Clinical Diagnosis of Vertebrobasilar Insufficiency: Resident s Case Problem

Transcription

1 Clinical Diagnosis of Vertebrobasilar Insufficiency: Resident s Case Problem Skulpan Asavasopon, MPT, OCS 1 John Jankoski, MPT, NCS, OCS 1 Joseph J. Godges, DPT, MA, OCS 2 Journal of Orthopaedic & Sports Physical Therapy Study Design: Resident s case problem. Background: Vertigo and visual disturbances are common symptoms associated with vertebrobasilar insufficiency (VBI), but the physical examination procedures to verify the existence of VBI have not been validated in the literature. The objective of this resident s case problem is to demonstrate how a patient s complaint of vertigo and visual disturbances, combined with positive clinical examination findings, can be a potential medical screening tool for VBI. Diagnosis: The patient in this report was initially referred to physical therapy for neck pain. However, the patient s chief concerns identified during the history were (1) vertigo, (2) visual disturbances, (3) headache, and (4) right shoulder region pain. Clinical VBI tests were performed, whereby the patient s vertigo and visual disturbances were reproduced with cervical spine extension. The patient was sent back to the referring physician to be evaluated for possible VBI. Diagnostic imaging tests were ordered. Carotid ultrasound revealed 80% to 90% stenosis in the proximal left internal carotid artery, and magnetic resonance angiography of the extracerebral vessels showed greater than 90% stenosis of the left internal carotid artery. Discussion: VBI may be present in patients with subjective reports of vertigo and visual disturbances that are reproduced with VBI physical examination procedures. J Orthop Sports Phys Ther 2005;35: Key Words: cervical spine, direct access, neck, primary care, vertebral artery Screening patients for potentially serious medical conditions is one of the most important components of a physical therapist s examination. It should not be assumed that a patient has undergone adequate medical screening, despite referral from other health care providers. Patients who present with neck pain, vertigo, and associated visual disturbances can be a challenging evaluation for a physical therapist because of the wide array of peripheral and central causes. 32,33,34 Differential diagnosis of these symptoms may include, but not be limited to, cervicogenic dizziness, benign paroxysmal positional vertigo, perilymphatic fistula, vestibular neuritis, labyrinthitis, hyperventilation, ototoxicity, Meniere s disease, orthostatic hypotension, and vertebrobasilar insufficiency (VBI). 32,33,34,37 Screening patients for cerebral ischemia, specifically VBI, as the primary cause of their symptoms remains a difficult clinical decision for physical therapists, because evidence-based guidelines for evaluating patients with 1 Clinical Faculty, Kaiser Permanente Southern California, Orthopaedic Physical Therapy Residency, Los Angeles, CA. 2 Coordinator, Kaiser Permanente Southern California, Clinical Residency and Fellowship Programs, Los Angeles, CA. Address correspondence to Skulpan Asavasopon, Kaiser Permanente Medical Center, 1526 North Edgemont Street, 4th Floor, Los Angeles, CA Skulpan.X.Asavasopon@kp.org vertigo and visual disturbances stemming from vascular causes is scarce. 16 The vertebral and basilar arteries supply blood to the pons, medulla, cerebellum, mesencephalon, thalamus, occipital lobes, and the central and peripheral vestibular system. 32,33 Disruption of normal blood flow in this area can produce any of the following symptoms: nausea, vertigo and syncope, and swallowing, speech, balance, auditory, and visual disturbances. 4,8,13 Inadequate perfusion to these areas of the brain can produce symptoms that usually have a rapid onset, vary in duration and frequency, and may occur in isolation or in some combination with one another. 10,11 Retrospective studies have reported that isolated episodes of vertigo (sudden onset, lasting minutes) can be a manifestation of cerebral ischemia, which can precede neurological symptoms by months. 10,11 In addition, visual disturbances are the most frequently reported symptom associated with vertigo caused by altered vertebral artery blood flow. 10,11,20,21 Unfortunately, VBI is not a benign condition and can eventually develop into a cerebral or brainstem ischemia, leading to severe morbidity or death. 10,11,13,20,26 Such evidence suggests it may be advisable for practitioners to appreciate that vertigo and visual changes associated with a patient s RESIDENT S CASE PROBLEM Journal of Orthopaedic & Sports Physical Therapy 645

