Bilateral Internuclear Ophthalmoplegia as a Presenting Manifestation of Primary Sjögren's Syndrome

The Experience of a Tertiary Reference Hospital in the Study of Rare Neurological Diseases

Background and Objectives: Rare diseases (RDs) are life-threatening or chronically impairing conditions that affect about 6% of the world's population. RDs are often called 'orphan' diseases, since people suffering from them attract little support from national health systems. Aim: The aim of this study is to describe the clinical characteristics of, and the available laboratory examinations for, patients who were hospitalized in a tertiary referral center and finally received a diagnosis associated with a Rare Neurological Disease (RND). Materials and Methods: Patients that were hospitalized in our clinic from 1 January 2014 to 31 March 2022 and were finally diagnosed with an RND were consecutively included. The RND classification was performed according to the ORPHAcode system. Results: A total of 342 out of 11.850 (2.9%) adult patients admitted to our department during this period received a diagnosis associated with an RND. The most common diagnosis (N = 80, 23%) involved an RND presenting with dementia, followed by a motor neuron disease spectrum disorder (N = 64, 18.7%). Family history indicative of an RND was present in only 21 patients (6.1%). Fifty-five (16%) people had previously been misdiagnosed with another neurological condition. The mean time delay between disease onset and diagnosis was 4.24 ± 0.41 years. Conclusions: Our data indicate that a broad spectrum of RNDs may reach a tertiary Neurological Center after a significant delay. Moreover, our data underline the need for a network of reference centers, both at a national and international level, expected to support research on the diagnosis and treatment of RND.

Total external ophthalmoplegia: First clinical manifestation of Sjögren's syndrome

Sjögren's syndrome (SS) is an autoimmune disease causing destruction of the exocrine glands secondary to lymphocytic infiltration. Common clinical symptoms of SS are xerostomia, xerophthalmia, myalgia, arthritis, and vasculitis. Neurological symptoms may precede the diagnosis of SS by up to 2 years in about 80% of patients. A 28-year-old female presented to us with complaints of horizontal and vertical diplopia along with inability to move the right eye and sudden drooping of the right upper eyelid. She was a recently diagnosed case of type 2 diabetes mellitus and had a history of foreign body sensation in both eyes for 4 months. Schirmers I test revealed less than 5 mm of wetting in both eyes after 5 min, suggesting dry eyes. On immunological blood investigations, serum c-peptide was normal, rheumatoid factor was negative, antinuclear antibodies were positive, and proliferating cell nuclear antigens were positive. Extractable Nuclear Ag profile RO 52 was strongly positive suggestive of primary SS. Lip biopsy revealed mild-to-moderate chronic inflammation showing irregular acanthotic epidermis, and dermis had perivascular lymphocytic infiltrate. Thus, the possible diagnosis of primary SS with type 2 diabetes mellitus and right-sided total external ophthalmoplegia was made. Patient was prescribed subcutaneous insulin, multivitamins, tear substitutes and alternate patching. Later on insulin was replaced by oral hypoglycemics. The external ophthalmoplegia completely resolved within 6 weeks. So, total external ophthalmoplegia can be added to the spectrum of central nervous system involvement in SS.