Bilateral Vestibulopathy

Bilateral impairment or loss of peripheral vestibular function, producing unsteadiness and oscillopsia rather than vertigo, since there is no asymmetry between the two sides to generate a sense of spinning. This absence of vertigo is precisely why the condition is missed, often for years, while patients are investigated for cerebellar and neurological disease.

Functional consequence

Loss of the vestibulo ocular reflex means that images are not stabilised on the retina during head movement, producing oscillopsia. Loss of vestibulospinal input means balance depends entirely on vision and proprioception, so patients are severely destabilised in darkness and on uneven or compliant surfaces where both of those channels are degraded.

Causes

Ototoxicity, principally aminoglycosides, which accounts for around 15 to 20 percent. Gentamicin is the classical agent and can produce complete bilateral vestibular loss with entirely preserved hearing at conventional doses and normal serum levels, since vestibulotoxicity is not dose predictable.
Idiopathic in around 20 to 50 percent.
Bilateral Ménière disease.
Meningitis, particularly bacterial.
Autoimmune inner ear disease, including Cogan syndrome with interstitial keratitis, and systemic vasculitis.
Neurodegenerative disease, notably cerebellar ataxia with neuropathy and vestibular areflexia syndrome, which combines cerebellar ataxia, sensory neuropathy and bilateral vestibulopathy and is commonly caused by biallelic RFC1 repeat expansions.
Bilateral vestibular schwannomas in neurofibromatosis type 2, and after bilateral tumour surgery.
Superficial siderosis, producing hearing loss, ataxia and vestibular loss with characteristic magnetic resonance findings.
Sequential bilateral vestibular neuritis, which is uncommon.
Congenital, in association with syndromic hearing loss including Usher type 1 and CHARGE syndrome, presenting as delayed independent walking.

Unsteadiness of gait, markedly worse in the dark, on uneven ground, and when visual or proprioceptive cues are removed. Patients describe being unable to walk at night without a light and being unsteady in the shower with the eyes closed.
Oscillopsia: the visual scene appears to bounce or jump during walking, running or driving on a rough surface. Patients report being unable to read road signs while walking or to recognise faces of people passing them.
Absence of vertigo, unless the loss developed asymmetrically.
Falls, and in the elderly this may be the only presentation.
Cognitive complaints, including spatial memory and navigation difficulty, since vestibular input contributes to hippocampal spatial processing.
Anxiety and avoidance of activity, with progressive deconditioning.
History of aminoglycoside exposure, meningitis, or the systemic conditions listed above. Ask specifically about intravenous gentamicin, which patients rarely volunteer.

Examination

Bilaterally positive head impulse test, with catch up saccades on turning to both sides. This is the key bedside finding.
Positive dynamic visual acuity: a drop of three or more lines on the Snellen chart when the head is oscillated at 2 Hz compared with the static acuity.
Positive Romberg test, dramatically worse with eyes closed, and inability to perform tandem gait.
Wide based unsteady gait, worse with eyes closed.
No spontaneous nystagmus, which is expected since the loss is symmetrical.
Examine for associated neurological signs: cerebellar signs, peripheral neuropathy with absent ankle reflexes and impaired vibration sense, and ocular abnormalities.

The diagnostic criteria require chronic vestibular syndrome with unsteadiness worse in darkness or on uneven ground, or oscillopsia during walking or head movement, plus objectively reduced bilateral vestibular function on testing.

Vestibular testing, which is required for diagnosis

Video head impulse testing with horizontal vestibulo ocular reflex gain below 0.6 bilaterally.
Caloric testing with a reduced response bilaterally, conventionally a sum of bithermal maximal peak slow phase velocity below 6 degrees per second on each side.
Rotational chair testing with a horizontal gain below 0.1 at 0.1 Hz and a phase lead above 68 degrees. Rotational testing is the most sensitive method for detecting bilateral loss and can identify partial loss missed by other tests.
At least one of these objective tests must be abnormal to establish the diagnosis.

