Isolated Cerebellar Abscess by Nocardia cyriacigeorgica in an Immunocompetent Patient: A Case Report and Systematic Review

Abstract

Nocardia is a Gram-positive bacillus characterized by branching filaments, accounting for approximately 2% of all cerebral abscesses. It predominantly affects immunocompromised individuals. Central nervous system nocardiosis is less frequently reported and carries a poorer prognosis. Clinical diagnosis is challenging due to its heterogeneous presentation, which typically follows an insidious course and lacks systemic inflammatory response signs. We present the case of a 46-year-old woman who presented with a 3-month history of suboccipital headache, accompanied by gait ataxia and dizziness for 7 days. Neurological examination revealed upbeat nystagmus in the right eye, dysarthria, right-sided dysmetria, and lateropulsion. Magnetic resonance imaging revealed an irregular, multiloculated, ring-enhancing cystic lesion in the right cerebellar hemisphere with evidence of restricted diffusion. The abscess was drained via stereotactic navigation, and culture identified Nocardia cyriacigeorgica. Targeted antibiotic therapy was initiated according to sensitivity testing, resulting in marked clinical improvement and resolution of the patient's cerebellar symptoms. This case presents an isolated cerebellar abscess caused by N. cyriacigeorgica in an immunocompetent patient, highlighting the diagnostic and therapeutic challenges involved.

Keywords

cerebellar abscess - brain abscess - immunocompetent - Nocardia - Nocardia cyriacigeorgica

Introduction

Nocardia is a Gram-positive bacillus with branching filaments, responsible for approximately 2% of all cerebral abscess.[1] It predominantly affects immunosuppressed patients as an opportunistic infection; however, immunocompetent patients can also be affected.[2] Patients become infected by inhalation, direct cutaneous inoculation, or by eating contaminated food.[3] The respiratory tract is the most frequent primary site.[3] The most common locations of Nocardia brain abscesses are the brainstem, basal ganglia, and cerebral cortex; spinal and cerebellar spinal locations are rare.[4]

Central nervous system (CNS) nocardiosis is less commonly reported and is associated with a worse prognosis due to significant morbidity and mortality (34%).[5] A clinical diagnosis is difficult because of the heterogeneous presentation characterized by an insidious course and absence of systemic inflammatory response signs. In immunocompetent patients, brain abscess due to Nocardia can be misdiagnosed as malignant brain tumors, delaying antibiotic treatment.[6]

We describe the clinical case of an isolated cerebellar abscess by Nocardia cyriacigeorgica in an immunocompetent patient, along with its diagnostic and therapeutic process. This case highlights the importance of recognizing brain infections caused by Nocardia in immunocompetent patients. Although rare, timely diagnosis is crucial to prevent severe complications. Accurate identification of Nocardia-induced brain abscesses allows for early initiation of appropriate antibiotic treatment, which is vital for improving patient outcomes. Additionally, we also conduct a systematic review to identify all the cases of cerebellar abscesses caused by Nocardia, providing valuable information to the medical community, contributing to the knowledge and management of this serious condition.

Methods

A systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, where applicable.[7] Two databases were searched for published literature on cerebellar abscesses caused by Nocardia: PubMed and Embase. The search strategy employed was (cerebellar AND abscess AND nocardia). The inclusion criteria stipulated that the studies presented case reports involving patients with cerebellar abscesses, with or without involvement of other regions of the CNS, irrespective of the functional status of the immune system. The literature search encompassed publications with no temporal limitations, extending to October 2024. Abstracts were screened by two investigators, and discrepancies were resolved by a third investigator ([Fig. 1]).

Fig. 1 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) flowchart.

Case Report

A 46-year-old woman, with a medical history significant for hypertension and left eye enucleation with prosthesis following a traumatic injury 7 years prior, presented with a 3-month history of suboccipital headache, accompanied by gait ataxia and dizziness for the preceding 7 days. Notably, there was no reported fever during the month leading up to admission. The patient had no history of steroid use or any other pertinent medical conditions, nor was there a relevant family medical history.

Upon examination, the patient was alert and oriented, with clear lung sounds and no evidence of wheezing or rales. Neurological assessment revealed upbeat nystagmus in the right eye, dysarthria, right-sided dysmetria, and lateropulsion. Laboratory tests at the time of admission showed a white blood cell count of 8,800/µL, with 90.4% neutrophils, and an erythrocyte sedimentation rate of 13 mm/h. A computed tomography (CT) scan of the head revealed a right cerebellar low-density lesion with surrounding edema and obstructive hydrocephalus ([Fig. 2]). Further CT imaging of the neck, chest, abdomen, and pelvis showed no abnormalities. Human immunodeficiency virus (HIV) testing was negative, and other potential causes of immunosuppression were excluded.

