Related Experiment Video

Updated: Aug 30, 2026

Hippocampal Neuronal Cultures to Detect and Study New Pathogenic Antibodies Involved in Autoimmune Encephalitis
08:20

Hippocampal Neuronal Cultures to Detect and Study New Pathogenic Antibodies Involved in Autoimmune Encephalitis

Published on: June 2, 2022

Neuropathological and ultrastructural features of amebic encephalitis caused by Sappinia diploidea

Benjamin B Gelman1, Vselevod Popov, Gregory Chaljub

  • 1Texas Center for NeuroAIDS Research, Department of Pathology, University of Texas Medical Branch at Galveston, Rt. 0785, Galveston, TX 77555-0785, USA. bgelman@utmb.edu

Journal of Neuropathology and Experimental Neurology
|October 25, 2003
PubMed

Insights

Newly identified pathogen Sappinia diploidea causes encephalitis presenting as a brain mass. Early diagnosis and treatment led to a favorable prognosis in a human case.

Area of Science:

  • Neuropathology
  • Infectious Diseases
  • Microbiology

Background:

  • Emerging infectious diseases pose significant public health challenges.
  • Accurate identification of novel pathogens is crucial for effective treatment and disease control.

Observation:

  • A 38-year-old male presented with neurological symptoms including visual disturbances, headache, and seizure.
  • Brain imaging revealed a solitary, tumor-like mass in the posterior left temporal lobe.
  • Neuropathological examination identified necrotizing hemorrhagic inflammation containing free-living amebae, later identified as Sappinia diploidea.

Findings:

  • Sappinia diploidea exhibits unique ultrastructural features, including a distinctive double nucleus in its trophozoite stage.
  • Immunofluorescence microscopy differentiated it from previously known amebic encephalitis pathogens.
  • The organism was observed to engulf host blood cells and was readily stained with Giemsa and periodic acid-Schiff.

Implications:

  • This case highlights Sappinia diploidea as a newly recognized cause of human encephalitis.
  • Key diagnostic guidelines are provided for recognizing future cases, focusing on radiological and pathological features.
  • Successful treatment with a combination of anti-amebic drugs resulted in a favorable long-term outcome, suggesting a positive prognosis with timely intervention.

More Related Videos

Exogenous Administration of Microsomes-associated Alpha-synuclein Aggregates to Primary Neurons As a Powerful Cell Model of Fibrils Formation09:16

Exogenous Administration of Microsomes-associated Alpha-synuclein Aggregates to Primary Neurons As a Powerful Cell Model of Fibrils Formation

Published on: June 26, 2018

Large-scale Scanning Transmission Electron Microscopy (Nanotomy) of Healthy and Injured Zebrafish Brain10:09

Large-scale Scanning Transmission Electron Microscopy (Nanotomy) of Healthy and Injured Zebrafish Brain

Published on: May 25, 2016

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...
Amebiasis01:28

Amebiasis

Entamoeba histolytica, a protozoan parasite, is responsible for intestinal and extraintestinal amebiasis. Though a significant proportion of infections remain asymptomatic, approximately 50 million individuals annually are estimated to present with clinical disease, resulting in up to 100,000 deaths globally. The disease burden is disproportionately high in regions with lower socioeconomic status, such as parts of India, Africa, Mexico, and Latin America.Etiology and TransmissionThe infective...
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...
Alzheimer Disease ll: Pathophysiology01:23

Alzheimer Disease ll: Pathophysiology

Alzheimer disease involves structural changes in the brain that begin long before symptoms appear. The most distinctive features are extracellular neuritic plaques and intracellular neurofibrillary tangles.Neuritic plaques form in the cerebral cortex and around blood vessels. These plaques contain a dense core of beta-amyloid (Aβ)—a toxic protein fragment that clumps outside neurons. The core is surrounded by damaged neuronal extensions, as well as reactive astrocytes and microglia. Abnormal...
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...
Hepatic Encephalopathy01:29

Hepatic Encephalopathy

DefinitionHepatic encephalopathy is a reversible neurologic syndrome that results from advanced liver dysfunction or portosystemic shunting. It leads to disturbances in cognition, behavior, and motor function due to the brain’s exposure to gut-derived toxins that the liver fails to detoxify.EtiologyThis condition develops either in the setting of acute fulminant hepatitis or progressively during chronic liver disease, such as cirrhosis and portal hypertension. Portosystemic shunting—including...