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A giant MS plaque mimicking PML during natalizumab treatment
1Associates in Neurology, Lexington, KY 40536-0284, USA.
Abstract:
We describe a patient with a giant MS plaque developing during natalizumab administration whose clinical presentations mimicked PML. This 27year-old man developed new onset confusion, altered behavior, left hemianesthesia and worsening dysarthria, gait and balance with a new, large, rim-enhancing, temporoparietal subcortical lesion after four infusions of natalizumab. Cerebrospinal JC virus polymerase chain reaction was negative. No neutralizing antibody to natalizumab was detected. Following discontinuation of natalizumab, plasma exchange, and a single dose of 1000mg of methylprednisolone, he demonstrated clinical and radiographic improvement. Distinguishing PML from MS may be very difficult in some instances. The frequency with which an aggressive demyelinating disorder due to MS occurs during treatment with natalizumab remains to be determined.
Insights
A rare case of progressive multifocal leukoencephalopathy (PML) mimicking multiple sclerosis (MS) occurred during natalizumab treatment. Prompt discontinuation and treatment led to patient recovery, highlighting diagnostic challenges.
Area of Science:
- Neuroimmunology
- Neurology
- Clinical Neuroscience
Background:
- Natalizumab is an effective treatment for multiple sclerosis (MS).
- Progressive multifocal leukoencephalopathy (PML) is a rare but serious opportunistic infection that can occur in MS patients treated with natalizumab.
- Distinguishing between MS relapses and PML can be challenging due to overlapping clinical and radiological features.
Purpose of the Study:
- To report a case of a giant MS plaque mimicking PML in a patient receiving natalizumab.
- To discuss the diagnostic challenges and management strategies in such cases.
Main Methods:
- Case report of a 27-year-old male patient treated with natalizumab.
- Clinical presentation, neuroimaging, and cerebrospinal fluid (CSF) analysis including JC virus PCR.
- Treatment with natalizumab discontinuation, plasma exchange, and methylprednisolone.
Main Results:
- The patient developed a large, rim-enhancing temporoparietal subcortical lesion with neurological deficits.
- CSF JC virus PCR was negative, and no natalizumab-neutralizing antibodies were detected.
- Clinical and radiographic improvement was observed after natalizumab discontinuation and treatment.
Conclusions:
- Aggressive demyelinating lesions in MS can mimic PML during natalizumab therapy.
- Negative JC virus PCR does not entirely rule out PML.
- Early recognition and appropriate management are crucial for favorable outcomes.
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