Case Reports and Clinical Images

Neurologic Symptoms with Lung Pathology on Imaging

Carter Winberg*, Alexander Grindal, Amitabha Chakroborty

McMaster Health Sciences Centre, Hamilton, Canada


A patient presented with ataxia with cerebellar dysfunction on examination. After lung imaging revealed a large consolidation, the patient was eventually diagnosed with Legionnaires’ disease during admission. The imaging and case demonstrate how clinicians must include Legionella on their differential diagnosis when there is a combination of respiratory and neurologic pathologies, even when respiratory symptoms are not the presenting concern.


Un patient présente une ataxie accompagnée d’un dysfonctionnement cérébelleux révélé à l’examen. Après que l’imagerie pulmonaire ait révélé la présence d’une consolidation importante, le patient a finalement reçu un diagnostic de légionellose lors de son admission. L’imagerie et le présent cas montrent aux cliniciens la nécessité d’inclure la légionelle dans leur diagnostic différentiel en présence d’une combinaison de pathologies respiratoires et neurologiques, même lorsque les symptômes respiratoires ne sont pas la principale préoccupation.

Corresponding Author: Carter Winberg:

Submitted: 22 February 2021; Accepted: 7 April 2021; Published: 12 February 2022


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A 51-year-old welder with a history of type 2 diabetes mellitus and active cigarette smoking presented to hospital with a 5-day history of progressive confusion and gait imbalance. His unsteadiness worsened, causing him to walk into objects and eventually fall off a chair while seated. On initial presentation, he was tachycardic (HR 137), hypoxic (93% room air), and febrile (Tmax 39.6°C).

The physical exam was significant for negative signs for meningitis and coarse crackles over the left lung zone. A neurologic exam was notable for left upper extremity dysmetria, hypometric saccades, confusion, and slurred speech.

Initial investigations revealed hyponatremia (Na+: 129), leukocytosis (neutrophilic predominance: 13.9), and mild elevation in bilirubin (28), aspartate aminotransferase (57), and C-reactive protein (319). Pertinent normal investigations included troponins, blood cultures, and lumbar puncture studies. Initial imaging included a CT of head, showing no acute intracranial pathology. A chest X-ray [A] and subsequent CT of chest [B] revealed a large consolidation in the left upper lobe (Figure 1).

Figure 1. Relevant imaging from the patient’s hospital admission. (A) Portable chest X-ray. (B) Coronal CT of chest image.

During admission, the urine legionella antigen turned positive, and he progressively improved with a prolonged course of azithromycin.

Identified in 1976, Legionnaires’ disease refers to the respiratory syndrome associated with Legionella pneumophila which causes 2–6% of community-acquired pneumonia cases that require hospitalization.1 Often found in water reservoirs, it is transmitted by inhalation of aerosols, commonly from plumbing systems and hot tubs.

Current recommendations advise urine antigen testing for all patients with severe pneumonia. Urine antigen testing detects the most common serogroup (Type 1) of L. pneumophila with a sensitivity of 70% and specificity of 100%.1 Treatment involves prolonged course of macrolides or fluroquinolones with no substantial evidence for optimal treatment duration, and a recent meta-analysis showed no mortality benefit between the groups.2

Legionella has a relatively unique ability to cause multisystem dysfunction, highlighted by the diversity of common patient presentations, that may include respiratory, gastrointestinal, and neurologic symptoms. Of the neurologic abnormalities, profound confusion and, more rarely, cerebellar dysfunction have been described.

A recent (2020) case series analyzed 24 cases of cerebellar dysfunction associated with L. pneumophila.3 The most common presenting symptoms were ataxia (22 cases) and dysarthria (18 cases). Of these cases, around 75% had normal head imaging and benign cerebrospinal fluid analysis. Although evidently rare, astute clinicians must consider Legionnaires’ disease in cases where a patient presents with both respiratory and neurologic disturbances, even if respiratory symptoms are not the presenting feature.

Competing Interests

None declared.

This article has been peer reviewed.

The authors have obtained consent from the patient.

Authors’ Contributions

All authors contributed to the conception and design of the work, drafted the manuscript, revised it critically for important intellectual content, gave final approval of the version to be published, and agreed to be accountable for all aspects of the work.


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2. Jasper AS, Musuuza JS, Tischendorf JS, Stevens VW, Gamage SD, Osman F, et al. Are fluoroquinolones or macrolides better for treating legionella pneumonia? A systematic review and meta-analysis. Clin Infect Dis. 2021;72(11):1979–89. 10.1093/cid/ciaa441

3. Lu M, Shen N, Zhu H, Yao WZ. Legionnaires’ disease with pronounced cerebellar involvement: Case report and literature review. Chin J Tubercul Respir Dis. 2020;43(2):126–31. 10.3760/cma.j.issn.1001-0939.2020.02.010

4. Schuetz P, Haubitz S, Christ-Crain M, Albrich WC, Zimmerli W, Mueller B. Hyponatremia and anti-diuretic hormone in Legionnaires’ disease. BMC Infect Dis. 2013;13:585. 10.1186/1471-2334-13-585