А favorable outcome of comprehensive treatment of a patient with locked-in syndrome due to post-traumatic vertebra-basilar artery occlusion

Introduction

Vertebrobasilar artery occlusion is associated with unfavorable clinical outcomes. These lesions are responsible for approximately 4% of all ischemic strokes and the untreated mortality is estimated to be as high as 80 to 90% (Caplan L.R., 1996). The advent of high quality imaging, surgical and pharmacological recannalization techniques in the acute setting have resulted in decreased morbidity and mortality (Levy E.I. et al., 2001). However, persistent neurological deficits and long-term disability following successful rescue therapy are still common with up to 26% of patients experiencing severe neurological deficit at the time of discharge (Nadeau S. et al., 1992). One of the most devastating consequences of vertebrobasilar artery occlusion is locked-in syndrome. The classic locked-in syndrome, which is characterized by quadriplegia and anarthria with preserved consciousness and vertical eye movements, is of particular distress to both patients and physicians as the prognosis may be unclear and interventions may yield little benefit (Leon-­Carrion J. et al., 2002; Smith E., De­largy M., 2005).

This case describes a young female with locked-in syndrome following traumatic vertebrobasilar artery occlusion. A favorable outcome was achieved by surgical, pharmacological and complex, multi-disciplinary rehabilitation treatment.

Case study

A 34-year-old previously healthy female, who worked as a chiropractic assistant was climbing a 30-foot pole as part of a rock clim­bing simulation training (in the USA). She suddenly slipped and dropped 8 feet; her harness prevented her from hitting the ground but the sudden deceleration jerked her neck in the process. She immediately developed neck pain and headache but was able to walk away. Approximately 30 min later she experienced gradually worsening neck pain, dizziness, slurred speech and left sided weakness. She was stabilized by emergency medical personnel and transferred via flight ambulance to the local hospital. Her mental status and neurological condition declined and she was intubated and transferred to a tertiary care site for further evaluation and treatment.

Upon arrival it was found that she had developed locked-in syndrome and was able to communicate only by blinking her eyes. Cerebral angiogram revealed a left vertebral artery dissection and occlusion, as well as occlusion of the basilar artery. TPA (tissue plasminogen activator)-therapy was not initiated as it had gone >3 h from the event onset. Emergent consultation with a neurovascular surgeon did take place and the patient underwent stent-assisted angioplasty of the vertebrobasilar arteries to reperfuse the affected region, followed by antiplatelet/anticoagulation therapy with clopidogrel, acetylsalicylic acid and intravenous heparin (Fig. 1). During the post-surgical period, the patient did undergo serial neuro-imaging studies.

Figure 1

Sagittal CT image of the cervical region demonstrates a left vertebral artery stent (arrow) extending from the C_II to the C_V level

Two days following stenting there was no improvement in her neurological status. Computer tomography (CT) of the brain showed the development of a subtle low-density lesion in the Pons (Fig. 2).

Figure 2

Axial CT image through the Pons shows a zone of low attenuation (arrow) eccentric to the right within the Pons suspicious for a pontine infarct

Magnetic-resonance imaging (MRI) performed later that day revealed the signs of showed an acute pontine infarct (Fig. 3).

Figure 3

A

B

C

Axial FLAIR (A) and diffusion-weighted images with ADC map (B and C) show increased T_II signal and restricted diffusion within the Pons eccentric to the right consistent with an acute pontine infarct (arrows)

MRI of the cervical spine revealed a probable tear of the right posterior annulus at C_V–C_VI as well as a micro fracture at C_IV (Fig. 4).

Figure 4

Midline sagittal STIR image of the cervical spine demonstrates increased signal in the posterior annulus at C_V–C_VI (lower arrow) consistent with an annular tear with associated disc bulging. Marrow edema anteriorly in the C_IV vertebral body (higher arrow) could be related to a micro fracture

Throughout the patient’s hospitalization, she was closely followed by the rehabilitation team including physiotherapy, occupational and speech language therapy. Once medically stable, she underwent tracheotomy and PEG tube placement, then she was transferred to Canada for further investigation and treatment.

Approximately two weeks following the injury, she presented with incomplete quadriplegia. At this time a repeat MRI showed a late sub-acute pontine infarct that appeared to be approximately 10–14 days old (Fig. 5).

