To report a case of parainfectious rhombo-cerebellitis in the setting of Legionnaires disease.

Legionnaire pneumophila is a common cause of community-acquired pneumonia, frequently associated with respiratory, gastrointestinal, and neurologic complications. Central nervous system manifestations occur in approximately 40% of cases ranging from encephalopathy to cerebellar syndromes. We report a case of Legionnaire pneumophila pneumonia with prolonged neurologic manifestations.

Neurological examination revealed right facial droop, dysarthria, ataxia and

severe coarse tremor. MRI of the brain was unremarkable. PET/CT of the brain demonstrated nonspecific diffusely decreased cortical uptake. Exhaustive workup including CSF, autoimmune, and paraneoplastic studies was unremarkable. He was subsequently diagnosed with legionnaire's disease based on urine antigen and positive respiratory cultures and treated with levofloxacin. Although the facial droop and dysarthria gradually improved, he continued to have persistent ataxia and tremor. Most recent neurological examination revealed overshoot saccades bilaterally, marked left>right ataxia with finger-nose-finger with in-plane and perpendicular dysmetria. Tone was normal without bradykinesia. He was noted to have a resting tremor with titubation of the head and chin tremor associated with left>right 4Hz supination/pronation tremor. He had a high-amplitude postural proximal tremor with outstretched arms. There was prominent intention component with overflow enhancement of tremor upon any repetitive or effortful movement of either limb (both ipsilaterally and contralaterally). He was initially started on trial of Sinemet and amantadine but recently switched to primidone after inadequate benefit was noted.

We discuss a case of persistent ataxia and rubral tremor secondary to legionella associated rhombo-cerebellitis. It is critical to be aware of prolonged neurological manifestations of Legionnaires disease in the absence of imaging findings.