Additional assessment

Pure tone audiometry, since concurrent hearing loss points to specific causes and influences rehabilitation.
Vestibular evoked myogenic potentials to assess otolith function.
Magnetic resonance imaging of the brain and internal auditory meati to exclude bilateral schwannomas, superficial siderosis with its characteristic hypointense rim on gradient echo sequences, and cerebellar atrophy.
Neurological assessment with nerve conduction studies for peripheral neuropathy, particularly where cerebellar ataxia with neuropathy and vestibular areflexia syndrome is suspected. Genetic testing for RFC1 repeat expansion where the triad is present.
Autoimmune screen: erythrocyte sedimentation rate, antinuclear antibody, antineutrophil cytoplasmic antibody, and syphilis serology.
Detailed drug history with specific enquiry about aminoglycosides, including intravenous courses during hospital admissions for other reasons.
Full blood count, renal function, glucose, vitamin B12 and thyroid function.

There is no treatment that restores lost vestibular function. Management centres on rehabilitation using sensory substitution, prevention of further loss, and falls prevention.

Treat identifiable causes

Stop and permanently avoid all ototoxic drugs, and flag the record clearly.
Immunosuppression for autoimmune disease: prednisolone 1 mg/kg daily initially with steroid sparing agents under rheumatology supervision, which may arrest progression in Cogan syndrome and vasculitis.
Treat the underlying systemic or neurological condition.
Identify the cause of superficial siderosis, which is usually a chronic source of subarachnoid bleeding, and treat it surgically where identified.

Vestibular rehabilitation, adapted to the absence of function

The strategy differs fundamentally from unilateral loss. There is no residual function to adapt, so the goal is substitution rather than adaptation.

Substitution training using vision and proprioception, teaching patients to use saccadic and pursuit strategies and pre programmed compensatory eye movements to reduce oscillopsia.
Gaze stabilisation exercises are still valuable in partial loss, where residual function can be enhanced.
Balance training progressing through conditions of reducing sensory input, always within safe limits.
Gait training with an emphasis on visual scanning strategies and on shortening stride and widening base on uneven terrain.
Aerobic conditioning, since deconditioning compounds the disability.
Programmes must be prolonged, typically 6 months or more, and outcomes are more modest than in unilateral loss.

Practical adaptations and safety, which matter more here than in any other vestibular condition

Night lighting throughout the home, particularly on stairs and the route to the bathroom, since darkness removes the visual channel on which the patient now depends entirely.
A walking aid, which provides both support and additional proprioceptive input through the hand.
Remove home hazards: loose rugs, trailing cables, poor lighting, and low contrast steps.
Advise against swimming alone and against swimming underwater, where disorientation is potentially fatal because visual and proprioceptive cues are removed simultaneously.
Advise against working at height, on ladders and with dangerous machinery.
Driving assessment, since head movement while driving produces oscillopsia. Many patients can drive safely with adaptations, but this requires formal assessment.
Review all medications for those that impair balance, particularly sedatives, antihypertensives and anticholinergics.
Falls prevention: strength and balance training, vitamin D supplementation where deficient, bone density assessment and osteoporosis treatment, and a formal falls service referral.

Emerging interventions

Vestibular implants, which deliver motion encoded electrical stimulation to the ampullary nerves, have shown restoration of a partial vestibulo ocular reflex and functional improvement in early trials and are available in a small number of specialist centres. They remain investigational.
Sensory substitution devices delivering head position information through vibrotactile or tongue based stimulation have shown benefit in trials but are not widely available.

Psychological support and follow up

Anxiety and depression are common and disabling. Screen for them and treat.
The condition is frequently misattributed for years before diagnosis, and patients often derive substantial benefit simply from having an explanation.
Regular review with objective vestibular testing to detect progression, annual falls risk assessment, and audiological review where hearing is also affected.
Genetic counselling where a hereditary cause is identified.

