Related Experiment Video

Updated: May 9, 2026

In Vivo Tracking of Edema Development and Microvascular Pathology in a Model of Experimental Cerebral Malaria Using Magnetic Resonance Imaging
09:04

In Vivo Tracking of Edema Development and Microvascular Pathology in a Model of Experimental Cerebral Malaria Using Magnetic Resonance Imaging

Published on: June 8, 2017

Acanthamoeba rhombencephalomyelitis: Novel white matter tract-based neuroinvasive pattern in a retrospective

Remya Prakash1, Aravind Reghukumar2, K Rammohan1

  • 1Department of Neurology, Government Medical College, Thiruvananthapuram, Kerala, India.

Journal of Neuroimmunology
|May 7, 2026
PubMed
Abstract

Insights

Free-living amoebae, such as Acanthamoeba species, can cause a distinct rhombencephalomyelitis in the central nervous system. Early diagnosis of this non-granulomatous infection is crucial for favorable outcomes.

Area of Science:

  • Neurology
  • Infectious Diseases
  • Neuroimaging

Background:

  • Central nervous system (CNS) infections due to free-living amoebae (FLA) typically present as granulomatous amoebic encephalitis.
  • A distinct pattern of rhombencephalomyelitis caused by Acanthamoeba species has been observed, differing from classical presentations.

Purpose of the Study:

  • To describe a unique rhombencephalomyelitis pattern in CNS infections caused by free-living amoebae.
  • To differentiate this pattern from granulomatous amoebic encephalitis.
  • To highlight the diagnostic and prognostic implications of this distinct presentation.

Main Methods:

  • Retrospective observational study of twelve patients with brainstem/spinal cord involvement due to Acanthamoeba CNS infection.
  • Diagnosis confirmed by cerebrospinal fluid (CSF) wet mount and 18S rRNA PCR.
  • Exclusion of bacterial, mycobacterial, fungal, and autoimmune etiologies.

Main Results:

  • Twelve patients (median age 50 years) presented with subacute cranial neuropathies and gait disturbance.
  • MRI revealed white matter tract-based spread in the spinal cord, pons, middle cerebellar peduncle, and medulla.
  • Acanthamoeba spp. confirmed by CSF PCR in 83.3% of patients; 75% survived with favorable functional outcomes.

Conclusions:

  • Acanthamoeba species cause a distinct, non-granulomatous, white matter tract-based rhombencephalomyelitis.
  • Neurologists should consider FLA CNS infection, even without traditional risk factors, as the pattern mimics demyelinating disorders.
  • Early identification of Acanthamoeba rhombencephalomyelitis is associated with a favorable prognosis.
Keywords:
AcanthamoebaDemyelinating disordersFLA-PINSGranulomatous amoebic encephalitis (GAE)RhombencephalomyelitisWhite matter tract–based spread

More Related Videos

Induction and Clinical Scoring of Chronic-Relapsing Experimental Autoimmune Encephalomyelitis26:48

Induction and Clinical Scoring of Chronic-Relapsing Experimental Autoimmune Encephalomyelitis

Published on: July 4, 2007

Related Concept Videos

Encephalitis ll: Pathophysiology01:26

Encephalitis ll: Pathophysiology

Encephalitis is inflammation of the brain parenchyma caused by direct viral invasion or immune-mediated mechanisms triggered by infections or tumors. Both processes lead to neuronal injury, disrupted neurotransmission, and diverse neurological symptoms, often with overlapping clinical and pathological features.Autoimmune EncephalitisIn autoimmune encephalitis, antibodies target neuronal antigens on cell surfaces, synapses, or within neurons. A key example is anti-NMDAR encephalitis, which can...
Arboviral Encephalitis01:25

Arboviral Encephalitis

Arboviral encephalitis refers to brain inflammation caused by arthropod-borne viruses, particularly those transmitted through mosquito vectors. Among these, West Nile virus (WNV), a member of the Flaviviridae family, is a significant public health concern. WNV is an enveloped, positive-sense, single-stranded RNA virus. Human infection typically begins when an infected mosquito introduces the virus into the dermis during feeding. The primary transmission cycle involves birds as amplifying hosts...
Encephalitis l: Introduction01:19

Encephalitis l: Introduction

Encephalitis is inflammation of the brain parenchyma, most often due to infections or autoimmune processes. It presents with neuropsychiatric features such as fever, altered mental status, behavioral changes, cognitive dysfunction, seizures, focal deficits, and sometimes autonomic instability. In some cases, the meninges are also involved, resulting in meningoencephalitis.Infectious CausesInfectious encephalitis is most commonly viral but can also result from bacterial, fungal, or parasitic...
Brain Abscess l: Introduction01:26

Brain Abscess l: Introduction

A brain abscess is a focal, intracerebral infection characterized by a localized collection of pus within the brain parenchyma, resulting from microbial invasion and the body’s inflammatory response. It progresses through stages: early and late cerebritis, followed by early and late capsule formation, reflecting tissue destruction, immune response, and eventual encapsulation.Etiology and PathogenesisCausative organisms vary with source and host factors, often involving polymicrobial infections,...
Viral Meningitis01:18

Viral Meningitis

Viral meningitis is the most common form of meningitis and is often referred to as aseptic meningitis to indicate the absence of bacterial involvement. It is generally milder than bacterial meningitis, with symptoms including fever, headache, stiff neck, drowsiness, nausea, photophobia, and vomiting. Rarely, more severe manifestations or death may occur. Common causative agents include enteroviruses, particularly coxsackie A and B viruses and echoviruses, all members of the Enterovirus genus...
Bacterial Meningitis I: Introduction01:22

Bacterial Meningitis I: Introduction

Bacterial meningitis is a severe, life-threatening inflammation of the meninges, particularly the pia mater and arachnoid mater, affecting the subarachnoid space, ventricles, and cerebrospinal fluid (CSF). If untreated, it can lead to significant neurological complications or death.Causative AgentsCommon pathogens vary with age and immune status. In adults, major organisms include Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae. Streptococcus agalactiae (group B...