Brainstem encephalitis in neuroborreliosis: typical clinical course and distinct MRI findings.

OBJECTIVE: In this retrospective observational study and referring to a historical case presented in 2009, we searched for typical clinical and imaging features of brainstem encephalitis in neuroborreliosis. METHODS: In addition to the historical case we describe five affected patients. RESULTS: All patients had a very similar prolonged clinical course with unspecific symptoms such as wasting, fatigue and headache. Brainstem signs were irregularly observed. MRI showed symmetrical brainstem alterations in all patients. In coronary FLAIR imaging these changes formed a figure resembling a Philippine tarsier. CONCLUSIONS: A subset of patients with neuroborreliosis develops a brainstem encephalitis with a typical clinical course and distinct MRI findings.