Fig. 2 Computed tomography (CT) scan. (A) Axial image. (B) Coronal image. (C) Sagittal image. CT shows a hypodensity in the lesion in the right cerebral hemisphere, which is associated with perilesional edema and mass effect. Supratentorial hydrocephalus.

Magnetic resonance imaging (MRI) of the brain demonstrated a 43-mm, irregular, multiloculated, ring-enhancing cystic lesion in the right cerebellar hemisphere. The lesion appeared hypointense on T1-weighted imaging, hyperintense on T2-weighted imaging, and diffusion-weighted imaging (DWI) exhibited a hyperintense signal within the lesion, with a corresponding hypointense signal on the apparent diffusion coefficient (ADC), indicative of restricted diffusion. Fluid-attenuated inversion recovery imaging showed hyperintense signals adjacent to the lesion, suggestive of vasogenic edema ([Figs. 3] and [4]). A cerebellar abscess was suspected, and empirical antibiotic treatment with vancomycin, ceftriaxone, and metronidazole was initiated. The abscess was subsequently drained via stereotactic navigation.

Fig. 3 Brain magnetic resonance imaging (MRI). Irregular, multiloculated, cystic lesion in the right cerebellar hemisphere, hypointense on T1-weighted (T1W) (A, B), hyperintense on T2W, fluid-attenuated inversion recovery (FLAIR) revealed hyperintense signals adjacent to the lesions suggestive of vasogenic edema (C, D), and diffusion-weighted imaging (DWI) showed hyperintense signal within the lesions with corresponding apparent diffusion coefficient (ADC) revealing hypointense signals suggestive of restricted diffusion (E, F).

Fig. 4 Brain magnetic resonance imaging (MRI) following intravenous gadolinium administration. (A, B, C) Shows an irregular, multiloculated, ring-enhancing cystic lesion in the right cerebellar hemisphere.

Preliminary histopathological analysis of the resected tissue confirmed the diagnosis of a brain abscess. Gram staining revealed Gram-positive, beaded bacilli with extensive filamentous branching in a background of polymorphonuclear leukocytes, which were later identified in culture as N. cyriacigeorgica. Antimicrobial therapy was adjusted to intravenous meropenem (2 g every 8 hours) for 6 weeks, alongside trimethoprim-sulfamethoxazole (TMP-SMX) (80/400 mg every 8 hours) for 6 weeks, followed by oral therapy with amoxicillin/clavulanate potassium (1 g every 8 hours) and TMP-SMX (160/800 mg every 8 hours). The patient's clinical condition improved significantly, with complete resolution of cerebellar symptoms. She continued to receive oral antibiotics and has remained asymptomatic at the 9-month follow-up.

Results

A total of 34 articles were included in the analysis, encompassing 37 cases with a mean age of 52.9 years (standard deviation [SD] 17.1 years; range 12–79 years). The distribution of cases by country was as follows: 9 from the United States, 4 from France, 3 from Turkey, 3 from Japan, 2 from India, 2 from Spain, and 1 each from Portugal, the Netherlands, Germany, Austria, Morocco, Italy, Colombia, Croatia, and China. Among the patients, 26 were male and 11 were female. Notably, 24 patients were immunocompetent, while 13 were immunosuppressed, with the primary cause of immunosuppression attributed to pharmacological immunomodulation (including corticosteroids, azathioprine, and methotrexate). Two cases were associated with HIV, and one with chronic lymphocytic leukemia. Ten studies reported tumor size, with a mean size of 2.92 cm (SD 0.86 cm; range 2–5.8 cm). In terms of etiology, 12 cases were attributed to Nocardia asteroides (31.6%), while the remainder were distributed among various Nocardia species, including Nocardia spp., farcinica, cryaudiogenica, paucivorans, otitidiscaviarum, elegans, brasiliensis, asiatica, exalbida, beijingensis, veterana, elegans/aobensis/africana, and abscessus complex. Symptomatically, 19 patients presented with cerebellar symptoms (52.7%), 18 with headaches (50.0%), 9 with cranial nerve deficits (25.0%), 8 with fever (22.2%), 6 with cognitive symptoms (16.6%), 5 with motor syndrome (13.8%), and 3 with altered consciousness (8.3%). Regarding treatment, 24 cases (64.86%) underwent surgical drainage in conjunction with antibiotic therapy, while 13 (36.14%) received either antibiotics alone or surgical interventions other than drainage. The antibiotic coverage varied, incorporating combinations with aminoglycosides, carbapenems, TMP/SMX, quinolones, vancomycin, linezolid, and amphotericin. Ultimately, 25 patients recovered (71.43%), while 10 succumbed to the disease (28.57%) ([Table 1]).

