LEARNING OUTCOMES
After completing this module the paramedic will be able to:
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A common phrase used by patients is that they ‘feel dizzy’. Dizziness can be subdivided into three categories of vertigo, syncope and non-syncope, and non-vertigo dizziness. Vertigo is a medical condition where a person feels as if they or the objects around them are moving when they are not. Syncope is a condition of transient loss of consciousness (commonly termed as a faint). The ability of the body to feel ‘stable’ is triangulated through three elements. Information from the eyes, fine-tuned information from the inner ears (the vestibular system), and the body senses, such as touch. An example would be motion sickness – the body is still, but the eyes can see things moving, this can result in an information mismatch to the brain.
Conditions associated with vertigo
The paramedic as a first contact practitioner will consult a variety of patients with different conditions of dizziness. Some will be related to vertigo and some to syncope. Determining that the symptom described is vertigo will involve some deduction in the form of a comprehensive history-taking from the paramedic. It is not always clear what a patient means and the patient may describe vertigo amongst other presentations, e.g. along with pain from a head injury, or otalgia from an ear infection. Phrases like ‘the room is spinning’ or ‘I feel like I am spinning’ may be synonymous with the vertigo symptom. Vertigo, like many of these descriptions, is a symptom and not a diagnosis. Vertigo-associated disorders for diagnosis are categorised into the six main conditions of Benign Paroxysmal Positional Vertigo (BPPV), Vestibular Neuronitis (VN), labyrinthitis, Meniere's disease, central vertigo and vertigo of unknown origin. Other causes of dizziness not associated with syncope or vertigo are vast.
BPPV
BPPV is defined as ‘a disorder of the inner ear characterised by repeated episodes of positional vertigo’ (symptoms with changes in the position of the head) (Baloh, Honrubia and Jacobson, 1987). For this element, while taking history, paramedics should ask about episodes and duration of symptoms, but importantly, what positions make the symptoms occur. This presentation is often present over an extended period of time. A head tilt left or right, up or down may make symptoms appear.
This condition is thought to be caused by something called otolith (particles), which become dislodged from the otolithic membrane and fall into the semi-circular canals. This results in movement of fluid in the inner ear. The causes of otolith do not always have precipitating factors, and so, can occur spontaneously (particularly in older people). It can be precipitated, which is more common in those under 50 years of age. Examples of things that could lead to a BPPV include a head injury, ear surgery, prolonged bed rest or following insult by inner ear infection (such as a viral otitis media). You can also get this along with another ear condition called Meniere's disease, which we will discuss later. Women for unknown reason are twice as likely to be affected by BPPV as men.
To diagnose BPPV, symptoms of vertigo should be confirmed. Symptoms are brought on by specific movements of the head (e.g. turning over in bed, looking upwards, or bending over). Other causes of vertigo should be considered including Meniere's disease, postural hypotension, and anxiety disorder should be excluded. MRI or CT imaging is not required to confirm the diagnosis of BPPV unless it is necessary to exclude another condition (e.g. if the person has atypical nystagmus or additional neurological symptoms associated with the presentation).
BPPV can usually be managed with advice and repositioning manoeuvres in primary care. Brandt-Daroff (BPPV) exercises available from the internet can be easily undertaken at home and can often help (Brandt and Daroff, 1980). The person should be advised to return for follow up within 4 weeks with a primary care practitioner if symptoms have not resolved (in case BPPV has been incorrectly diagnosed). There is a medical process called the Epley manoeuvre which is sometimes used to treat BPPV which are a series of calculated positions and tilts to try and reposition the otolith (Cranfield, Mackenzie and Gabbay, 2010).
Specialist referral (to the ENT service) typically occurs where local GPs do not have the expertise to provide the Epley manoeuvre, the Epley manoeuvre has been performed and repeated and symptoms are still present, symptoms or signs are atypical, symptoms and signs have not resolved in four weeks, there have been three or more periods during which the person has experienced episodes of vertigo (Bird et al, 1998).
Conditions affecting hearing
Vestibular neuronitis and labyrinthitis
Vestibular neuronitis (sometimes called vestibular neuritis) is a syndrome of acute vertigo of peripheral origin (i.e. not a central vertigo). The terms ‘vestibular neuronitis’ and ‘labyrinthitis’ have been used interchangeably in the past, but specific terminology is now recommended. Vestibular neuronitis is thought to be due to inflammation of the vestibular nerve (this is one that wraps around the inner ear) and often occurs after a viral infection. Labyrinthitis is a different diagnosis that involves inflammation of the labyrinth and the vestibular nerve, but is often attributed to a viral infection as well. Hearing loss is a feature of labyrinthitis, but hearing is not affected in vestibular neuronitis, so can be helpful in the differential of diagnosis. This is typically a younger person disease and the history is that of a person who is often well, then they develop inner ear infection symptoms. This inflammation alters the transmission of the vestibular system information and thus vertigo can occur.
Vestibular neuronitis typically self-resolves, but often takes weeks to months to fully settle down. Symptoms include spontaneous onset of vertigo, which usually settles over a few days. They also typically have nausea or vomiting. Tinnitus and hearing loss are not present in vestibular neuronitis. Occasionally nystagmus may be linked with this condition which flares after movement, but then settles. There should be no other focal neurological signs or persisting nystagmus.