2 neck pain may be potential indicators of VBI. However, the risk factors from a patient s history leading to suspicion of VBI have not been clearly identified. 7,13,17,19,31 In an effort to identify patients at risk for potential VBI, the Australian Physiotherapy Association (APA) in 1988 approved, 1 and has since revised, 24 a protocol for premanipulative testing of the cervical spine. The first aspect of the APA guidelines involves the subjective examination, in which a screening questionnaire is used to ascertain the presence of symptoms suggestive of VBI, such as vertigo, visual disturbances, syncope, disarthria, dysphagia, nausea, and headaches. 24 Although, in some instances, an acute onset of neck pain with or without headache can be the only manifestation of vertebrobasilar ischemia secondary to dissection of the vertebral artery. 19,31 In addition, the progression of neurological deficits associated with a vertebral or carotid artery ischemic event can take hours to weeks to appear. 17,19 The physical examination portion of VBI screening involves placing and holding the patient s head in several positions while monitoring for signs and symptoms of VBI. 23,25 If the subjective symptoms associated with VBI are provoked during or after the physical examination procedure, then physical therapy intervention and especially cervical spine manipulation are considered to be contraindicated. 1 However, 27 patients who developed cerebrovascular accidents following cervical spinal manipulative procedures showed no adverse response to VBI physical examination screening procedures before the manipulation. 13 Thus, while the use of screening protocols to assess VBI is advocated, 24 the sensitivity and specificity of these protocols are poor. 6,12,13,22,29 Assessment of the vertebrobasilar circulatory system and detection of occlusive disease in this area can be done with imaging studies. Ultrasound imaging is a valid diagnostic tool for detection of carotid stenosis. 34 Magnetic resonance angiography (MRA) has also been shown to have excellent sensitivity and specificity in picking up distal vertebral artery pathologies. 30 Nevertheless, evaluating the smaller branches of the vertebrobasilar circulatory system remains limited even with these imaging studies. 2 VBI is considered to be a rare but unpredictable condition that is not easily detected from data collected during the history and physical examination. 13 In the absence of clear evidence, a reasonable approach is to err on the side of avoiding harm. The purpose of this resident s case problem is to describe a case where the patient s history and physical examination suggested the presence of VBI, which was verified with diagnostic imaging. This case also serves to demonstrate appropriate measures taken for a patient with clinical findings consistent with VBI. DIAGNOSIS History The patient was a 63-year-old female referred to physical therapy by a family practice physician with a diagnosis of neck pain. The referral requested the physical therapist to treat this diagnosis by addressing stiffness and posture. During the patient s initial physical therapy visit, the following information was ascertained. The patient was currently employed as a property manager. The patient s past medical history was significant for hypertension, hyperlipidemia, and an uncomplicated surgery for a hiatal hernia. Approximately 1 month after the hiatal surgery she experienced intermittent vertigo, which occurred while lying down and sitting up in bed. After visiting a physician, she was diagnosed with benign paroxysmal positional vertigo (BPPV) and was treated with meclizine HCl. No prior history of trauma was reported. The patient reported that the vertigo had continued for another week and progressed to the point at which turning her head to the right caused intermittent vertigo as well. The physician requested an audiogram to assess for inner ear disorders. Lesions to the inner ear and vestibulocochlear nerve (cranial nerve VIII) can produce vertigo along with auditory symptoms such as hearing loss, tinnitus, sensation of pressure or fullness in the ear, or ear pain. 3,37 The patient was found to have asymmetrical hearing loss, but this loss was considered within normal limits. The result of the audiogram suggested that inner ear pathology was not the cause of the patient s symptoms. At a subsequent visit to a physician approximately 5 months after the initial onset of vertigo the patient complained of head stuffiness, tiredness, and neck pain, and it was at this time that a referral to physical therapy was made. The patient was seen in physical therapy 4 days later. During the subjective evaluation the patient identified the following 4 complaints: (1) intermittent vertigo lasting approximately 1 minute when turning the head to the right, (2) visual changes, described as black spots and distortion in her right eye, which could last up to a half hour and were reportedly becoming more frequent, (3) occasional right frontal-occipital area headaches, and (4) intermittent right shoulder area pain. Medications taken at this time were ibuprofen for headache, and triamterine, and conjugated estrogens for hypertension. Physical Examination The patient did not experience any of the aforementioned complaints while sitting upright during the subjective examination. Given the history of 646 J Orthop Sports Phys Ther Volume 35 Number 10 October 2005