Table 1 Nocardia cerebellar abscess case reports in literature

	Author, year	Sex, age	Immune status	Steroid use	Brain image findings	Pathology	Treatment	Antibiotics	Involvement of other sites	Outcome
1	Koruga et al, 2022 [13]	M, 67	IC	No	MRI: Hyperintense infratentorial mass lesion at the cerebellar vermis	Nocardia cyriacigeorgica	Suboccipital craniectomy + external ventricular drainage + antibiotics	Ceftriaxone + TMP/SMX	Lungs	Passed away
2	Park et al, 2023[17]	M, 70	IC	No	MRI: peripherally enhancing lesions in the cerebellar vermis	Nocardia abscessus complex	Antibiotics	1. TMP/SMX, imipenem, and amikacin	Lungs	Recovered
3	White et al, 2023[18]	M, 54	IC	No	MRI: ring-enhancing lesions in the right cerebellar hemisphere	Nocardia abscessus complex and Nocardia exalbida	Abscess drainage	1. Linezolid and meropenem	Chest	Passed away
4	Yu et al, 2023[19]	M, 57	IC	No	MRI: Contrast-enhancing lesion in right cerebellar hemisphere	Nocardia brasiliensis	Craniectomy with abscess drainage	1. Linezolid + meropenem 2. Amikacin + imipenem	Lungs (Nocardia and Acinetobacter baumannii), pneumoconiosis	Recovered
5	Adhikary et al, 2021[20]	M, 41	Myasthenia gravis with thymectomy and long-term steroids for nephrotic syndrome	Yes	MRI: Left cerebellar enhancing lesion with edema + hydrocephalus	Nocardia farcinica	Midline suboccipital craniotomy and excision of cerebellar abscess + EVD	1. Ceftriaxone 2. TMP/SMX	No	Recovered
6	Srivastava et al, 2020[21]	M, 53	HIV-AIDS, CD4 < 200 cells/μL	No	MRI: Two irregular ring-enhancing cystic lesions in right cerebellar hemisphere	Nocardia asiatica	Suboccipital craniotomy with abscess drainage + antibiotics	1. TMP/SMX	No	Recovered
7	Trujillo et al, 2020[2]	F, 50	IC	No	MRI: multifocal involvement in the supratentorial region and another lesion in the right cerebellar hemisphere	Nocardia beijingensis	Antibiotics	1. Ceftriaxone 2. TMP/SMX	Lungs and right sixth costal arch	Recovered
8	Raziq and Usama, 2020[22]	M, 55	IC	No	MRI: Multiseptated cerebellar mass. Mild vasogenic edema right cerebellar hemisphere. Stenosis fourth ventricle + hydrocephalus	Nocardia cyriacigeorgica	Abscess drainage	1. Vancomycin, ceftriaxone and levofloxacin 2. TMP/SMX + meropenem	Right middle lung abscess. Multiple bilateral pulmonary nodules	Passed away
9	Shimizu et al, 2019[6]	F, 52	IC	No	MRI: Multiple necrotic cystic ring-enhancing lesions in right cerebellar juxtaventricular region with edema	Nocardia paucivorans	Craniotomy, partial resection of the mass	1. Ceftriaxone 2. TMP/SMX + Oral levofloxacin	No	Recovered
10	Senard et al, 2018[23]	M, 12	Immunocompetent	No	MRI: Numerous abscesses in the cerebellum and left middle cerebral artery infarction. Hydrocephalus	Nocardia elegans/aobensis/africana complex	EVD	1. Piperacillin-tazobactam/amikacin 2. Imepinem + ciprofloxacin + amphotericin B	Renal abscess	Passed away
11	Iftikhar et al, 2018[24]	M, 46	IC	No	MRI: Centrally necrotic, right cerebellar mass and ring-enhancing lesion in right parietal lobe	Nocardia cyriacigeorgica	Craniectomy with abscess drainage	1. Levofloxacin + clindamycin 2. Vancomycin + TMP/SMX + metronidazole + meropenem	Right mid lung mass with right lower lobe pneumonia + right parietal lobe	Passed away
12	Pascual-Gallego et al, 2016[5]	M, 62	IC	No	MRI: Right cerebellar hemisphere cystic, bilobulated, ring enhanced mass, vasogenic edema	Nocardia farcinica	Suboccipital craniotomy with remotion of mass and necrotic content	1. Linezolid 2. Vancomycin + imipenem + ciprofloxacin 3. Linezolid + ciprofloxacin	Upper lobule right lung	Recovered
13	Schiaroli et al, 2016[15]	M, 54	IC	No	MRI: Multiloculated right cerebellar abscess + hydrocephalus	Nocardia paucivorans	Antibiotics	1. Ceftriaxone + metronidazole 2. Meropenem + linezolid 3. Imipenem + linezolid 4. Ceftriaxone + metronidazole + meropenem 5. Vancomycin + rifampin + ceftriaxone + co-trimoxazole 6. Ceftriaxone + co-trimoxazole + linezolid 7. Ceftriaxone + oral co-trimoxazole + rifampin + linezolid	Right ventriculitis + abscess septum pellucidum	Recovered
