Tolosa Hunt Syndrome
Tolosa Hunt Syndrome is a rare idiopathic, non specific granulomatous inflammation of the cavernous sinus and/or superior orbital fissure which causes painful ophthalmoplegia or painful restriction movements of extraocular muscles. The estimated incidence of this syndrome is one case per million per year. It considers a benign condition but sometimes it can cause permanent neurological deficit.
It is rare to occur during the first two decades of life. These painful movements occur due to inflammation of cranial nerves that pass through cavernous sinus and superior orbital fissure. These cranial nerves are Oculomotor (III), Trochler (IV), Abducens (VI) and first branch of Trigeminal Nerve (V).
Causes of Tolosa Hunt Syndrome
Tolosa Hunt Syndrome is an idiopathic disease with no known causes.
Signs and Symptoms of Tolosa Hunt Syndrome
Tolosa Hunt Syndrome has the clinical course of remission and recurrence and it is characterized by acute onset of unilateral:
1- Retro orbital or Periorbital Pain.
2- In 4% to 5% the condition can be bilateral .
3- Painful Ophthalmoplegia or Ophthalmoparesis which can lead to diplopia or double vision.
4- Dysfunction of the pupil. Pupil is innervated by sympathetic and parasympathetic fibers. Sympathetic fibers are responsible for Pupil dilation while parasympathetic fibers are responsible for pupil constriction or miosis. Parasympathetic fibers are passing through Oculomotor nerve while sympathetic fibers are passing through Abducens nerve and also around arteries.
5- Paresthesia or loss of sensation of the cornea and forehead. These areas are supplied by Trigeminal nerve.
6- Sometimes the optic nerve can be affected by the inflammation which can lead to blurred vision.
7- Mild Proptosis and lid swelling can occur if the condition affects the orbit and its content.
Diagnosis of Tolosa Hunt Syndrome
International headache society criteria for Tolosa Hunt Syndrome include:
1- One or more episodes of unilateral orbital pain that lasts for 8 weeks if left untreated.
2- Paralysis of Oculomotor, Trochler and Abducens cranial nerves that begins within 2 weeks of orbital pain.
3- Improvement of symptoms within 48-72 hours of initiation of corticosteroid treatment.
4- Exclusion of other diseases by investigations which include neuroimaging. MRI with Contrast is the modality of choice.
Tolosa Hunt Syndrome is a diagnosis of exclusion because there are many diseases that can mimic its clinical presentations such as tumors, sarcoidosis, Wegener's granulomatosis, systemic lupus erythematosus, Multiple sclerosis and thyroid eye disease. For this reason laboratory tests are very important to rule out these diseases.
Treatment of Tolosa Hunt Syndrome
Corticosteroid is the drug of choice to treat this condition. High dose corticosteroid for two to six weeks followed by tapering the dose within weeks to several months.
There is significant reduction of pain within 24-72 hours of the initiation of corticosteroid and this can help to confirm the diagnosis.
Improvement of cranial nerves functions and regression of MRI abnormalities can occur within 1-8 weeks.