3 FIGURE 1. Vertebrobasilar insufficiency screening procedure: end range cervical spine rotation with the patient supine. FIGURE 2. Vertebrobasilar insufficiency screening procedure: end range cervical spine extension with the patient supine. hypertension and complaints of headaches, the patient s blood pressure was measured and found to be 130/70. Active cervical range of motion was then assessed in a sitting position. Active cervical movements were observed to be within normal limits although specific goniometric measurements were not taken. The patient did report a pulling sensation on the right side of the neck at the end ranges of flexion, left rotation, and left side bending. Upon returning to a midline head position the pulling sensation had resolved for all the provocative movements. No other symptoms were reported with active cervical movements. An attempt was then made to detect the existence of VBI as a possible cause of the patient s vertigo, visual disturbances, and neck pain. The APA protocol for vertebral artery testing was used. 24 Initial testing using this protocol includes sustained end range rotation only, performed either in a supine or sitting position. In addition to cervical rotation, cervical extension can be added to the examination, with continual questioning about provocation of VBIrelated symptoms. In this patient, the physical examination procedures were performed with the patient in supine. The patient s head was supported by the therapist in a neutral position, and baseline resting symptoms of vertigo, visual disturbances, and headache were absent. The patient s head was passively turned into right rotation and held at end range for 30 seconds while the therapist monitored for symptoms of VBI (Figure 1). The patient s head was returned to neutral and remained in this position for 30 seconds to allow for a potential latent response. No symptoms were provoked, and nystagmus was not observed with this part of the protocol. The same procedure and results were found for left cervical rotation. When the patient s cervical spine was passively placed into extension, familiar symptoms of vertigo were produced and persisted as long as the head was maintained in extension (Figure 2). The patient s head was immediately repositioned into neutral and remained there (approximately 60 seconds) until the symptoms abated. When the cervical extension position was repeated, the patient reported having symptoms of visual disturbance, specifically seeing black spots. The patient s head was again repositioned to neutral and supported on the treatment table until the symptoms resolved. The remainder of the VBI screening protocol was not performed because of the possible nature of her problem, namely VBI. Once these symptoms resolved, the patient was assisted into an upright sitting position. A written copy of the physical therapy evaluation, including an assessment of possible vertebrobasilar insufficiency, was given to the patient for her previously scheduled medical appointment the following day. An attempt was also made to reach the physician by phone, but because he was unavailable, a detailed message was left on the physician s voic system to inform him of the significant findings. The patient was advised to delay further physical therapy services until receiving clearance by her physician. She was also advised to avoid any symptom-provoking positions of her neck and to monitor any changes or occurrences of any signs and symptoms she might encounter. Diagnostic Testing Shortly after a follow-up visit with her physician, cervical spine radiographs, carotid ultrasound, magnetic resonance angiogram (MRA), and magnetic resonance imaging (MRI) were ordered. Cervical spine radiographs and MRI yielded normal results. Carotid ultrasound revealed 80% to 90% stenosis in the proximal left internal carotid artery. MRA findings demonstrated greater than 90% stenosis of the same artery. A medical diagnosis of left carotid artery RESIDENT S CASE PROBLEM J Orthop Sports Phys Ther Volume 35 Number 10 October

