[Immunohistochemical methods in the diagnosis of diffuse axonal injury]

Diffuse axonal injury (DAI) was diagnoses according to axonal reaction proved as balls by Palmgren's silver impregnation and axonal lesions by immunohistochemical investigation of ubiquitin and low molecular weight neurofilaments (68 kD). Diffuse axonal injury was found in 16 cases from a group of 36 persons deceased of craniocerebral trauma (44%). Diagnosis was based on the presence of axonal retraction balls in 15 cases; the balls showed also a striking positivity with antibodies against ubiquitin and low molecular neurofilaments as well. In the last patient who died 10 hours after a head injury, too early for axonal retraction balls to be formed, diagnosis of DAI could be settled because of the presence of axonal swellings immunohistochemically positive for ubiquitin and neurofilaments. A control groups of 6 persons after sudden death showed both axonal widenings and swellings but their immunohistochemistry was negative. Immunohistochemical methods of proving ubiquitin and low molecular weight neurofilaments represent substantial contribution to diagnosis of diffuse axonal injury. Earlier phase of axonal lesions than in simple histology can be observed and histological diagnosis of axonal injury independently confirmed.