TOLOSA-HUNT SYNDROME IN CHILDREN

caused by proliferation of non specific inflammatory tissue in the cavernous sinus, superior orbit fissure or orbital apex. It manifests by painful ophtalmoplegia and paralysis of one or more oculomotor cranial nerves. TSH is characterized by rapid sustained response to corticosteroid therapy. In 1954, Tolosa reported the first clinical features and revealed a low-grade granulomatous inflammation in an autopsy of a patient with left ophthalmoplegia (1). In 1960, Hunt and al. reported the clinical criteria of Tolosa-Hunt syndrome (2). The evolution of sectional imaging (CT and MRI) has encouraged the International Headache Society (IHS) to include the presence of abnormal inflammation tissue in cavernous sinus and orbital apex by MR in the diagnostic criteria (3). This implies that TSH is no longer diagnosed by elimination.

Tolosa-Hunt syndrome (TSH) is caused by proliferation of non specific inflammatory tissue in the cavernous sinus, superior orbit fissure or orbital apex. It manifests by painful ophtalmoplegia and paralysis of one or more oculomotor cranial nerves. TSH is characterized by rapid sustained response to corticosteroid therapy. In 1954, Tolosa reported the first clinical features and revealed a low-grade granulomatous inflammation in an autopsy of a patient with left ophthalmoplegia (1). In 1960, Hunt and al. reported the clinical criteria of Tolosa-Hunt syndrome (2).
The evolution of sectional imaging (CT and MRI) has encouraged the International Headache Society (IHS) to include the presence of abnormal inflammation tissue in cavernous sinus and orbital apex by MR in the diagnostic criteria (3). This implies that TSH is no longer diagnosed by elimination.

Case report
A 4-year-old girl presented with several episodes of convulsions. Clinically she had right-sided hemiparesis and contralateral ophthalmoplegia related to sixth nerve palsy. CT scan revealed a soft tissue mass in the left cavernous sinus extending to the skull base and enhancing strongly after contrast injection (Fig. 1). MRI also showed enlargement of the cavernous sinus occupied by abnormal tissue (hypointense on T1 and isointense on T2 compared to gray matter) and done without delay showed at this time still an occlusion of the intracavernous segment of the internal carotid by the lesion and signs of cytotoxic oedema in watershed areas (hyperintense on diffusion imaging and hypointense on corresponding ADC map) (Fig. 3). These findings were consistent with an ischaemic cerebrovascular accident. Diagnosis of TSH was proposed and the child was started on high-dose corticosteroids for a period of 2 months.
After that period, a control MRI showed few sequelae of the ischaemic lesion in the left hemisphere presenting as T2 hyperintensities in the white matter, compatible with gliosis. The soft tissue mass occupying the cavernous sinus had completely disappeared and the internal carotid artery looked patent and of normal size (Fig. 4). Clinically, the child had almost completely recovered from the motor deficits.

We report a case of Tolosa-Hunt syndrome in a 4-year-old girl. Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) revealed a left cavernous sinus involvement with internal carotid artery occlusion. Clinical signs
included left ophthalmoplegia, convulsions and right hemiplegia. Etiopathogenesis of this syndrome is unclear but as in our case, response to corticosteroid therapy is spectacular and avoids unnecessary invasive diagnostic procedures. We underline the importance of cross-sectional imaging in the diagnostic approach. Several other diseases including tumors, vascular lesions and infections can have a similar clinical and/or imaging presentation. However, closely monitored evolution on imaging proves to be decisive in the establishment of final diagnosis of this syndrome.

Discussion
TSH syndrome is defined as the presence of granulomatous and inflammatory soft tissue in the cavernous fossa, in the orbit apex or in the orbit itself (4). Its etiology remains unclear. As in our case, it is characterized by rapid response to corticosteroids and obviates the need for surgical exploration which can be hazardous due to small amount of pathological tissue and its relative inaccessibility. Clinical presentation which associates ophtalmo-ernous fistula can develop giving rise to exophtalmia and chemosis. In that case, MRI shows ophtalmic and cavernous veins dilatation (7).
Although rare in children, cavernous meningioma can give the same symptoms and presents the same features on MRI (hypointense on T1 and strong enhancement after injection) (8). Nevertheless, there is no response to steroid treatment.
Primitive lymphoma is rare and usualy bilateral. It can particularly mimic THS as it also responds to steroid therapy (9). However, its plegia during more than 2 months and one or more cranial nerve palsy with rapid response to steroid treatment allows the diagnosis to be evoked (5), after having discarded other diseases with a similar presentation. These include aneurysm of the intracavernous segment of internal carotid artery, carotid-cavernous fistula, intra-cavernous meningioma, primitive lymphoma, tuberculosis and sarcoidosis (6).
CT or MR angiography can easily exclude an aneurysm of the carotid artery. If complicated, a carotid-cav-  CT and MRI carried out in our patient have shown abnormal tissue (designated by Tolosa as being granulomatous) strongly enhancing after gadolinium injection and causing enlargement of the cavernous sinus with convex bulging of the external borders of the dura-mater. These correspond to the 3 primary criteria of THS on MRI (10). Low intensity on T1 imaging and strong contrast enhancement are in agreement with other case published in the literature (11).
As in the first case published by Tolosa in 1954, we found a stenosis of the intra-cavernous segment of one internal carotid artery in our patient. Potentially damaging cerebral lesion stresses on the gravity of this syndrome and on the importance of an early diagnosis. We also highlight the use of an early and aggressive steroid therapy (5) which, in our case, almost completely resolved the lesions and the symptoms.

Conclusions
TSH is a rarely reported affection in children. Its consequences can be damaging especially by the occurrence of cerebral complications. Early diagnosis can be established by associating the clinical setting and the use of cross-sectional imaging. Steroid therapy can hence be started without delay, with spectacular results.