Does thoracic outlet syndrome cause cerebrovascular hyperperfusion? - Diagnostic markers for occult craniovascular congestion, Larsen et al. 2019

[borko2100]

https://www.researchgate.net/public..._markers_for_occult_craniovascular_congestion

Abstract

Thoracic outlet syndrome (TOS) is known to be associated with diffuse craniological comorbidities (CCM), such as occipital headaches, migraines, vestibular dysfunction, tinnitus and fatigue. Conventionally, these problems have been suggested to be a manifestation of positional vertebrobasilar insufficiency.

Angiography tends to be normal in TOS sufferers, however, and doppler ultrasonography of the vertebral artery fails to demonstrate severe flow reduction. TOS is attributed to the brachial plexus and subclavian artery being compressed in the interscalene triangle, costoclavicular or subpectoral passages. The vertebral and carotid arteries arise from subclavian artery proximal to the sites of obstruction in TOS.

Numerous reports of resolved CCM post scalenectomy and first-rib resection, despite lacking vertebral artery impairment, have been documented. TOS CCM, moreover, share many of the symptoms seen in systemic and intracranial hypertension. Reports of subclavian thromboembolus migrating to the head have been documented in incidences of TOS, showing the potential for flow retrogradation.

We postulate that the blood prevented from entering the brachium due to distal subclavian compression, retrogrades to the brain via the carotid and vertebral arteries, resulting in craniovascular hyperperfusion and congestion.

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[borko2100]

https://www.researchgate.net/public..._markers_for_occult_craniovascular_congestion

mechanism:

We postulate that the compression imposed on the distal subclavian artery in TOS not only inhibits some blood from entering the brachium, but that the obstructed blood reverts toward the head, resulting in, to some extent, continuous TOS-induced cerebrovascular hyperperfusion (CVH). In this case, systemic blood pressures will generally be normal or may even be hypotensive. Cerebral MRI, venography, and angiographies will also appear normal, thus rendering this problem almost entirely occult, as there will be no conspicuous indicators of hypertension, despite the patient presenting with suggestive symptoms. Verily, the symptoms of TOS CVH are consistent with those of hypertension or even malign hypertension, but with normal systemic pressures

similarities to ME/CFS:

With regards to implications, little existing evidence forelies for moderate degrees of cerebrovascular hyperperfusion, as seen in TOS. However, its many potential symptoms are consistent with those of systemic and intracranial hypertensive states.

Headaches and migraines, chronic fatigue, and vestibular dysfunction are perhaps some of its most common sequelae. Tinnitus, both ordinary as well as pulsatile, is also common. Unilateral (or, rarely, bilateral), mild to moderate forms of hemifacial weakness or ptosis, dysarthria, aphasia, and amnesia, may also be seen, in many circumstances. Rarely, usually in incidences of cervical whiplash or concurrent [severe] anxiety disorder, sporadic syncope,34 narcolepsy and seizures35 may develop as well, as mentioned earlier. I

t is known that chronic hypertension may impair cerebral autoregulation.46,47 Continuous cerebrovascular hypertension may predispose the patient to aneurysmic development,48 and intima-media thickening through the processed named by Miller as lipohyalinosis, 49 which may result in unexpected strokes or hemorrhages. TOS symptoms are highly prevalent in migraineurs. This may explain why some migraineurs are at higher risk for both ischaemic as well as hemorrhagic strokes, 50,51,52,53,54,55 and also present with seemingly idiopathic hypertensive retinal signs.56,57,58 Saxton et al.27 documented a case where a patient with migraine since 4 childhood, whose symptoms exacerbated with neck extension and ipsilateral rotation and brachial elevation, and whose MRA demonstrated sole subclavian artery obstruction within the interscalene triangle, entirely resolved post scalenectomy.

Research has also suggested that chronic hyperperfusion may result in deterioration of the blood-brain barrier (BBB). Deliberate BBB breakdown in animal experiments have shown that secondary seizures, epilepsy and neuronal damage may occur.59,60,61 It may also cause cerebral swelling and demyelination, 48,62,63,64

Some authors have postulated that cerebral edema may be the underlying cause of pathologies such as multiple sclerosis,65,66 although this remains a controversial topic. Up to 69% of people living with multiple sclerosis also suffer from migraines.67 TOS CVH often causes pronounced fatigue, and is a common co-finding in patients with myalgic encephalomyelitis (ME) / chronic fatigue syndrome. We also believe that the compensatory cerebroarterial vasodilation that occurs in chronic CVH may play a role in postural orthostatic tachycardia syndrome, another common sub-component of ME.

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[ScottTriGuy]

Thanks for sharing @borko2100 -- I was diagnosed with TOS a few years ago and will bring this to my doctor's appointment this week.

 

[borko2100]

Thanks for sharing @borko2100 -- I was diagnosed with TOS a few years ago and will bring this to my doctor's appointment this week.

Glad to be able to help. I think the paper's theory is not that far fetched. After all if the blood cannot go to the arms it has to go somewhere, so if it goes to the brain instead, it might indeed cause some problems. Just my opinion as a layman, I hope some others with more expertise will chime in.

I also realized I might have this condition as well, considering I have had almost constant low grade pain / burning / warmth sensation in my hands since 2019. I also experience the majority of the cranial symptoms mentioned by the paper.

 

[Bowser]

Over the past year, I have had many consultations with the author of this paper who diagnosed me with TOS-CVH.

Subjectively, the diagnosis bears out in my personal experience. I always get much worse after common TOS triggers, such as washing my hair and doing any overhead work. And exertion of the scalenes using a targeted exercise increases my symptoms dramatically. I could literally feel the blood pulsing towards my head. My main symptoms are fatigue, head heaviness and head pressure.

I have put forth much effort in trying to fix this problem with conservative measures by trying to strengthen the super weak scalenes and other musculature in the neck. However this has proven difficult, painful and impossible. Thus, I have started to seriously consider a scalenectomy and first rib resection, the surgical option for TOS.