All of the following statements regarding progressive multifocal leucoencephalopathy are true except aEUR'

Exclusively diagnosed by brain biopsy Progressive multifocal leucoencephalopathv :? Progressive multifocal leucoencephalopathy is a progressive disorder cause by J.C. viruso. The main cells affected in the disease are oligodendrocytesQ. Since oligodendrocytes are concerned with myelination, progressive multifocal leucoencephalopathy is characterized by multifocal areas of dernyelinationQ of varying size distributed throughout the brain but sparing the spinal cord and optic nerves. Patholocv Besides demyelination there are characteristic cytological alterations in both astrocytes and oligodendrocytes - Astrocytes2 Enlarged and contain, hyperchromatic, deformed and bizarre nuclei and frequent mitotic figures. Oligodendrocytesdeg These have enlarged densely staining nuclei that contains virus inclusions, formed by crystalline arrays. Symptoms of progressive multifocal leucoencephalopathy :? Focal neurological signs -> Speech defect (aphasia), dysahria hemiparesis, Ataxia Visual defects (45%) -> Homonymous hemianopia Mental impairment (38%) -> Dementia, confusion, personality changes Weakness -> Hemi or monoparesis and ataxia Seizures (20%) Progressive multifocal leucoencephalopathy is predominantly seen in patients with immunosuppressive disorders : - Most commonly associated conditions are :? - AIDS (80%)Q - Hematological malignancies (13%) - Transplant recipients (5%) - Chronic inflammatory disease (2%) Prognosis of progressive multifocal leucoencephalopathy In most cases death occurs in 3-6 months from onset of neurological symptoms and even more rapidly in patients with AIDS unless aggressive interetrul treatment is undeaken. Diagnosis MRI is used for the diagnosis of PML - MRI is better than CT scan in the diagnosis of PML and is frequently used for the diagnosis of PML. - On MRI the lesion appears as multifocal asymmetric coalescing white matter located periventricularly. - These lesions have increased signals on T2 and FLAIR images and decrease signal on T,-weighted images. - PML lesions are classically nonenhancingu. Brain biopsy in diagnosis of progressive multifocal leuco encephalopathy - It has a sensitivity of 74-92% and specificity of 92-100%. - Brain biopsy demonstrates multiple demyelinative foci in cerebral, cerebellar and brainstem white matter. - Perivascular inflammatory infiltrates are seen - Nuclear inclusions may be seen - Microscopic hallmark of the disease is intranuclear basophilic or eosinophilic inclusions within the swollen nucleus of oligodendrocytes often at the periphery of lesions. - Large multinucleated astrocytes arc also seen. PCR amplification of JCV DNA. - The PCR amplification of JCV DNA in association with typical MRI lesion in the appropriate clinical setting is diagnostic of PML