Medical Literature: Chiropractic Cervical Manipulation and Stroke

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(Miller and Burton 1974; Easton and Sherman 1977; Parkin, Wallis et al. 1978; Scoville and Bettis 1979; Krueger and Okazaki 1980; Schellhas, Latchaw et al. 1980; Sherman, Hart et al. 1981; Dahl, Bjark et al. 1982; Braun, Pinto et al. 1983; Braun, Pinto et al. 1983; Cellerier and Georget 1984; Marati-Vilalta 1984; Gittinger 1986; Carmody, Buckley et al. 1987; Chen and Chen 1987; Jentzen, Amatuzio et al. 1987; Phillips, Maloney et al. 1989; Frisoni and Anzola 1990; Frumkin and Baloh 1990; Braune, Munk et al. 1991; Friedman and Flanders 1992; Johnson, Whiting et al. 1993; Peters, Bohl et al. 1995; Alimi, Tonolli et al. 1996; Cote, Kreitz et al. 1996; Janati 1996; Donzis and Factor 1997; Mascalchi, Bianchi et al. 1997; Hufnagel, Hammers et al. 1999; Jones, Waggoner et al. 1999; Parenti, Orlandi et al. 1999; Devereaux 2000; Moser 2000; Saeed, Shuaib et al. 2000; Di Duro 2001; Haldeman, Carey et al. 2001; Kapral and Bondy 2001; Krakauer 2001; Norris and Beletsky 2001; Rosner 2001; Rothwell, Bondy et al. 2001; Siegel and Neiders 2001; Ellrodt 2002; Jeret and Bluth 2002; Jones 2002; Norris, Beletsky et al. 2002; Sedat, Dib et al. 2002; Turgut 2002; Di Duro 2003; Jeret 2003)

Alimi, Y., I. Tonolli, et al. (1996). "[Manipulations of cervical vertebrae and trauma of the vertebral artery. Report of two cases]." J Mal Vasc 21(5): 320-3.

Vertebrobasilar-distribution stroke is a rare but sometimes severe complication of chiropractic neck manipulation. We report two patients with dissections of the vertebral arteries authenticated two and six days after the cervical manipulation. In the first case, a Wallenberg's syndrome occurred due to a dissection of the right intracranial vertebral artery; the patient was treated with anticoagulant therapy but little improvement of the disorder was noted. The second patient had transitory neurologic manifestations which led to the discovery of an intimal tear of the ostium of the right vertebral artery with a floating clot. Further embolic complications were avoided by performing a venous bypass between the right common carotid and the vertebral artery at the base of the skull. Therapists should be aware of vertebrobasilar complications after spinal manipulations and should ask for early explorations (brain CT, cerebral angiography) to institute rapidly the most appropriate treatment.

Braun, I. F., R. S. Pinto, et al. (1983). "Brain stem infarction due to chiropractic manipulation of the cervical spine." South Med J 76(12): 1507-10.

A case of brain stem infarction after chiropractic manipulation of the cervical spine is presented. Proposed mechanisms and sites of possible arterial injury are discussed. A diagnosis of vertebral artery occlusion was made using conventional brachial angiography. Digital intravenous angiography, a relatively new and less invasive vascular imaging technique which was used as an adjunct for evaluating the remainder of the cervicocephalic vessels, documented the vertebral occlusion. Chiropractic manipulation, which is increasing in popularity, may be a cause of potentially devastating neurologic disease.

Braun, I. F., R. S. Pinto, et al. (1983). "Brain stem infarction due to chiropractic manipulation of the cervical spine." South Med J 76(9): 1199-201.

A case of brain stem infarction after chiropractic manipulation of the cervical spine is presented. Proposed mechanisms and sites of possible arterial injury are discussed. A diagnosis of vertebral artery occlusion was made using conventional brachial angiography. Digital intravenous angiography, a relatively new and less invasive vascular imaging technique which was used as an adjunct for evaluating the remainder of the cervicocephalic vessels, documented the vertebral occlusion. Chiropractic manipulation, which is increasing in popularity, may be a cause of potentially devastating neurologic disease.

Braune, H. J., M. H. Munk, et al. (1991). "[Cerebral infarct in the circulatory area of the arteria cerebri media following chiropractic therapy of the cervical spine]." Dtsch Med Wochenschr 116(27): 1047-50.

