Dizziness: A Screening Examination and Differential Diagnostic Decision-Making Process for Physiotherapists

Transcription

1 Landel R. Dizziness: A Screening Examination and Differential Diagnostic Decision- Making Process for Physiotherapists. Physiotherapy Singapore 2002; 5 (3): Dizziness: A Screening Examination and Differential Diagnostic Decision-Making Process for Physiotherapists Dr. Rob Landel Introduction Complaints of dizziness in a patient are not uncommon. The prevalence of dizziness in the community ranges from 1.8% in young adults to more than 30% in the elderly (1). The physiotherapist, by virtue of the on-going nature of the typical physiotherapy (PT) course of care, often uncovers a complaint of dizziness in the course of providing treatment for another disorder. Once dizziness is reported, the physiotherapist must decide on the appropriate course of action. The purpose of this article is to present the possible causes for complaints of dizziness that a patient in a PT clinic might have, and offer a process for the physical therapist to determine the appropriate course of action. The focus of the discussion will be aimed at the physiotherapist who discovers a complaint of dizziness by a patient, which has not been previously investigated. There are many possible causes of dizziness, ranging from the benign to the potentially life-threatening. The objective of an examination is to identify serious pathology (e.g., central nervous system lesion, brainstem ischemia, and cardiac arrhythmia) (2) where a greater course of action may have to be taken. Fortunately, life-threatening causes of dizziness are rare (3, 4). The final diagnosis can be divided broadly into several useful categories (Table 1). These categories will be used in this article as part of the screening process by physiotherapists. Cases such as those presented in this article are examples in which the presenting signs and symptoms are clear, and the proper decision is obvious. In the real world, things are not often so clear. It should be emphasised that in the screening process proposed here, the presence of any doubt in the physiotherapist s mind as to the suitability of any patient for PT intervention should be a warning sign that a referral for further medical investigation or at least communication with the referring physician is required. Dr. Rob Landel, DPT, OCS is Associate Professor of Clinical Physical Therapy and co-director of Residency Programs at the Department of Biokinesiology and Physical Therapy, University of Southern California. Correspondence to: Dr Rob Landel, Department of Biokinesiology and Physical Therapy, University of Southern California, 1540 E. Alcazar St, CHP 155, Los Angeles, CA rlandel@usc.edu The Screening Process: Determining the Physiotherapist s Role Delitto and colleagues proposed a diagnostic process that physiotherapists could use in cases of acute low back pain (5). The first step in that process can be used for a wide variety of diagnoses and patient presentations, and is applicable to a patient complaining of dizziness. In this first step the physiotherapist must decide if physiotherapy is an appropriate management option for the patient. There are three possible outcomes from making this decision. The physiotherapist may: 1. recognise that PT is inappropriate and refer the patient to the appropriate provider; or 2. initiate a physical therapy plan of care with a consultation with other health care providers; or 3. initiate PT without a consultation. In the first case, the physiotherapist may decide that PT intervention should not be attempted, and that a referral to another health care provider is required. If a referral is required, the therapist must determine the severity of the condition and take appropriate action. Emergency referrals Table 1: Possible causes of dizziness Cardiovascular conditions Cerebrovascular conditions, including migraine Cardiac disease (arrhythmia, CHF) Vasovagal conditions Hypertension, postural hypotension Vertebrobasilar insufficiency (VBI) Infection (viral syndrome, otitis media, sinusitis) Adverse effects of drugs, including alcohol Psychiatric conditions Metabolic or endocrine conditions Anaemia Diabetes Neurologic conditions Central neurologic conditions Head injury Peripheral Vestibular Disease Labyrinthitis or vestibular neuronitis BPPV Other recurrent vestibulopathy Musculoskeletal conditions cervical spondylosis temporomandibular joint syndrome 46 Physiotherapy Singapore September 2002 Vol. 5 No. 3

2 may be necessary in some cases, whereas halting further PT intervention and contacting the referring physician by phone may be sufficient in others. Typically, those patients not amenable to PT will have diagnoses in the cardiovascular and infection categories (Table 1). Dizziness in the presence of cardiac arrhythmias, symptoms of brainstem ischaemia, and evolving central nervous system lesions require immediate referral to the appropriate physician, if not to the emergency department (4,6). Other serious illnesses, such as tumours, multiple sclerosis, and encephalitis are rare and dizziness is not typically the only symptom (7). Other diagnoses requiring referral, but not on an emergency basis, will likely be in the psychological, drug interaction, or metabolic and endocrine categories. In a