Clinical toolsCalculators

BMI GCS EDD Parkland Formula

Corrected Sodium Corrected Calcium Anion Gap Creatinine Clearance Insulin Calculations qSOFA Wells PE Wells DVT CHA₂DS₂-VASc HAS-BLED CURB-65 Centor/McIsaac

Adenoid Hypertrophy

Enlargement of the nasopharyngeal tonsil, that is the adenoid, causing nasal obstruction, Eustachian tube dysfunction and sleep disordered breathing.

Anatomy and natural history

The adenoid is a midline aggregate of subepithelial lymphoid tissue on the posterosuperior wall of the nasopharynx, covered by respiratory ciliated pseudostratified epithelium with surface folds rather than true crypts. It forms part of Waldeyer ring together with the palatine tonsils, tubal tonsils of Gerlach and lingual tonsil. It has no capsule in the sense the palatine tonsil does, and it lies on the pharyngobasilar fascia over the basisphenoid and basiocciput.

It is present at birth, enlarges progressively to peak in size between 3 and 7 years, and then involutes so that it is usually of little significance after 12 to 15 years. Because the nasopharynx grows while the adenoid regresses, the ratio of adenoid to airway is most unfavourable in the preschool years, which is precisely when symptoms peak.

Consequences of obstruction

Nasal obstruction with obligatory mouth breathing.
Obstructive sleep disordered breathing, ranging from primary snoring to obstructive sleep apnoea. Adenotonsillar hypertrophy is the commonest cause of obstructive sleep apnoea in children.
Eustachian tube dysfunction from both mechanical obstruction of the tubal orifice and from the adenoid acting as a biofilm reservoir of pathogens, producing otitis media with effusion and recurrent acute otitis media.
Chronic and recurrent rhinosinusitis from obstruction of nasal drainage and from bacterial reservoir effect.
Craniofacial consequences of long standing mouth breathing, that is the adenoid facies: an elongated face, a short upper lip, an open mouth posture, a high arched narrow palate, dental crowding and malocclusion with an anterior open bite, retrognathia and a dull expression. These changes are only partly reversible if obstruction is relieved late, which is an argument for timely intervention.
Consequences of untreated obstructive sleep apnoea: growth failure through disrupted growth hormone secretion, behavioural disturbance and inattention frequently misattributed to attention deficit disorder, poor school performance, enuresis, and in severe long standing cases pulmonary hypertension and cor pulmonale.

Chronic nasal obstruction and mouth breathing, present day and night.
Snoring, which is the commonest presenting complaint.
Witnessed apnoeas, gasping, choking, restless sleep, unusual sleeping positions with neck hyperextension, and profuse sweating during sleep.
Hyponasal speech, that is rhinolalia clausa, in which the child cannot produce the nasal consonants m, n and ng properly.
Chronic rhinorrhoea and postnasal drip.
Recurrent otitis media and hearing loss.
Daytime symptoms: mouth breathing, dry mouth, halitosis, poor appetite, fatigue, and behavioural problems including hyperactivity, irritability and inattention. Daytime sleepiness is less characteristic in children than in adults, and hyperactivity is the more usual presentation.
Nocturnal enuresis, particularly secondary enuresis after a period of dryness.
Failure to thrive and poor weight gain.

Examination

Mouth breathing posture, open mouth, and the facial features described above.
Assess the palate for a submucous cleft: bifid uvula, a translucent zona pellucida in the midline of the soft palate, and a notched posterior border of the hard palate. This is essential before adenoidectomy, since removal in a patient with a submucous cleft causes velopharyngeal insufficiency.
Anterior rhinoscopy showing mucosal oedema and secretions.
Flexible nasoendoscopy, which is the definitive assessment, allowing direct visualisation of adenoid size relative to the choana, the tubal orifices, and any dynamic collapse.
Otoscopy and tympanometry for effusion.
Growth parameters plotted on a chart.
Cardiovascular assessment where severe long standing obstruction is suspected.

