name ;umenzekwe c topic;subdural/epidural haematoma
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DESCRIPTIONNAME ;UMENZEKWE C TOPIC;SUBDURAL/EPIDURAL HAEMATOMA. ANATOMY OF THE MENINGES. ANATOMY OF EPIDURAL SPACE. - PowerPoint PPT Presentation
NAME ;UMENZEKWE C
ANATOMY OF THE MENINGES
ANATOMY OF EPIDURAL SPACEThe epidural space is the space between the dura (the outermost membrane covering the brain and spinal cord) and skull, or the bony vertebrae that form the spinal canal. In the spine, the epidural space contains lymphatics, small arteries, and the epidural venous plexus. In the brain the epidural space is a potential space, meaning that the space does not exist under normal conditions.
ANATOMY OF SUBDURAL SPACEThe subdural space: The space between the dura mater and the arachnoid mater, this is a potential space in both the skull and the spine.
SUB DURAL HAEMATOMAIt is the collection of blood in the subdural space.It is the most common form of traumatic intracranial mass leision.Could present as acute,sub acute or chronic forms.A reversible cause of demential
ACUTE SUBDURAL HEMATOMACommon in young personsSymptoms usually present within 48hrResults from high velocity skull trama with rapid acceleration/deceleration of brain tissues as against fixed dura mater and the skull leading to tearing of bridging veins.Has high mortality rate if asso with cerebra contusion or if not rapidly treated by surgical decompression.
CHRONIC SUBDURAL HEMATOMA
Common in elderly persons.Often due to minor unrecorgnised injury.Presents after several weeks or month.It is a treatable cause of dementialThe bleeding is gradual with characteristic repeated bleeds.
RISK FACTORSAgeMale sexCoagulopathy or medical anticoagulation;heparin,haemophilia,liver disease and thrombocytopenia.
Alcoholism.NB bilateral subdural hematomas are present in infants bcos of absence of adhesions in the subdural space.Also is interhemispheric subdural hematomas
AETIOLOGY 1) Usually traumatic.in abt 75% of cases. -trauma may be trivial and unrecorgnised especialy in the elderly. -the most common cause2) Undetermined/spontaneous in 25% of cases.this is asso with;anticoagulant and antiplatelet therapy.Cerebral aneurysmArteriovenous malformationTumor (meningioma or dural metastasis)
PATHOGENESISFor traumatic aetiology,foliowing high speed impact on the skull.This causes brain tissue to accelerate/decelerate relatively to the fixed dural structure,tearing blood vessel majorly veins.These are veins running from cerebral cortex to the dural venous sinuses.these are called the bridging vein.
Pathogenesis contnIn elderly persons,the bridging veins may already be stretched because of brain atrophy making them more susceptible to trauma.Damage can also come from laceration or direct injury
pathophysiologyFollowing the haematoma,there wil be rise in intracranial pressure.This causes herniation;subfalcial(cyngulate gyrus) and transtentorial.Subfalcial herniation may cause a cerebral infarct via compression of anterior cerebral arteryTranstentorial herniation wil cause infarction via the compression of posterior cerebral artery.it can also cause pressure on the 3rd cranial nerve resulting ipsilateral pupilary dilatation. progressive transtentorial herniation,pressure on the brain stem tears blood vessels that supply the brain stem resulting in duret haemorhage and dealth.
