray and white matter
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CHI's
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brain whiplash
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neurons not completely severed may
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resprout axonal projections
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penetrating head injury
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damage dependent on location (brainstem=fatal vs cortical association areas) and infection, hemorrage
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large caliber gunshots wounds fatal because
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significant tearing of blood vessels and destruction of brain tissue
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small caliber gunshots fatal because
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bullet can bounce around in skull
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>25,000 deaths in US every years by
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suicide, majority by gunshot
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James Brady's R hemisphere removed after
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Hinckley's assassination attempt on president Reagan causing Brady to be left hemiplegic
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Brady Bill
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control handgun prchases by former mental patients and people w/ criminal records
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closed head trauma types
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acceleration or deceleration
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velocity formula
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v=gt
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acceleration formula
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a=v/t
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hitting asphalt vs. water
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25x the g-force
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Indy racecar drivers and NHL players undergo
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neuropsychological testing to establish baseline cognitive abilites incase of CHI
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impact injury vs. countercoup injury
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brain tissue damage at point of impact vs. brain tissue ripping away from skull
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diffuse brain injury common at frontal and temporal lobes because
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uneven sandpaper-like surface of tentorial plates that hold those brain structures in place
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edema
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swelling caused by fluid in your body's tissues
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glasgow coma scale (GCS)
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rapid, reliable measure of coma depth by assessing language, consciousness, and motor domains (mild confusion >13 to deep coma >5)
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coma defined as
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score of 8 or less on GCS, patient cannot open his or her eyes, make recognizable sounds, or follow commands
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good recovery after coma associated with GCS scores of
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8 and above
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EEG shows coma patients have
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sleep-awake cycles
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coma associated with injury to areas involved in
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arousal; lower brainstem, RAS
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linear acceleration does not result in a coma but
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free movement blow does result in coma
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limitations of GCS
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1) eye swelling preventing eye opening and endotracheal tube/ barbiturates or anticonvulsants preventing speech
2)small lesion to brainstem can cause coma so GCS not good indicator of overall brain damage |
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number of days to reach GCS of 15 is good prognositic indicator of
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patients survival
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major complications of CHI are
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edema and associate brain herniation, bleeding, and skull fractures
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Edema
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swelling as result of tramua causing internal pressure of brain increases
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tramua team routinely places intracranial monitoring
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to monitor intracranial pressure (ICP) caused by edema
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brain herniation
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displacement of brain structures resultant of ICP (often caused by hematoma)
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in >75% of severe CHI
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ICP of greater than 20mm Hg (normal is 0-15mm Hg)
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transtentorial herniation
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downward displacement of the parahipocampal gyrus and uncus of temporal lobes through the tentorial hiatus
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brain herniation causing pressure on lower brainstem through formen magnum causes
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oculomotor nerve cut off and comprimises brainstem integrity
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oculomotor nerve cut off causes
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constriction followed by dialation of pupil on herniated side and may lose motor fxn ipsilateral of herniation
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compression of posterior cerebral artery may
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obstruct blood flow causing necrosis
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herniation left untreated
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causes respitory failure
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edema progresses into brain herniation so controlling
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ICP is important in acute CHI
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treatment of high ICP
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reduction of patients blood pressure or hyperventilation, in extreme cases a pharmacologically induced coma induction
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pharmacologically induced coma used in
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treatment of high ICP becuase it reduces brain metabolism and hence swelling
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last resort high ICP treatment:
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removal of lobe to make room for swelling brain (ex: R frontal lobe)
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subdural and extradural bleeding
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cerebral blood vessels tear, producing pools of blood within and between meninges
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subdural or intercerebral bleeds cause
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initial unconsciousness followed by consciousness, then blood pushes brain lateral and inferior, causing herniation
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subdural hematoma is
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bleed between dura and arachnoid space sinus
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subdural hematoma occur over
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typically over frontal and parietal lobes
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subdural hematoma caused by
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caused by acute venous hemorrhage (such as superior sagittal) often associated with skull fractures
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subdural hematoma occurs within
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1 hour to 1 week after injury
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alcohol is a catalyst in
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subdural hematomas becuase of its anticoagulant properties in blood
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subdural hematoma symptoms
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contralateral hemiparesis, ipsilateral pupil dilation, changes in level of consciousness
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extradural hematoma is a
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bleed occuring between skull and dura
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extradural hematoma often caused by
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bleeding of large middle meningeal artery
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epidural hematoma is a
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bleed between the meninges and the skull
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cause of epidural hematoma
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rupture of atery or meningeal wein or dural sinus
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treament of epi-/subdural hematoma
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drilling burr hole over parieto-occipital and temporal regions
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space-occupying clots appear in
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15% of fatal CHI's
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space-occupying clots caused by
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microscopic hemorrhages by shearing blood vessels in subcortical white mater, corpus callosum, and orbital surfaces of frontal and temporal lobes.
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contusion
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bruising of brain tissue
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linear fracture
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relatively benign, produces a straight line
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depressed skull fracture
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fragments of skull driven into underlying tissue
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fractures to base of skull are (2)
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1) hard to detect by x-ray
2) entail more damage than simple linear fractures |
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skull fracture risks (3)
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1)infection
2)cerebrospinal fluid leaks 3)bleeding |
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post traumatic epilepsy in what percentage of CHI's and PHI's?
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10% CHI and 40% of penetrating head injuries
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causes of post traumatic epilepsy
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scar tissue buildup causes alterations in neuronal membrane fxn and structure
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onset of post traumatic epilepsy
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up to 2 years
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risk factors for post traumatic epilepsy
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penetrating head injury, severity of injury, prolonged coma periods, PTA, inflammation, and residual neurological symptoms
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prophylactically
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routinely
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Jeffrey T. Barth from U of Virginia Med School (80's) reported
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investigated patients with concussions that were turned away from Emergency Room
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concussion entails
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dizziness, fatigue, headaches, with no loss or brief loss of consciousness
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mild head injurys usually
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go medically unnoticed
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mild head injurys constitute physical energy transferred to the brain in which
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related acceleration forces that can result in necrosis
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head injuries are
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cumulative in effect
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Gronwall and Wrightson (1975) concluded that
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after 2nd concussion, capacity of adults to process info declined significantly
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1.3 million individuals a year have a
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mild TBI, (half of which result from MVA's, sports injuries falls, violence, and industial accidents, respectively)
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sports related head injuries a year
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>300,000
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football helmets available in
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1896
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1905 Roosevelt met with Harvard, Yale, and Princeton representatives to
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discuss making football less dangerous
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studies of mild head injury in 80's found
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neuropsychological deficits in new an rapid problem solving, attention, and memory, lasting up to 3 months after trauma
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Gennarelli (1983) and Ommaya performed
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primate studies on mild acceleration head trauma
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Gennarelli (1983) and Ommaya found in primates that
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mild acceleration caused axonal shearing and straining in brainstem
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Jeff Barth et al. at U of Virginia (UVA) found
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neuropsychological decline in areas of information problem solving and attention with mild head injury without unconsciousness, but would rapidly recover
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Mark Lovell et al. spearheaded
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movement called Pittsburgh Sports concussion program in late 80's/ early 90's
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