"Peripheral vertigo in general practice"
Continuing Medical Education Peripheral vertigo in general practice Tim Mathews FRCS (Ed) FCS (SA) Correspondence to: P O Box 2388, Tauranga Balance is maintained in a patient by the complex interpretation by the CNS integrative apparatus (the ves- Tim Mathews trained as an Otorhinolaryngologist in Cape tibular nuclei and cerebellum) of in- formation from the labyrinth (balance Town before emigrating to NZ in 1987. He works in public and organ), eyes, skin pressure receptors and muscle and joint proprioceptors. private in Tauranga and Whakatane. Special interests include A balance disturbance may occur when there is pathology in any of suppurative ear disease and endoscopic sinus surgery. these systems and there is abnormal- ity in the sensory input into the CNS. There are many descriptions of balance problems such as unsteadiness, in a gelatinous substance in the rior semicircular canal (cupulo- dizziness, giddiness, light headedness, maculae of the otolith organs (utri- lithiasis) or lie free within the canal fainting etc. but the principle symp- cle and saccule) stimulating mech- itself (canalithiasis), which is prob- tom of labyrinthine pathology is ver- anoreceptor hair cells. ably the more common scenario. Ab- tigo – a sensation of rotation or spin- The key to clinical assessment of normal vestibular signals lead to con- ning, an illusionary movement either the vestibular system is the vestibulo- flicting and confusing central infor- of self or of the environment. ocular reflex. The vestibular system mation causing symptoms of vertigo. A detailed history is therefore cru- stabilises the visual system and any The cause is usually idiopathic but cial to differentiate between the dif- pathology disturbing this equilibrium it is also seen following head injury, ferent balance disorders. This paper results in nystagmus. In general, the vestibular neuronitis and post-surgery. is limited to vertigo as a result of eyes slowly drift towards the relative common pathologies affecting the pe- hypofunctioning labyrinth with an History ripheral vestibular system (labyrinth opposite fast phase cortical correction This is typical and describes a brief and vestibular nerves) and how they giving the direction of the nystagmus. episode (usually seconds) of severe can be managed in general practice. Vestibular nystagmus (as opposed to vertigo precipitated by specific head central causes) can usually be sup- positions, e.g. rolling over in bed. Basic anatomy and physiology pressed by visual fixation, which can The labyrinth consists of three semi- be removed using Frenzel glasses (20 Examination circular canals, a utricle and saccule diopter lenses preventing image focus). Producing vertigo and nystagmus as well as the cochlear organ. This with the Dix-Hallpike test1 is diagnos- contains two fluid compartments; the Benign paroxysmal positional tic. With the patient sitting on a couch, endolymph within the membranous vertigo hold their head, eyes open, and lie labyrinth and the perilymph. This is the most common cause of them flat with the head extended 30° Rotatory head movements set up peripheral vestibular vertigo and is over the edge – to align the posterior fluid movements within the canals the most easily treated. semicircular canal in the vertical po- stimulating hair cells embedded in a sition. In the same movement, rotate jelly-like cupula contained in the Pathogenesis the head 45° to test the undermost ear. ampulla of each canal. Linear forces, Intact or degenerate utricular otoco- Both sides are tested with separate e.g. gravity, affect the otoconia (cal- nia become displaced to lodge in the manoeuvres and careful observation cium gluconate granules) contained cupula in the ampulla of the poste- of any nystagmus is made. The nys- Volume 33 Number 4, August 2006 267 Continuing Medical Education tagmus is mixed torsional and verti- tated slowly through 90° to the no hearing loss or tinnitus (i.e. should cal with the following characteristics: opposite side and then the body is not be diagnosed as labyrinthitis). I. Usually begins after latency of few turned so the head looks directly seconds downwards for about 15 seconds. Diagnosis II. Short duration (usually less than The patient is slowly brought into Requires careful history and exami- one minute) the seated position and should try nation. In the acute phase, brisk hori- III. Reverses direction on return to and remain quiet for 48 hours and zontal nystagmus towards the unin- upright position sleep with head elevated. (The volved ear is present and audiology IV. Fatigable (i.e. gets less with re- Sermont manoeuvre3 requires is normal. Past pointing and the peated manoeuvres). abrupt head movements and is un- Romberg test are often positive to- comfortable for patient). wards the side of the lesion. Management • Surgery – rare: includes singular • Medication has no value. neurectomy, vestibular neurec- Management • The condition often resolves spon- tomy and posterior semicircular • Symptomatic with labyrinthine taneously after a few months. canal occlusion. suppressants; • Labyrinthine fatiguing exercises. • Systemic steroids (prednisone) The principle is to repeat the ma- Vestibular neuronitis and antivirals (acyclovir) in the noeuvre causing the vertigo to acute phase may lessen the sever- promote CNS adaptation. (Often Pathogensis ity of symptoms; useful when the history suggests This is an infection of the vestibular • May benefit from vestibular re- BPPV but Dix-Hallpike test is nerves by a neurotrophic virus, par- training exercises in recovery negative for nystagmus). ticularly herpes. It is often preceded phase. • Canalith repositioning manoeuvre by an URTI characterised by a sudden (Epley2). The aim is to relocate free- onset of severe vertigo, lasting sev- Ménière’s disease floating debris from the posterior eral days before gradual improvement semicircular canal back into the over weeks; the later stages may re- Pathogenesis utricle. The patient is placed in the semble BPPV (occasionally lasting Endolymphatic hydrops may occur supine position with head rotated several months). The disease often secondarily to many disease proc- 45° to produce the nystagmus as occurs in mini-epidemics and vomit- esses, for example, viral labyrinthi- in the Dix-Hallpike test, i.e. the ing can be severe enough to require tis and neuronitis, auto-immune affected ear is dependent. Once the hospitalisation for rehydration. As the mechanisms, syphilis etc. and is nystagmus settles, the head is ro- vestibular nerve is involved there is called Ménière’s syndrome. Usually however, no cause is iden- Figure 1. Principle of canalith repositioning using the Epley manoeuvre tifiable and the exact pathogenesis is unknown. This primary condition is 1 2 called Ménière’s disease and is char- acterised by severe vertigo, sen- sorineural hearing loss and increased tinnitus (typically described as whis- tling or roaring). There may also be a ‘full’ sensation in the affected ear. Ménière’s disease usually affects Utricle the 40–60 age group, either sex and Ampulla is occasionally bilateral. ‘Attacks’ Particles in posterior canal tend to come in clusters and last min- 3 4 utes to several hours before settling down to periods of inactivity. The hearing loss is fluctuating but there is a progressive fall-off with each attack; particularly in the low fre- quencies. Permanent labyrinthine damage is suspected as being caused by rupture of the membranous layer with decompression of potassium rich endolymph discharging into the peri- 268 Volume 33 Number 4, August 2006 Continuing Medical Education lymph – this event is thought to cor- Figure 2 respond with resolution of the attack. The clinical course is very vari- HISTORY TRUE VERTIGO able. There is a range between single sporadic attacks to periods of unre- YES lenting recurrent attacks, from mild inconveniences to complete incapaci- GENERAL MEDICAL NO tation. EXAMINATION e.g. C.V.S. C.N.S. Diagnosis ABNORMAL This requires a meticulous history, examination of the ears, tuning fork NORMAL tests and audiometry. An MRI is of- MEDICAL/ ten useful to completely exclude NEUROLOGY retrocochlear pathology (acoustic neuroma). It is important to explain ENT EXAMINATION Otoscopy NORMAL that there is poor understanding of endolymphatic hydrops and that each Tuning forks Nystagmus patient tends to run a different clini- Positional tests cal course. Audiometry Management This is individual and primarily aimed at relieving acute attacks and ABNORMAL increasing the period of remission. • Attempts should be made to iden- tify any triggering event, e.g. ENT SPECIALIST stress, allergy, foods (chocolate, coffee etc.); • Salt restriction and diuretics of- C.V.S. Cardiovascular system ten help as first line medical C.N.S. Central nervous system therapy; • Betahistine (an oral histamine so avoid with atopy) is used as a va- sodilator; some work suggests hy- drops is a result of strial ischae- Dizziness cope, cervical arthritis, defective vi- mia. Patients learn to titrate the As this paper is designed to help gen- sion, migraine and anxiety/depres- dose to best manage the symptoms; eral practitioners with practical man- sion causes. • Prochlorperazine should be used agement strategies to tackle vertigo, a In general terms, patients with only for acute attack, not as short section on dizziness is appro- chronic dizziness without other oto- prophylaxis; priate. Many referrals to ENT Depart- logical symptoms are unlikely to have • There is no documented scientific ments get a low priority because of a peripheral vestibular disorder. evidence to show that acupunc- inadequate history, examination and ture, naturopathy, or