Traumatic Brain Injury: Department Of Neurosurgery,the First Affiliated Hospital Of Zhengzhou University Xu Bin

Traumatic Brain Injury (Ⅲ) Department of Neurosurgery,The First Affiliated Hospital of Zhengzhou University Xu Bin

Traumatic Intracranial Hematoma

Overview

 Traumatic intracranial hematoma accounts

for 10% of the closed craniocerebral injury.  The hematoma is a secondary brain injury

and gives rise to increased intracranial pressure, herniation, and brain death.  It is very important for neurosurgeons to

diagnoses the hematoma and deal with it immediately

Classification Depending on the time of presence of symptoms: Acute hematoma (within three days) Subacute hematoma(3 days~3 weeks) Chronic hematoma (after 3 weeks)

Classification  According

to

the

site

hematoma: Extradural hematoma Subdural hematoma Intracerebral hematoma.

of

the

Epidural hematoma  A collection of blood that lies

outside of the dura mater (between the dura mater and the skull)  Biconvex high-density

Acute Extradural Hematoma  Site: A collection of blood between the

skull and the dura  Bleeding source: middle meningeal artery and veins; dural sinuses such as the superior sagittal and transverse sinuses; the dura is separated from the bone, diploic veins.

An epidural hematoma occurs as a result of skull fracture and laceration of a meningeal vessel,usually the posterior branch of the middle meningeal artery.All skull fractures are accompanied by small epidural hematomas,usually venous in origin and arising from the diploic space.

When the dura is stripped from the inner table of the skull adjacent to a fracture and arterial bleeding from a lacerated meningeal artery begins filling the space,the dura is further stripped and a large extradural mass that causes severe brain compression may occur.

Occasionally,the space is filled with venous blood,most commonly when fracture lines cross the superior or transverse sinuses;the venous collection arising either from laceration of the sinuses or venous tributaries to the sinuses.Epidural hematomas may occur after minor head injury.There may be no loss of consciousness or only a transient concussive state with rapid return of normal brain function.

Epidural hematomas also may accompany more severe head injury with skull fracture.Only one-third of patients with

epidural hematomas will have a classic “lucid interval” with a definite period of essentially normal brain function following impact,before the expanding epidural hematomas causes progressive loss of consciousness and focal neurological deficits.

Epidural hematomas are the most common lateral to the temporal lobes where the skull is thinned and the meningeal vessels are numerous.With expansion of the hematoma,there is medial compression of the temporal lobe that causes a contralateral hemiparesis and eventual transtentorial herniation as the medial temporal lobe compresses midbrain structures at the tentorial incisure.

As many as one-third of patients with epidural hematoma do not present to a physician until the onset of coma.The death rate from epidural hematomas approaches 30-50% in some series,chiefly because of a delay in recognition of the expanding intracranial hematoma.Therefore,admission for observation is justified for head-injured patients who loss consciousness for 2 minutes or more or if skull x-rays shows a new fracture.

Clinical Findings  Disturbance of consciousness:

Coma (caused by primary injury)

called primary coma Lucid interval Coma (caused by hematoma, this coma is the symptoms of the cerebral herniation). Called secondary coma.

Clinical Findings If the primary brain injury is severe, the sufferer may have not lucid interval. And when the primary brain injury is slight, the sufferer may have not first coma. So the key point is the disturbance of consciousness may appear some later or aggravated progressively after head injury.

Clinical Findings Pupillary Alteration: ipsilateral constricted or dilated pupil caused by the oculomotor nerve injury. This is the symptoms of the cerebral herniation.

Clinical Findings  Motor disturbance: paralysis on

the contralateral side caused by compression of the ipsilateral cerebral peduncle.  Vital signs alteration: Cushing’s response.

Diagnosis Measures  A: clinical finding and signs  B: CT examination is very

important for definition of the diagnosis.

Extradural hematomas may be seen in the posterior fossa and are most reliably demonstrated on CT scan or vertebral angiography.