4 stenosis was given, and a surgical decision to perform an endarterectomy was made to correct the occlusion. DISCUSSION This case report describes a 63-year-old woman with chief complaints of intermittent vertigo, visual disturbances, occasional headache, and right-sided neck and shoulder pain. Although the referral requested the physical therapist to treat her neck and shoulder symptoms by addressing stiffness and posture, evaluation of the symptoms of vertigo, visual disturbances, and headache carried a higher priority than evaluation of her neck and shoulder pain. To discern whether the patient s complaints were of vascular, vestibular, or cervicogenic origin a differential diagnostic approach was used. Recognizing that VBI can potentially cause all or some of the patient s symptoms, the clinician decided to screen for this medical condition. If the examination findings were not consistent with VBI, the clinician would have considered other vascular disorders that could cause vertigo and visual disturbances, such as postural hypotension or cardiac abnormalities. Reproducing the patient s vertigo and visual hallucination of black spots with the passive cervical extension portion of the physical examination suggests VBI as a possible cause of the patient s symtoms. 1,24 Although, symptoms of vertigo that are associated with head and neck movements can have a vestibular or cervicogenic origin as well. Among these differential diagnoses, VBI has the potential to develop into the most serious condition and therefore, should be evaluated first. An attempt to rule in or rule out VBI as the primary diagnosis was made by using a provocative screening exam despite the poor sensitivity and specificity associated with such tests. 6,12,13,22 Although, exposing the patient to this provocative physical examination procedure may have theoretically increased the potential for causing harm, this potential was minimized by closely monitoring the patient during the procedure. The potential benefits of eliciting positive results that expedited the patient s scheduling of the definitive diagnostic imaging were felt to outweigh the risks. Additionally, there is no evidence in the literature that the performance of such a test is harmful. Because the test was found to be positive, along with the patient s subjective examination findings, the decision was made to cease further physical therapy examination or intervention until the diagnosis of VBI could be ruled out with certainty. Had the test been negative, the authors would have considered cautiously examining the patient for musculoskeletal impairments in addition to referring the patient back to her physician. Failure to acknowledge the potential of false negative results when using VBI screening tests can lead to serious errors in the clinical decision-making process and unwanted complications. In a retrospective study of 64 patients who sustained complications related to cerebrovascular ischemia following cervical spine manipulation, Haldeman and associates 14 reported that none of the patients demonstrated adverse responses to screening tests believed to assess the patency of the vertebral artery. False-negative results were also reported in Cote et al s 6 study of vertebral artery blood flow with a extension-rotation screening test. Despite having VBI signs and symptoms when placed in an extended-rotated position, blood flow measures through the vertebral artery did not decrease, as measured with Doppler ultrasonography. 6 Two possible explanations for false-negative results during VBI screening tests are an inadequate occlusion of the vertebral artery and compensation by the collateral circulation. 36 If the vertebral artery is not completely occluded during the provocative test position (ie, passive cervical end range position is not achieved), then perfusion to cortical tissue is maintained. Collateral circulation through larger (internal and external carotids) or smaller (anterior and posterior communicating arteries) vessels can potentially provide adequate blood supply during the occlusion of the vertebral artery screening tests. Indeed, it has been suggested that VBI screening tests essentially evaluate the status of collateral circulation in the presence of a compromised vertebral artery. 29 The results of this case report support this premise. Our patient demonstrated greater than 90% stenosis of the left internal carotid artery during MRA. Perhaps this amount of occlusion in the left carotid artery was sufficient to prevent adequate perfusion of brain tissue while the patient s head was held at an endrange extension position. Confirmation of suspected cerebral ischemia was confirmed with carotid ultrasound and MRA. The importance of being able to convey our subjective and objective examination findings to the patient s physician was pivotal in facilitating the patient through the appropriate channels of care. It is important to be well versed in the clinical decision making process when patients present with vertigo or visual disturbances. Being knowledgeable about appropriate diagnostic studies and medical management (medications, surgical options) is essential for effective communication with other health care practitioners. Having a working knowledge base of the potential differential diagnoses is also essential in the delivery of standard care. Because vertigo and visual disturbance symptoms are also associated with vestibular, vascular, or cervicogenic disorders, the authors did attempt to collect data in the physical examination to at least rule in or rule out such disorders. Keeping in mind that the priority of vascular compromise was of primary concern, the authors felt the need to justify 648 J Orthop Sports Phys Ther Volume 35 Number 10 October 2005