14	Somerville and Gay, 2015[25]	F, 58	High dose systemic corticosteroids and methotrexate	Yes	MRI: Innumerable 5–35 mm peripherally enhancing lesions in the cerebellum, supratentorial brain, cervical spine, and right brachial plexus	Nocardia veterana	None	1. Ceftazidime + meropenem + TMP/SMX	Bilateral cavitary lung lesions all lobes	Recovered
15	Beuret et al, 2015[1]	F, 64	IC	Yes, during treatment	MRI: Right cerebellar and middle cerebellar peduncular lesion. Moderate mass effects	Nocardia spp.	Antibiotics	1. Amoxicillin + TMP/SMX 2. Imipenem + TMP/SMX	No	Recovered
16		M, 51	IC	Yes, during treatment	MRI: Heterogeneous lesion in cerebellar vermis with hemorrhagic changes	Nocardia farcinica	Craniectomy with drainage	1. Cefotaxime 2. Cefotaxime + TMP/SMX	No	Passed away
17		M, 68	IC	Yes, during treatment	CT: Multiloculated vermis lesion that extends to the left side of cerebellum. Mild mass effect	Nocardia spp.	Surgical evacuation of the abscess	1. TMP/SMX	No	Recovered
18	Kozodoy et al, 2015[26]	F, 23	SLE, steroids and azathioprine	Yes	CT: Multiple ring-enhancing lesions at gray-white matter interface of cerebral and cerebellar hemispheres	Nocardia otitidiscaviarum	Antibiotics	1. TMP/SMX + amikacin + meropenem	Basilar left pleural based loculated effusions + cerebral abscesses	Recovered
19	Ueda et al, 2014[27]	M, 69	SLE, high dose steroids	Yes	MRI: Contrast-enhancing lesion in right cerebellar hemisphere	Nocardia elegans	Antibiotics	1. TMP/SMX + meropenem + amikacin 2. TMP/SMX + clarithromycin	Lung, right middle lobe	Recovered
20	Malhotra et al, 2013[28]	M, 64	IC	No	MRI: Left cerebellar mass with edema	Nocardia spp.	Stereotactic biopsy	Not specified	No	Recovered
21	El Hymer et al, 2011[29]	M, 56	Pulmonary sarcoidosis with steroids treatment	Yes	CT: Enhancing, hypodense lesion in left cerebellar and occipital lobes with mass effect and edema	Nocardia asteroides	Suboccipital craniotomy with drainage	1. Sulfadiazine + cefotaxime	Occipital left lobe	Recovered
22	Hernández Quero and Retamar, 2010[30]	F, 26	Mesalazine + azathioprine + steroids	Yes	MRI: Ring-enhancing right cerebellar lesion, right frontal lesion and right parasagittal parietal lesion; each one with edema + hydrocephalus	Nocardia farcinica	Suboccipital craniotomy with drainage	1. Caspofungin + sulfadiazine + pirimetamine + cloxacillin + metronidazole + cefotaxime + dexamethasone 2. TMP/SMX 3. Clotrimazole	Right frontal and parietal lobes and right apical lung	Recovered
23	Frank et al, 2010[3]	M, 83	ITP with steroids	Yes	MRI: Right cerebellar abscess + hydrocephalus	Nocardia spp.	Antibiotics	1. Amoxicillin 2. Caspofungin + piperacillin + meropenem 3. TMP/SMX 4. Sultamicillin + meropenem	Both lungs, big enhancing mass in right upper lobe. Occipital lesions	Passed away
24	Horwitz et al, 2008[31]	M, 49	IC	Yes	MRI: Multiple enhancing lesions in the right hemisphere, left occipital lobe, and frontal lobe	Nocardia asteroides	Antibiotics	Not specified	Previews pneumonitis with nocardia. Left frontal lobe, left occipital lobe	Not specified
25	Uchihashi, 2006[32]	M, 61	IC	No	MRI: Left posterior fossa lesion with hydrocephalus	Nocardia spp.	Ventriculoperitoneal shunt + occipital craniectomy with abscess drainage	1. Ceftriaxone 2. Meropenem 3. Minocycline + TMP/SMX	No	Recovered
26	Borchers et al, 2006[33]	F, 71	IC (COPD with steroids)	Yes	MRI: Ring enhancement lesion in right cerebellar hemisphere. Bilateral hemispheric contrast, with a hypothalamic lesion	Nocardia farcinica	Antibiotics	1. Isoniazide + ethambutol + pyrazinamide + rifampin 2. 1 + ceftriaxone + metronidazole 3. Imipenem + amikacin	Lungs and right eye	Recovered