Positions of exploratory trephination

Treatment  When patient with mild symptoms

and CT scan shows only a small degree of hemorrhage the dehydration and careful observation can be applied.  Performing operation at once to removing the hematoma is a main selection for severe patients.

Subdural Hematomas

Subdural hematomas are the most common intracranial mass lesions that result from head injury.Most subdural hematomas are the result of torn bridging veins that drain blood from cerebral cortex to major overlying dural sinuses.

They may go unrecognized for a time or may accompany devastating primary cerebral injury in patients who are unconscious from the time of injury;these patients have a high death rate.

Subdural hematomas may be small at onset of symptoms if there is marked accompanying cerebral edema.In an elderly patient with a “brain smaller than the skull,”a hematoma may become quite large before neurologic symptoms or signs appear. Subdural hematomas are often classified according to the length of time between injury and onset of symptoms.

Subdural haematoma 1.Tear of veins that bridge dura mater cause a collection of blood under the dura mater adjacent to the brain 2.Acute SDH is a surgical emergency  Acute stage: high density  2-4weeks: iso-dense (with the brain tissue)  3-4weeks later: lower density  Mix-density: may be a fresh bleeding into a chronic lesion

SDH

Acute Subdural Hematoma  Site:

A collection of blood between the dura and arachnoid.  Bleeding source: cerebral surface blood vessel, dural sinuses.

These present within 24 hours after injury.The death rate is higher in acute subdural hematomas than in any other category of closed head injury.There is often associated severe brain contusion or laceration,which leads to progressive cerebral edema and cerebral injury even after the acute subdural hematoma is recognized and removed.

Although most acute subdural hematomas are venous in origin,laceration of cortical arteries occasionally gives rise to a more rapidly evolving hematoma.Early evacuation of these mass lesions is mandatory,although the death rate remains above 75% for patients with the combination of extrinsic brain compression and intrinsic brain damage.

Clinical Findings

 Because

the hematoma is always combined with cerebral contusion and laceration, it may be difficult to diagnosis in some case depending on signs and symptoms merely. At this time the CT examination is very important for diagnosis.

Clinical Findings  Unconsciousness

from the beginning and rapid deterioration  The signs and symptoms of the cerebral herniation  Diagnosis mainly depends on CT scan

Treatment Selecting conservative or operative treatment depending on patient’s signs and symptoms and CT scan.

Chronic subdural hematoma

 Chronic subdural hematoma is a

common disease caused by head injury in the elderly. The injury itself is often trivial and it may be weeks or months before it declares.  Bleeding source: small vein crossing the subdural space.

Chronic SDH  In the chronic form, only blood

effuses into the subdural space as a result of rupture of the bridging veins, usually due to closed head injury. The effusion is a gradual process resulting, weeks after the injury, in headache and progressive focal signs that reflect the location of the mass.

Clinical feature  The onset of symptoms is

characteristically insidious. Headache, mental changes, drowsiness and vomiting usually occur. There is often a mild hemiplegia but signs of raises intracranial pressure are not prominent.

These hematomas are discovered with progressive neurological deficits that occur later than two weeks following head injury.In some instances,the initial head injury is completely forgotten and patients may be evaluated for possible brain tumors or dementias such as Alzheimer’s disease.

Headache is common and focal neurological deficits may appear,dementia and increasing lethargy usually cause the patient to be brought in for medical evaluation.The initial hemorrhage may be relatively small or may occur in elderly patients with large ventricles or a dilated subarachnoid space.Membranes deriving from dura mater and arachnoid encapsulate the hematoma,which remains clotted for 2-3 weeks and then gradually liquefies.

The patient may have no symptoms for prolonged periods,only to become symptomatic when the hematoma enlarges by additional bleeding into the cavity from friable blood vessels in the capsule.

Chronic subdural hematomas are most common in infants and in adults over sixty years of age.Because of the slow and insidious development of symptoms,the patient’s behavior may be attributed to a psychiatric rather than physical cause.

Chronic subdural hematomas are bilateral in 20% of patients and best demonstrated with CT or MRI scans or radionuclide brain scan,all of which will accurately demonstrate the lesion.The liquefied chronic subdural hematoma usually can be removed adequately by bur holes placed over the cavity.

