Bilateral visual loss in the Tolosa-Hunt syndrome

This paper describes a 65-year-old man with Tolosa-Hunt syndrome who presented with unilateral painful ophthalmoplegia and bilateral visual loss. Cranial CT scan revealed an enhancing mass at the right superior orbital fissure and optic canal but a biopsy showed only chronic inespecific inflammation. Treatment with corticosteroid resulted in marked improvement although ODe eye rem ained blind. The inflammatory process involved the right superior orbital fissure and optic nerve and presumably extended across the skull base to involve the contralateral optic nerve.


INTRODUCTION
The Tolosa-Hunt syndrome (THS) is a non specific inflammatory condition of the cavemous sinus and superior orbital fissure area.Clinical fr ndings incIude headache, involvementofthe third, fo urth and sixth cranial nerves and sensory loss in the ophthalmic division of the tri geminal nerve (I).Severe visual loss is uncommon and usually restricted to the side of the ophthalmoplegia (2.7).
This paper documents one patient with THS who presented with the unique com bination of unilateral painful ophthal moplegia and bilateral visual loss.

CASE REPORT
A 65-year-old previously healthy man was admitted to the hospital because of a two months history of increasingly severe right sided headache radiating from the right retroorbital region and progressive visual loss in the right eye (00).Two weeks prior to admission the headache worsenedandhe becameblind in OD.One week later he noticed droopiness of the right eyelid and blurr ed vision in the infe rior field of vision on the left eye (OS).
On examination, the vision was no light perception in 00 and 20/20 in OS.There was an almost complete ptosis and absence of elevation of 00.Adduction, abduction and depression of this eye as well as the movements of the left eye were normal.There was no proptosis.Slit lampexaminationandintraocularpressure measurements were normal in both eyes.The right pupil was slightly larger than the left and showed no direct reaction to light but would react normally when the left eye was ilIuminated.Ophthalmoscopy showed only slight paleness of the right optic disco The left eye was normal.Goldmann perimetry discIosed an infe rior depression of the isopters in OS.
General physical and neurological examination were otherwise unremark able.The results of a complete blood count, erythrocyte sedimentation rate, glucose, VDRL, FI A-ABS, creatinine, serum protein electrophoresis, electrolites, PPD and chest X-ray were normal.A spinal tap was normal except for the http://dx.doi.org/10.5935/0004-2749.19930026finding of II cells, mostly Iymphocytes.Acranial CT scan did not show abnor malities but on1y thick axial cuts ,were obtained.A right temporal artery biopsy was negative.
Ris headache persisted and there was progressive worsening of the ophthal moplegia.One week later he had com plete third and fourth nerve palsies.A repeat visual field showed worsening of the defectin OS (Figute I).Treatment with 100 mg of oral prednisone a day was initiated.A fe w hours after the fiest dose the pain was gone.Over the fo llowing weeks there was gradual improvement of the ophthalmoplegia on the right side and ofthe field defect in OS.Prednisone was slowly tapered to 10 mg a day.Two months later there was on1y 1 mm ofright ptosis.The right eye remained blind but the left visual field had returned to nor mal.The right optic disc showed severe atrophy and the left appeared normal.
Shortly thereafter, the headache re curred.A repeat CT scan revealed an enhancing mass occupying the right su perior orbital fissure and enlargement of the optic nerve at the optic canal and orbital apex (Figures 2 and 3).A biopsy througharight frontotemporal craniotomy was performed in order to rule out an underlying neoplastic processo At suc-gery, the cbiasm, optic nerves and adj a cent structures seemed normal.The optic canal was unroofed butno tumor couId be found.It was remarkable that there was on1y soft tissue separating the medial side ofthe optic canal and the sphenoid sinus.
The impression was that the bone was decalcified in this area.Several biopsy specimens were obtained from the intracranial and intracanalicuIar portions of the right optic nerve, the adj acent dura and the bone of the optic canal.
Histologic sections showed only perivascular infiltration of lymphocytes in the optic nerve and duramater.Special stains for fungi and acid fast bacteria were negative.The pathologic diagnosis was chronic inespecific inflamm atory process, consistent with the diagnosis of THS.
Post operative recovery was unevent fuI.Follow up examinations up to four years later showed that bis condition was unchanged.Headache had not recurr ed.

