Carotid dissection associated with a handheld electric massager.

Abstract: The extracranial internal carotid artery (ICA) is susceptible to injury and dissection from external shear forces applied to the neck. Traumatic ICA dissection usually occurs in the setting of a sudden, high amplitude force causing significant distortion of surrounding soft tissues. Weaker, repetitive forces applied for longer intervals may also pose a risk for ICA dissection. A 38-year-old woman with no significant stroke risk factors had sudden onset of severe dysarthria and left hemiparesis several days after receiving an approximately 20-minute neck massage with a handheld electric massager. The moving elements consisted of two approximately 2-cm-diameter spheres that percuss the skin with low amplitude and high frequency. Magnetic resonance imaging and angiography demonstrated acute infarction in the right middle cerebral artery territory and dissection of the extracranial right ICA. Handheld electric massager units may cause ICA dissection and disabling stroke.

Key Words: dissection, internal carotid artery, massage, stroke, trauma

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Carotid and vertebral artery dissection account for 10% to 25% of strokes in otherwise low-risk patients younger than 45 years of age, (1) and outcome is generally worse with dissection occlusion than with atherosclerotic occlusion. (2) Not surprisingly, carotid dissection has been associated with many sources of nonpenetrating neck trauma, including strangling, seatbelts, whiplash, horse hoof, (3) and softballs. (4) Even presumably safe therapeutic interventions such as chiropractic manipulation have on rare occasions been associated with carotid or vertebral artery dissection, (5,6) and two cases of "sympathectomy" without stroke caused by internal carotid artery (ICA) dissection were attributed to neck massage with a shiatsu-type electric massage chair. (7) We report a case of ICA dissection and massive stroke associated with use of a handheld electric massager.

Case Report

A 38-year-old woman with a history significant only for migraine headaches and smoking 3 cigarettes per day for 15 years had a stereotypical unilateral right-sided headache with pain extending into the neck. Nonprescription analgesics provided little relief. After several days of continuing pain, she underwent an approximately 20-minute neck massage with a handheld electric massager consisting of two spherical massage elements about 2 cm in diameter that percuss the skin with low amplitude and high frequency (3,000 pulses/min). A friend without any medical training held the device at the area of greatest discomfort, described as being below the angle of the jaw and over the sternocleidomastoid muscle. Five days later, the patient awoke from a nap with dysarthria and severe left-sided hemiparesis. There was no evidence of Horner syndrome. Neuroimaging confirmed a large ischemic stroke in the right middle cerebral artery territory (Figure, left). Angiography demonstrated dissection of the right extracranial ICA (Figure, right). The left ICA was tortuous, but there was no evidence of fibromuscular dysplasia, vasculitis, or any other vascular abnormality. Echocardiography was unremarkable, and the erythrocyte sedimentation rate was 6 mm/h.

Discussion

Between the carotid bulb and base of the skull, the ICA is vulnerable to traumatic injury from force applied to the neck. In particular, shear forces can tear the intimal wall and precipitate dissection. (1) The shiatsu-type electric massage chair implicated in two prior cases of ICA dissection had a massage element fixed at the level of the neck that moved slowly but with considerable excursion to provide a deep, "pressure point" massage. (7) In the present case, two spherical elements pulsated at low amplitude and high frequency, with the device applied to a limited region of the neck corresponding well to the location of the right ICA. The 5-day interval between the massage and the onset of symptoms is not unusual in traumatic ICA dissection, (7) and there were no other risk factors for carotid injury. This case underscores the vulnerability of the extracranial carotid artery to traumatic injury from relatively small but repetitive and sustained shearing forces.

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Neck pain is common, as are many styles of electric massagers. A limited review of web sites selling handheld electric massagers revealed several photographs showing the devices being applied to the lateral neck region, although instruction manuals generally advise to keep the unit moving and caution against holding it in any one location for more than a few minutes. Unfortunately, these widely used devices are generally considered harmless, and such instructions are easily ignored. Perhaps a specific warning of the risk of stroke and injury to critical blood vessels would prompt more cautious use of electric massagers on the neck. Tragically, in this instance a device intended to relieve pain appears to have resulted in a disabling stroke in an otherwise healthy young woman.

Conclusion

A middle-aged woman with no significant stroke risk factors had an ICA dissection and large middle cerebral artery ischemic stroke in association with use of a handheld electric massager on her neck. The massager consisted of two spherical elements that percuss the skin with low amplitude but very high frequency. Used around the world for treatment of muscle "tension" and ache, electric massagers can have devastating neurologic consequences when used improperly on the neck.

Accepted June 22, 2004.

References

1. Schievink WI. Spontaneous dissection of the carotid and vertebral arteries. N Engl J Med 2001;344:898-906.

2. Milhaud D, de Freitas GR, van Melle G, et al. Occlusion due to carotid artery dissection: a more severe disease than previously suggested. Arch Neurol 2002;59:557-561.

3. Fletcher J, Davies PT, Lewis T, et al. Traumatic carotid and vertebral artery dissection in a professional jockey: a cautionary tale. Br J Sports Med 1995;29:143-144.

4. Shievink WI, Atkinson JL, Bartleson JD, et al. Traumatic internal carotid artery dissections caused by blunt softball injuries. Am J Emerg Med 1998;16:179-182.

5. Peters M, Bohl J, Thomke F, et al. Dissection of the internal carotid artery after chiropractic manipulation of the neck. Neurology 1995;45:2284-2286.

6. Ernst E. Life-threatening complications of spinal manipulation. Stroke 2001;32:809-810.

7. Elliott MA, Taylor LP. "Shiatsu sympathectomy": ICA dissection associated with a shiatsu massager. Neurology 2002;58:1302-1304.

RELATED ARTICLE: Key Points

* A 38-year-old woman with no significant stroke risk factors had sudden onset of severe dysarthria and left hemiparesis several days after receiving an approximately 20-minute neck massage with a handheld electric massager.

* The moving elements consisted of two approximately 2-cm-diameter spheres that percuss the skin with low amplitude and high frequency.

* Magnetic resonance imaging and angiography demonstrated acute infarction in the right middle cerebral artery territory and dissection of the extracranial right internal carotid artery.

* Handheld electric massager units may cause internal carotid artery dissection and disabling stroke.

Arthur C. Grant, MD, PHD, and Norman Wang, MD

From the Department of Neurology, University of California Irvine, Irvine, CA.

Reprint requests to Dr. Arthur Grant, UCI Medical Center Bldg 22C, Neurodiagnostics, Rte 13, 101 The City Drive, South Orange, CA 92868. E-mail: [e-mail]