Chiropractic manipulation of the neck can occasionally cause severe neurological complications, as demonstrated by this case report. A 59-year-old man who had previously sustained a cardiac infarction and a femoral-popliteal bypass operation, suffered from painful spasms of the cervical muscles for several weeks. After chiropractic manipulation, a left, predominantly brachiofacial, hemiparesis developed during the subsequent 24 hours. Computed tomography demonstrated a recent infarction in the area supplied by the ascending central and parietal branches of the right medial cerebral artery. Doppler sonography revealed occlusion of the right internal carotid artery as the cause. Marked improvement followed hypervolaemic haemodilution daily with 500 ml hydroxyethyl starch and intensive physiotherapy. Blood flow through the internal carotid artery was restored after seven days (demonstrated by Doppler ultrasound). In the presence of arteriosclerotic vessel changes particular care should be exercised in deciding on and execution of chiropractic manipulations.

Carmody, E., P. Buckley, et al. (1987). "Basilar artery occlusion following chiropractic cervical manipulation." Ir Med J 80(9): 259-60.

Cellerier, P. and A. M. Georget (1984). "[Dissection of the vertebral arteries after manipulation of the cervical spine. Apropos of a case]." J Radiol 65(3): 191-6.

Dissecting aneurysm of the vertebral arteries following chiropractic manipulation of the spine. A thirty-five years old man had a Wallenberg Syndrome following chiropractic manipulation of the spine. Plain films and hypocycloidal tomography showed a foramen arcuale on both side. Arteriography lead to the diagnosis of dissecting aneurysm of the vertebral arteries. The favourable course point to the value of the posterior communicating arteries and the spinal artery as collateral pathways of the vertebro-basilar circulation.

Chen, T. W. and S. T. Chen (1987). "[Brainstem stroke induced by chiropractic neck manipulation--a case report]." Zhonghua Yi Xue Za Zhi (Taipei) 40(6): 557-62.

Cote, P., B. G. Kreitz, et al. (1996). "The validity of the extension-rotation test as a clinical screening procedure before neck manipulation: a secondary analysis." J Manipulative Physiol Ther 19(3): 159-64.

OBJECTIVE: To determine the validity of the neck extension-rotation test as a clinical screening procedure to detect decreased vertebrobasilar blood flow that might be associated with dizziness. DESIGN: Secondary analysis of a clinical screening test. METHODS: Twelve subjects with dizziness reproduced by the extension-rotation test and 30 healthy control subjects had Doppler ultrasonography examination of their vertebral arteries with the neck extended and rotated. Vascular impedance to blood flow was measured and the presence of signs and symptoms of vertebrobasilar ischemia was recorded. RESULTS: Cut-off points for validity estimates were derived through the percentile and Gaussian methods using impedance to blood flow as the standard. The sensitivity of the extension-rotation test for increased impedance to blood flow was 0%, regardless of the selected cut-off point. The specificity rates for the left vertebral artery were 71% and 67% for the percentile and Gaussian methods, respectively. The extension-rotation test was more specific on the right side, with a rate varying from 90% with the percentile method to 86% with the Gaussian technique. The positive predictive value of the test was 0% and its negative predictive value ranged from 63% to 97%. CONCLUSION: We were unable to demonstrate that the extension-rotation test is a valid clinical screening procedure to detect decreased blood flow in the vertebral artery. The value of this test for screening patients at risk of stroke after cervical manipulation is questionable.

Dahl, A., P. Bjark, et al. (1982). "[Cerebrovascular complications following manipulation of the neck]." Tidsskr Nor Laegeforen 102(3): 155-7.

Devereaux, M. W. (2000). "The neuro-ophthalmologic complications of cervical manipulation." J Neuroophthalmol 20(4): 236-9.

Cervical manipulation, specifically chiropractic manipulation, is an important cause of vertebrobasilar and occasionally carotid distribution strokes. Neuro-ophthalmologic findings are a common and at times relatively isolated feature of cervical manipulation-induced stroke. A case of chiropractic-induced occipital lobe infarction with homonymous hemianopsia is reported, and the literature regarding neuro-ophthalmologic findings is reviewed.