Figure 5

A

B

Axial T_II (А) and axial T_I-weighted (В) images demonstrate increased T_II and mildly decreased T_I signal (arrows) within the pontine infarct without evidence of diffusion restriction. This would be consistent with a late sub-acute time course

During her nine-week stay in the Canadian acute care hospital, rehabilitation treatment continued including passive range of motion, stretching, augmentative communication and visual exercises. After her tracheo­stomy tube was removed, she was able to communicate using a communication board and blinking to identify letters to spell words. Vocally her speech was very soft and barely audible. She was started on a soft diet.

She was next transferred to a stroke rehabilitation unit at that time was able to move her right arm with gravity elimination and communicate audibly in whispers. There was no voluntary movement of the left lower extre­mity outside of an extensor synergy with spasticity. She was non-ambulatory, and required assistance for transfers with a slide board due to poor sitting balance and trunk control. She also needed assistance with grooming, dres­sing, bathing and bed mobility. She stayed in the rehabilitation unit for nine weeks and underwent extensive task oriented, complex rehabilitation treatment including physio, occupational, speech language therapy, electromyo-stimulation, pain management, and psychological evaluation and therapy. While in the stroke rehabilitation unit, she made significant improvements to the point where she was able to transfer independently, ambulate independently with a single point cane indoors and a four-wheeled walker outdoors. She independently climbed the stairs with one rail. Mild motor deficits remained to the left upper and lower extremity and she required an ankle-foot orthosis (AFO) to control left foot drop.

Approximately 7 months following the patient’s acute vertebrobasilar dissection and occlusion, catheter cerebral angiography revealed patency of the left vertebral and basilar arteries (Fig. 6).

Figure 6

Cerebral angiography image from a left vertebral artery injection demonstrates a patent left vertebral artery and basilar artery with arrows denoting the left vertebrobasilar stents

Results

Fifteen months after discharge from physical rehabilitation, she ambulates independently without gait aids. Cognition and memory are intact. Speech is slightly dysarthric. Manual muscle test is 5/5 throughout all myotomes except left foot dorsiflexion and plantar flexion at 4/5. She has subtle difficulty with fine motor movement in the left upper extremity and mild dysmetria. She uses the AFO only for long distance ambulation. She lives independently in an apartment, conti­nues to be active, well motivated and plans to return to work in the near future.

Discussion

This case highlights a number of points in diagnosis and treatment of patient with posttraumatic vertebral artery dissection and consequent acute basilar artery occlusion. Dissection of the vertebral arteries has been increasingly recognized as a cause of ische­mic attacks and stroke (Lee V. et al., 2006). Overall, these conditions are estimated to account for only 3–4% of all ischemic strokes but they are an important factor in young people and account for approximately 20% of strokes in patients <45 years of age (Schievink W., 2001). Many dissections of the extra cranial vertebral artery are spontaneous though some are preceded by head and neck trauma (Caplan L.R. et al., 1985; Mas J.L. et al., 1987; Povlsen U.J. et al.,1987). Traumatic cervical vascular injuries occur most commonly after motor vehicle accidents or other impact mechanisms that cause rapid acceleration — deceleration mechanisms associated with cranio-cervical trauma (Kraus R. et al., 1999; Inamasu J., Guiot B., 2006). Also vertebrobasilar ischemia associated with abrupt head turning or chiropractic manipulation and arteriographic vertebral artery abnormalities at the C1 to C_II vertebral level have been reported (Caplan L.R. et al., 1985; Mas J.L. et al., 1987; Povlsen U.J. et al.,1987). Sherman et al. reviewed over 50 cases of vertebral basilar infarction associated with an abrupt change in head position (Teasell R.W., Marchuk Y., 1999).

Recent developments in non-invasive neurovascular imaging (magnetic-resonance angiography (MRA), CT, angiography etc.) have led to growing awareness of the problem and have revealed significant number of cervical vessel dissections in patients with blunt trauma (Redekop G.J., 2008). In patients with blunt trauma causing vascular injuries in the neck, manifestation of neurological symptoms may be delayed for hours and days. Although emerging high quality reliable, non-invasive technology has made diagnosis possible even in early stages, the highly variable course of vertebral artery dissection and possible devas­tating consequences of ischemia remains a major challenge for physicians.

