One of very interesting phenomena in Vascular Medicine, it shows the beauty of human body anatomy, every blood vessels should be in its place for the blood to flow in the right direction when its pumped by the heart. Any disturbance in this system can lead to many condition that vary in its severity. For example Artirovenous fistula (permanent connection between artery and vein) due to malformation or an injury can cause heart failure if not corrected properly.
I have seen some patient in Neuro clinic refereed as a stroke and some of them already in full stork prophylaxis medication for months.
People suffer from SSS usually miss diagnosed as they came with similar symptom as TIA (Transient Ischemic Attack), which is type of stroke. All symptoms are Neurological so General practitioner refer them to a Neurologist as suspected ischemic stroke or TIA.
How it presented (Symptoms)
As mentioned above it looks like a Neurological problem, to be specific like TIA, patient feel arm cramps and with excretion or exercise to this arm he\she can feel dizzy or syncope (fainting) or even have a difficulty in speech, patient also might complain of blurred vision or diplopia. These symptom often episodic, comes and goes and associated with exertion, exercise and anything require moving affected arm above head.
In a nutshell the hallmark for this syndrome that symptoms is associated with exercise and resolved rapidly with rest.
How it happen (Mechanism)
This is the best part. Subclavian artery deliver the blood from Aorta to the upper limbs, every one have 2 artery supply both forearms & arms. If there is any block before the origin of subclavian artery there will no direct flow to the arm, as a compensation affected arm will take the blood needed from Vertebral artery which is an artery that supply part of the brain, in rest or static condition nothing significant. But if demand increased more blood will flow from vertebral artery to feed your arm and forearm and this what cause all neurological symptoms.
To make it simple. Arm have a secret backdoor to brain blood and stealing from it when there is a need. It is like your son draining internet data from you by playing online games while you watching movie online. the glitch in your movie is not because internet connection is bad (Neurological problem), it is due to someone taking it or steal the flow (Upper limb steal blood from brain)
Take a look in left Subclavian artery of this man, it is occluded just before take off from Aorta, am sure that you noticed that it is also connected with Vertibral artery, the back door to brain blood.
This image might make more sens to you , look at the direction of blood flow in right side and compare it to the left side, it is obvious that there is something wrong in left, flow should go from 3 (Aorta) to 2 (Suclavian) but since it blocked or narrowed in point 5 , blood will reverse from 1 (Vertibral)
Still don't get it, just watch this video
Diagnosis & Treatment
Images study is the way to go if SSS suspected like Doppler Ultrasound which is image Technic to see the blood flow. CT with angiography would be accurate, other option rarely needed.
The treatment depend on what causes SSS(Atherosclerosis, cervical rip & Takayasu's arteritis), for instant atherosclerosis with mild symptom usually get medical treatment only as prophylaxis, It is clinical decision if surgical intervention is needed.
I hope you enjoyed this blog, just trying to make medicine easy for every one
Thank you for reading this blog
Links for more
uptodate.com/contents/subclavian-steal-syndrome (you need to rigester to see ths site)
emedicine.medscape.com
ncbi.nlm.nih.gov/pmc/articles
en.wikipedia.org/wiki/Subclavian_steal_syndrome
Senior medical resident at King Fahad specialist hospital
Bachelor in Medicine & surgery from University of El Imam El Mahdi
Diploma in Family medicine - Sudanese center for medical training ( SCMT )
Partial membership of royal collage of physician of United Kingdom (MRCPUK part1)
Partial membership of royal collage of physician of Ireland (MRCPI part1)
passed United States medical licencing examination - USMLE (passed step 2 CK)
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