prospective study designed to identify the causes of dizziness in older patients, 50 consecutive patients presenting to the general practitioner with dizziness were referred for further evaluation for cardiovascular and otolaryngologic diagnoses (8). In this population (over 60 years of age), 28% had a cardiovascular diagnosis, 18% had a peripheral vestibular disorder (benign paroxysmal positional vertigo (BPPV), vestibular neuronitis or labyrinthitis, and Meniere s disease), and 15% had a central neurological disorder. The latter category included diagnoses of severe cervical spondylosis, drop attacks, cerebrovascular disease, significant bilateral carotid stenosis (>70%), and basilar artery migraine. In 18% of the sample two or more diagnoses existed, and in 22% no attributable cause of the symptoms was identified. The authors went on to correlate the final diagnosis to the patient s presenting clinical characteristics, in an attempt to see if there was any predictive value. A cardiovascular diagnosis was likely if the symptoms of dizziness were: accompanied by syncope, or accompanied by pallor, or if the dizziness was described as light-headedness, or if the patient had to sit or lie down during the symptoms, or if the patient had other cardiovascular co-morbidities (angina, myocardial infarction, peripheral vascular disease, and sustained hypertension), or if the symptoms were brought on by prolonged standing. A peripheral vestibular disorder was predicted by a description of the symptoms as vertigo (an illusion of selfmovement or of the environment moving). Using these findings may prove useful when deciding how to manage the dizzy patient. Diagnoses that fall into the musculoskeletal condition category require special mention for physiotherapists, since many of the patients seen for PT are referred for treatment of such a condition. The therapist should be particularly alert whenever a history of neck pain precipitated by a traumatic event accompanies a complaint of dizziness. For example, a 62-year-old female is referred to PT for evaluation of her neck pain after suffering a whiplash injury. In the process of the examination, the patient reports complaints of dizziness that began since the injury. Further questioning reveals that the referring physician has not yet evaluated this complaint, and in fact the patient s doctor may not even be aware of it. The patient notices the dizziness most when turning her head or looking up, and this is confirmed with active range of motion testing. In addition, nystagmus is noted when these movements are held at the end of her available range of motion. In this case, further physical therapy examination should be deferred and no treatment should be initiated until vertebrobasilar artery insufficiency (VBI) has been ruled out. Since much has been made of the presence of VBI in patients being treated by physiotherapists, especially appropriate in light of the potential catastrophic consequences if left unrecognised and untreated, some mention of this particular condition is necessary. With most patients, obtaining a good history from the patient will allow the diagnosis to be made. When the chief complaint is dizziness, however, the history may not prove as helpful. This is because the complaints for vertebral artery insufficiency and vestibular disorders are so similar. The list of complaints for both can include dizziness, nausea and vomiting, neck pain, blurred vision, and frequent headaches. The differential diagnosis, therefore, must be made on something other than the chief complaint. How then should one proceed? It should be noted that the incidence of VBI in the general population is quite rare. Within the primary care setting, dizziness accounts for about 2% of all consultations (6). Of these patients, less than 1% are ultimately found to have a diagnosis of VBI (7), confirmed using either angiography or magnetic resonance angiography. Due to the potentially catastrophic consequences of true vertebral artery insufficiency and the prevalence of dizzy complaints in verified VBI (100% of patients with confirmed VBI (9)), the diagnosis of VBI must be considered in any patient complaining of dizziness. Even so, other symptoms must also be present, such as transient numbness, dysarthria or diplopia (10). In other instances where a referral is required would include a new onset of dizziness during therapy. For example, an elderly patient referred to outpatient PT after a simple knee surgery starts to complain of dizziness during one of the therapy session, while riding a bicycle. In addition, the therapist also notes slurred speech and slowed verbal responses. It is possible that this patient is experiencing an acute onset of a cerebrovascular event and an emergency referral is warranted. Once it has been determined that the dizziness does not represent an emergency situation, further screening can proceed to determine the physiotherapist s role. Even if PT is not indicated, further evaluation by the physiotherapist Physiotherapy Singapore September 2002 Vol. 5 No. 3 47