27	Kilincer et al, 2006[34]	M, 43	IC	High dose methylprednisolone	MRI: Ring-enhanced left cerebellar lobe multiloculated abscess + triventricular hydrocephalus	Nocardia asteroides	Suboccipital craniectomy: Gross total excision of the capsule of the abscess with drainage of pus	1. Ceftriaxone + metronidazole 2. TMP-SMX	Two frontal right small lesions	Recovered
28	Durmaz et al, 2001[35]	M, 59	IC (DM2)	No	MRI: Right cerebellar hemisphere. Multiple contrast-enhancing lesions in right temporal, left frontal, and frontoparietal lobes	Nocardia asteroides	Suboccipital craniotomy + C2–4 laminectomy. Drainage and resection of abscesses. Second time surgery for supratentorial lesions	1. Amikacin + ceftriaxone + TMP/SMX	Right temporal left frontal and frontoparietal lobes. Cervical spinal cord C3-T1	Passed away
29	Öktem et al, 1999[36]	F, 27	Renal transplant from a living-donor	No	MRI: Large multiloculated lesion in central cerebellum	Nocardia asteroides	Posterior fossa craniectomy with excision of immature capsule	1. Penicillin G + chloramphenicol 2. Cefotaxime + amikacin	No	Recovered
30	Oerlemans et al, 1998[37]	M, 54	IC	No	MRI: Multilobulated cystic mass in the right cerebellar hemisphere with extension to middle cerebellar peduncle and vermis, with ring-enhancement and edema + obstructive hydrocephalus	Nocardia asteroides	Stereotactic biopsy + suboccipital craniotomy	1. TMP/SMX	Asymptomatic pulmonary alveolar proteinosis. Bilateral interstitial and alveolar lesions in chest X-ray	Recovered
31	Aguiar et al, 1995[38]	M, 39	HIV-AIDS	Yes, during hospitalization	MRI: Left cerebellar mass with edema, expansion to vermis + hydrocephalus	Nocardia spp. + CMV	Suboccipital craniectomy	1. Ceftriaxone	Lung	Passed away
32	Schwartz et al, 1988[39]	F, 39	SLE with steroids	Yes	CT: Old infarcts and enhancing lesions in right frontoparietal lobe, temporo-occipital lobe. The posterior fossa was not clear	Nocardia asteroides	Antibiotics	1. Cyclophosphamide	Cavitary lesion in lung. Temporo-occipital and right frontoparietal abscesses	Passed away
33	Cabot et al, 1980[40]	F, 79	Chronic lymphocytic leukemia. Prednisone, chlorambucil	Yes	CT: Ring-enhancing lesion in cerebellar vermis with edema, small fourth ventricle, and enlargement of third and lateral ventricle	Nocardia asteroides	Craniotomy	1. Gentamicin	No	Not specified
34	Tyson et al, 1979[41]	M, 57	IC	Yes, during treatment	CT: Irregular enhancing mass in cerebellar vermis. Hydrocephalus	Nocardia asteroides	Ventriculoperitoneal shunt. Suboccipital craniectomy with abscess drainage	1. Nafcillin + chloramphenicol 2. Sulfisoxazole + ampicillin	No	Recovered
35		F, 22	IC	Yes, during treatment	CT: Contrast-enhancing lesion in superomedial portion of left cerebellar hemisphere. It extended to rostral vermis	Nocardia asteroides	Ventriculoperitoneal shunt + suboccipital craniectomy with abscess drainage and partially excision. Reintervention with abscess resection	1. Sulfadiazine + ampicillin 2. Sulfadiazine + ampicillin + minocycline 3. Sulfisoxazole, ampicillin, and minocycline	No	Recovered
36	Rosenblum and Rosegay, 1979[42]	M, 64	IC	Yes, during treatment	CT: Multiple ring-like lesions of various sizes in left frontal and right cerebellar lobes. Hydrocephalus	Nocardia asteroides	Suboccipital craniectomy with drainage and excision of abscess. Left frontal osteoplastic craniotomy, complete excision of abscess	1. Penicillin + chloramphenicol + methicillin 2. TMP/SMX 3. Sulfisoxazole	Right frontal lobe	Recovered
37	List et al, 1954[43]	M, 48	IC	No	Ventriculography with lateral and 3rd ventricles enlargement. Expanding mass in left cerebellar hemisphere	Nocardia asteroides	Left suboccipital craniectomy	1. Penicillin + dihydrostreptomycin 2. Penicillin + sulfadiazine	Lung infiltrative lesions	Recovered

