Vertebral artery dissection with thrombosis causing neuralgic amyotrophy

Dr. Sivaranjani, Dr. Aslesha Sheth*

bDepartment of Emergency Medicine, Kauvery Hospital, Chennai India

*Correspondence: Email: draslesha@kauveryhospital.com

Case Presentation

A 34 years old female, with no known comorbidities presented to emergency room (ER) with complaints of:

  1. Sudden onset right upper limb weakness and inability to lift her right arm in the last three days
  2. History of right sided neck pain radiating to right shoulder and right arm for 10 days.
  3. No associated history of headache, vomiting, fever or trauma.
  4. On probing history further, it was noted that the patient had undergone first sitting of external massage for right shoulder pain, following which she had developed this weakness.
  5. She was on oral analgesics for symptomatic pain relief in the last three days, with no obvious reduction in pain intensity.

On examination in emergency

Table 1. Laboratory data on examination

PR 68/min,
BP 140/70mmhg,
SPO2 99% on room air,
CBG 111mg/dl,
RR 22/min
GCS 15/15

Detailed neurological examination

  1. Conscious, oriented
  2. Cranial nerves – NAD
  3. Both lower limb examination: Normal
  4. Tandem walking: Normal
  5. No cerebellar signs
  6. Rest of the neurological examinations were normal.

Table 2. Examination of upper limb

Right upper limb Left upper limb
Shoulder adduction 1/5 5/5
Shoulder abduction 1/5 5/5
Elbow flexion 2++/5 5/5
Wrist extension / flexion 5/5 5/5
Finger grip Normal Normal
Biceps reflex Depressed ++
Supinator reflex Depressed ++

Investigations done

After obtaining urgent neurologist opinion, patient was shifted for MRI brain with MRA and MRI cervical spine imaging.

MRI brain showed no evidence of acute infarct, hemorrhage, mass lesion, AVM/demyelination.

MRI cervical spine showed

  1. Mild spondylotic changes and posterior bulge of C3-C4, C4-C5, C5-C6 and C6-C7 intervertebral discs causing anterior thecal sac indentation with mild spinal canal compromise.
  2. No significant disc herniation/ nerve root compression/ discitis.

MRA showed

images-7-21
images-7-22
  1. Eccenteric intramural crescenteric T1 hyperintensity in the medial aspect of right vertebral artery (V2 segment) within the transverse foramen.
  2. Flap like structure in axial sections of the TOF MR angiogram.
  3. Luminal irregularity of right cervical vertebral artery (V2 segment).
  4. Suspicious internal hematoma in left V2 segment.
  5. Features suspicious of bilateral vertebral artery dissection with intramural hematoma.
images-7-23

CT neck angiogram done on next day showed

  1. Intimal flap in right cervical vertebral artery (V2 segment-C6 level) with transverse foramen in axial section, with focal dilation.
  2. Intimal flap in left cervical vertebral artery (V2 segment-C5 level) with transverse foramen in axial sections.
  3. The above features are consistent with bilateral vertebral artery dissection with intramural hematoma in left V2 segment.

Management

  1. Subcutaneous anticoagulants (Inj Clexane 0.6 ml S/C BD) for 2 days
  2. Advised to have limited physiotherapy or exercises in view of vertebral artery dissection.
  3. Patient was stable and then discharged on day 3 with oral anticoagulants for vertebral artery dissection and thrombus.

3. Discussion

  1. Vertebral artery dissection is spontaneous / traumatic, if left untreated or undetected, it can lead to significant infraction.
  2. History of delay between the onset of headache or posterior neck pain and subsequent neurological deficit should raise a suspicion of vertebral artery dissection.
  3. The root lesion in vertebral artery dissection is an intimal tear or an expanding hematoma in the vessel wall impinging over roots causing neurological deficits is a rare event.
  4. Flap in right cervical vertebral artery (V2 segment – C6 level) with transverse foramen in axial sections with focal dilation intimal flap in left cervical vertebral artery (V2 segment – C5 level) explains the patient’s right sided weakness of C5 – C6 myotomes.

