Subdural Heamatoma

Question 1

Tell me about a subdural haematoma?

Answer 1

Collection of blood in the subdural space (a potential cavity between the dura and arachnoid mater, containing a small volume of serous fluid).

Question 2

Subdural space.

Answer 2

A potential cavity between the dura and arachnoid mater, containing a small volume of serous fluid.

Question 3

A cause and effect of subdural haematoma?

Answer 3

Usually resulting from tears in bridging veins which cross the subdural space, subdural hemorrhages may cause an increase in intracranial pressure (ICP), which can cause compression of and damage to delicate brain tissue.

Question 4

Signs & Symptoms?

Answer 4

May be immediate (acute) or may only show weeks after injury-
A history of recent head injury
Loss of consciousness or fluctuating levels of consciousness
Irritability
Seizures
Pain
Numbness
Headache (either constant or fluctuating)
Dizziness
Disorientation
Amnesia
Weakness or lethargy
Nausea or vomiting
Loss of appetite
Personality changes
Inability to speak or slurred speech
Ataxia, or difficulty walking
Loss of muscle control
Altered breathing patterns
Hearing loss or hearing ringing (tinnitus)
Blurred Vision
Deviated gaze, or abnormal movement of the eyes.

Question 5

Causes of SDH?

Answer 5

Subdural hematomas are most often caused by head injury, when rapidly changing velocities within the skull may stretch and tear small bridging veins.
Subdural hematoma is also commonly seen in the elderly and in alcoholics, who have evidence of cerebral atrophy. Cerebral atrophy increases the length the bridging veins have to traverse between the two meningeal layers, hence increasing the likelihood of shearing forces causing a tear.

Question 6

SDH Classification:

Answer 6

Acute: haematoma formation immediate
Sub-Acute: haematoma formation up to a week after injury
Chronic: haematoma formation two-three weeks after initial injury

Question 7

Risk factors of SDH?

Answer 7

65+ years
Previous history of brain surgery
Condition that makes you bleed easier (haemophilia)
Condition making you clot easier (thrombophilia)
Anticoags

Question 8

SDH Pathophysiology:

Answer 8

Collected blood from the subdural bleed may draw in water due to osmosis, causing it to expand, which may compress brain tissue and cause new bleeds by tearing other blood vessels. The collected blood may even develop its own membrane.

In some subdural bleeds, the arachnoid layer of the meninges is torn, and cerebrospinal fluid (CSF) and blood both expand in the intracranial space, increasing pressure.

Substances that cause vasoconstriction may be released from the collected material in a subdural hematoma, causing further ischemia under the site by restricting blood flow to the brain. When the brain is denied adequate blood flow, a biochemical cascade known as the ischemic cascade is unleashed, and may ultimately lead to brain cell death.

The body gradually reabsorbs the clot and replaces it with granulation tissue.