Title: Unilateral Abducens and Occulomotor Nerve Neuroborreliosis

Author(s): Ashim Rupakheti, MD; Rasik Neupane, MD; Michael Kentris, DO

Email: arupakheti@mercy.com

Introduction: Lyme disease is caused by the spirochete Borrelia burgdoferi transmitted by Ixodes tick in the United States[1]. In 2022, approximately 63,000 cases of Lyme disease Lyme disease were reported to CDC by state health departments. Invasion of central nervous system by the spirochete causes Neuroborreliosis. This case describes a patient with atypical presentation of Lyme disease.

Case Report(s): A 77-year-old male with a past medical history of Diabetes mellitus, Hypertension, Heart failure with preserved ejection fraction, Atrial fibrillation on Eliquis, and chronic kidney disease presented to the hospital with complaints of worsening double vision for 2 months. On examination, findings showed dilated and limited reaction to direct and consensual light of the right pupil and restricted abduction and elevation of extraocular muscles with ptosis of the right eye. The remainder of the neurological examination was unremarkable. Other systemic examination and lab findings were normal. Workup before presentation with imaging of brain and vessels was unremarkable. Repeat imaging with CT head was unremarkable with CTA neck and head showing no flow-limiting stenosis or evidence of cerebral venous sinus thrombosis. Acetylcholine binding antibody, ANA, and angiotensin-converting enzyme were normal. Lyme serology showed increased antibody levels with increased IgG which was confirmed by western blot IgG. The patient was discharged on a 30-day course of Doxycycline and followed up in the outpatient clinic. The patient had 99% improvement of symptoms at follow-up.

Discussion: Lyme disease is multisystem inflammatory disease caused by spirochete. Most common vector-borne disease in US. Transmitted by Ixodes ticks. Can be early localized disease to early and late disseminated disease. About 25% of patients with Lyme disease recall  tick bite.  Neuroborreliosis is used to describe Lyme disease of the CNS. Cranial neuritis is common presentation in Lyme neuroborreliosis and can occur in upto 43%. Facial nerve palsy accounts up to 95% of cases presenting with CN palsy followed by oculomotor nerve palsy. Our case presented with unexplained double vision with unilateral Abducens and Oculomotor nerve involvement. As facial nerve palsy is  most common clinical manifestation of Neuroborreliosis, unilateral to bilateral cranial nerve involvement require evaluation. Early initiation of appropriate antibiotics helps achieve best outcomes.

Conclusion: Unexplained cranial nerve palsies and other neurological manifestations must be evaluated for atypical Lyme disease. Early diagnosis and management decrease chronicity and better neurological outcomes.