2016 Volume 33 Issue 3 Pages 373-377
Diagnostic neuropathology of central nervous system leading to treatment is divided into two domains. One is brain biopsy and the other is autopsy proven pathological diagnosis. Brain biopsy is useful in difficult cases, in which less invasive measures have been unable to yield a definitive diagnosis, especially associated with space occupying lesions of white matter on imaging studies. These lesions include primary central nervous system lymphoma (PCNSL), tumefactive demyelinating lesions (TDL), progressive multifocal leukoencephalopathy (PML), and amyloid β–related angiitis (ABRA). Brain biopsies lead to early pathological diagnosis and suitable treatment. As brain biopsies often consist of small pieces of tissue, sampling error might occur. Preoperative discussion among neurologists, neurosurgeons, neuroradiologists, and pathologists is very important about differential diagnosis and biopsy regions. Furthermore, preoperative steroid or immunosuppressive therapy often obscure or obliterate pathological findings from naive inflammatory reaction. Therefore, it is recommended to plan a brain biopsy before steroid or immunosuppressive therapy.
In neurodegenerative disorders or dementias, correct pathological diagnosis is obtained in autopsy. The worldwide decrease of autopsy rate has been reported, which make correct pathological diagnosis difficult. The characteristic pathological findings of neurodegenerative disorders consist of disease specific inclusions in neurons and glia composed of abnormally aggregated disease specific proteins. Alzheimer's disease has neurofibrillary tangle with tau aggregation and senile plaques with amyloid β fibrils. Parkinson disease and dementia with Lewy bodies shows α–synuclein positive Lewy bodies and Lewy neurites. In multiple system atrophy α–synuclein positive glial cytoplasmic inclusions in oligodendroglia are pathological hallmark. Major tauopathies consist of Pick disease with Pick bodies composed of 3 repeat tau, progressive supranuclear palsy and corticobasal degeneration with glioneuronal inclusions composed of 4 repeat tau. Amyotrophic lateral sclerosis and frontotemporal lobar degeneration present TDP–43 proteinopathies. In elderly overlapping of several neurodegenerative diseases is not uncommon. Pathological confirmations contribute the verification and understanding of clinical and neuroradiological findings, and treatment.