4. Conclusion

  1. In most cases of vertebral artery dissection, excellent recovery is expected in 70 – 85% of patients. The rate of recurrent ischemic symptoms after dissection ranges from 0-13% in various studies.
  2. Arterial dissection is one of the many nonatherosclerotic vasculopathies that can cause brain ischaemia.
  3. Vertebral artery dissection is an uncommon disorder with a variable reported frequency
  4. Estimated annual incidence of approximately 1 – 1.5 cases per 10,000.
  5. Most cases of vertebral artery dissection are in the age group of 25 – 55 years, with a slight female preponderance.
  6. It is an important cause of posterior circulation ischaemia in young and middle-aged patients and accounts for nearly one-fifth of such cases, compared to 2.5% in older patients, although, the estimation of prevalence in elderly may be limited by co-existence of atherosclerosis as a confounding factor.

Dissection of an artery occurs, when blood under pressure finds its way into the vessel wall, along a line of cleavage which is usually near the endothelial surface. It either leads to luminal narrowing and/or occlusion, if the tear is subintimal, or formation of a pseudoaneurysm with potential risk of bleeding if the dissection is sub-adventitial.

Clinical symptomatology

  1. Nuchal and/or head pain, which was followed by symptoms suggestive of brainstem ischaemia, predominantly in the distribution of PICA territory and simulating a lateral medullary syndrome.
  2. Headache and neck pain are important warning symptoms of dissection with reported incidence of neck pain in half and headache in two-thirds of patients.
  3. Pain often precedes neurological features by hours, days or rarely weeks. It usually starts suddenly, is sharp in quality and majority of time on the side of arterial dissection.
  4. Pain is possibly caused by excitation of nociceptors in the vessel wall as extracranial cerebral arteries are known to be pain sensitive. However, exact mechanisms are still elusive.
  5. Lateral medullary ischaemia has been seen in most of the patients, although involvement of thalamus and cerebral/cerebellar hemisphere is seen frequently.
  6. Spinal cord infarction occurred in some patients, chiefly involving the cervical segment.
  7. Although uncommon, ischaemic myelopathy is being increasingly recognised as a complication of vertebral artery dissection.
  8. Both anterior and posterior spinal cord infarction have been described.
  9. Presentations with features of radiculopathy and focal motor deficits are also recognised.

Pathophysiological mechanisms

Underlying neural damage following an arterial dissection may be diverse. Stenosis or occlusion of the vertebral artery results in direct ischaemia of the brainstem or spinal cord.

  1. It may result from an intraluminal thrombus or by compression of the true lumen due to blood in the vessel wall.
  2. Progressive thrombosis or artery to artery embolization can cause distal ischaemia and branch artery occlusions.
  3. The process can obstruct distal basilar artery flow, compress cranial nerves or cause a subarachnoid haemorrhage.
  4. Spinal cord infarction is possibly related to hypoperfusion and watershed infarction, embolization or anterior spinal artery occlusion.

Vertebral artery dissection is routinely labelled ‘spontaneous’ or ‘traumatic’, with cases related to minor, non-penetrating neck trauma or torsion placed in between the two.

This classification is possibly ambiguous. A review of the literature on arterial dissections shower, then and in many so-called ‘spontaneous’ dissections, a history of abnormal neck movement, exercise or subtle trauma was present.

In a recent Canadian survey, 81% of dissections were associated with sudden neck movement ranging from therapeutic neck manipulation to a rigorous volleyball game, but some occurred during mild exertion such as lifting a pet dog or during a bout of coughing. Such causal potential trauma such as violent coughing, trampoline exercises, neck turning during a parade, basket-ball game, dancing, swimming and minor falls have immediately antecedated the initial symptoms of dissection. Chiropractic neck manoeuvres have been strongly associated with arterial dissection, with many cases reported in literature. Many patients had a definite temporal correlation between onset of symptoms and preceding neck movements in two and a minor fall in the third. However, since the onset of dissection may precede the clinical symptoms by several hours or days, it might loosen the association between the two.

