Evaluation of orbital disorders and cranial nerve innervation of the extraocular muscles

A Case of Orbital Myositis Presenting With Dizziness

BACKGROUND:

Orbital myositis is an idiopathic, inflammatory, non-infectious condition, typically confined to more than one extraocular muscle and usually targeting young females in their third decade.

CASE REPORT:

We describe a case of orbital myositis uncommonly afflicting an adult male. He initially presented with a sensation of dizziness when turning his head and mobilising, together with right-sided orbital pain that failed to respond to the vestibular sedative cinnarizine. Failure to resolve and development of diplopia initially prompted a working diagnosis of ocular myasthenia gravis. On further investigation using HESS charting, paresis in the inferior and medial rectus and superior oblique ocular muscles of the right eye were elicited correlating with clinical examination. However, the lack of response to low dose steroids and acetylcholinesterase inhibitors, together with a negative screen for myasthenia antibodies, precluded a diagnosis of ocular myaesthenia gravis from being made. Other investigations included a high creatinine kinase and lactate dehydrogenase which indicated pathology in the extraocular muscles themselves. An MRI scan showed normal extraocular muscle thickness while excluding other orbital pathology. Exclusion of a variety of other conditions subsequently led to a diagnosis of orbital myositis.

CONCLUSION:

Response to high dose steroids consolidated this diagnosis with a rapid response ascertained clinically by resolution of pseudo-vertigo and pain, as well as the ophthalmoplegia with follow-up on HESS charting. We aim to raise awareness of this rare condition that carries a good response to steroids.

Magnetic Resonance Imaging in Orbital Pathologies: A Pictorial Review

Orbital lesions form a wide range of pathologies, that create challenges in diagnosis, management, and treatment. The high-resolution soft tissue detail provided by magnetic resonance imaging (MRI) has allowed for better lesion characterization. Especially in cases where history and clinical evaluation are insufficient, MRI plays a crucial role. MRI is also important in the detection of the extent of orbital diseases. The aim of this study was to examine the MRI characteristics of common and/or rare diseases arising from or extending into the orbita to aid radiologists in the correct diagnosis of orbital lesions.

Orbital inflammatory disease: Pictorial review and differential diagnosis

Orbital inflammatory disease (OID) represents a collection of inflammatory conditions affecting the orbit. OID is a diagnosis of exclusion, with the differential diagnosis including infection, systemic inflammatory conditions, and neoplasms, among other conditions. Inflammatory conditions in OID include dacryoadenitis, myositis, cellulitis, optic perineuritis, periscleritis, orbital apicitis, and a focal mass. Sclerosing orbital inflammation is a rare condition with a chronic, indolent course involving dense fibrosis and lymphocytic infiltrate. Previously thought to be along the spectrum of OID, it is now considered a distinct pathologic entity. Imaging plays an important role in elucidating any underlying etiology behind orbital inflammation and is critical for ruling out other conditions prior to a definitive diagnosis of OID. In this review, we will explore the common sites of involvement by OID and discuss differential diagnosis by site and key imaging findings for each condition.