Abbreviations: CMV, cytomegalovirus; COPD, chronic obstructive pulmonary disease; CT, computed tomography; EVD, external ventricular drainage; F, female; HIV-AIDS, human immunodeficiency virus-acquired immunodeficiency syndrome; IC, immunocompromised; ITP, immune thrombocytopenia; M, male; MRI, magnetic resonance imaging; SLE, systemic lupus erythematosus; TMP/SMX, trimethoprim-sulfamethoxazole.

Discussion

Nocardiosis is a rare opportunistic infection associated with several risk factors, including chronic steroid use, organ transplantation, diabetes mellitus, HIV, cancer, and chronic infections.[8] Nocardia spp. Gram-positive bacilli are characterized by branching filaments; they are aerobic, nonmotile, acid-fast, and exhibit variable Gram staining, ranging from Gram-negative to Gram-positive.[9] The majority of nocardial infections in humans (86%) are caused by Nocardia asteroides, consistent with the case series reported in this study, where infections caused by this species predominated. In rarer instances, CNS infections may arise from N. cyriacigeorgica, N. brasiliensis, and N. farcinica.[8]

Primary infection occurs through inhalation or direct cutaneous inoculation, leading to pulmonary or cutaneous manifestations, respectively. The respiratory tract serves as the most frequent primary site of infection. The infection can be either localized or disseminated via hematogenous spread in approximately 50% of cases.[10] It is estimated that 25 to 40% of patients with systemic nocardiosis develop cerebral infections, which may present as abscesses or meningitis.[5] The occurrence of a nocardial abscess in the CNS without an identified primary site is rare.

The clinical features of this condition are often nonspecific, insidious, and heterogeneous, complicating the diagnostic process. The most common neurological manifestations in patients with CNS nocardiosis include focal neurological deficits and seizures.[5] [11] However, in this study, which exclusively reported cases with cerebellar involvement, the most frequent manifestation was secondary to dysfunction of this structure. When fever is present, it typically arises from extracranial involvement. Another challenging factor is the imaging characteristics that resemble malignant tumors, which can delay appropriate treatment and lead to the inappropriate use of corticosteroids, thereby worsening the prognosis.[12] [13]

CT and MRI reveal multiloculated lesions with a necrotic core and ring enhancement following gadolinium or iodine administration.[1] [6] [14] DWI and ADC are supportive of a cerebral abscess diagnosis. The most common sites for nocardia brain abscesses are the brainstem, basal ganglia, and cerebral cortex; however, spinal and cerebellar locations are rare.[4]

Microbiological identification is essential for guiding treatment. It is recommended to perform culture or biopsy followed by species identification using polymerase chain reaction, as this allows for the implementation of specific therapeutic strategies tailored to the unique sensitivities of each species.[3] [15] Most species exhibit susceptibility to TMP-SMX, imipenem, amikacin, and linezolid.[5] Treatment duration may range from 6 weeks to 1 year, depending on clinical and imaging progression. Various therapeutic alternatives have been proposed, including conservative management through stereotactic aspiration or open craniotomy with enucleation. Surgical intervention should be considered for large, accessible lesions or in cases where lesions continue to progress despite antibiotic treatment.[16] Mamelak et al reported a mortality rate of 33% in patients with a single abscess, with even higher rates observed in patients with multiple abscesses. Close monitoring of the patient's clinical and radiological evolution is paramount to guide ongoing therapeutic decisions, with timely surgical intervention potentially reducing morbidity and mortality in select cases.[16]

To the best of our knowledge, no previous study has systematically compiled all reported cases of cerebellar abscesses caused by Nocardia spp. Our article provides a comprehensive review and analysis of these cases, offering valuable insights into the epidemiology, clinical presentation, management, and outcomes of this rare yet serious condition. Specifically, it highlights relevant epidemiological features, such as the increased prevalence of this condition in immunocompetent populations. By consolidating this information, we aim to raise clinical awareness, guide diagnostic and therapeutic decision-making, and establish a reference point for future research.

Conclusion

Nocardia cerebral abscesses pose significant diagnostic and therapeutic challenges due to their low incidence, insidious clinical course, elevated mortality rates, and the prevalence of immunosuppression among affected patients. Early identification of microbiological etiology, coupled with appropriate antibiotic treatment and a surgical approach, is essential for achieving favorable outcomes. Although nocardial abscesses are rare in immunocompetent individuals, maintaining a high level of clinical suspicion is critical. The absence of any indicated immunosuppression, the cerebellar location of the abscess, the lack of another primary site, and the specific Nocardia subspecies involved render this case particularly exceptional.

Conflict of Interest

None declared.

Patients' Consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient has given her consent for her images and other clinical information to be reported in the journal. The patient understands that her name and initials will not be published, and due efforts will be made to conceal her identity, but anonymity cannot be guaranteed.

