NeuroradiologyNeuroradiologyTraumatic Traumatic

HemorrhageHemorrhageBy: Luke Aldo, MSIVBy: Luke Aldo, MSIV

LECOMLECOMErie, PennsylvaniaErie, Pennsylvania

Layers of the Layers of the MeningesMeninges

Epidural HematomaEpidural Hematoma

• Accumulation of blood in the Accumulation of blood in the potential space between dura mater potential space between dura mater and boneand bone

• EDH is considered to be the most EDH is considered to be the most serious complication of head injury, serious complication of head injury, requiring immediate diagnosis and requiring immediate diagnosis and surgical intervention (mortality rate surgical intervention (mortality rate associated with epidural hematoma associated with epidural hematoma has been estimated to be 5-50%)has been estimated to be 5-50%)

PathophysiologyPathophysiology

• Usually results from a brief linear contact Usually results from a brief linear contact force to the calvaria that causes separation of force to the calvaria that causes separation of the periosteal dura from bone and disruption the periosteal dura from bone and disruption of interposed vessels due to shearing stress of interposed vessels due to shearing stress

• Skull fractures occur in 85-95% of adult cases Skull fractures occur in 85-95% of adult cases • Extension of the hematoma usually is limited Extension of the hematoma usually is limited

by suture lines owing to the tight attachment by suture lines owing to the tight attachment of the dura at these locations.of the dura at these locations.

• The The temporoparietaltemporoparietal region and the region and the middle middle meningeal arterymeningeal artery are involved most are involved most commonly (66%) commonly (66%)

FrequencyFrequency

• Epidural hematoma complicates 2% of cases of Epidural hematoma complicates 2% of cases of head trauma (approximately 40,000 cases per head trauma (approximately 40,000 cases per year)year)

• Alcohol and other forms of intoxication have been Alcohol and other forms of intoxication have been associated with a higher incidence of epidural associated with a higher incidence of epidural hematomahematoma

• SexSex– more frequent in men, with a male-to-female ratio of 4:1more frequent in men, with a male-to-female ratio of 4:1

• AgeAge – rare in individuals younger than 2 yearsrare in individuals younger than 2 years– rare in individuals older than 60 years because the dura rare in individuals older than 60 years because the dura

is tightly adherent to the calvariais tightly adherent to the calvaria

HistoryHistory

• Head traumaHead trauma• Lucid intervalLucid interval between the initial loss of between the initial loss of

consciousness at the time of impact and a consciousness at the time of impact and a delayed decline in mental status (10-33% delayed decline in mental status (10-33% of cases)of cases)

• HeadacheHeadache• Nausea/vomitingNausea/vomiting• SeizuresSeizures• Focal neurological deficits (eg, visual field Focal neurological deficits (eg, visual field

cuts, aphasia, weakness, numbness)cuts, aphasia, weakness, numbness)

Diagnostic ImagingDiagnostic Imaging

• Noncontrast CT scanningNoncontrast CT scanning of the head of the head (imaging study of choice for intracranial (imaging study of choice for intracranial EDH) not only visualizes skull fractures, but EDH) not only visualizes skull fractures, but also directly images an epidural hematomaalso directly images an epidural hematoma

• It appears as a It appears as a hyperdensehyperdense biconvex or biconvex or lenticular-shapedlenticular-shaped mass situated between mass situated between the brain and the skull, though regions of the brain and the skull, though regions of hypodensity may be seen with serum or hypodensity may be seen with serum or fresh bloodfresh blood

• MRIMRI also demonstrates the evolution of an also demonstrates the evolution of an epidural hematoma, though this imaging epidural hematoma, though this imaging modality may not be appropriate for modality may not be appropriate for patients in unstable conditionpatients in unstable condition

Subdural HematomaSubdural Hematoma• Rapidly clotting blood collection below the Rapidly clotting blood collection below the

inner layer of the dura but external to the inner layer of the dura but external to the brain and arachnoid membranebrain and arachnoid membrane

• Typically, low-pressure venous bleeding of Typically, low-pressure venous bleeding of bridging veinsbridging veins (between the cortex and (between the cortex and venous sinuses) dissects the arachnoid away venous sinuses) dissects the arachnoid away from the dura and layers out along the from the dura and layers out along the cerebral convexitycerebral convexity

• It conforms to the shape of the brain and the It conforms to the shape of the brain and the cranial vault, exhibiting cranial vault, exhibiting concave inner concave inner margins and convex outer margins (crescent margins and convex outer margins (crescent shape)shape)

• Frequency is related directly to the incidence Frequency is related directly to the incidence of blunt head trauma of blunt head trauma

• It’s the most common type of intracranial It’s the most common type of intracranial mass lesion, occurring in about a third of mass lesion, occurring in about a third of those with severe head injuries those with severe head injuries

