Abstract
Tolosa–Hunt syndrome (THS) consists of a painful ophthalmoplegia with typical features in magnetic resonance imaging (MRI). The recurring nature of this affliction has been known since its first description. However, compromise of the contralateral cavernous sinus, known as alternating THS, is very rare and has never been examined using MRI. We report clinical data, laboratory data and imaging features of a patient with alternating THS. According to our literature review, this is the first MRI study of THS.
Introduction
Tolosa–Hunt syndrome (THS) consists of a painful ophthalmoplegia caused by an idiopathic chronic granulomatous inflammation of the cavernous sinus that can extend to the superior orbital fissure. The 2004 revised diagnostic criteria of THS of the international classification of headache disorders, 2nd edn (1) include magnetic resonance imaging (MRI) as a complementary diagnostic tool capable of demonstrating the local inflammatory process, thereby reducing the necessity for biopsy (2).
There are reports in the literature of the occurrence of bilateral idiopathic painful ophthalmoplegia (3, 4). There are also reports of a peculiar and rare alternating form of this disease that compromises the contralateral sinus with a variable interval after the first outbreak (5–8). However, when searching the Medline database, we found no report on the MRI characteristics of alternating THS. Our search included the following terms: English language, humans, image, MRI and alternating Tolosa–Hunt syndrome. Even in the most comprehensive study, recurrence predominantly involved the previously compromised sinus (2).
In this study we describe the clinical and laboratory data of a patient with alternating THS. We also discuss our MRI findings to support its applicability as a complementary diagnostic method for THS (2), including its alternating form.
Case report
A 23-year-old woman complained of intense occipital headache lasting 1 month, with insidious onset and holocranial irradiation. The headache was characterized by pressure and was associated with phono- and photophobia, nausea and vomiting. As it evolved, it also presented diplopia, left palpebral ptosis, periorbital pain and paraesthesia in the homolateral hemiface. Physical examination demonstrated hypoaesthesia in the left V1 territory and paresis of the left superior and inferior rectus muscles, denoting compromise of the III cranial nerve. The results from various standard laboratory examinations (blood count, C-reactive protein, cerebrospinal fluid) were normal. MRI was performed using T1 and T2 thin slices (2.0 mm thickness) to evaluate both cavernous sinuses and orbital apices, in three orthogonal planes. We added fat suppression to all the sequences and acquired the T1 images after intravenous administration of gadolinium. These images showed compromise of the left cavernous sinus, which was filled with tissue that presented an intermediate signal in T1 and a hyposignal in T2-weighted images. This tissue bulged into the lateral wall of the sinus, extending anteriorly towards the superior orbitary fissure. Intravenous injection of gadolinium showed marked enhancement of the affected area. In addition, the left intracavernous internal carotid artery displayed luminal narrowing (Figure 1a,b).
(a,b) MR axial and coronal T1 post-contrast using fat saturation depicting luminal narrowing of the left internal carotid artery associated with compromise of the left cavernous sinus. Observe the asymmetric enhancement of the left cavernous sinus extending towards the superior orbital fissure (arrow). (c,d) MR axial and coronal T1 post-contrast obtained during the recurrence event (117 days later) show an identical pattern, but now affecting the contralateral cavernous sinus (small open arrow).
Corticotherapy with 60 mg/day of prednisone was prescribed. This led to prompt recovery from the headache and to partial resolution of the diplopia, with the patient leaving hospital 5 days after admission.
After a 4-month interval during which there were no complaints, nor any corticoid treatment, the patient returned to hospital with a new episode of headache associated with diplopia. Physical examination confirmed right convergent strabismus, denoting an affect on the VI cranial nerve. There were no other clinical findings. Results from the laboratory examinations were again normal. In contrast to the first episode, the MRI conducted using a protocol identical to the one used 4 months before showed normal aspect of the left cavernous sinus. However, when examining the contralateral sinus, MRI showed the occurrence of alterations similar to those previously described, configuring the alternating THS (Figure 1c,d). Once again, corticotherapy with 60 mg/day of prednisone was prescribed. The patient left the hospital 3 days after admission with complete resolution of the pain.
