The special senses

Answer 1

Most patients with vertigo improve within days but continuous true vertigo with nystagmus suggests a central lesion. Physiotherapy helps the ‘compensation’ process by the brain.

Answer 2

No; the best treatment is the Epley manoeuvre, which consists of gentle but specific manipulation and rotation of the patient’s head to shift the loose otoliths from the semicircular canals.

Answer 3

The absence of nystagmus would bring the diagnosis into doubt, although the sensitivity of the Hallpike manoeuvre is variable (50-80%). Frenzel’s goggles are used to prevent visual fixation, which suppresses nystagmus due to a peripheral lesions such as BPPV; they might help.

Answer 4

Answer 5

The treatment is that of the underlying cause, e.g. removal of earwax, treatment of otitis media. Drugs (e.g. betahistine dihydrochloride) are often used; their benefit is variable. Carbamazepine and phenytoin are used in persistent cases. Intolerable tinnitus can sometimes be masked by a hearing aid.

Answer 6

Many have middle ear defects with impairment of hearing in addition to the change in the ear itself.

Answer 7

There are two reasons: first, the sinusitis is usually secondary to an upper respiratory tract infection (often viral); second, there is nasal obstruction. Both of these will cause difficulty with breathing.

Answer 8

Primary open-angle glaucoma is the common type and of course it does lead to irreversible blindness (Box 20.1). The aim of treatment is to reduce the intra-ocular pressure. This can be done either by reducing aqueous production (with a topical beta-blocker, e.g. timolol) or increasing aqueous drainage (uveoscleral outflow) with a prostaglandin analogue, latanoprost. Sympathomimetics and carbonic anhydrase inhibitors are also used. Reduction in the intraocular pressure reduces visual loss. Apart from medical treatment, laser therapy and surgery are used but without good evidence of their efficacy.

Answer 9

A number of treatments have been introduced for neovascular (or wet) age-related macular degeneration (ARMD) in the last few years. Photodynamic therapy with verteporfin was the first to show a decrease in visual loss. This has, however, been superseded by bevacizumab and ranibizumab, both monoclonal antibodies that neutralize endothelial growth factor A. They are very expensive.

Answer 10

The term is sometimes used for conditions that simulate disc oedema.

Answer 11

Long-sighted refractive errors make the disc appear pink and ill-defined. Opaque (myelinated) nerve fibres at the disc margin and hyaline bodies can be mistaken for disc swelling.

Answer 12

Diabetes mellitus is the most common cause. There is gradual onset of blurring of vision. Fundoscopy often shows no other evidence of retinopathy. Annual visual acuity should be checked.

Answer 13

Venous congestion is present in true papilloedema. Fluorescent retinal angiography is occasionally necessary to show true papilloedema.

Answer 14

Preservation of disc cup – no papilloedema.

Answer 15

The early changes are macular oedema, increased pigmentation and granularity of the retina. The characteristic lesion is a central area of depigmentation of the macula surrounded by an area of pigmentation – a ‘bull’s eye lesion’. This is usually accompanied by visual disturbances.

Answer 16

A macular star is a ring of exudates between the disc and the macula. It occurs with oedema of the disc, for example in hypertensive encephalopathy, and in some infections, for example cat scratch fever.

Answer 17

Yes.

Answer 18

Copper and silver wiring imply arteriolar thickening and both indicate mild hypertensive retinopathy.

Answer 19

Papilloedema means bilateral optic disc swelling. It is due to raised intracranial pressure damaging the optic nerve sheath, giving rise to optic disc swelling.