Di Duro, J. O. (2001). "Vertebral artery dissection and pontine infarct after chiropractic manipulation--a reply." Am J Emerg Med 19(7): 601-2.

Di Duro, J. O. (2003). "Stroke in a chiropractic patient population." Cerebrovasc Dis 15(1-2): 156.

Donzis, P. B. and J. S. Factor (1997). "Visual field loss resulting from cervical chiropractic manipulation." Am J Ophthalmol 123(6): 851-2.

PURPOSE: To report a complication of chiropractic cervical manipulation. METHOD: Case report. A healthy 39-year-old woman developed sudden left peripheral visual field loss after chiropractic neck manipulation. RESULTS: Visual field testing disclosed a left superior homonymous hemianopsia. A magnetic resonance imaging scan performed the day of the event disclosed acute infarction of the ventromedial aspect of the inferior right occipital lobe. CONCLUSION: Cerebral infarct may occur as a result of chiropractic neck manipulation.

Easton, J. D. and D. G. Sherman (1977). "Cervical manipulation and stroke." Stroke 8(5): 594-7.

Three patients are described who experienced vertebro-basilar distribution infarctions associated with neck manipulation. Two of the manipulations were chiropractic. Twenty-two previously reported cases are reviewed. Evidence favoring the use of anticoagulation in these patients is discussed along with the relative risk of such therapy.

Ellrodt, A. (2002). "Assessing the risks of cervical manipulation for neck pain." Cmaj 166(9): 1134-5.

Friedman, D. P. and A. E. Flanders (1992). "Unusual dissection of the proximal vertebral artery: description of three cases." AJNR Am J Neuroradiol 13(1): 283-6.

We report three cases that reveal an array of etiologic and radiologic findings associated with dissection of the proximal segment of the vertebral arteries. Regardless of etiology, the proximal segment may be the principal site of dissection in these vessels.

Frisoni, G. B. and G. P. Anzola (1990). "Neck manipulation and stroke." Neurology 40(12): 1910.

Frumkin, L. R. and R. W. Baloh (1990). "Wallenberg's syndrome following neck manipulation." Neurology 40(4): 611-5.

We describe 4 patients ages 28 to 41 with lateral medullary infarction (Wallenberg's syndrome) following chiropractic neck manipulation. In 3 patients, angiography documented dissection of the extracranial 3rd segment of the vertebral artery near the atlantoaxial joint. The onset of neurologic symptoms following manipulation varied from immediate to 4 days. All had good recovery with minor residual deficits. Although the association between chiropractic neck manipulation and vertebral-basilar artery distribution infarction is well known, we emphasize its occurrence in young healthy individuals without commonly regarded predisposing factors.

Gittinger, J. W., Jr. (1986). "Occipital infarction following chiropractic cervical manipulation." J Clin Neuroophthalmol 6(1): 11-3.

A 44-year-old man developed a complete homonymous hemianopia 2 days after undergoing chiropractic cervical manipulation. Thromboembolism from the vertebrobasilar circulation--as the consequence of trauma to the vertebral arteries by adjacent bones, muscles, and ligaments during twisting and extension of the neck--is the probable mechanism for occipital infarction and other strokes in this and previous cases. Other neuroophthalmic manifestations reported include Horner's syndrome and sixth nerve and gaze palsies.

Haldeman, S., P. Carey, et al. (2001). "Arterial dissections following cervical manipulation: the chiropractic experience." Cmaj 165(7): 905-6.

Hufnagel, A., A. Hammers, et al. (1999). "Stroke following chiropractic manipulation of the cervical spine." J Neurol 246(8): 683-8.

We analyzed the clinical course and neuroradiological findings of ten patients aged 27-46 years, with ischemic stroke secondary to vertebral artery dissection (VAD; n = 8) or internal carotid artery dissection (CAD; n = 2), all following chiropractic manipulation of the cervical spine. The following observations were made: (a) All patients had uneventful medical histories, no or only mild vascular risk factors, and no predisposing vascular lesions. (b) VAD was unilateral in five patients and bilateral in three. VAD was located close to the atlantoaxial joint in all eight patients and showed additional involvement of lower sections in six, as well as temporary occlusion of one vertebral artery in three. (c) Nine of ten patients had brain infarction documented by magnetic resonance imaging or computed tomography. (d) Onset of symptoms was immediately after the manipulation (n = 5) or within 2 days (n = 5). (e) Progression of neurological deficits occurred within the following hours to a maximum of 3 weeks. (f) Maximum neurological deficits were severe in nine of ten patients. (g) Outcome after 4 weeks-3 years included no or mild neurological deficits in five patients, marked deficits in three, persistent locked-in syndrome in one, and persistent vegetative state in one. (h) Informed consent was obtained in only one of ten patients. Thus, patients at risk for stroke after chiropractic manipulation may not be identified a priori. Neurological deficits may be severely disabling and are potentially life threatening.

