brain, spinal cord, and nerve disorders
Progressive Multifocal Leukoencephalopathy (PML)
Diagnosis of PML
Magnetic resonance imaging A spinal tap Unexplained, progressively worsening symptoms in people with a weakened immune system suggest progressive multifocal leukoencephalopathy. Magnetic resonance imaging (MRI) of the head is done. It can usually detect abnormalities that suggest the diagnosis. A Spinal Tap (lumbar puncture) is done to obtain a sample of cerebrospinal fluid (the fluid that flows through the tissues that cover the brain and spinal cord). The polymerase chain reaction (PCR) technique, which produces many copies of a gene, is used to detect the JC virus's DNA in the cerebrospinal fluid. 