3 may prove helpful. This is because an appropriate referral is best made with as much additional information as can be gleaned from the patient, so that the correct diagnostic and therapeutic decision can be made. The second possible outcome in this decision process is that PT intervention is appropriate and can be independently done, without requiring a referral or consultation. In this case, the physiotherapist determines that the patient s problem is not life threatening, and is mechanical in nature or is otherwise amenable to PT. For example, suppose a patient were to complain of dizziness upon sitting or standing after receiving a PT intervention in the supine position. Further investigation reveals a progressive drop in serial measurements of blood pressure taken as the patient goes from supine to sitting and sitting to standing, suggesting postural hypotension as the aetiology. This presentation is not life threatening and certainly physiotherapy intervention can continue with appropriate care taken during transfers. Of course, the underlying cause of the postural hypotension may need investigation, and should the condition persist or adversely affect the patient s progress in physiotherapy, contact with the referring physician is warranted. The third and last outcome of the decision-making rule is the decision that PT is appropriate but that consultation with another health care provider is necessary. This example underscores the idea that while there are conditions, which PT can proceed without interruption, most conditions will warrant at least communication with the patient s primary care provider. In addition, while a physiotherapist may practise with relative autonomy within the framework of the healthcare system, this is not the same as practising independently in which the resources of the medical community are ignored or forsaken. Another example where PT intervention can continue but consultation is required will be an elderly patient who during the course of treatment for another disorder reports a concomitant complaint of dizziness. Appropriate screening examination suggests that the problem may be benign paroxysmal positional vertigo (BPPV), the therapist may decide to refer the patient for the appropriate treatment (a repositioning manoeuvre) while continuing to care for the initial problem. Screening for Physiotherapy Management The key in the process of determining appropriate physiotherapy intervention is the screening process mentioned above. The purpose of the screen is not to diagnose a medical condition, but to determine the proper disposition of the patient. The rest of this paper will focus on the screening examination that should occur once it has been determined that PT management is appropriate, whether with or without referral. If a vestibular disorder is suspected, the next step for the physical therapist is to differentiate between central and peripheral vestibular disorders. Examples of central disorders include those in which the central nervous system is involved, such as multiple sclerosis, cerebrovascular accident or traumatic brain injury. The importance of the distinction for physical therapists lies in the prognosis. Central disorders tend to improve more slowly and the final outcome is more guarded. Peripheral disorders, such as benign paroxysmal positional vertigo (BPPV), episodic vertigo (e.g., Meniere s disease), unilateral or bilateral vestibular dysfunction (labyrinthitis, vestibular neuronitis or ototoxic vestibular loss), can have good to excellent resolution of functional limitations and disabilities with appropriate intervention (11-13). In a study of 812 patients referred to a multidisciplinary clinic for complaints of dizziness, 65% were found to have a peripheral disorder, 8% with a central disorder, 5% with a mixture of both, 9% were of psychogenic causes, and 13% of the cases could not be formally classified (7). Of those with peripheral vestibular causes of dizziness, 43% had BPPV. The diagnostic test for this disorder is the Dix-Hallpike manoeuvre, and a positive test is one in which nystagmus is observed after the patient assumes the position. The next most common diagnosis was recurrent vestibulopathy (20% of the patients), in which patients suffer attacks of vertigo similar to Meniere s disease but without hearing changes. Vestibular neuronitis was diagnosed in 10% and Meniere s disease in 5% of the patients (7). It is beyond the scope of this paper to describe in total, the various tests and measures used in the evaluation of vestibular disorders. The reader is referred to the excellent text by Herdman for further study (14). In short, a complaint of dizziness combined with the presence of upper motor neurone signs, resting nystagmus in the chronic case (more than a Table 2: Signs differentiating central from peripheral vestibular disorders. Central Occulo-motor tests Resting nystagmus Abnormal smooth pursuit Abnormal saccades Etc. Signs of CNS disorder Upper motor neurone signs Others Constant vertigo Peripheral No resting nystagmus (unless time since onset is < 1 week) Position/ movement provoked Good smooth pursuit No upper motor neurone signs Transient dizziness Positive head shake Positive head thrust Etc. 48 Physiotherapy Singapore September 2002 Vol. 5 No. 3