Symptomatic treatment is often helpful. Prochlorperazine is available as buccastem from the Pharmacist and is often a good recommendation to make. IM anti-emetics may also be helpful and are carried by paramedics. If nausea or vomiting is so severe that they cannot take oral fluids, they should be admitted to hospital as there is risk of dehydration and electrolyte imbalance. Referral is necessary if there are atypical symptoms (e.g. additional neurological symptoms), symptoms are not improving after a week of treatment, or symptoms persist for more than four weeks.
Saccades
As previously mentioned, hearing loss is a feature of labyrinthitis, but hearing is not affected in vestibular neuronitis. Tinnitus may also be a feature of labyrinthitis, but not vestibular neuronitis. Nystagmus can be present in both vestibular neuronitis and labyrinthitis. If corrective eye movements (saccades) occur after head movement in one direction, a peripheral vestibular lesion (of the labyrinth or 8th cranial nerve) affecting that side is likely. In normal people there are no saccades because their gaze remains fixed on the target. Non-settling unilateral tinnitus should be investigated for an acoustic neuroma.
If labyrinthitis is suspected (vertigo associated with hearing loss or tinnitus), admit the person to hospital or refer as an emergency to an ENT specialist. This is because evidence suggests that sudden-onset unilateral deafness (as found in labyrinthitis) can indicate acute ischaemia of the labyrinth or brainstem (but can also occur with infection or inflammation). Emergency treatment may restore hearing, so the person should be seen within 12 hours of the onset of symptoms by an ENT specialist (Bird et al, 1998).
Meniere's disease: diagnostic features
Meniere's disease
Meniere's disease is a rare progressive disorder of the inner ear of unknown cause characterised by recurrent acute episodes of vertigo, hearing loss, tinnitus, and a sense of pressure in the ear (aural fullness). Vertigo (causing dizziness, nausea, and vomiting) is often the most prominent symptom.
The cause of Meniere's disease is not known but is likely to be multifactorial and associated with endolymphatic hydrops (raised endolymph pressure in the membranous labyrinth of the inner ear) (Bachor and Karmody, 1995). Some people will develop progressive hearing loss (which may be bilateral), but resolution of vertigo occurs in around three-quarters of people over a 5-10 year time period.
Meniere's disease diagnosis involves three symptoms:
To help alleviate nausea, vomiting, and vertigo in people with acute Meniere's disease, a seven day (14 days if required previously) course of prochlorperazine (available from the pharmacist) or an antihistamine (e.g. cinnarizine, cyclizine, or promethazine teoclate) should be considered (again some of these are available from the pharmacist) (Beynon and Bottrill, 1997). The paramedic may be able to signpost the patient to purchase some of these, although obviously if vertigo occurs whilst moving the head (such as when checking a mirror in a car), driving should not be advised. If symptoms are severe enough, people may require hospital admission for intravenous (IV) labyrinthine sedatives and fluids to maintain hydration and nutrition (Coelho and Lalwani, 2008). Patients may be on Betahistine for long term treatment of this condition.
Central causes of vertigo representing serious pathology
Central Vertigo
Some diagnoses of central vertigo (i.e. stroke) are medical emergencies. Where neurological assessment and history are suggestive of acute stroke, emergency referral through the local stroke network should be considered. Spontaneous vertigo, often without previous history may be a stroke symptom.
Certain other medical conditions can cause dizziness, because they affect the systems that maintain balance. For example, the inner ear is very sensitive to changes in blood flow. Medical conditions such as high blood pressure or low blood sugar can affect blood flow. For the paramedic, these conditions are frequently assessed as part of routine baseline observations and should be corrected where possible.
Other causes are head injury, ear infection, allergies, and nervous system disorders which providing there was no loss of consciousness (or other risk factors), can often be approached conservatively for management. Migrainous vertigo can be treated with vestibular suppressants and treatments similar to those for standard migraine (such as triptans for acute attacks, which the patient may already be prescribed). Previous history of migraine is often helpful here is supporting the probability of repeat presentation. It is suggested that most people with new-onset headache and vertigo will need admission to hospital, unless there is a history of recurrent similar episodes, to exclude other potentially more serious diagnoses (Seemungal and Bronstein, 2008; Barraclough and Bronstein, 2009).
| Category | Example of conditions that can cause dizziness: | |
|---|---|---|
| V | Vascular |
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| I | Infection/inflammatory |
|
| N | Neoplastic |
|
| D | Drugs |
|
| I | Iatrogenic/unknown |
|
| C | Congenital or degenerative |
|
| A | Auto-immune |
|
| T | Trauma |
|
| E | Endocrine |
|
Summary
For the paramedic vertigo should never be presumed an answer, but merely a symptom of underlying pathology. A careful history-take will help build a picture of acute vs chronic, vs repeating episodes of vertigo. If you think the presentation is a vertigo, important differential between vestibular neuritis and labyrinthitis should be made with the assessment of hearing and for tinnitus. Nystagmus which occurs as a result of moving and settles may be as a result of a vertigo condition, but careful exclusion of other conditions, such as hypertension, hypoglycaemia, head injury, intoxication, hypothermia and similar should be made, before attributing vertigo to a more benign category of diagnosis.
In all cases, follow-up and safety netting advice of a maximum of 4 weeks should be made where acute admission is not the selected pathway. Symptomatic relief is often available in the community and a one off stat IM injection is often helpful. Central vertigo, specifically stroke presentations are the red flag conditions and it is often difficult to exclude serious pathology without exclusionary imagery and biochemistry.