Transient visual loss, headache and neurological emergencies

Establish what happened and where it localizes

Transient visual loss is a symptom with vascular, inflammatory, pressure-related and migraine causes. Ask the patient to describe whether one eye or both were affected, whether there was a dark curtain or positive visual phenomenon, how long it lasted and whether headache or neurological symptoms occurred. People can mistake a homonymous field loss for monocular loss, so clarify the geometry rather than accepting the first label.

Examine vision, pupils, fields, discs and retina, and record blood pressure and neurological findings. A normal eye between episodes does not exclude a transient ischaemic attack. Sudden negative monocular loss can reflect retinal or optic-nerve ischaemia and requires an urgent vascular pathway. Associated jaw claudication, scalp tenderness or systemic symptoms in an older person raise concern for giant-cell arteritis and demand immediate assessment.

Vascular loss and migraine

Retinal transient ischaemia may arise from embolism, carotid disease or haemodynamic compromise. Stroke-team investigation and risk reduction follow the suspected mechanism. Do not treat an embolic episode as a routine refractive complaint or advise waiting for another attack. The duration and recovery do not alone establish a benign cause.

A typical migraine aura often develops gradually with positive scintillating or zigzag phenomena, may spread across a homonymous field and is followed by or associated with headache. First, atypical, persistent or neurologically complicated episodes require appropriate evaluation. Retinal migraine is rare and requires exclusion of other causes of truly monocular symptoms; it is not a default explanation for a curtain in one eye.

Brief visual obscurations lasting seconds, especially with posture change, can accompany papilloedema but also have other causes. Check the discs and assess headache, pulsatile tinnitus and neurological signs. The patient may retain good central acuity despite pressure-related optic-nerve risk. Investigate a suspected raised intracranial pressure syndrome with the appropriate imaging and lumbar-puncture pathway rather than using symptom duration as proof.

Pituitary apoplexy

Pituitary apoplexy involves acute haemorrhage or infarction in the pituitary region, often within a tumour. Severe headache, reduced vision, bitemporal loss, ocular motor palsies or altered consciousness are warning features. Acute cortisol deficiency can be life-threatening. Arrange emergency endocrine, neurosurgical and imaging assessment rather than treating the diplopia in isolation.

Assess haemodynamic state and obtain urgent blood samples where feasible without delaying resuscitation. If adrenal crisis is suspected, Society for Endocrinology guidance supports immediate hydrocortisone and fluid resuscitation followed by ongoing replacement under specialist care. Ophthalmic documentation of acuity, fields and ocular motor findings helps guide treatment, but inability to complete formal perimetry must not delay emergency care. Surgical decompression versus medical management depends on visual, neurological and endocrine severity and multidisciplinary assessment.

Cavernous sinus and painful ophthalmoplegia

The cavernous sinus contains several ocular motor and sensory pathways beside the internal carotid artery. Multiple nerve deficits, pain, proptosis, chemosis, fever or trigeminal sensory change can indicate infection, thrombosis, fistula, aneurysm or tumour. A carotid–cavernous fistula may produce venous congestion, bruit and raised eye pressure. Cavernous sinus thrombosis with systemic infection is an emergency requiring antimicrobial and multidisciplinary management.

Tolosa–Hunt syndrome is a diagnosis requiring exclusion of mimics; steroid-responsive pain alone is insufficient. Infection and neoplasia can also temporarily improve or change after steroids. Request imaging suited to the cavernous sinus and vascular question, and reassess an atypical or recurrent course.

Headache, cortical vision and reduced consciousness

A sudden severe headache, new focal deficit, fever, cancer history or altered consciousness changes the urgency. Ophthalmology should contribute pupil, disc, field and motility findings while ensuring appropriate emergency neurological care. Cortical visual loss can occur with normal pupils and normal ocular structures because the afferent reflex pathways are spared. Posterior reversible encephalopathy can combine headache, seizures and visual symptoms in a hypertensive or systemic setting.

In coma, pupils and ocular reflexes must be interpreted with medication, temperature and systemic physiology. Avoid unsafe head manoeuvres when cervical injury is possible. Ophthalmic findings alone do not determine prognosis or brain-death status. Treat exposure and corneal protection while the underlying emergency is managed.

Clinical application

A recovered monocular curtain in an older adult still needs urgent ischaemia and GCA consideration. Sudden headache with bitemporal loss and hypotension suggests a pituitary emergency. Describe the localization, immediate systemic threat and referral pathway before discussing longer-term visual treatment.

Source: Society for Endocrinology adrenal-crisis guidance and EBO neuro-ophthalmology curriculum.