Immunohistochemical study of intracytoplasmic inclusion bodies of the thalamus in myotonic dystrophy.

Intracytoplasmic inclusion bodies of the thalamus in eight patients with myotonic dystrophy (MyD) were studied immunohistochemically. The intracytoplasmic inclusion bodies of the thalamus (thalamic inclusions, TIs) were strongly immunostained with anti-ubiquitin antibody (Ab) and some of them were mildly stained with anti-microtubule associated protein 1 (MAP 1) and anti-MAP 2 antibodies. However, TIs did not react with any of the following: anti-neurofilament protein Ab, anti-tau Ab, anti-paired helical filament Ab, anti-tubulin Abs (alpha and beta), anti-neuron-specific enolase Ab, anti-glial fibrillary acidic protein Ab, anti-synaptophysin Ab, anti-myelin basic protein Ab, anti-actin Ab and anti-phosphorylated epitope of neurofilaments Ab. Thus, our study demonstrates the unique immunohistochemistry of TIs in MyD which differentiates them from other intracytoplasmic inclusions in various neurodegenerative disorders.