During her following visits, we obtained additional MR images to evaluate clinical correlation and theprogressive improvement of the affection (Figure 2). Complete resolution of MR abnormalities was first observed by the third medical appointment (152 days after the second episode).
Comparative MR post-contrast images obtained 36 days after the second event (a,b) show persistent asymmetric enhancement of the cavernous sinus and luminal narrowing of the right internal carotid artery (open arrow). (c,d) Complete resolution is observed 152 days after the second event. Observe the normal appearance of both cavernous sinuses and internal carotid arteries.
Discussion
In 1954, Tolosa reported a case of idiopathic painful ophthalmoplegia and established the granulomatous nature of the disease, emphasizing the compromise of the cavernous sinus and the internal carotid artery (9). In 1961, Hunt et al. described similar clinical features in six additional patients, and they proposed the first diagnostic criteria for this disease. These authors also emphasized the recurrent nature of the process, and the dramatic response of the pain to systemic corticotherapy (10).
With long-term follow-up, the recurrent nature of the disease has been observed in up to 40% of patients (2, 5). The simultaneous compromise of both cavernous sinuses has been described in 3–4% of all cases of THS (3, 4). However, current literature emphasizes that secondary aetiology must be ruled out in the setting of bilateral compromise (3).
There are only a few clinical reports of alternating THS. Using the aforementioned Medline search parameters, we were able to find only the set of cases reported by Jiménez-Caballero et al. (5), which described the clinical features of an alternating form of THS, yet did not include any MRI findings. Ohyama (6) also described a case of alternating THS, which presented marked response to corticotherapy. Other reports of this clinical affection were found (7, 8), but all lacked structural MRI data.
The angiographic patterns of the alternating THS are relevant to the understanding of the inflammatory abnormalities in both compartments (venous: cavernous sinus and superior orbitary vein; and arterial: intracavernous internal carotid artery) (6). However, this method is currently considered obsolete for the specific diagnosis of THS and for the establishment of its differential diagnosis. Schuknecht et al. proposed the diagnostic criteria for the employment of MRI to the diagnosis of THS and showed its usefulness in a series of THS patients (including recurrent THS) (2). Moreover, MRI has been shown to be highly accurate in the diagnosis of several affections involving the cavernous sinus (2,11,12). This further reinforces its inclusion in the proposed criteria for THS syndrome.
Our report confirms the usefulness of MRI for demonstrating the typical abnormalities of THS, particularly when fat suppression and gadolinium intravenous administration are incorporated into the MR protocol. It is also helpful for diagnosis and follow-up, corroborating the applicability of the criteria proposed by Schuknecht et al. MRI is also useful for the differential diagnosis of THS (13) and to confirm clinical reversion after corticotherapy, although it is not possible to exclude this affection with normal MRI (14–16). Despite the prompt relief of pain after corticotherapy, usually within the first 72 h, the resolution of the underlying process shown by MRI may take longer, sometimes several months (12, 14). Our observation of a complete resolution of MR abnormalities 5 months after the relief of pain is consistent with previous reports (12).
Inflammatory affections such as tuberculosis and sarcoidosis, and neoplasms such as lymphoma and metastasis, constitute the main differential diagnoses. It is important to emphasize that some diseases, such as lymphoma and idiopathic inflammatory vasculopathies, can recrudesce after corticotherapy (14). Cavernous sinus dural biopsy is rarely employed these days because of its technical complexity and inherent risks. ICHD-II diagnostic criteria (1) conclude that MRI is a useful alternative to biopsy, reserving the latter for those patients with rapidly progressive neurological deficits, in the absence of clinical improvement and persistence of imaging findings even with corticotherapy (17).
Despite the inherent limitations of a case report, our description reinforces the use of appropriate MRI protocols for diagnosis and imaging follow-up of THS, including its alternating form. Our report is consistent with previous research regarding the clinical features and the response to corticotherapy of alternating THS. Furthermore, it confirms that the disappearance of MRI findings take longer than the relief of pain, further suggesting that MRI could be used to monitor the progression of the disease. We also believe that the MRI patterns can be useful for diagnosis and clinical intervention in this rare affection and should be used simultaneously with THS criteria.