Janati, A. (1996). "Carotid dissection." Neurology 47(2): 610-1.

Jentzen, J. M., J. Amatuzio, et al. (1987). "Complications of cervical manipulation: a case report of fatal brainstem infarct with review of the mechanisms and predisposing factors." J Forensic Sci 32(4): 1089-94.

Medical and surgical complications of chiropractic manipulation occur infrequently in relation to the number of procedures performed. These complications include intracranial hemorrhage, spinal cord injuries, trauma to the carotid and vertebral arteries, and vertebral-basilar distribution infarction. This is a report of a case of vertebrobasilar infarction following chiropractic manipulation leading to a comatose state within 1 h following the manipulative procedure. This case report should alert the forensic pathologist to the possibility of cervical manipulation as a cause of acute brainstem infarction, and the mechanism and the predisposing factors to injury should be reviewed. The importance of careful autopsy technique and use of postmortem arteriographic techniques are emphasized.

Jeret, J. S. (2003). "Stroke following Chiropractic Manipulation: A Genuine Risk. a response to the letter by j.o. di duro." Cerebrovasc Dis 15(1-2): 157.

Jeret, J. S. and M. Bluth (2002). "Stroke following chiropractic manipulation. Report of 3 cases and review of the literature." Cerebrovasc Dis 13(3): 210-3.

We present 3 cases of stroke due to arterial dissection following chiropractic manipulation: (1) a 31-year-old woman with left vertebral dissection developed a large cerebellar infarct, (2) a 64-year-old man developed a left parietal infarct due to left carotid dissection and (3) a 51-year-old man developed right Horner's syndrome, fluctuating dysarthria, left facial droop, and left arm weakness due to right carotid dissection. Imaging studies and the literature are reviewed.

Johnson, D. W., G. Whiting, et al. (1993). "Cervical self-manipulation and stroke." Med J Aust 158(4): 290.

Jones, J. (2002). "Neurologists warn about link between chiropractic, stroke." Cmaj 166(6): 794.

Jones, M. R., R. Waggoner, et al. (1999). "Cerebral polyopia with extrastriate quadrantanopia: report of a case with magnetic resonance documentation of V2/V3 cortical infarction." J Neuroophthalmol 19(1): 1-6.

This is a case report of the occurrence of cerebral diplopia with right-side superior homonymous quadrantanopia in a young woman after chiropractic neck manipulation. Magnetic resonance imaging confirmed an infarct in the left inferior V2/V3 (extrastriate) cortex. The characteristics of the diplopia are illustrated with the patient's drawings, and persisting abnormalities in perception are described in the area of the initial field defect after static (computed) visual field testing yielded normal results.

Kapral, M. K. and S. J. Bondy (2001). "Cervical manipulation and risk of stroke." Cmaj 165(7): 907-8.

Krakauer, J. (2001). "Literature alert." Curr Neurol Neurosci Rep 1(5): 408-9.

Krueger, B. R. and H. Okazaki (1980). "Vertebral-basilar distribution infarction following chiropractic cervical manipulation." Mayo Clin Proc 55(5): 322-32.

Previous case reports of vertebral-basilar system infarction following chiropractic cervical manipulation have emphasized the role of predisposing factors such as cervical spondylosis, atherosclerosis, and congenital asymmetry of the posterior circulation. Ten patients without prior neurologic symptoms had vertebral-basilar system infarction promptly after chiropractic maneuvers. One patient, who was free of clinical and radiographic evidence of predisposing factors, subsequently died. Autopsy studies revealed massive nonhemorrhagic brainstem infarction due to bilateral vertebral artery thrombosis. Nine patients survived with residual neurologic deficits due to lesions in various locations of the posterior circulation. No patient received anticoagulants. Previous case reports are summarized and the kinetic anatomy of the vertebral arteries is reviewed to clarify the potential mechanisms involved in the pathogenesis of this entity. Although a causal relationship may be difficult to establish in individual cases, cervical manipulation seems to be the major identifiable factor in the pathogenesis of stroke in some patients.

