Related Experiment Video

Updated: Jan 21, 2026

Multifocal Electroretinograms
16:49

Multifocal Electroretinograms

Published on: December 4, 2011

18.8K

Diagnosing progressive multifocal leukoencephalopathy: clinical features, neuroimaging findings, confirmatory testing

Katherine M Sawicka1, Jacob Houpt2,3, Kamala Sangam3,4

  • 1Department of Medicine, Division of Neurology, University of Toronto, Toronto, Ontario, Canada.

Practical Neurology
|January 19, 2026
PubMed

Insights

Progressive multifocal leukoencephalopathy (PML), a severe central nervous system infection caused by John Cunningham virus (JCV), requires prompt diagnosis. This review aids clinicians in identifying PML, even in immunocompetent individuals, by detailing clinical, imaging, and testing strategies.

Area of Science:

  • Neurology
  • Infectious Diseases
  • Neurovirology

Background:

  • Progressive multifocal leukoencephalopathy (PML) is a severe, opportunistic central nervous system infection.
  • It is caused by the John Cunningham virus (JCV), a common polyomavirus rarely causing neurological disease.
  • Diagnosis is challenging due to varied presentations, occurrence in immunocompetent individuals, and imperfect diagnostic tests.

Purpose of the Study:

  • To review clinical features, neuroimaging findings, and diagnostic methods for PML.
  • To propose an algorithm to aid in the accurate and timely diagnosis of PML.

Main Methods:

  • Literature review of clinical presentations, neuroimaging characteristics, and laboratory diagnostic techniques for PML.
  • Synthesis of information to develop a diagnostic algorithm.

Main Results:

  • PML presents with diverse neurological symptoms and characteristic, though sometimes subtle, neuroimaging findings.
  • Cerebrospinal fluid (CSF) analysis for JCV DNA has imperfect sensitivity.
  • A diagnostic algorithm integrating clinical, imaging, and testing data is proposed.

Conclusions:

  • Accurate and prompt diagnosis of PML is crucial for patient management.
  • The proposed algorithm facilitates diagnosis by consolidating key diagnostic information.
  • Improved diagnostic strategies are needed, especially for cases in relatively immunocompetent hosts.
Keywords:
INFECTIOUS DISEASESMRINEUROPATHOLOGY, VIROLOGYNEUROVIROLOGYVIROLOGY

More Related Videos

Basics of Multivariate Analysis in Neuroimaging Data06:35

Basics of Multivariate Analysis in Neuroimaging Data

Published on: July 24, 2010

17.3K
Identification of Disease-related Spatial Covariance Patterns using Neuroimaging Data14:27

Identification of Disease-related Spatial Covariance Patterns using Neuroimaging Data

Published on: June 26, 2013

16.2K

Related Concept Videos

Myocarditis II: Clinical Features and Diagnostic Tests01:27

Myocarditis II: Clinical Features and Diagnostic Tests

Myocarditis is an inflammation of the heart muscle. The symptoms vary widely, encompassing asymptomatic presentations to severe, acute manifestations.Clinical PresentationAsymptomatic cases: In some instances, myocarditis may be asymptomatic, with the infection resolving without intervention. These cases often go undetected unless discovered incidentally through diagnostic imaging or tests conducted for other reasons.General Early Symptoms: Early symptoms of myocarditis are non-specific and can...
271
Pericarditis II: Clinical Features and Diagnostic Tests01:19

Pericarditis II: Clinical Features and Diagnostic Tests

Pericarditis is distinguished by inflammation of the pericardium, the fibrous sac that encases the heart. It can be acute, lasting less than six weeks, or chronic, persisting for over three months. Understanding its clinical manifestations and diagnostic findings is crucial for timely and effective management.Clinical ManifestationsWhile pericarditis can be asymptomatic, it usually presents with characteristic symptoms such as:Chest Pain: The most characteristic symptom of pericarditis is chest...
293
Mitral Stenosis II: Clinical features and Diagnostic Tests01:23

Mitral Stenosis II: Clinical features and Diagnostic Tests

Mitral stenosis is a heart condition in which the mitral valve, which allows blood to flow from the left atrium to the left ventricle, becomes narrowed or stenotic. This narrowing hinders blood flow and leads to clinical symptoms requiring specific medical evaluations and management strategies. The following overview outlines the clinical symptoms, assessments, diagnostic findings, prevention methods, and treatments for mitral stenosis.Clinical ManifestationsDyspnea (shortness of breath): This...
225
Aortic Regurgitation II: Clinical Features and Diagnostic Tests01:22

Aortic Regurgitation II: Clinical Features and Diagnostic Tests

Aortic valve regurgitation (AR) occurs when the aortic valve fails to close properly, allowing blood to flow backward from the aorta into the left ventricle. This backflow can result in two distinct clinical presentations: acute and chronic AR, each characterized by its own set of symptoms and physical findings.Acute Aortic RegurgitationAcute AR presents with a sudden onset of severe symptoms. Patients typically experience profound dyspnea (shortness of breath), chest pain, and signs of left...
425
Mitral Regurgitation II: Clinical Features and Diagnostic Tests01:23

Mitral Regurgitation II: Clinical Features and Diagnostic Tests

Mitral regurgitation (MR) is a valvular heart disorder in which the mitral valve fails to close tightly, allowing blood to leak backward into the heart. Understanding the clinical manifestations, assessment, diagnostic findings, and medical management of MR is crucial to effectively managing affected patients.Clinical Manifestations of Mitral RegurgitationMitral regurgitation can be acute or chronic, each presenting differently and requiring different approaches:1. Acute Mitral...
386
Atherosclerosis II: Clinical Manifestations and Diagnostic Tests01:27

Atherosclerosis II: Clinical Manifestations and Diagnostic Tests

Atherosclerosis is a progressive disorder that leads to the thickening and narrowing of arterial walls due to plaque buildup. This condition can cause various symptoms depending on the arteries affected:Coronary Artery Disease (CAD): This condition affects the coronary arteries and may lead to chest pain (angina), shortness of breath (dyspnea), heart attacks, and other heart disease symptoms.Cerebrovascular Disease: This affects blood flow to the brain, causing transient ischemic attacks (TIAs)...
479