Red flags requiring urgent or different management

Unilateral nasal obstruction or a unilateral nasopharyngeal mass, requiring imaging and biopsy.
Epistaxis with nasal obstruction in an adolescent male, indicating juvenile nasopharyngeal angiofibroma. Never biopsy this.
A nasopharyngeal mass in an adult, particularly with unilateral serous otitis media, cranial neuropathy or a neck node, indicating nasopharyngeal carcinoma. Adenoid tissue is not normally present in adults, and apparent adenoid hypertrophy in an adult requires nasoendoscopy with biopsy, HIV testing and consideration of lymphoma.
Severe obstructive sleep apnoea with cardiorespiratory compromise.
Failure to thrive.

Flexible nasoendoscopy, which is the investigation of choice, assessing adenoid size as a percentage of choanal obstruction and directly visualising the tubal orifices. It avoids radiation and gives dynamic information.
Lateral soft tissue nasopharyngeal radiography, which gives an adenoid to nasopharynx ratio and remains widely used where endoscopy is unavailable, though it is a static two dimensional assessment of a dynamic three dimensional problem and correlates imperfectly with symptoms.
Tympanometry and age appropriate audiometry in every child with adenoid hypertrophy, since coexisting otitis media with effusion is common and changes management.
Overnight polysomnography, which is the reference standard for obstructive sleep apnoea, measuring the apnoea hypopnoea index. In children, an index above 1 event per hour is abnormal, with 1 to 5 considered mild, 5 to 10 moderate and above 10 severe. Polysomnography is not required before surgery in a straightforward child with clear symptoms and adenotonsillar hypertrophy, but is indicated where there is diagnostic uncertainty, in children under 2 years, in obesity, in Down syndrome, in craniofacial anomalies, in neuromuscular disease, in sickle cell disease, in mucopolysaccharidoses, and where the severity will determine the level of postoperative monitoring.
Overnight pulse oximetry as a practical alternative where polysomnography is unavailable. A positive study with clusters of desaturation confirms obstructive sleep apnoea and identifies children needing high dependency monitoring; a negative study does not exclude it.
Growth monitoring.
Echocardiography where pulmonary hypertension is suspected.
Nasopharyngeal biopsy in any adult, and in any child with unilateral or atypical findings.

Medical management

Appropriate for mild to moderate symptoms, as a trial before surgery, and for children in whom surgery is being deferred.

Intranasal corticosteroid, which reduces adenoid size and improves obstruction: mometasone furoate 50 micrograms per nostril once daily in children aged 3 to 11 years, or fluticasone furoate 27.5 micrograms per nostril once daily from 2 years. A trial of at least 6 to 8 weeks is required. Benefit is real but modest and frequently not sustained after cessation.
Montelukast 4 mg daily in children aged 2 to 5 years, or 5 mg daily aged 6 to 14 years, which reduces adenoid size and improves symptoms, particularly when combined with intranasal corticosteroid. Counsel families about neuropsychiatric adverse effects including nightmares, agitation, aggression and mood change, and advise stopping if these occur.
Treat coexisting allergic rhinitis with an antihistamine and allergen avoidance.
Nasal saline irrigation.
Treat reflux where present.
Eliminate tobacco smoke exposure, which is strongly associated with adenoid hypertrophy and recurrent infection.
Weight management in obese children.

Adenoidectomy

Indications:

Obstructive sleep disordered breathing with adenoid hypertrophy. This is the principal indication and is usually combined with tonsillectomy where the tonsils also obstruct.
Chronic nasal obstruction with mouth breathing not responding to medical therapy.
Otitis media with effusion requiring a second set of ventilation tubes, and in children over 4 years at first insertion, since adenoidectomy reduces the need for further surgery independently of adenoid size.
Recurrent acute otitis media, as an adjunct in children over 4 years and in those requiring repeat tube insertion.
Chronic and recurrent rhinosinusitis in children not responding to medical management, where adenoidectomy is the first line surgical intervention before any consideration of sinus surgery.
Chronic adenoiditis with persistent purulent rhinorrhoea.
Suspected malignancy, requiring tissue.