• References

• 1 Beuret F, Schmitt E, Planel S, Lesanne G, Bracard S. Subtentorial cerebral nocardiosis in immunocompetent patients: CT and MR imaging findings. Diagn Interv Imaging 2015; 96 (09) 953-957
• 2 Trujillo DE, Ortiz S, Pérez O, Cortés CA, Carrillo JA. Multiple brain abscesses due to Nocardia spp. in an immunocompetent patient. Biomédica 2020; 40 (01) 27-33
• 3 Frank M, Woschnagg H, Mölzer G, Finsterer J. Cerebellar nocardiosis and myopathy from long-term corticosteroids for idiopathic thrombocytopenia. Yonsei Med J 2010; 51 (01) 131-137
• 4 Vialle R, Aghakhani N, Otayza F, Monteanu V, Safi H, Tadie M. Nocardia farcinica brain abscess: clinical and specific radiological findings and management. Report of two cases in immunononcompromised patients [in French]. Neurochirurgie 2002; 48 (06) 516-521
• 5 Pascual-Gallego M, Alonso-Lera P, Arribi A, Barcia JA, Marco J. Nocardia farcinica abscess of the cerebellum in an immunocompetent patient: a case report and review of the literature. Asian J Neurosurg 2016; 11 (04) 454-455
• 6 Shimizu Y, Tsuchiya K, Fujisawa H. Nocardia paucivorans cerebellar abscess: surgical and pharmacotherapy. Surg Neurol Int 2019; 10 (01) 22-25
• 7 Page MJ, McKenzie JE, Bossuyt PM. et al. The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. BMJ 2021; 372: n71
• 8 Baldawa S, Nayak N, Kukreja S, D'souza D, Diyora B, Sharma A. Cerebral nocardiosis. Asian J Neurosurg 2014; 9 (04) 245
• 9 Zakaria A, Elwatidy S, Elgamal E. Nocardia brain abscess: severe CNS infection that needs aggressive management; case report. Acta Neurochir (Wien) 2008; 150 (10) 1097-1101 , discussion 1101
• 10 Lin YJ, Yang KY, Ho JT, Lee TC, Wang HC, Su FW. Nocardial brain abscess. J Clin Neurosci 2010; 17 (02) 250-253
• 11 Mamelak AN, Obana WG, Flaherty JF, Rosenblum ML. Nocardial brain abscess: treatment strategies and factors influencing outcome. Neurosurgery 1994; 35 (04) 622-631
• 12 Cianfoni A, Calandrelli R, De Bonis P, Pompucci A, Lauriola L, Colosimo C. Nocardia brain abscess mimicking high-grade necrotic tumor on perfusion MRI. J Clin Neurosci 2010; 17 (08) 1080-1082
• 13 Koruga N, Reljac G, Roncevic A. et al. A rare case of cerebellar abscess caused by Nocardia cyriacigeorgica. Surg Neurol Int 2022; 13 (510) 36-37
• 14 Roldán NG, Cure GC, Quiñones GP, Hakim F. Cerebral abscesses by Nocardia spp in an immunocompetent patient. Acta Neurológica Colombiana 2010; 26 (03) 149-154
• 15 Schiaroli E, Pasticci MB, De Carolis E. et al. Diagnosis of Nocardia paucivorans central nervous system infection by DNA sequencing from paraffin-embedded tissue. Infez Med 2016; 24 (02) 147-152
• 16 Valarezo J, Cohen JE, Valarezo L. et al. Nocardial cerebral abscess: report of three cases and review of the current neurosurgical management. Neurol Res 2003; 25 (01) 27-30
• 17 Park CS, Nasir S, Nicholas J. Nothing to savor, this food has no flavor: a case of profound dysgeusia in disseminated Nocardia. Poster presented at: 2022 URMC Resident Poster Day; Rochester, NY. Accessed December 1, 2025 at: https://www.urmc.rochester.edu/MediaLibraries/URMCMedia/medicine/awards/resident-poster-day/documents/2022/abstract-park-nothing-to-savor-Nocardia.pdf
• 18 White CJ, Mclemore S, White B. Disseminated nocardiosis in an immunocompetent patient. Chest 2023; 164 (04) A1159
• 19 Yu W, Lu Z, Zhang J, Wang Z. Cerebellar abscess caused by Nocardia brasiliensis in a patient with pneumoconiosis. Asian J Surg 2023; 46 (10) 4655-4656
• 20 Adhikary R, Shetty SR, Mv B, Acharya UV. Primary cerebellar nocardiosis in a patient with myasthenia gravis. Indian J Med Microbiol 2021; 39 (01) 125-127