CLINICAL FEATURESHISTORYUsually involves moderately severe to severe blunt head trauma Acute deceleration injury from a fall or motor vehicle accident, but rarely associated with skull fractureGenerally loss of consciousnessAny degree or type of coagulopathy should heighten suspicion of SDHCommonly seen in alcoholics because theyre prone to thrombocytopenia, prolonged bleeding times, and blunt head traumaPatients on anticoagulants can develop SDH with minimal trauma and warrant a lowered threshold for obtaining a head CT scan
CF CONTNOther symptoms includes headaches,altered mental status,hemiparesis,gait disturbances and aphasia.Chronic subdural haematoma is a cause of reversible demential
EPIDURAL HAEMATOMAAccumulation of blood in the potential space between dura mater and boneAetiology is principally traumatic;mild or severe.It is usually from arterial bleeding into the epidura space.When at the level of the spinal cord, it is mainly venous
Involved blood vesselsTemperoparietal locus-middle meningeal atery.(65%)Frontal locus-anterior ethmoidal artery(10%).Occipital locus-transverse or sigmoid sinuses(10%)Vertex locus-superior sagital sinus
EPIDEMIOLOGY 1) Occurs in 1-2% of head trauma in the USA. 2) Mortality is 5-43%. It is nil for patient who were not in coma.10% for obtuded pxt and 20% for those who were deeply comatous preoperatively.high mortality rates are asso with; -advance age, -intradural leision. -temporal location. -increased hematoma volume. -increased ICP -low GCS -Pupilary dilation -Rapid clinical progressionM0rtality is more in under 5yrs and those above 55yrs
EPID CONT3) Age; commoner in teenagers and young adult who are less than 20yrs.-less common in elderly bcos the dura is strongly attatched to the inner surface the skull.
aetiologyMajorly associated with skull fracture in aduit unlike in children where there is calvarium plasticity.Fracture is asso with laceration of the above listed vessels.can also be venous especialy in 1/3 of cases esp in parieto occipital region or the posterior fossa.
CLINICAL FEATUREHISTORY;May or may not loose consciousnessIf consciousness is lost,pxt may cont to be unconscious.Lucid interval occurs in about 20-35% of the cases.Other symptoms includes severe headache,vommitting and seisures.
ON EXAMINATIONCushings response;raised BP,bradycardia and bradypnoea.Scalp lacerations may be presentDilated slugish pupil at the ipsilateral or bilateral may suggest compression of CN 3 from raised ICP.Hemiplegia contralateral to the injury may be present.Classical triad of herniation are coma,fixed and dilated pupil and decerebrate posture.
Diffrerences between the twoEpidural Hematoma subdural hematoma
Potential space between -between the dura mater and the the dura and the inner table arachnoid mater of the skull
Cant cross sutures -can cross suture lines-
-Lenticular or biconvex shape -crescent shape
Lucid interval followed by -Gradualy increasing headachethen unconsciousness confusionloss or unconsciousness
DIAGNOSTIC IMAGINGNON CONTRAST CT SCAN. -IN EPIDURAL HEMATOMA;shows both skull fracture and the hematoma in the epidural space. -epidural hematoma appears as a hyperdense biconvex or lenticular-shaped mass situated between the brain and the skull.
CT FINDINGSNoncontrast head CT scan (imaging study of choice for acute SDH) The SDH appears as a hyperdense (white) crescentic mass along the inner table of the skull, most commonly over the cerebral convexity in the parietal region. The second most common area is above the tentorium cerebelliContrast-enhanced CT or MRI is widely recommended for imaging 48-72 hours after head injury because the lesion becomes isodense in the subacute phaseIn the chronic phase, the lesion becomes hypodense and is easy to appreciate on a noncontrast head CT scan
Acute sub dural haematoma with midline shift
subacute sub dural hematoma
MRI is superior for demonstrating the size of an acute SDH and its effect on the brain, however noncontrast head CT is the primary means of making a diagnosis and suffice for immediate management purposes
TREATMENTMEDICAL;Anti imflammatory such as use of steroid to modulate imflammation at the post traumatic period.Seisure prophylasisMedication to lower intracranial pressure eg mannitol,glycerol and hypertonic saline.
SUGERY;most for epidural hematoma -indications;Hematoma of greater than 1cm in its thickest diameter.Deterioriation in brain function.Severe headache.Midline shift of greater than or equal to 5mm.In a comatose pxts who do not met the above criterial and have; -GCS score decrease by 2 or more pts from initial value at presentation. - pxts who have dilated and fixed pupil -ICP greater than 20mmHg this surgery simply implies making a burr hole on the afted area of the skull.
PROGNOSISPrognosis is good for epidura hematoma with hx of lucid interval,otherwise,a marker of poor prognosis.For subdural hematoma,prognosis is good for the chronic form but poor for the acute subdural hematoma.acute subdural hematoma has a high mortality rate even more than the epidural hematoma.