| Viral infections |
| Herpes virus family |
Limbic encephalitis-like syndrome (HSV, CMV, HHV-6), rhombencephalitis (HHV- 7), ventriculitis (CMV), myelitis (CMV, VZV, HHV-7), stroke (VZV), PTLD (EBV) |
Bilateral lesions in the anterior hippocampus, uncus, and amygdala |
|
CSF PCR |
Depends on the herpes virus: acyclovir (HSV1, VZV), foscarnet, ganciclovir (CMV), and cidofovir |
| Polyomavirus |
|
Subcortical lesions with cortical preservation |
|
CSF PCR DNA |
Discontinuation of immunosuppressant drugs |
| Bacterial infections |
| Nocardiosis |
Fever, headache, conscious impairment and seizures |
|
|
Positive culture (CSF, Bx) |
Trimethoprim–sulfamethoxazole, imipenem or a third-generation cephalosporin and amikacin are treatment options. Reversal of immunosuppression is beneficial |
| Listeriosis |
Meningitis or meningoencephalitis presenting with fever, headache, altered sensorium and seizures.1010. Cohen BA, Stosor V. Opportunistic Infections of the Central Nervous System in the Transplant Patient. Curr Neurol Neurosci Rep. 2013;13(9):376. https://doi.org/10.1007/s11910-013-0376-x
https://doi.org/10.1007/s11910-013-0376-...
,2222. Lanternier F, Sun HY, Ribaud P, Singh N, Kontoyiannis DP, Lortholary O. Mucormycosis in organ and stem cell transplant recipients. Clin Infect Dis. 2012;54(11):1629-36. https://doi.org/10.1093/cid/cis195
https://doi.org/10.1093/cid/cis195...
Cranial neuropathies, dysarthria, paresis, and ataxia occur in approximately 40% due to brainstem involvement (rhombencephalitis) |
Nonspecific encephalitis |
Polymorphonuclear or lymphocytic pleocytosis with elevated protein, and hypoglycorrhachia |
CSF gram stain identifies Listeria monocytogenes in only 30-40% and CSF culture is often negative |
Ampicillin or penicillin for 21 days |
| Neurotuberculosis |
Meningitis complicated by hydrocephalus and vasculitis. |
MRI demonstrates basilar meningeal enhancement (Figure 3) and abscesses and tuberculomas may present with enhancement with surrounding edema. |
Lymphocytic pleocytosis with low glucose and elevated protein. CS acid-fast stains are positive in 10-40% of cases. |
Diagnosis of tuberculosis can be established by tissue biopsy and culture of infected tissue. PCR assay is the recommended method to investigate infection with moderate sensitivity and high specificity |
Empiric treatment with adjunctive dexamethasone is warranted in suspected cases, as well as reduction of immunosuppression with serial CSF monitoring |
| Fungal infections |
| Aspergillosis |
Fever, altered mental status, seizures, stroke, and focal neurologic deficits |
MRI demonstrates ring-enhancing or hemorrhagic lesions |
Lymphocytic pleocytosis, elevated protein, fungal smears and cultures of CSF are usually negative |
Serologic assays showing galactomannan antigen or 1,3-beta-d-glucan supports the diagnosis |
Voriconazole is the first-line therapy for aspergillosis. Surgical management of aspergillomas is associated with better outcomes |
| CNS mucormycosis |
Fever, headache, unilateral facial pain, nasal/sinus congestion, impaired vision, periorbital swelling, proptosis, and ophthalmoplegia |
MRI shows cavernous sinus invasion or thrombosis, internal carotid artery thrombosis or intracerebral abscesses |
|
The diagnosis can be established by histopathological examination and culture of necrotic tissue |
Emergent intervention with surgical debridement, antifungal therapy, reversal of immunosuppression, and correction of hyperglycemia. Liposomal amphotericin B is the treatment of choice |
| Cryptococcosis |
Fever, night sweats, weight loss, headache, impaired sensorium, nausea, and vomiting. Meningismus is infrequent |
MRI may disclose mass lesions, cerebral edema or hydrocephalus |
Elevated opening pressure with variable CSF mononuclear pleocytosis, elevated protein, and low glucose |
Diagnosis is based on antigen detection in the CSF or serum or CSF culture |
Lipid formulations of amphotericin B plus flucytosine for at least 2 weeks followed by consolidation and maintenance with fluconazole. Elevated intracranial pressure is managed with serial lumbar punctures and CSF shunts for drainage, Reduction of immunosuppression is desirable, preferably with the use of calcineurin inhibitors |
| Protozoan infections |
| Toxoplasmosis |
|
MRI shows ring-enhancing lesions, edema or hemorrhage |
CSF analysis show elevated toxoplasma-specific IgG titers or evidence of toxoplasma DNA |
Serologic and imaging tests. A definite diagnosis can only be provided by histopathology, which is hardly ever necessary |
Sulfadiazine and pyrimethamine is recommended on suspected infection |
