INTRODUCTION: Lyme disease is not uncommon and can sometimes progress to neurological complications. We report here an unusual case of bilateral diaphragmatic paralysis secondary to Lyme neuroborreliosis. CASE REPORT: A 79-year-old man was admitted to the intensive care unit for acute respiratory distress requiring intubation and the long-term use of nocturnal non-invasive ventilation. Three months beforehand he had been bitten by a tick and developed erythema migrans which was treated with Doxycycline for 10 days. This clinical presentation became complicated a few days later by the progressive onset of severe dyspnoea. At admission, chest radiography revealed bilateral elevation of the diaphragm. Pulmonary function tests revealed a severe restrictive disorder aggravated by decubitus. A diaphragmatic electromyogram showed bilateral axonal polyneuropathy of the phrenic nerves. IgG and IgM antibodies to Borrelia burgdorferi were detectable in serum and cerebrospinal fluid, leading to the diagnosis of Lyme disease. He was treated with intravenous ceftriaxone 2g per day for 21 days, leading to a substantial improvement in symptoms. CONCLUSION: In the presence of unilateral or bilateral diaphragmatic paralysis of undetermined aetiology, it seems relevant to perform Lyme serology in the blood and, in positive cases, to follow up with a lumbar puncture in order to detect intrathecal IgG synthesis.< Leer menos