Tolosa Hunt Syndrome(THS) is a painful opthalmoplegia caused by idiopathic granulomatous inflammation of cavernous sinus or superior orbital fissure. It is a diagnosis of exclusion with an estimated annual incidence of one case per million per year(1U). We present a patient who presented with isolated 6th nerve palsy and was diagnosed for THS.
Case Report
A 50 year old Hispanic female with no relevant medical history presented with isolated pain in the left eye since 2 weeks and diplopia of sudden onset. She denied fever, trauma, recent surgery or travel. On examination, patient had lateral gaze paralysis , decreased visual acuity due to poor gaze fixation and diplopia. She did not have any other cranial nerve deficits. The rest of the systemic examination including the nervous system was unremarkable. MRI brain did not show any focal lesions. Lumbar puncture, Antibody assays for Connective Tissue Disorders, Lyme’s Disease ,Serum Protein Electrophoresis and other laboratory examinations failed to reveal any abnormality. After consultation with neurology and ophthalmology and their thorough investigation, patient was diagnosed for THS. She was started on prednisone 1mg/kg dose daily with resolution of symptoms in a few days.
Discussion
THS is described as “episodic orbital pain associated with paralysis of one or more of the third, fourth, and/or sixth cranial nerves”(6U). It is seen at almost any age without any gender or race discrimination. MRI shows changes in 44% of case only. In most cases it is diagnosed when all other vascular, neoplastic and inflammatory causes of painful opthalmoplegia are ruled out. Orbital pseudotumor is an important differential diagnosis as it differs only in relation to anatomic localization. Remission is possible in 40% of cases with ipsilateral, bilateral or contralateral involvement. Steroids are the mainstay for treatment. Initially given high dose upto 80mg daily, gradually the doses are tapered off. If need be other immunosuppresants like methotrexate, cyclosporine, mycophenolate mofentil and azathioprine can be tried. Usually the radiological improvement lags behind the clinical response to therapy. Though essentially a benign disease, neurological deficits are possible requiring long term immunosuppresion. The purpose of this case report is to reinforce the fact that THS can be a severely debilitating disease with dangerous consequences but at the same time if diagnosed appropriately, it can completely cure the patient. Thus THS should be at the back of the mind of all internists when a patient presents with similar signs and symptoms.
History
Patients present with usually severe retro-orbital or periorbital pain of acute onset. This pain may be described as constant and "boring" in nature.
Diplopia related to ophthalmoparesis follows the onset of pain (in rare cases, the ophthalmoparesis precedes the pain, sometimes by several days).
Patients may report visual loss. This is noted if the inflammation extends into the orbit to affect the optic nerve, and it is not a factor in disease limited to the cavernous sinus.
Paresthesias along the forehead may be described if the first division of the trigeminal nerve is involved.
THS is most often unilateral, although bilateral cases have been described.
THS frequently mimics other conditions; a single characteristic that is pathognomonic for this process does not exist. As such, realizing that this is a diagnosis of exclusion becomes even more important. Many of the processes that are found within the differential diagnosis of THS can have significant associated morbidity if not diagnosed and treated appropriately.
Physical
Painful ophthalmoparesis or ophthalmoplegia is the hallmark of this syndrome.
In addition to the optic and trigeminal nerves (V1, rarely V2 distribution), any of the ocular motor nerves may be involved. The oculomotor and abducens nerves are most commonly affected. Evidence of incomplete third nerve palsy with or without pupillary sparing may be present. Conversely, inflammatory involvement of the sympathetic nerves passing through the interior of the cavernous sinus may produce Horner syndrome with miosis. The combination of unilateral oculomotor palsy and Horner syndrome increases the localization specificity for the cavernous sinus.
Ptosis may be observed related to oculomotor palsy. Lid swelling is more likely to occur with orbital disease rather than inflammation limited to the cavernous sinus.
Mild proptosis and/or optic disc edema may be noted if the orbit is involved.
Evidence of trigeminal nerve involvement is suggested by loss of the ipsilateral corneal reflex.
The International Headache Society criteria for THS include the following:
Episode(s) of unilateral orbital pain for an average of 8 weeks if left untreated
Associated paresis of the third, forth, or sixth cranial nerves, which may coincide with onset of pain or follow it by a period of up to 2 weeks
Pain that is relieved within 48 hours of steroid therapy initiation Exclusion of other conditions by neuroimaging and (not compulsory) angiography
Causes
The cause of THS is unknown (idiopathic).
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