5 that such symptoms of vertigo could potentially underlie and overlap objective data pointing to vestibular or cervical origins. It was recognized that vestibular disorders can stem from vascular compromise of the vertebrobasilar artery system. 11 Differentiating vascular compromise from benign paroxysmal positional vertigo (BPPV) was done by examining the characteristics of the patient s dizziness and other symptoms experienced during the vertebral artery test protocol. BPPV produces episodes of vertigo lasting less than 1 minute and is always induced by a specific head movement in relation to gravity (ie, lying down, looking up, or rolling onto one s side). 2,9 The patient described her episodes of vertigo as lasting about 1 minute, which were produced with cervical rotation alone. With BPPV the intensity of vertigo should gradually decrease when the patient is placed and held in a provocative position (Dix- Hallpike 9 ). Familiar symptoms of vertigo were produced but persistent when the patient was placed and held in a position of cervical extension. When this condition was repeated the patient experienced visual changes (specifically, the patient saw black spots). Although the presence of persistent vertigo and visual disturbances with sustained cervical extension are not definitive diagnostic signs, they did help to differentiate the possible cause of these symptoms as vascular compromise of the vertebrobasilar artery rather than BPPV or a cervicogenic problem. Visual disturbances are a reported neurological symptom associated with cerebrovascular ischemia following manipulation and the use of screening tests. 6,13,17 To help determine if isolated symptoms of vertigo (or posturally induced vertigo or balance disturbances) come from a lesion in the vestibular labyrinth rather than the brainstem/cerebellum area, clinicians can perform a vestibular evaluation, which includes caloric testing. Findings of vestibular decruitment and hyperactive caloric responses have been found to be sensitive ( 86%) to identify patients with impedance of blood flow to the vertebral artery or infarcts in the brainstem/cerebellum region. 21 The patient s medical history was significant for hyperlipidemia and hypertension. Hyperlipidemia and hypertension, along with heart disease, diabetes, carotid disease, smoking, and alcoholism, have been identified as risk factors in patients who experience symptoms associated with VBI. 21 Ohashi et al 27 studied relationships between abnormal blood pressure and symptoms of vertigo, dizziness, and disequilibrium. They found that peripheral vestibular disease was associated with hypotension, while central nervous system disorders were linked to hypertension. These 2 risk factors of hypertension and hyperlipidemia provide further support for an underlying vascular origin to the patient s symptoms. The authors hypothesized that the accompanying symptoms of headache and visual changes may be a result of vascular compromise as well. The authors emphasize that the patient would have been referred back to her physician regardless of the physical examination findings. The subjective history alone warranted increased attention for the potential of VBI, and the basis of the decision-making process was not based solely on the physical examination. CONCLUSION This resident s case problem presents a patient with complaints of vertigo, headache, and visual changes, which were consistent with VBI and later confirmed with carotid ultrasound and MRA. Episodic vertigo, especially when lasting more than 1 minute, occurring in isolation or with other associated VBI symptoms, should be considered a potential medicalscreening red flag, and should increase the index of suspicion of vascular insufficiency. Further research is needed to validate the use of VBI risk factors and physical examination procedures. Although the value of cervical extension and/or rotation screening procedures is questionable at the present time, positive findings with these tests should warrant caution. Patients who exhibit hallmark symptoms and signs of VBI should be referred to their physician for further diagnostic testing. ACKNOWLEDGMENTS The authors would like to acknowledge Chris Powers, PT, PhD for his contributions as a consultant and reviewer of this report. REFERENCES 1. Australian Physical Therapy Association. Clinical Guidelines for Pre-Manipulative Procedures of the Cervical Spine. Victoria, Australia: Australian Physical Therapy Association; Baloh RW. Clinical Neurophysiology of the Vestibular System. New York, NY: Oxford University Press; Baloh RW. Vertigo. Lancet. 1998;352: Bergan JJ, Levy JS, Trippel OH, Jurayj M. Vascular implications of vertigo. 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