Mortality/AgeMortality/Age

• MortalityMortality– Simple SDH (no parenchymal injury) is associated with a Simple SDH (no parenchymal injury) is associated with a

mortality rate of about 20%mortality rate of about 20%– Complicated SDH (parenchymal injury) is associated with Complicated SDH (parenchymal injury) is associated with

a mortality rate of about 50% a mortality rate of about 50% • AgeAge

– It’s associated with age factors related to the risk of blunt It’s associated with age factors related to the risk of blunt head traumahead trauma

– More common in people older than 60 years (bridging More common in people older than 60 years (bridging veins are more easily damaged/falls are more common)veins are more easily damaged/falls are more common)

– Bilateral SDHs are more common in infants since Bilateral SDHs are more common in infants since adhesions existing in the subdural space are absent at adhesions existing in the subdural space are absent at birthbirth

– Interhemispheric SDHs are often associate with child Interhemispheric SDHs are often associate with child abuseabuse

HistoryHistory

• Usually involves moderately severe to severe Usually involves moderately severe to severe blunt blunt head traumahead trauma

• Acute deceleration injury from a fall or motor Acute deceleration injury from a fall or motor vehicle accident, but rarely associated with skull vehicle accident, but rarely associated with skull fracturefracture

• Generally Generally loss of consciousnessloss of consciousness• Any degree or type of coagulopathy should Any degree or type of coagulopathy should

heighten suspicion of SDHheighten suspicion of SDH• Commonly seen in alcoholics because they’re Commonly seen in alcoholics because they’re

prone to thrombocytopenia, prolonged bleeding prone to thrombocytopenia, prolonged bleeding times, and blunt head traumatimes, and blunt head trauma

• Patients on anticoagulants can develop SDH with Patients on anticoagulants can develop SDH with minimal trauma and warrant a lowered threshold minimal trauma and warrant a lowered threshold for obtaining a head CT scan for obtaining a head CT scan

Diagnostic ImagingDiagnostic Imaging• MRI is superior for demonstrating the size of an acute MRI is superior for demonstrating the size of an acute

SDH and its effect on the brain, however noncontrast SDH and its effect on the brain, however noncontrast head CT is the primary means of making a diagnosis head CT is the primary means of making a diagnosis and suffice for immediate management purposesand suffice for immediate management purposes

• Noncontrast head CT scanNoncontrast head CT scan (imaging study of choice (imaging study of choice for acute SDH) for acute SDH) – The SDH appears as a The SDH appears as a hyperdensehyperdense (white) (white) crescentic masscrescentic mass

along the inner table of the skull, most commonly over the along the inner table of the skull, most commonly over the cerebral convexity in the parietal region. The second most cerebral convexity in the parietal region. The second most common area is above the tentorium cerebellicommon area is above the tentorium cerebelli

• Contrast-enhanced CT or MRI is widely recommended Contrast-enhanced CT or MRI is widely recommended for imaging 48-72 hours after head injury because for imaging 48-72 hours after head injury because the lesion becomes isodense in the subacute phasethe lesion becomes isodense in the subacute phase

• In the chronic phase, the lesion becomes hypodense In the chronic phase, the lesion becomes hypodense and is easy to appreciate on a noncontrast head CT and is easy to appreciate on a noncontrast head CT scanscan

SummarySummary• Epidural HematomaEpidural Hematoma

– Potential space Potential space between the dura in the between the dura in the inner table of the skullinner table of the skull

– Can’t cross suturesCan’t cross sutures– Skull fractures in Skull fractures in

temporoparietal regiontemporoparietal region– Middle meningeal Middle meningeal

arteryartery– Lenticular or biconvex Lenticular or biconvex

shapeshape– Lucid intervalLucid interval– Common in alcoholicsCommon in alcoholics– Medical emergencyMedical emergency– CT without contrastCT without contrast– Evacuate via burr holesEvacuate via burr holes

• Subdural HematomaSubdural Hematoma– Between the dura mater Between the dura mater

and the arachnoid materand the arachnoid mater– Can cross suturesCan cross sutures– Cortical bridging veinsCortical bridging veins– Crescent shapeCrescent shape– Loss of consciousnessLoss of consciousness– Common in elderlyCommon in elderly– Common in alcoholicsCommon in alcoholics– Medical emergencyMedical emergency– CT without contrastCT without contrast– Evacuate via burr holesEvacuate via burr holes

BibliographyBibliography

• Abramson, Nina, MD. Subdural Hematoma. Abramson, Nina, MD. Subdural Hematoma. Brigham Radiology: 1994 Nov.Brigham Radiology: 1994 Nov.

• Azmoun, Leyla, MD. Epidural Hematoma. Azmoun, Leyla, MD. Epidural Hematoma. Brigham Radiology: 1995 Nov.Brigham Radiology: 1995 Nov.

• Liebeskine, David, MD. Epidural Hematoma. Liebeskine, David, MD. Epidural Hematoma. Emedicine.com: 2006 Apr; 1-10.Emedicine.com: 2006 Apr; 1-10.

• Scaletta, Tom, MD. Subdural Hematoma. Scaletta, Tom, MD. Subdural Hematoma. Emedicine.com: 2006 May; 1-10.Emedicine.com: 2006 May; 1-10.