Clinically Isolated Brainstem Progressive Multifocal Leukoencephalopathy: Diagnostic Challenges.

Area of Science:

• Neurology
• Infectious Diseases
• Neuroimaging

Background:

• Acute brainstem syndrome (ABS) is rarely the initial presentation of progressive multifocal leukoencephalopathy (PML).
• Accurate diagnosis requires considering a broad spectrum of differential diagnoses for ABS.
• Neurodiagnostic testing and thorough patient history are crucial.

Observation:

• A 47-year-old woman with HIV presented with acute neurological deficits suggestive of ABS.
• Brain MRI revealed extensive white matter lesions in the brainstem and cerebellum.
• Initial misdiagnosis as multiple sclerosis led to inappropriate steroid treatment.

Findings:

• Cerebrospinal fluid analysis revealed oligoclonal bands, initially supporting an inflammatory diagnosis.
• Deterioration prompted further investigation, revealing JC polyomavirus (JCV) DNA in CSF via PCR.
• The patient was diagnosed with clinically isolated brainstem PML.

Implications:

• This case underscores the necessity of including isolated brainstem PML in the differential diagnosis for acute-onset brainstem symptoms.
• Awareness of PML variants, including brainstem and diencephalic forms, is vital for timely diagnosis.
• Improved treatments, including highly active antiretroviral therapy (HAART), offer better prognoses for PML patients.