Contraindications and cautions:

Overt cleft palate, submucous cleft, bifid uvula and any velopharyngeal insufficiency, where adenoidectomy causes hypernasal speech and nasal regurgitation. Where surgery is unavoidable in such a child, a partial or superior adenoidectomy preserving the inferior adenoid pad may be performed, with speech and language therapy assessment beforehand.
Neuromuscular disease with poor palatal function.
Bleeding disorders, which require haematological management.
Active infection, for which surgery should be deferred 2 to 4 weeks.

Technique

Performed under general anaesthesia with the patient supine and head extended, using a Boyle Davis gag, with the soft palate retracted with catheters passed through the nose.
Curettage with a St Clair Thomson adenoid curette under indirect mirror vision, which is the traditional technique and remains effective.
Suction diathermy adenoidectomy under mirror or endoscopic vision, which allows precise removal with excellent haemostasis and lower blood loss, and is now widely used.
Microdebrider adenoidectomy under endoscopic vision, which permits precise removal including of tissue around the tubal orifices and choanae, and is particularly useful where obstruction is choanal.
Coblation adenoidectomy.
Endoscopic transnasal or transoral visualisation improves completeness of removal and reduces the risk of residual tissue, particularly at the choanae and around the Eustachian tube orifices, which is the commonest cause of persistent symptoms after apparently adequate surgery.
Avoid deep curettage or diathermy over the basisphenoid and near the tubal orifices, which causes scarring, tubal stenosis and, rarely, atlantoaxial instability.

Postoperative care and complications

Adenoidectomy alone is far less painful than tonsillectomy, and most children recover within a few days.
Analgesia with paracetamol and ibuprofen.
Primary haemorrhage in around 0.5 percent, requiring return to theatre with a postnasal pack or diathermy of the adenoid bed under direct vision.
Secondary haemorrhage, which is uncommon.
Velopharyngeal insufficiency, occurring transiently in a proportion and persisting in around 1 in 1500 to 1 in 3000. Persistent hypernasality beyond 6 to 8 weeks requires speech and language therapy assessment, nasoendoscopic evaluation of velopharyngeal closure and, occasionally, a pharyngoplasty.
Nasopharyngeal stenosis, which is rare and results from excessive diathermy.
Eustachian tube injury with subsequent tubal stenosis.
Grisel syndrome, that is atlantoaxial rotatory subluxation presenting with persistent torticollis and neck pain after adenoidectomy, particularly in children with Down syndrome. It requires cervical spine imaging and orthopaedic or neurosurgical involvement, and it is missed when postoperative torticollis is dismissed as muscular.
Recurrence from regrowth of residual tissue, occurring in around 2 to 5 percent, particularly in younger children and where removal was incomplete.

Postoperative monitoring for obstructive sleep apnoea

Children with severe obstructive sleep apnoea require overnight monitoring in a high dependency setting after adenotonsillectomy, since respiratory complications occur in the first postoperative night. High risk groups are children under 3 years, apnoea hypopnoea index above 10 or oxygen saturation nadir below 80 percent, obesity, Down syndrome, craniofacial anomalies, neuromuscular disease, cerebral palsy, sickle cell disease, mucopolysaccharidoses, cor pulmonale and failure to thrive. Opioids must be used with great caution in these children, and codeine is contraindicated.

Follow up

Review at 6 weeks with assessment of nasal breathing, snoring, speech and hearing, with repeat tympanometry and audiometry where otitis media was present. Persistent symptoms require nasoendoscopy to assess for residual adenoid tissue, and reassessment for other causes of obstruction including turbinate hypertrophy, allergic rhinitis, septal deviation and, in the older child, tongue base or laryngeal contributions.

Bilateral Vestibulopathy

Overview

Clinical Features

Diagnosis

Management

Overview

Clinical Features

Diagnosis

Management