Marati-Vilalta, J. L. (1984). "[Risk factors in cerebrovascular pathology]." Med Clin (Barc) 82(9): 418-22.

Mascalchi, M., M. C. Bianchi, et al. (1997). "MRI and MR angiography of vertebral artery dissection." Neuroradiology 39(5): 329-40.

A review of 4,500 angiograms yielded 11 patients with dissection of the vertebral arteries who had MRI and (in 4 patients) MR angiography (MRA) in the acute phase of stroke. One patient with incidental discovery at arteriography of asymptomatic vertebral artery dissection and two patients with acute strokes with MRI and MRA findings consistent with vertebral artery dissection were included. Dissection occurred after neck trauma or chiropractic manipulation in 4 patients and was spontaneous in 10. Dissection involved the extracranial vertebral artery in 9 patients, the extra-intracranial junction in 1, and the intracranial artery in 4. MRI demonstrated infarcts in the brain stem, cerebellum, thalamus or temporo-occipital regions in 7 patients with extra- or extra-intracranial dissections and a solitary lateral medullary infarct in 4 patients (3 with intracranial and 1 with extra-intracranial dissection). In 2 patients no brain abnormality related to vertebral artery dissection was found and in one MRI did not show subarachnoid haemorrhage revealed by CT. Intramural dissecting haematoma appeared as crescentic or rounded high signal on T1-weighted images in 10 patients examined 3-20 days after the onset of symptoms. The abnormal vessel stood out in the low signal cerebrospinal fluid in intracranial dissections, whereas it was more difficult to detect in extracranial dissections because of the intermediate-to-high signal of the normal perivascular structures and slow flow proximal and distal to the dissection. In two patients examined within 36 h of the onset, mural thickening was of intermediate signal intensity on T1-weighted images and high signal on spin-density and T2-weighted images. MRA showed abrupt stenosis in 2 patients and disappearance of flow signal at and distal to the dissection in 5. Follow-up arteriography, MRI or MRA showed findings consistent with occlusion of the dissected vessel in 6 of 8 patients.

Miller, R. G. and R. Burton (1974). "Stroke following chiropractic manipulation of the spine." Jama 229(2): 189-90.

Moser, U. (2000). "[With head and neck pain rather not consult a chiropractic?]." MMW Fortschr Med 142(11): 14.

Norris, J. W. and V. Beletsky (2001). "Update from the Canadian Stroke Consortium." Cmaj 165(7): 887.

Norris, J. W., V. Beletsky, et al. (2002). ""Spontaneous" cervical arterial dissection." Stroke 33(8): 1945-6; author reply 1945-6.

Parenti, G., G. Orlandi, et al. (1999). "Vertebral and carotid artery dissection following chiropractic cervical manipulation." Neurosurg Rev 22(2-3): 127-9.

A 50-year-old woman presented a sudden left occipital headache and a posterior circulation stroke after cervical manipulation for neck pain. Magnetic resonance imaging documented a left intracranial vertebral artery occlusive dissection associated with an ipsilateral internal carotid artery dissection with vessel stenosis in its prepetrous tract. This is the first reported case showing an associate vertebral and carotid artery dissection following cervical manipulation. Carotid dissection was asymptomatic and, therefore, its incidence may be underestimated. We emphasize that cervical manipulation should be performed only in patients without predisposing factors for artery dissection and after an appropriate diagnosis of neck pain.

Parkin, P. J., W. E. Wallis, et al. (1978). "Vertebral artery occlusion following manipulation of the neck." N Z Med J 88(625): 441-3.

A 23-year-old woman developed brainstem infarction following cervical manipulation. Vertebral angiography showed total occlusion of the left vertebral artery with a thrombus extending into the basilar artery. The literature dealing with this rare but serious complication of cervical manipulation is reviewed.

Peters, M., J. Bohl, et al. (1995). "Dissection of the internal carotid artery after chiropractic manipulation of the neck." Neurology 45(12): 2284-6.

