Acute vertigo

                                                                                  

 

Benign paroxysmal positioning vertigo (BPPV): The characteristic clinical features of this type of vertigo are transient rotatory vertigo (seconds or minutes) precipitated by a change in attitude of the head relative to gravity (offending ear down, e.g., turning over in bed, looking to a high shelf, getting out of or into bed), or rarely by exposure to imposed linear acceleration (elevator, car). Patients often describe a tumbling, rolling, cartwheeling sensation, with nausea, vomiting and imbalance. The bedside maneuver of Dix-Hallpike (vertigo and nystagmus in posterior canal BPPV predominantly torsional with upper pole of rotation beating toward the floor (=affecting ear); in horizontal BPPV horizontal nystagmus towards or away from affected ear. The usually appears after a latency of several to 30-45 seconds and lasts less than 30 seconds) is diagnostic. There is typical fatigability of the nystagmus on repeated testing. Patients may have persistent dysequilibrium that diminishes as the day goes on. Symptoms are maximum for days to weeks, usually resolves in months, but may recur. Canalolithiasis is the most common mechanical cause of posterior canal BPPV. Autoimmune disease and migraine may be associated with BPPV since it appears to be prevalent in patients with BPPV. The majority of cases are however idiopathic or post-traumatic.  The three step (20 seconds each) Epley maneuver or Daroff maneuver can be used as repositioning technique.

 

Vestibular neuritis: Clinically it is characterized by acute onset (develops over a period of hours) of prolonged severe rotatory vertigo aggravated by head motion and change in position and which is associated with spontaneous nystagmus (typically horizontal with a rotational component and does not change direction with a change in gaze (in contrast to a spontaneous nystagmus of central origin), postural imbalance with veering to one side (affected side), and vegetative symptoms (nausea) without accompanying cochlear or neurological symptoms (or acute unilateral peripheral vestibulopathy) with preserved hearing and no other symptoms or signs of brainstem dysfunction. The nystagmus is typically away from and Romberg sign positive towards the side of the lesion. The nystagmus is fatigable and inhibited by visual fixation. Head thrust test (quick 10º rotation of the head while fixating a distant target) is associated with corrective saccades which appear when thrust is given towards the affected side (no corrective eye movement occurs in cerebellar infarction). Caloric responses are usually decreased. HSV-1, ischemia and inflammation have been implicated in the pathophysiology of this disease. Although a peripheral vestibular dysfunction, unilateral central vestibular lesions in the ponto-medullary junction can present in a similar way. ENG demonstrates unilateral caloric hypoexcitability. BAEP, blink reflex and MRI can be useful diagnostic tools to differentiate peripheral from central vestibular dysfunction. Treatment consists of antihistamines im (promethazine 25 mg w or w/o prochloperazine 10 mg im if vomiting) or promethazine (Phenergan®) 25 mg tid (max 100 mg/day)  w/ or w/o prochlorperazine (Stemetil®) 5 mg tid (max 30 mg/day) followed by mild oral sedative antihistamines (meclizine 25 mg or dimenhydrinate 50 mg) are useful. The course of vestibular neuritis is benign. Recovery takes months, but BPPV may develop as sequel.

 

Drop attacks: Sudden falls without loss of consciousness are defined as drop attacks. In 64% of patients they are idiopathic. Other causes are vertebrobasilar insufficiency, Ménière syndrome and delayed endolymphatic hydrops.

 

Vertebrobasilar insufficiency (VBI): Overall about 60% of patients with VBI have dizziness as a symptom and 15-25% of patients with VBI have isolated dizziness as their initial manifestation. 70% patients also have visual disturbances (change or loss of vision or diplopia) and 60% have at least one isolated attack of vertigo. Less than 25% have vertigo as the initial symptom (2 days to 1.5 years before other symptoms) and lasts usually minutes (in contrast to hours for Ménière syndrome). In the infarction patients all had a prolonged bout of vertigo -- hours or days, but always with other CNS symptoms.

 

Bilateral vestibular loss: Causes of bilateral vestibular loss includes drug-induced ototoxicity (e.g. gentamicin can induce gait ataxia in every patient but only 50% report oscillopsia, rarely hearing loss and never vertigo. The onset of symptoms could be as long as 1 week after the medication was stopped), immune-mediated processes, familial bilateral vestibular loss (which is possibly responsive to diamox), trauma, chronic meningitis (syphilis, Lyme disease, neoplastic, granulomatous), viral and Ménière syndrome. The two most characteristic symptoms and signs are imbalance made worse with eyes closed and on uneven surfaces, and loss of visual acuity with head rotation. An inadequate compensatory slow-phase response to both slow and rapid head rotations is usually easily appreciated at the bedside.