hypnosis has failure to differentiate dizziness, which Physiological dizziness benefit but anecdotal stories sug- encompasses a wide range of balance This may occur when there is in- gest some help in some patients. disorders, from true aural vertigo. creased stimulation of the vestibular Referral to an otologist is important Dizziness includes unsteadiness, system, e.g. repeatedly turning round if there is incapacitating vertigo not fainting, near-syncope, light- and round in circles. Another form responding to the above measures. headedness and non-specific disequi- occurs when there is decreased sen- Consideration will be given to grom- librium. It may be physiological, e.g. sory input e.g. height dizziness when met insertion, intra-tympanic gen- motion sickness or pathological, in- there is loss of visual clues and in- tamicin, endolymphatic sac decom- corporating a wide spectrum of medi- creased distance from nearest station- pression or vestibular neurectomy. cal problems. Examples include CNS ary background. These procedures are controversial pathology, cardiovascular disease, Motion sickness occurs during and subject to evolving philosophies. metabolic disorders, vasovagal syn- travel (land, sea and air) when there Volume 33 Number 4, August 2006 269 Continuing Medical Education is conflicting sensory stimulation of the CNS from the visual and vestibu- earth before vestibular recalibration occurs. Key Points lar systems. Looking inside the car, • It is important to distinguish e.g. reading, leads to visual vestibu- Disequilibrium of ageing dizziness and unsteadiness lar imbalance as the visual environ- This, to a varying degree, is a com- from true aural vertigo. ment is stationary for the person but mon symptom in the elderly. It usu- • BPPV (canalithiasis) is best the labyrinth registers movement. Tips ally presents as an unsteadiness on treated with the canalith to manage motion sickness include walking or moving and is often part repositioning manoeuvre of improving the match between visual of the ‘multisystem degenerative’ Epley. and vestibular signals by sitting in spectrum. the front seat and looking out the Medical conditions need to be • Most important causes of window. investigated and treated. It is gener- peripheral vertigo: Anti-emetics e.g. Avomine, ally inappropriate to send these pa- – BPPV Dramamine, Sea-Legs are effective in tients to an ENT specialist. The ex- controlling motion sickness espe- ception is the patient with an asym- – Vestibular neuronitis cially prophylactically in patients metrical sensorineural hearing loss – Endolymphatic hydrops prone to this malady. in which case an MRI scan may be (Ménière’s). Space sickness is an interesting indicated to exclude an acoustic neu- variant experienced by 50% of as- roma (more accurately called a ves- • Patients with chronic dizziness tronauts. Lack of gravity leads to a tibular schwannoma). without other otological mismatch between the otoliths, symptoms are unlikely to have semicircular canals and visual sig- GP approach to vertigo a peripheral vestibular disorder. nals leading to symptoms similar to The flow chart shown in Figure 2 may motion sickness. Most adapt within prove useful in the practical manage- two to three days and some recur ment of a patient with a balance dis- Competing interests with a milder form on returning to order in general practice. None declared. References 1. Dix MR, Hallpike CS. The pathology, symptomatology and di- of benign paroxysmal positional vertigo. Otolaryngol Head Neck agnosis of certain common disorders of vestibular system. Proc Surg. 1992 Sep; 107(3):399-404. R Soc Med. 1952 Jun; 45(6):341-54. 3. Semont A, Freyss G, Vitte E. Curing the BPPV with a liberatory 2. Epley JM. The canalith repositioning procedure: for treatment maneuver. Adv Otorhinolaryngol. 1988; 42:290-3. Further reading Cummings CW et al. Otolaryngology – Head and Neck Surgery: 2nd Ed. Volume 4. Chapters 141: Pages 2525–2548; 144: Pages 2604–2643; 146: Pages 2652–2683; 181: Pages 3152–3177 ASCOT ‘ASCOT is one of the largest studies of high blood pressure ever conducted in Europe, involving nearly 20,000 patients with high blood pressure and additional risk factors for heart disease and stroke. Patients were randomized to receive either calcium channel blocker- based (amlodipine + the ace inhibitor perindopril) or beta blocker-based (atenolol + the diuretic bendroflumethiazide-K) treatment regimens and their blood pressure was monitored using the traditional arm cuff measurements. The ASCOT study showed that patients receiving the amlodipine-based treatment did better than those getting the atenolol-based treatment on all cardiovascular endpoints, including a 24 percent reduction in cardiovascular death.’ http://www.ascotstudy.org/get_doc.php?id=101 Accessed 18 Jul 2006. 270 Volume 33 Number 4, August 2006