A 29-year-old woman died from a right hemispheric infarction caused by dissection and subsequent thrombosis of the internal carotid artery after chiropractic manipulations of the neck. Pathologic study of several arteries of muscular and elastic type revealed a mediolytic arteriopathy with widespread mucoid degeneration and cystic transformation of the vessel wall caused by segmental degeneration of smooth muscle cells of the tunica media. We hypothesize that mediolytic arteriopathy was a predisposing factor for the dissection of the internal carotid artery after chiropractic manipulations in our patient.

Phillips, S. J., W. J. Maloney, et al. (1989). "Pure motor stroke due to vertebral artery dissection." Can J Neurol Sci 16(3): 348-51.

A 39-year-old man presented with a pure motor stroke 9 days after cervical chiropractic manipulation. Computerised tomographic scanning showed a pontine infarct. Cerebral angiography showed changes consistent with the diagnosis of bilateral vertebral artery dissection. It is postulated that the infarct resulted from artery-to-artery embolism.

Rosner, A. L. (2001). "Chiropractic manipulation and stroke." Stroke 32(9): 2207-8.

Rothwell, D. M., S. J. Bondy, et al. (2001). "Chiropractic manipulation and stroke: a population-based case-control study." Stroke 32(5): 1054-60.

BACKGROUND AND PURPOSE: Several reports have linked chiropractic manipulation of the neck to dissection or occlusion of the vertebral artery. However, previous studies linking such strokes to neck manipulation consist primarily of uncontrolled case series. We designed a population-based nested case-control study to test the association. METHODS: Hospitalization records were used to identify vertebrobasilar accidents (VBAs) in Ontario, Canada, during 1993-1998. Each of 582 cases was age and sex matched to 4 controls from the Ontario population with no history of stroke at the event date. Public health insurance billing records were used to document use of chiropractic services before the event date. RESULTS: Results for those aged <45 years showed VBA cases to be 5 times more likely than controls to have visited a chiropractor within 1 week of the VBA (95% CI from bootstrapping, 1.32 to 43.87). Additionally, in the younger age group, cases were 5 times as likely to have had >/=3 visits with a cervical diagnosis in the month before the case's VBA date (95% CI from bootstrapping, 1.34 to 18.57). No significant associations were found for those aged >/=45 years. CONCLUSIONS:While our analysis is consistent with a positive association in young adults, potential sources of bias are also discussed. The rarity of VBAs makes this association difficult to study despite high volumes of chiropractic treatment. Because of the popularity of spinal manipulation, high-quality research on both its risks and benefits is recommended.

Saeed, A. B., A. Shuaib, et al. (2000). "Vertebral artery dissection: warning symptoms, clinical features and prognosis in 26 patients." Can J Neurol Sci 27(4): 292-6.

BACKGROUND AND OBJECTIVES: Internal carotid artery dissection has been extensively studied and well-described. Although there has been a recent increase in the number of reported cases of vertebral artery (VA) dissection, the clinical variety of presentation and the early warning symptoms have not been well-described before. Our objectives in this study include: (1) To determine the early symptoms and warning signs which may help the clinician in the early identification and treatment of patients with VA dissection. (2) To explore the variety of clinical presentation of VA dissection and its relation to prognosis. DESIGN AND SETTING: Retrospective analysis of hospital records in a tertiary academic centre for the period 1989-1999. RESULTS: Twenty-six patients were identified (13 men and 13 women). The mean age was 48. Possible precipitating factors were identified in 14 patients (53%). Sporting activity and chiropractic manipulations were the most common (15% and 11% respectively). Headache and/or neck pain was the prominent feature in 88% of patients and was a warning sign in 53%, preceding onset of stroke by up to 14 days. The most common clinical features included vertigo (57%), unilateral facial paresthesia (46%), cerebellar signs (33%), lateral medullary signs (26%) and visual field defects (15%). Bilateral VA dissection presented in six patients (24%). The most common region of dissection was the C1-C2 level (16 arteries, 51%). Intracranial VA dissection was found in eight arteries (25%). The majority of patients (83%) had favorable outcome. Poor prognosis was associated with (1) bilateral dissection; (2) intracranial VA dissection accompanied by subarachnoid hemorrhage. Only two patients reported stroke recurrence. CONCLUSIONS: Our findings show that VA dissection affects mainly middle age persons and involves both sexes equally. Headache and/or neck pain followed by vertigo or unilateral facial paresthesia is an important warning sign that may precede onset of stroke by several days. Although the majority of patients will have excellent prognosis, this was less likely in patients presenting with subarachnoid hemorrhage or bilateral VA dissection. Recurrence rate was low.