• 21 Srivastava S, Kanaujia R, Sahoo SK. et al. Isolated cerebellar abscess by Norcardia asiatica: a case report with review of literature. J Family Med Prim Care 2020; 9 (02) 1232-1235
• 22 Raziq F, Usama M. Nocardiosis presenting like a metastatic lung cancer. Chest 2020; 158 (04) A1600
• 23 Senard O, Blanot S, Jouvion G. et al. Fulminant nocardiosis due to a multidrug-resistant isolate in a 12-year-old immunocompetent child. Pediatrics 2018; 141 (02) e20163131
• 24 Iftikhar MH, Shah SJ, Dawani O, Laird-Fick H. Disseminated Nocardia cyriacigeorgica in an immunocompetent male. Am J Respir Crit Care Med 2018;197:A3619
• 25 Somerville L, Gay E. Disseminated Nocardia veteran . Chest 2015; 148 (04) 161A
• 26 Kozodoy N, Ali A, Boulos A, Safi F, Sidhu N. Bactrim resistant disseminated nocardiosis in an immunosuppressed host. Am J Respir Crit Care Med 2015 191. A1836
• 27 Ueda Y, Yamamoto K, Watanabe K, Yamashita H, Ohmagari N, Mimori A. Obstructive pneumonia and brain abscess due to Nocardia elegans in a patient with systemic lupus erythematosus [in Japanese]. Kansenshogaku Zasshi 2014; 88 (03) 282-287
• 28 Malhotra K, Rana S, Aziz K. Cerebellar abscess with Nocardia: a rare diagnosis. Neurology 2013; 80 (07) , supplement):
• 29 El Hymer W, Lmejjati M, Skoumi M. et al. Nocardia brain abscess - case report and literature review. Afr J Neurol Sci 2011; 30 (02) 82-86
• 30 Hernández Quero J, Retamar P. Cefalea y visión borrosa en una mujer de 26 años. Med Clin (Barc) 2010; 134 (13) 600-604
• 31 Horwitz JL, Barisa MT, Davis AS. The neurocognitive outcome of nocardia: a brief, longitudinal case study. Appl Neuropsychol 2008; 15 (03) 220-223
• 32 Uchihashi Y, Sasayama T, Ikeda M, Saitoh M, Kohmura E. Nocardial Cerebellar Abscess successfully treated with Short − term Minocycline Treatment in an Immunocompetent Patient. Jpn J Neurosurg 2006; 15 (09) 652-656
• 33 Borchers M, von der Mülbe B, Teikemeier F, Theegarten D. Pulmonary nocardiasis with abscesses spreading to cerebrum, cerebellum and orbits [in German]. Dtsch Med Wochenschr 2006; 131 (19) 1085-1088
• 34 Kilincer C, Hamamcioglu MK, Simsek O. et al. Nocardial brain abscess: review of clinical management. J Clin Neurosci 2006; 13 (04) 481-485
• 35 Durmaz R, Atasoy MA, Durmaz G. et al. Multiple nocardial abscesses of cerebrum, cerebellum and spinal cord, causing quadriplegia. Clin Neurol Neurosurg 2001; 103 (01) 59-62
• 36 Öktem IS, Akdemir H, Sümerkan B, Koç RK, Menkü A, Tümtürk F. Cerebellar abscess due to Nocardia asteroids. Acta Neurochir (Wien) 1999; 141 (02) 217-218
• 37 Oerlemans WGH, Jansen ENH, Prevo RL, Eijsvogel MMM. Primary cerebellar nocardiosis and alveolar proteinosis. Acta Neurol Scand 1998; 97 (02) 138-141
• 38 Aguiar PH, Pahl FH, Uip DE. et al. Cerebellar abscess by Nocardia: a case report [in Portuguese]. Arq Neuropsiquiatr 1995; 53 (02) 307-311
• 39 Schwartz JG, McGough DA, Thorner RE, Fetchick RJ, Tio FO, Rinaldi MG. Primary lymphocutaneous Nocardia brasiliensis infection: three case reports and a review of the literature. Diagn Microbiol Infect Dis 1988; 10 (02) 113-120
• 40 Cabot RC, Scully RE, Galdabini JJ, McNeely BU, Geschwind N, Kleinman GM. Cerebellar mass in an elderly woman with chronic lymphocytic leukemia. N Engl J Med 1980; 302 (21) 1194-1199
• 41 Tyson GW, Welsh JE, Butler AB, Jane JA, Winn HR. Primary cerebellar nocardiosis. Report of two cases. J Neurosurg 1979; 51 (03) 408-414
• 42 Rosenblum M, Rosegay H. Resection of multiple nocardial brain abscesses: diagnostic role of CT. Neurosurgery 1979; 4: 315-318
• 43 List CF, Williams JR, Beeman CB, Payne CA. Nocardiosis with multilocular cerebellar abscess report of a cured case. J Neurosurg 1954; 11 (04) 394-398

Publication History

Article published online:
09 December 2025