1323 - A Novel Presentation of Lyme Neuroborreliosis: Cranial Nerve III Palsy with Contralateral Brachial Plexopathy

Thursday, February 19, 2026

5:00 PM - 6:30 PM AST

Presenting Author(s)

TS

Tanvee Sinha, MD, MPH

PGY1 Resident Physician
Georgetown/Medstar
Birmingham, District of Columbia, United States

Co-Author(s)

HK

Hassan Khuram, MD

Resident Physician
Medstar Georgetown University Hospital
mclean, Virginia, United States
NS

Nicholas Streicher, MD MPH

Assistant Professor
MedStar Georgeotwn University
Washington, District of Columbia, United States

Submitter(s)

TS

Tanvee Sinha, BS, BA

University of Alabama at Birmingham
Birmingham, Alabama, United States

Case Diagnosis: Lyme neuroborreliosis (LNB) can present with cranial neuropathies and radiculomyelopathies, diagnosed by two-tier serum testing and CSF inflammation and treated with oral doxycycline.

Case Description: A 55-year-old man presented with acute left eye pain and partial left cranial nerve III palsy, accompanied by right upper extremity (RUE) pain followed by weakness, 2 weeks later, consistent with Parsonage-Turner syndrome. The exam confirmed the partial oculomotor palsy and RUE sensory predominant deficits with mild distal weakness, impacting dexterity and fine motor control. Labs showed eosinophilia with elevated ESR/CRP, and CSF showed monocytic pleocytosis with elevated protein. EMG/NCS showed motor unit potential abnormalities and reduced interference patterns in C8-T1 myotome. MRI brain showed mild perineural enhancement along CN III, and serum Lyme IgM/IgG were positive. The constellation of subacute left CN III palsy and right upper limb plexopathy, positive serology, inflammatory CSF and imaging supports LNB. Confirmatory testing returned with CSF positive for B. burgdorferi IgG antibody index.

Discussions: Given no parenchymal CNS involvement, oral doxycycline 100mg twice daily was initiated for 21 days. One week later, patient reported that eye pain had resolved and his upper extremity was much improved. Neurology advised continuation of antibiotics and complete confirmatory testing with positive CSF LNB antibodies. Rehabilitation focus includes targeted proximal and distal RUE strengthening, sensory re-education, task-specific fine motor retraining, and workplace accommodations. For the residual brachial plexopathy, typical recovery times range from several months to 3 years, with most initial motor recovery occurring within the first 6-12 months.

Conclusions: This case represents a novel LNB phenotype of CN III neuropathy with contralateral brachial plexopathy. Guideline-concordant diagnostics (serum serology, CSF inflammation) and MRI enhancement informed treatment and
rehabilitation planning. The approach emphasizes early mobilization and graduated functional restoration, with expected recovery trajectory of 6-12 months for most motor function based on Parsonage-Turner syndrome natural history.