Tolosa-Hunt syndrome: painful eye palsy explained

The name describes a painful ophthalmoplegia, which means pain around the eye along with weakness or paralysis of the eye muscles. A 2020 case report in Case Reports in Neurological Medicine describes it as a rare neurological condition of unknown cause, caused by non-specific inflammation in the region of the cavernous sinus and the sphenoid cleft.

The cavernous sinus is a channel at the base of the brain through which several nerves to the eye pass. A 2023 report in Cureus describes the inflammation as extrinsic compression of the structures crossing the cavernous sinus, and says it can extend into the orbital apex, the narrow back part of the eye socket.

Tolosa described the first patient in 1954 and Hunt described the condition in six patients in 1961, which is how it got its name.

The 2023 report says patients typically have orbital pain accompanied by weakness of the third, fourth or sixth cranial nerves, commonly causing double vision. The 2020 report describes one-sided, severe, constant, non-throbbing pain behind or around the eye, with a drooping eyelid and paralysis of the eye movements on the same side, without loss of vision in that case.

Vision can be affected in some people. The 2023 report describes a man with vision loss and limited eye movement. Face numbness was also reported in that case. It is usually one-sided, although bilateral cases have been reported, according to the 2020 report.

• Constant pain behind or around one eye

• Double vision

• A drooping eyelid

• Limited movement of the eye

• Sometimes face numbness or reduced vision

The cause is not known. The 2020 report says the underlying mechanisms are controversial. The 2023 report describes infiltration of the cavernous sinus by lymphocytes and plasma cells with thickening of the dura, and says recent viral infection has been proposed as a risk factor.

It has been reported alongside autoimmune or inflammatory conditions including systemic lupus erythematosus, sarcoidosis and granulomatosis with polyangiitis, according to the 2023 report. That report also describes one patient whose symptoms began 14 days after cataract surgery, and notes this may be coincidence.

The 2020 report says patients range in age from 4 to 75 years, with no clear difference between men and women.

Because many serious conditions can cause painful eye palsy, the diagnosis is made after others are ruled out. The 2020 report lists the clinical criteria as one or more episodes of one-sided orbital pain lasting weeks without treatment, weakness of the third, fourth or sixth nerves or granuloma on MRI or biopsy, onset of weakness around the same time as pain, and pain and weakness that settle within 72 hours of adequate steroid treatment, with other causes excluded.

MRI is the imaging of choice. The 2023 report says it helps confirm inflammation and rule out alternatives such as lymphoma. The 2020 report mentions meningioma and sarcoidosis. MRI is not always abnormal at first. The 2023 report says studies found that between about 18% and 57% of people with the syndrome had normal imaging when steroid response was counted as a criterion, which may reflect the stage of disease, and repeat MRI at follow-up may show changes.

Tests for other causes are part of the work-up. In the 2020 case, tests for infection, inflammation, autoimmune markers and spinal fluid were all normal. Biopsy is reserved for unusual cases, because it carries risks.

Steroid medicine is the mainstay. The 2020 report says treatment consists of a high dose of oral prednisone for 4 weeks, with significant improvement often evident within the first 24 hours. It cites a study in which 77.5% of patients had complete relief of orbital pain within a week of starting steroids.

The 2023 report describes a more unusual case treated with intravenous methylprednisolone followed by oral prednisone, with partial improvement. Doses and duration are individual and decided by a specialist, so none of these figures are a guide for self-treatment.

The 2020 report adds that a good response to steroids supports the diagnosis but is not specific, so longer monitoring over several months is needed before the diagnosis is considered definite.

Eye pain with double vision, a drooping eyelid or any loss of vision needs prompt assessment. Contact NHS 111, an eye casualty or A&E the same day. Sudden severe headache, weakness, speech or facial changes, or sudden vision loss are emergencies for 999.

These symptoms can have other serious causes, including blood vessel, tumour and inflammatory conditions. This guide cannot tell you which applies to you. Ask for a doctor to examine you rather than waiting to see whether it settles.

In the NHS this is handled by hospital neurology, ophthalmology or neuro-ophthalmology teams, usually after an urgent referral from a GP, optometrist or emergency department. MRI and blood tests are part of that assessment.

A private neurologist or ophthalmologist can arrange MRI and specialist review quickly. Ask whether the clinician has experience with cavernous sinus and orbital inflammation, how other causes will be excluded, and how follow-up scanning and steroid monitoring will be arranged.