94 Chapter 6: Failure of pattern recognition

Table 6.2 Etiologies of cavernous sinus syndrome

Tumors meningioma lymphoma

nasopharyngeal carcinoma pituitary tumor

metastatic disease Vascular abnormalities

internal carotid artery aneurysm carotid or dural fistula cavernous sinus fistula

Inflammatory disorders sarcoidosis

syphilis tuberculosis

Wegener’s granulomatosis fungal disease (e.g. aspergillosis)

Figure 6.4 Another example of the radiographic findings in a cavernous sinus syndrome. Axial post-contrast T1-weighted MR image of a 60-year-old woman with a cavernous sinus meningioma shows expansion of the left cavernous sinus producing loss of the usual concavity seen on the normal right side (arrow). This is an early (though non-specific) sign of cavernous sinus disease.

abnormality is present but wrongly attributed to normal asymmetry of venous flow within the cavernous sinuses.

The radiographic abnormalities associated with THS are non-specific and can also be seen in other inflammatory conditions and with a variety of

neoplasms including meningioma, lymphoma and metastatic tumors. There are no established MRI criteria for the diagnosis of THS. In addition to highquality imaging, investigations should include serologic tests for inflammatory disorders (complete blood count (CBC), erythrocyte sedimentation rate (ESR), angiotensin converting enzyme (ACE), fluorescent treponemal antibody (FTA) and antineutrophilic cytoplasmic antibodies), tests for tuberculosis (TB skin test and chest radiograph), urinalysis and lumbar puncture. Referral to an otolaryngologist should be considered to further investigate for nasopharyngeal tumor or fungal disease. In some cases, a biopsy of the nasopharynx is appropriate, even in the absence of abnormalities on the mirror examination.

The etiology of the inflammatory process in THS is unknown. As in other forms of idiopathic inflammation, corticosteroids are the mainstay of treatment. Resolution of pain within 24–48 hours of initiation of steroids is characteristic but non-specific, as other inflammatory and even neoplastic processes involving the cavernous sinus may also be dramatically steroid-responsive.

Diagnosis: Tolosa Hunt syndrome

Tip: The clinical features of a cavernous sinus/superior orbital fissure syndrome are highly localizing, but radiographic abnormalities are easily overlooked.

Painful ophthalmoplegia and visual loss

Case: A 58-year-old homemaker with a past history of breast cancer experienced left-sided headaches followed one month later by vertical diplopia. Examination at that time showed slight left upper lid ptosis and a mild left hypotropia with normal afferent visual function. Over the next few weeks, left eye movements became increasingly limited and she developed dimming of vision in that eye. A CT scan was reportedly normal. Neuro-ophthalmic examination two months after onset of symptoms showed complete ophthalmoplegia of the left eye and a left optic neuropathy. Visual acuity was 20/80 OS with

poor color vision and a central scotoma (Figure 6.5A and B). All findings in the right eye were normal.

Based on the clinical findings, where is the lesion?

Based on the clinical features, a lesion at the orbital apex was suspected. A new CT scan showed a lesion at the left superior orbital fissure extending into the orbital apex (Figure 6.5C).

The clinical and radiographic findings were most consistent with metastatic disease. A nuclear bone scan revealed increased uptake in the thoracic and lumbar spine and in several ribs, confirming widespread metastatic disease beyond the orbit. She received radiation therapy to the left orbital apex and was started on chemotherapy. Just as radiation was begun she suffered additional loss of vision in

the left eye due to central retinal artery occlusion. Following completion of radiation, her ocular motility improved but vision in that eye failed to recover.

Discussion: Involvement of the ocular motor nerves as they enter the orbit through the superior fissure accompanied by optic neuropathy comprises the orbital apex syndrome. Clinical findings are the same as those seen in the spheno-cavernous syndrome with the addition of ipsilateral visual loss and variable proptosis. In its complete form there is paralysis of all eye movements, oculosympathetic palsy and sensory loss and/or pain in the distribution of the first division of the trigeminal nerve, as well as optic neuropathy. Incomplete forms are common, however, and should be recognizable to the clinician. Because of the close