The possible explanation of this causation is still not well defined. Authors have suggested the association of vertebral artery anomalies, tortousity, atherosclerosis as well as duration and force of the movement. It is also likely that inherent vessel wall abnormalities predispose to dissection upon subtle trauma.

Anatomically, the vertebral artery is divided into four arbitrary parts, designated V1 to V4.

  1. V1 extends from its origin to its entry into the foramen transversarium of the cervical vertebra.
  2. The entire length within the vertebral column is labelled as V2.
  3. V3 extends between its exit from the atlas upto its entry into the foramen magnum and
  4. The entire intracranial part is termed as V4.

Most of the traumatic dissections involve the atlanto occipital segment. It is likely that increased mobility, poor anchoring into the neighbouring tissue and increased mechanical torsion and stretch at C1-C2 region predispose to mechanical injury.

This also explains the increased incidence of dissection along this segment during chiropractic manoeuvres.

Reduction in vertebral artery blood flow during neck movements has been shown angiographically.

Hyperextension of the neck has been considered as an important precipitating factor for occlusion and dissection, especially in the presence of vascular abnormalities and bony changes.

Management of this condition

  1. Commonly involves anticoagulation with heparin followed by oral warfarin therapy, although no general agreement exists on the best management of this condition.
  2. Anticoagulation possibly aims at preventing thromboembolic complications, commonly seen to be associated with acute dissections. Some authors consider intradural extension of dissection as a contraindication for anticoagulation, because of risk of precipitating subarachnoid haemorrhage.
  3. Although, conservative management of dissection presenting as SAH has been practiced, yet rebleeding is common and potentially fatal, making surgical intervention imperative and crucial for survival.
  4. Endovascular treatment is usually practiced in centres equipped with intervention facilities.
  5. Surgical treatment of dissections, consisting of an in-situ interposition graft or extracranial – intracranial bypass, is indicated only for patients with persisting symptoms, refractory to maximal non-invasive management and who are not candidates for endovascular therapy.
  6. Continuation of anticoagulation therapy may be guided by MRA or ultrasound. Persisting irregularity or stenosis at 3rd month necessitates continuation of therapy for another 3 months. If features of stenosis persist beyond 6 months, it is advisable to shift the patient on antiplatelet agents.

Overall prognosis

  1. Of this clinical entity is good and encouraging, although factors like severity of ischaemic insult and extent of collateral flow do influence the overall outcome.
  2. Nearly 75% of patients make excellent recovery and overall death rate is less than 5%.
  3. Almost 90% of the stenosis resolve, two-thirds of the occlusions are recanalised and one-third of aneurysms reduce in size.
  4. Recovery is slow with associated spinal cord infarction.
  5. Extracranial dissections hold a better prognosis than the intracranial ones, because risk of aneurysmal bleeds is much lower.

References

  1. Schievink WI. Spontaneous dissection of the carotid and vertebral arteries. N Engl J Med. 2001;344:898-906.
  2. Blunt SB, Galton C. Cervical carotid or vertebral artery dissection – an underdiagnosed cause of stroke in young. BMJ 1997;314:243–245.
  3. Bogousslavsky J, Regli F. Ischaemic stroke in adults younger than 30 years of age. Neurol. 1987;44,479–482.
  4. Mokri B, Houser OW, Sandok PA et al. (1988). Spontaneous dissections of the vertebral arteries. Neurol. 1998;38:880–885.
  5. Brayde J.M., Penisson-Besnier I., Dubas F. et al. Extracranial and intracranial vertebrobasilar dissections: diagnosis and prognosis. J Neurol Neurosurg Psychiatry. 1997;63:46–51.
  6. Hinse P, Thie A, Lachenmayer L. Dissection of extracranial vertebral artery. Report of four cases and review of literature. J Neurol Neurosurg Psychiatry. 1991;54:863–869.

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