DlSCUSSION
This case fuIfils the criteria for the diagnosis of Tolosa-Hunt syndrome (ll.However, it showed the unusual finding of bilateral visual loss with complete optic atrophy in one eye.Visual loss is uncommon in the THS.KIine (l)reviewed , 145 cases ofthe syndrome reported up to 1982.Analysis ofthese patients revealed only 10 with documented visual loss (2.8).The optic nerve involvement was always unilateral and generally improved with corticosteroid treatment although 4 pa tients developed optic atrophy (2,4.6.7) .
The present case is unusual because of the complete optic atrophy and blindness that developed on the side of the ophthalmoplegia and the contralateral optic nerve involvement.This is remark able since THS has generally been con sidered a unilateral disease.However, due to the rarity of detailed post mortem studies, very limited information on the extent ofthe pathologic process is avail able in this condition.Untilrecently, only Tolosa' s original case had been studied at autopsy.A second, still unreported case was studied at the University of Califor nia San Francisco.A 75-year-old patient had painful ophthalmoplegia with involve ment of the left II through VIII cranial nerves.Treatment with bigh dose of ster oids was complicated with gastrointestinal bleeding that culminated with bis death.At autopsy, there was thickenning ofthe dura overlying the left cavemous sinus, clivus and superior orbital fissure.These changes extended across the midline to involve the right side.Microscopic sec tions showed granulomatous inflamma tion containing bistiocytés, lymphocytes and plasma cells, This case shows that the pathologic process in the THS may not be restricted to the cavemous sinus and su perior orbital fissure.It can be much mQre diffuse, involving other cranial nerves and extending to the contralateral side.Six out of 146 cases reviewed by Kline were bilateral although none ofthem had bilateral optic nerve involvement (I).
ln the present study, the CT scan and bistolog i c findings indicated that the right sided blindness was caused by the exten sion of the inflamm atory process to the right optic nerve at its intracranial, intra canalicular or proximal orbital segment.Presumably, tb.e contralateral visual field 4RQ.BRAS.OITAL.56, (5), OUlUBRO/1993

Bilateral visual loss in the
To losa-Hunt sy ndrome loss was caused by extension of the in flamm atory process across the skull base to involve the opposite optic nerve.Al though the altitudinal type offield defect in OD suggested an ischemic event, its complete reversal with treatment is much more compatible with an inflamm atory processo The presence of a mass at the superior orbital fissure and the enlargement ofthe optic nerve demonstrated by the CT scan in this case is also very unusual.These findings led us question the accuracy of the diagnosis of THS and .
prompted the performance of the biopsy.Classically, radiologic abnormalities in the THS have been restricted to carotid artery narr ow ing on angiography, occlusion ofthe su perior orbital vein and sella turcica ero sion on plainX-ray tomography.CT scan have generally been considered to be normal (I).With improved resolution of CT scanandmagneticressonance imaging studies, more recent studies have demon strated the presence of enhancing lesions in the area of the cavemous sinus and superior orbital fissure, similar to the one we have observed in our patient (10,11) .Such findings could also have been caused by anumber of other conditions including me ru ngioma, carcinoma, metastasis, lym phoma, sarcoidosis and Wegener' s granu lomatosis (1,1 0 .11) .Some ofthese conditions can present clinically as painful oph thalmoplegia and simulate the THS.Fur thermore, the dramatic improvement with bigh dose corticosteroid therapy, that has beenrecommended as a diagnostic test fo r THS, has also been reported with other causes of painful ophthalmoplegia includ ing neoplasms (I).Therefore, it is impor tant to emphasize that the THS should still be a diagnosis of exclusion.