Med 4 Flashcards
Subarachnoid space
- The space between Arachnoid matter and Pia mater
- Contains cerebrospinal fluid and major blood vessels
Subarachnoid hemorrhage
Bleeding in the basal cisterns
Bleeding in the subarachnoid spaces
How does the Subarachnoid hemorrhage appears on CT scan?
Appears as hyperdense area
Subarachnoid hemorrhage Appears as hyperdense area on CT scan:
Surrounding the brain stem
In the Sylvian (lateral) fissure
Anterior interhemispheric fissure
Basal cisterna:
Dilatation of the subarachnoid space
Found mainly around the brain stem
What are the four main basal cisterna?
1- Anterior: interpeduncular cistern
2- Posterior: quadrigeminal cistern
3- Lateral: two ambient cisterna
شكل الsubarachnoid haemorrhage
Diffuse sunburst appearance
Star sign = “death star”
Epidural hemorrhage
Banana-like hemorrhage
Concave along the convexity
Subdural hemorrhage
Lemon-like hemorrhage
Biconvex hemorrhage
Signs and symptoms of SAH
Headache
Nausea and vomiting
Drowsiness and loss of consciousness
Meningeal signs are positive
Headache
Headache is the main presenting symptom
Described as the worst headache in the entire life
Sudden onset thunderclap headache
Meningeal signs are positive:
Nuchal rigidity
Kernig’s sign
Brudzinski’s sign
Kernig sign:
Supine
Knee is flexed to 90 degrees
Hip is flexed to 90 degrees
Extension of the knee is painful or limited in extension
Brudzinski sign:
Passive flexion of neck
Patient: elicits hip and knee flexion
Causes of SAH
Traumatic
Spontaneous (non-traumatic)
the most common cause of SAH in general is
Traumatic
Spontaneous (non-traumatic)
Berry (saccular) aneurysm Arteriovenous malformation (AVM)
the most common cause of spontaneous SAH is
Berry (saccular) aneurysm
the 2nd most common cause of spontaneous SAH
Arteriovenous malformation (AVM)
The most common artery to be affected by berry (saccular) aneurysm
In general: anterior communicating artery
In the anterior circulation: anterior communicating artery
In the posterior circulation: tip of basilar artery
The most important factor in development and rupture of aneurysms and in stroke is
HTN
Types of aneurysms
Saccular aneurysm
Fusiform aneurysm
Saccular aneurysm:
associated with SAH
Fusiform aneurysm:
associated with dissection of ICA
Diagnosis of SAH
The golden standard investigation is non-contrast CT scan
If non-contrast CT is inconclusive then we do lumbar puncture (LP)
The golden standard investigation is non-contrast CT scan:
Can detect SAH in 95 – 96% in the first 48 hours
In 4-5% of cases, CT scan to be normal (doesn’t exclude SAH)
If non-contrast CT is inconclusive then we do lumbar puncture (LP):
To confirm the diagnosis of SAH if non-contrast CT is normal
What we will find when we do LP?
Blood is uniform in all tubes RBC count is also uniform Blood doesn’t clot on standing Pink or yellow supernatant Increased CSF pressure Increased CSF protein
Investigation to determine the cause of SAH
4 Vessel angiograms (conventional carotid and cerebral angiography)
MRA (Magnetic resonance angiography)
CTA (Computed Tomography Angiogram)
procedure of choice for evaluation of brain aneurysm
4 Vessel angiograms (conventional carotid and cerebral angiography
The main complications of SAH
- Re-bleeding
- Vasospasm
Management of aneurysm
Surgical clipping
Endovascular coiling
Surgical clipping:
The first option in treatment of aneurysm
A surgical clip can be applied to the neck of the
aneurysm
A surgical clip will separate the aneurysm from
the circulation
Endovascular coiling:
The second option in treatment of aneurysm
The sac of aneurysm is obliterated by insertion
of surgical coils
A surgical coil will separate the aneurysm from
the circulation