Schellhas, K. P., R. E. Latchaw, et al. (1980). "Vertebrobasilar injuries following cervical manipulation." Jama 244(13): 1450-3.

Four cases of brainstem stroke syndromes followed mechanical cervical manipulation; vascular injury was confirmed angiographically. A comprehensive review of the literature on vertebrobasilar injuries disclosed the various mechanisms of injury and pathogenesis of subsequent vascular complications following cervical manipulation. Emphasis is given to the potentially devastating neurological complications, particularly in view of the increasing utilization of chiropractic therapy.

Scoville, W. B. and D. B. Bettis (1979). "Motor tics of the head and neck: surgical approaches and their complications." Acta Neurochir (Wien) 48(1-2): 47-66.

Motor tics of the head and neck, especially hemifacial spasm and spastic torticollis, are the substance of this paper. Forty-six cases are presented, and surgical techniques are described. In hemifacial spasm the intracranial neurovascular lysis of Jannetta is a valid operation with the best results to date but has a 7 1/2% risk of unilateral deafness. The extracranial submastoid partial section of Scoville is completely safe and gives excellent results, but there is a probability of mild to moderate return of the spasm in one to two year's time. In spastic torticollis the accepted radical operation consists of bilateral anterior rhizotomy of the upper three roots plus bilateral spinal accessory nerve section in the neck. A tragic complication of this operation has recently been observed by ourselves, Sweet, and Hamlin. This complication is bilateral infarction of the medulla (bilateral Wallenberg's syndrome). This has also been reported as occurring following chiropractic manipulations. For this reason the writer does limited unilateral sectioning of the spinal accessory nerve in the neck and resection of the upper third of the sternomastoid muscle, as a first stage procedure, in those cases in which rotation of the neck is the principal symptom, before doing the radical operation. Safeguards to prevent this complication include preoperative vertebral arteriography and preservation of both motor and sensory radicular arteries under magnification and maintenance of adequate neck support during the early postoperative days.

Sedat, J., M. Dib, et al. (2002). "Stroke after chiropractic manipulation as a result of extracranial postero-inferior cerebellar artery dissection." J Manipulative Physiol Ther 25(9): 588-90.

OBJECTIVE: To describe a case of dissection of the postero-inferior cerebellar artery (PICA) after cervical manipulation. Clinical Features: After cervical manipulation, a 42-year-old woman had a cerebellar syndrome related to an infarct in the area supplied by the PICA, confirmed by computed tomography of the brain. Cerebral angiography showed a normal appearance of the vertebral artery, a cervical extradural origin of PICA, and a dissection of the latter at the C1-C2 level. Intervention and Outcome: Anticoagulant treatment with heparin was implemented. A positive outcome was achieved after 3 weeks. CONCLUSION: Anatomical variations of the vertebral arteries and their branches are not infrequent and may constitute a predisposing factor to complications after neck manipulation.

Sherman, D. G., R. G. Hart, et al. (1981). "Abrupt change in head position and cerebral infarction." Stroke 12(1): 2-6.

Eight patients are described who developed infarctions in the vertebral-basilar artery distribution following chiropractic neck manipulation or spontaneous head turning. The angiographic and autopsy findings indicate that injury to the intima of the vertebral artery at the atlantoaxial joint forms a nidus for thrombus formation which may propogate or embolize to involve other vessels in the vertebral-basilar system and result in progressive brainstem infarction. The role of anticoagulation in these patients is discussed.

Siegel, D. and T. Neiders (2001). "Vertebral artery dissection and pontine infarct after chiropractic manipulation." Am J Emerg Med 19(2): 171-2.

Turgut, M. (2002). "Ischemic stroke secondary to vertebral and cartid artery dissection following chiropractic manipulation of the cervical spine." Neurosurg Rev 25(4): 267.