 

Ménière syndrome: This syndrome is due to endolymphatic hydrops (glaucoma of the ear!) and is characterized by a tetrad of (1) pressure, discomfort, fullness in the ear, (2) fluctuating hearing loss, (3) fluctuating tinnitus and (4) episodic vertigo lasting minutes to hours up to a day (usually minutes for TIAs). Full blown attacks are typically characterized by a variable period of ear pressure or fullness, an increase in tinnitus (especially an accentuation of the low-pitched, roaring component around the time of the attack) and muffled hearing, and followed by vertigo. Hearing and tinnitus may sometimes improve just when the vertigo begins. The direction of the spontaneous nystagmus in or following an attack of Ménière syndrome is not a reliable sign of the side of the lesion because there may be an "irritative" phase during the attack (slow phases directed toward uninvolved ear) or there may be a "recovery" nystagmus. Involvement of the contralateral ear is common (30-60%). Audiometry is particularly helpful in the diagnosis of Ménière syndrome. There may be a low frequency or mixed low and high frequency, "Pike's Peak" pattern. A documented fluctuating hearing loss, especially in the low frequencies is diagnostic. Postural imbalance is common. Transtympanic electrocochleography (ECOG) can show evidence for cochlear involvement. The syndrome may be idiopathic, in which case it is called "Ménière disease", or secondary to various processes that lead to interference with the normal resorption of endolymph, e.g. neurosyphilis (and possibly Lyme disease), following viral infections (sometimes years later), after trauma, with congenital anomalies. TIA, microvascular compression syndromes, thyroid disease, autoimmune processes (especially sarcoidosis, PAN, temporal arteritis, Susac and Cogan syndromes) otosclerosis, perilymphatic fistula, MS, diamox responsive recurrent vertigo and ataxia, vestibular epilepsy and vestibular migraine belong also to the list of differential diagnoses. There is a particularly high incidence of migraine in patients with Ménière disease. Acute attacks of Ménière syndromes are treated with sedative antihistamines and benzodiazepines. Long-term treatment is initially medical - rigid salt restriction (1.5 gm sodium/day) and thiazide diuretics (or diamox, but avoid the potentially toxic loop diuretics). Caffeine and nicotine should be eliminated. Occasionally chemoablation (intratympanic gentamicin instillations) or surgical ablation (labyrinthectomy when hearing is already lost, vestibular nerve section when it is not) is necessary for refractory disease. The course of the disease is benign showing spontaneous remissions in up to 80% within 5-10 years.

 

Perilymph fistula: The characteristic clinical features of perilymph fistula are acute (trauma) or episodic vertigo (often induced by swallowing) and sensorineural hearing loss. There is often extreme motion sensitivity. A variant of perilymph fistula is the superior canal dehiscence syndrome which consists of recurrent attacks of vertigo with vertical-rotational oscillopsia induced by intracranial or middle ear pressure changes or loud sounds (Tullio phenomenon). It is caused by dehiscence of bone overlying the superior semicircular canal. ENG demonstrates unilateral caloric hypoexcitability. Audiography shows mild-to moderate ipsilateral sensorineural hearing loss. High resolution temporal bone CT scan demonstrates the defect of the bone overlying the anterior or superior semicircular canal. Perilymph fistula may occur follow head trauma, Valsalva maneuvers (always rule out craniocervical junction anomalies in patients with valsalva-induced vertigo, headache, or facial or neck pain), vigorous exercise, stapes surgery, barotrauma (descent from an airplane, ascent from diving), erosive lesions in the petrous bone including tumors such as cholesteatoma, inflammatory processes in the petrous bone including syphilis, congenital malformations (Mondini malformation), and a large vestibular (cochlear) aqueduct.

