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Multifocal Electroretinograms
Published on: December 4, 2011
Understanding progressive multifocal leukoencephalopathy: links between milky-way appearance and mismatch T2/FLAIR
Emiliano Ruiz Romagnoli1, Manuel Perez Akly1, Luis A Miquelini1
137533Hospital Italiano de Buenos Aires, Argentina.
Background:
Magnetic resonance imaging is essential to diagnose progressive multifocal leukoencephalopathy. The broad radiological spectrum may partially be explained by genetic viral mutations and their differential neurotropism. Recent pharmacovigilance-magnetic resonance imaging studies have provided new insight into pathophysiology and radiological markers of early stages. However, how lesions evolve and why certain anatomical locations are more frequently affected remains unknown. We aim to describe a new sign - T2/fluid-attenutated inversion recovery mismatch - as a complementary marker of cavitated lesions and propose a link with the milky-way appearance, a key early sign. Furthermore, we hypothesise viral dissemination routes.
Methods:
We conducted a retrospective longitudinal study from January 2010 to January 2020, to analyse clinical and magnetic resonance imaging features of 13 progressive multifocal leukoencephalopathy individuals at the symptomatic stage (mean age 58.3 years (SD ± 16.8) - 61.5% were women).
Results:
The most prevalent pathology was HIV (61.5%) and motor deficit prevailed regarding other symptoms (76.9%). Frontal lobes (76.9%), middle cerebellar peduncle (61.5%), cerebellum (61.5%), and pons (53.8%) were most commonly affected, and the cortico-ponto-cerebellar pathway seemed involved in these patients. Five patients had a pure radiological pattern. Milky-way appearance was the most frequent radiological sign (58.3%). Five patients with milky-way appearance had concomitantly T2/fluid-attenuated inversion recovery mismatch (P = 0.02). This sign showed high sensitivity and specificity (100-71%, P = 0.02) to assess evolved lesions besides diffusion.
Conclusion:
The possible tract-dependent spread, as well as clinical and genetic, have implications on the MRI variability of progressive multifocal leukoencephalopathy. The milky-way appearance could reflect a transitional phase towards evolved lesions, the latter demonstrated by T2/fluid-attenuated inversion recovery mismatch. Both could be key magnetic resonance imaging signs to diagnose progressive multifocal leukoencephalopathy at the symptomatic stage.
Insights
New MRI signs, T2/fluid-attenuated inversion recovery mismatch and milky-way appearance, aid in diagnosing progressive multifocal leukoencephalopathy (PML). These findings help understand lesion evolution and viral spread in PML patients.
Area of Science:
- Neurology
- Radiology
- Infectious Diseases
Background:
- Magnetic resonance imaging (MRI) is crucial for diagnosing progressive multifocal leukoencephalopathy (PML).
- Understanding the radiological spectrum, lesion evolution, and anatomical predilection in PML is limited.
- New insights into PML pathophysiology and early radiological markers are emerging from recent studies.
Purpose of the Study:
- To introduce the T2/fluid-attenuated inversion recovery (FLAIR) mismatch sign as a marker for cavitated PML lesions.
- To explore the relationship between the T2/FLAIR mismatch sign and the milky-way appearance, an early PML sign.
- To hypothesize about viral dissemination routes in PML.
Main Methods:
- Retrospective longitudinal study of 13 progressive multifocal leukoencephalopathy patients.
- Analysis of clinical and MRI features from January 2010 to January 2020.
- Focus on patients at the symptomatic stage of the disease.
Main Results:
- HIV was the most prevalent underlying pathology (61.5%).
- Motor deficit was the most common symptom (76.9%).
- Frontal lobes, middle cerebellar peduncle, cerebellum, and pons were frequently affected.
- Milky-way appearance was observed in 58.3% of patients.
- T2/FLAIR mismatch was found in 5 patients with milky-way appearance (P=0.02).
- T2/FLAIR mismatch demonstrated high sensitivity and specificity (100-71%) for evolved lesions.
Conclusions:
- Tract-dependent spread, clinical, and genetic factors influence MRI variability in PML.
- The milky-way appearance may indicate a transitional phase to evolved lesions.
- T2/FLAIR mismatch is a key MRI sign for diagnosing evolved PML lesions.
- Both milky-way appearance and T2/FLAIR mismatch are valuable for diagnosing symptomatic PML.