Diagnosis  Early diagnosis

depends upon the possibility being borne constantly in mind when fluctuating physical and mental changes occur in the elderly.  MRI examination is a non-traumatic and best method for diagnosis.

Treatment  Burr

hole in the ipsilateral parietal bone should be made to remove the hemorrhage. The prognosis is always good for most of patients.

Intracerebral hematoma

 Intracerebral hematoma is always

accompanied with severe contusion and laceration of cerebral tissues. The symptoms and signs depend on the location of the lesion.

Subarachnoid hemorrhage  A acute condition involving

sudden hemorrhage into the space between the arachnoid membrane and the pia mater

Intracerebral hemorrhage  From small arterioles within the   1. 2.

brain The frontal and temporal lobes are classic sites High density Traumatic ICH Spontaneous ICH

Clinical Findings  .Progressing

deterioration of state of consciousness.  .Severe headache, vomiting.  .The hemiparesis may be found.

Diagnosis Clinical findings CT scan

ICH ICH

ICH ICH

ICH ICH

Treatment  The conservative and operative

treatment should be chosen according to the sufferer’s clinical manifestation and CT scan. When the symptoms of cerebral herniation appear, the operation of removing the hematoma should be done.

PENETRATING HEAD INJURY •Penetrating injury to the brain occurs from the impact of a bullet, knife or other sharp object that forces hair, skin, bone and fragments from the object into the brain. •Objects traveling at a low rate of speed through the skull and brain can ricochet within the skull, which widens the area of damage.

A "through-and-through" injury occurs if an object enters the skull, goes through the brain, and exits the skull. Through-and-through traumatic brain injuries include the effects of penetration injuries, plus additional shearing, stretching and rupture of brain tissue.

The devastating traumatic brain injuries caused by bullet wounds result in a 91% firearm-related death rate overall. Firearms are the single largest cause of death from traumatic brain injury.

This would be either high velocity injury which is uncommon in our society or slow velocity injury as a result of penetration of the base of the scalp with sharp objects. The base of the skull is thin bone and could easily be penetrated especially in children with sharp objects as tree branches and knitting needles. This results in skull base fracture and damage to the brain overlying that area.

Outcome of brain injury Outcome after head injury depends on many factors.Increasing age and preexisting illness contribute to a poor prognosis.Penetrating injuries,particularly gunshot wounds are associated with poorer outcome compared with blunt trauma.

The presence of an intracranial hemorrhage also implies a suboptimal result. Subdural hematoma has a poorer prognosis than epidural hematoma. Combined subdural and intracerebral hemorrhage has the worst prognosis of all severe head injury subtypes.

Other important factors that influence outcome include delay in treatment,multiple trauma and systemic insults such as acidosis,hypoxia and hypotension.Predictors of poor prognosis include evidence of brainstem dysfunction on the initial examination and refractory intracranial hypertension within the first few days of injury.

Subacute subdural hematomas become apparent several days after injury and are associated with progressive lethargy,confusion,hemiparesis or other hemispheric deficits.Removal of hematoma usually produces striking improvement.

Malignant Brain Edema Syndrome  Head trauma causes clot; swelling

↑due to hyperemia; ↑intracranial pressure  Rapid neurological deterioration, coma , death  EMS (life-threatening)

The summary Head Injury Scalp injury == hematoma, laceration. Skull fracture == vault of the skull (linear fracture, depressed fracture). Base of the skull (linear fracture) Cerebral injury == primary cerebral injury and secondary cerebral injury

The summary  Primary cerebral injury

Injury -- coma -- relieve or lucid  Secondary cerebral injury

injury -- lucid -- coma  primary + secondary injury

injury -- coma (primary) --lucid

interval -- coma (secondary)

The summary  Primary cerebral injury

concussion -- conservative treatment contusion and laceration -- conservative

treatment  Secondary cerebral injury dehydration, brain edema diuretic, cortisone. hematoma operation

IIP