4 week since onset), and abnormal oculomotor tests are suggestive of a central disorder. Resting nystagmus can also be present in the acute stages (less than a week since onset) of certain peripheral vestibular disorders (notably unilateral vestibular loss). Chronic peripheral disorders do not exhibit nystagmus at rest, and have no suggestion of upper motor neurone lesions or abnormalities in the oculomotor tests. Table 2 summarises findings, which distinguish central and peripheral vestibular disorders. In situations where once other causes have been ruled out and a peripheral vestibular disorder is suspected, BPPV is the most likely cause (7). Typical complaints are dizziness of short duration (lasting only a minute or two), most often aggravated when assuming a reproducible position, such as lying on one side. If the offending position is avoided, the dizziness is not experienced. Treatment using a repositioning manoeuvre which aims to restore dislodged particles within the inner ear (15, 16), can be very effective (11, 15, 17). In contrast to BPPV, recurrent vestibulopathy and Meniere s disease are characterised by episodes of severe dizziness that may last for hours, and tend to resolve gradually and spontaneously. During such attacks there is no change in symptoms associated with positional changes. If after a thorough examination the patient s condition doesn t appear to be either central or peripheral in nature, cervicogenic dizziness should be considered. In other words, cervicogenic dizziness is a diagnosis of exclusion. The existence of this disorder is still hotly debated in the literature (18), but recent work suggests that should other causes of the dizziness be ruled out, and if there is a concomitant complaint of neck pain (19, 20), intervention directed at the cervical spine may prove beneficial (21, 22). Special note should be made of the problems presented by the patient who presents with a history of cervical trauma such as whiplash and complaints of cervical pain, associated with a complaint of dizziness. These patients may come to PT via a primary care physician, general practitioner, family practitioner or orthopaedic surgeon, or in areas where first contact or direct access is being practised, may self refer to PT without other medical work up. In each of these cases, the referral to physiotherapy may be for treatment of the neck pain, with the dizzy complaints being secondary. The physiotherapist must recognise the possibility of co-existing central or peripheral vestibular disorders, which must be ruled out via appropriate examination. Cervicogenic dizziness should be considered after the other causes have been ruled out. The history of trauma further complicates the examination because special attention must be given to rule out upper cervical spine hypermobility and VBI (23). In addition, several studies have shown abnormalities on otolaryngologic testing indicating the presence of central and peripheral vestibular lesions (19, 24, 25). These findings suggest that patients with persistent problems after suffering a whiplash injury should be referred to an otolaryngologist for a thorough work up. Alternatively, patients referred to PT by Ear, Nose and Throat (ENT) department with a primary diagnosis of a vestibular problem commonly have co-existing cervical impairments that have not been fully evaluated. Thus, a patient whose chief complaint is vertigo, dizziness or dysequilibrium should be asked about a history of neck pain or trauma, and the cervical region should at least be screened for active range of motion for primary symptom reproduction. Conclusion The nature of physiotherapy practice is one in which patients are referred for treatment for a variety of disorders from a variety of medical disciplines. Interventions typically take place multiple times over a period of days, weeks or months. This increases the likelihood that patients referred for one condition may have secondary conditions uncovered by the physiotherapist. Dizziness is a common complaint in the general population and in primary care physician practice. While dizziness is not routinely referred to physiotherapy for treatment as yet, it is nevertheless often encountered by the physiotherapist as a secondary complaint. The physiotherapist must be able to decide what to do with this patient: halt all treatment and refer to a physician for further evaluation, continue PT despite the dizziness and without further referral to other health care disciplines, or continue PT but refer to the suitable health care discipline. Special consideration must be made for those disorders, which may prove life threatening, rare as they may be. A screening examination and decision-making process is required in order to make the appropriate choice. Once it is determined that PT is the correct management strategy for the patient, central versus peripheral vestibular causes must be differentiated in order that a reasonable prognosis can be made and the correct intervention applied. References 1. Sloane PD, Coeytaux RR, Beck RS, Dallara J. Dizziness: state of the science. Ann Intern Med 2001;134((9 (Part 2)) Suppl): Lambert PR. Evaluation of the dizzy patient. [Review] [13 refs]. Compr Ther 1997;23: Kroenke K, Hoffman RM, Einstadter D. How common are various causes of dizziness? A critical review. [Review] [40 refs]. South Med J 2000;93: Sloane PD, Coeytaux RR, Beck RS, Dallara J. Dizziness: state of the science. [Review] [65 refs]. Ann Intern Med 2001;134: Delitto A, Erhard RE, Bowling RW. 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