The Distribution of the Virus of Poliomyelitis in the Cerebrospinal Axis of Monkeys

The lesions of poliomyelitis are found mainly in the central nervous system and take the form of inflammatory changes and nerve cell destruction. The latter is the outstanding pathological feature of the disease, but even in severe cases the reaction to the virus of poliomyelitis has an irregular distribution and varies in intensity throughout the cerebrospinal axis of monkeys. Thus, in the spinal cord, most of the neurones are affected, in the pons and medulla there may be considerable inflammatory exudate but there is decidedly less nerve cell destruction and specific changes are rarely present in the brain. Whether the virus acts directly or indirectly upon the nerve cells, it appears reasonable to suppose an irregular distribution of the virus in the central nervous system, with greatest concentration in those areas having most nerve destruction.