Most patients with dissection of vertebral artery show signs of unilateral low brainstem ischemia only and have a relatively benign course and good recovery (Rae-Grant A.D. et al., 1989; Schievink W., 2001). However in patients with extension occlusion to the basilar artery, recovery is usually poor and mortality is high (Mokri B. et al., 1988; Leon-Carrion J. et al., 2002).

Vertebral artery dissection occurs when a tear in the endothelial surface of the artery allows blood to track into the wall of the artery leading to obstruction, ischemia, occlusion, and in some cases subarachnoid hemorrhage. Many cases that were originally described as due to thrombosis or obstruction may in fact have occurred secondary to a vertebral artery dissection (Teasell R.W., Marchuk Y., 1999).

The basilar artery is the most important artery in the posterior circulation. It is formed at the pontomedullary junction by the confluence of both vertebral arteries. Given the anatomy of the posterior circulation and the circle of Willis, the clinical manifestations depend on the location of the occlusion, the extent of thrombus and collateral flow. The actual frequency, incidence, and prevalence of basilar artery occlusion are not known. Basilar artery occlusion was reported in 2 cases per 1000 autopsy cases. However, in stroke registries, basilar artery thrombosis may explain as many as 27% of ischemic strokes occurring in the posterior circulation (Nadeau S. et al., 1992).

The prognosis of basilar artery occlusion is generally poor, although it depends on several factors that include decreased level of consciousness, dysarthria, pupillary abnormalities, bulbar symptoms, diplopia, bilateral cerebellar lesions, tetraplegia, and a cardiac cause of embolism. Up to 90% of patients with no such factors have a good functional outcome, while all patients with such factors either died or had severe disability (Caplan L.R., 1996; Leon-Carrion J. et al., 2002).

Dissection of cervical and intracranial arteries of the posterior circulation is characterized by the sudden onset of pain, frequently severe, localized in the cranio-cervical region, followed by an abrupt, delayed, or progressive onset of ischemic symptoms.

Selection of appropriate therapy for vertebral artery dissection is dependent upon the presenting symptoms, imaging and associated clinical factors. Arterial dissection can cause ischemic stroke either by thromboemboli forming at the site of injury or as a result of hemodynamic insufficiency due to severe stenosis or occlusion. In patients with symptoms and imaging consistent with this mecha­nism, and in whom there is no contraindication to antithrombotic therapy, anticoagulation or antiplatelet medication administering are the current standard of care for spontaneous or traumatic dissections (Teasell R.W., Mar­chuk Y., 1999).

In patients with severe occlusion unres­ponsive or with contraindications to traditional antiplatelet/anticoagulation therapy, intracranial angioplasty stenting may be an efficient intervention option (Ralea I.C. et al., 2008).

Recent advances in stent technology have allowed for a novel treatment of symptomatic, medically refractory, vertebrobasilar artery stenosis. Among 11 patients who were treated with stent assisted angioplasty of basilar or vertebral arteries 7 patients (64%) experienced symptoms resolution and have resumed their preprocedural activities of daily living (Levy E.I. et al., 2001).

In another study, authors concluded that intracranial stent placement appeared to be an efficacious additional or alternative procedure for the treatment of intracranial artery thrombosis in patients with neurological symptoms lasting >6 h (Amista P. et al., 2007).

Traumatic vertebrobasilar artery occlusion has been increasingly recognized as a common cause of stroke in young patients (Lam C.S., 1999). There is a growing body of evidence that early diagnosis and comprehensive differential treatment of this condition in early stage of ischemic neurologic event can lead to improved outcome. Identification and treatment of these injuries prior to the development of irreversible cerebral ischemia should be priority and demand a high degree of vigilance in patients with high-risk mechanism and injury patterns (Lam C.S., 1999; Redekop G.J., 2008).

Conclusions

Intracranial angioplasty stenting may be an efficient and life saving procedure in patients with vertebro basilar occlusion in addition to traditional pharmacological recanalization thrombolysis techniques. This case illustrated a perfect combination of early diagnostic and surgical intervention followed by complex, multifaceted intensive rehabilitation treatment that led to an excellent recovery and long term neurological outcome!

References

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Contacts:
Yuri Marchuk
1453 Prince Rd, Windsor,
ON N9C 3Z4, Ontario, Canada
Hotel Dieu Grace Hospital
E-mail: [email protected]