Red flags in neuro-ophthalmology

Red flags in neuro-ophthalmology Some diseases of the brain presenting with visual symptoms are life threatening and need urgent management. This article discusses possible causes of double vision, vision loss with headache, and non-ocular vision loss. T he three most important 'red flag' symptoms that indicate that a patient may need neuro-ophthalmological assessment are: 1 Sudden onset of double vision (diplopia) 2 Headache accompanied by vision loss (without an ocular cause) 3 Visual loss after ocular causes have been excluded If a patient presents with any of the symptoms above, you must take a detailed history (Table 1). Each eye is moved by six muscles which are innervated by three " cranial " nerves (the 3rd, 4th and 6th nerve) (Figure 1). If the nerves are affected then the eye cannot move normally, which results in double vision. The 3rd nerve also innervates the upper eyelid (Table 2). First exclude monocular diplopia by asking the patient to cover each eye in turn. If the double vision persists when looking with just one eye, then this is usually due to an ocular problem (e.g. cataract) and does not have a neurological cause. Is the double vision worse in any direction of gaze? The direction of gaze in which the double vision is worst signifies the most likely eye muscle involved. Are the images side by side; or is one image tilted and above the other? In 6th nerve palsies the images are side by side; In 4th nerve palsies one image is tilted. Has there been a recent head injury? Trauma to the brain or orbit can affect the nerves which control eye muscle movements. Does the double vision get worse as the day progresses or after exercise? If the condition gets worse with use of the muscle then this is typical for myasthenia gravis; there may be eyelid drooping (ptosis) or diplopia as the day proceeds. Is there any head or eye pain? Pain is an important clue: it usually indicates infection or inflammation. Tumours are less likely to be painful. Are there any systemic symptoms or diseases? Hypertension and diabetes can both cause loss of vision and diplopia. Is the upper eyelid drooping? Ptosis may be due to myasthenia gravis or a third nerve palsy, or may be congenital. How do the eyes move (each eye alone and both eyes together)? Assess the position of the eyes looking straight …