 

Peripheral vestibular paroxysmia: Short attacks (seconds to minutes) or a series of rotational vertigo rarely precipitated by changing head position and in less than 30% associated with hyperacusis and tinnitus. Postural imbalance is found in 75% of patients. No central ocular motor signs during attack-free interval. In less than 50% peripheral vestibular or audiometry deficit. Provoking factors may be rest, certain (changes in) head, body positions. BAEP is often abnormal. Hyperventilation-induced nystagmus on ENG. MRI may be useful in the diagnosis since it may demonstrate neurovascular cross-compression of the vestibulo-cochlear nerve. It may result in progressive functional loss. There is often a salutary response to carbamazepine.

 

Vestibular epilepsy: This rare cortical vertigo syndrome secondary to focal epileptic discharges in either the temporal lobe or parietal association cortex.

 

Vestibular migraine: The diagnostic criteria are the following: 1) recurrent vestibular vertigo attacks; 2) migraine according to the IHS; 3) migrainous symptoms during at least two vertiginous attacks (migrainous headache, photophobia, phonophobia, or aura symptoms); and 4) vertigo not attributed to another disorder. Precipitating factors may be irregular sleep, alcohol intake and certain foods. Spontaneous rotational and positional vertigo is observed in over 65% and 24% of patients, respectively. Only 24% present consistently headache with their vertigo. Commonly ocular motor abnormalities in the symptom-free interval (vertical or horizontal saccadic pursuit, gaze-evoked nystagmus, and moderate positional nystagmus) are found. Postural imbalance occurs. Only 5% of patients have a consistent relationship between the headache and the vestibular syndrome, while in 30% the headaches and vertigo always occur independently. In 25% of patients the duration lasts from minutes to 2 hours, in 50% it is greater than 24 hours and occasionally up to weeks of motion sickness and sensitivity, dizziness and imbalance, often punctuated by spells of vertigo. The age of onset is variable with peak in the 4th decade in men and 3rd to 5th decade in women. The duration of rotational vertigo last seconds to hours (occasionally days) and is associated with auditory symptoms in only 16% of patients. Combinations with other forms of migraine were found in approximately 50% of cases. Antihistamines (promethazine, dimenhydrinate), topiramate, calcium channel blockers, tricyclics as well as clonazepam may be effective.

 

Labyrinthitis: This develops over a period of minutes to hours and may be associated with systemic, ear or meningeal infections. The findings are similar to vestibular neuritis. ENG demonstrates unilateral caloric hypoexcitability. Audiography shows moderate-to-severe ipsilateral sensorineural hearing loss.

 

Labyrinth infarction: Abrupt onset in a patient with previous vascular disease is suggestive for labyrinth infarction. The clinical findings are similar to vestibular neuritis but there are also unilateral hearing loss and may be associated with neurologic signs. ENG demonstrates absence of unilateral caloric response. Audiography shows severe ipsilateral sensorineural hearing loss. Brain MRI may show silent brain infarcts.

 

Central paroxysmal positioning nystagmus: The characteristic clinical features of this type of vertigo are attacks of paroxysmal vertigo and nystagmus elicited by head movements. In contrast to BPPV the nystagmus is often torsional or downbeat.

 

Vertebral artery occlusion syndrome: VBI could be responsible for vascular vertigo, but its role is overestimated. Similarly, the rotational vertebral artery occlusion syndrome, consisting of recurrent attacks of vertigo (minutes), nystagmus, and ataxia resulting from head rotations compressing the vertebral artery. In contrast to vestibular lesions, nystagmus is marked and the vertigo mild. Nystagmus is often multidirectional and increases with attempted visual fixation.  MRA is useful in the diagnosis. Anticoagulation is justified in its management.

 

Paraneoplastic cerebellar ataxia

 

Delayed endolymphatic hydrops: Delayed endolymphatic hydrops (DEH) differs from Ménière disease in that it occurs in pre-existing ear pathology in patients who have a profound unilateral or total deafness that was caused by infection, trauma, or unknown causes (idiopathic) during childhood or adulthood. Idiopathic hydrops most commonly occurs in middle-aged patients (between the age of 30 and 50 years). Idiopathic hydrops is characterized by the following symptoms: vertigo often accompanied by nausea and vomiting (identical to those of Ménière disease); tinnitus; profound sensorineural hearing loss in one ear, usually fluctuating; and sensation of pressure or fullness in the affected ear. It may involve one or both ears and usually exibits fluctuating hearing loss and episodic vertigo, although one symptom may precede the other by months or years. Medical treatment has not been found to be effective in patients with DEH. Pharmacological labyrinthectomy with ototoxic drugs could be the therapy of choice