Poliomyelitis Virus and Degeneration of Peripheral Nerves. ∗

Abstract

After intracerebral injection of poliomyelitic virus in M. rhesus monkeys, O'Leary, Heinbecker and Bishop 1 showed that motor paralysis preceded noticeable changes in the axones of somatic nerves coming from the segments, the nerves of which supplied the paralyzed muscles. In brief, destruction of nerve cells occurred first, and destruction of nerve fibers secondarily. Since paralysis is produced in from 5 to 8 days following the intracerebral injection of the Flexner strain of virus in M. rhesus monkeys, at least that same period of time and perhaps more would elapse before changes would become obvious in the fibers of the somatic nerves, after this method of injection.

Forty-two monkeys were injected subserosally with 25 cc. of a 1% suspension of virus, 10 animals with the same amount and percentage of virus contained in enteric toxin (paratypho-coli filtrate) 2 subserosally and 7 animals with 0.1 cc. of a 1% suspension of virus intracerebrally. Somatic nerves coming from the lumbar and sacral segments were removed and studied by polarized light between crossed Nicol's prisms. 3 Within 24 hours after the injection, the somatic nerves were found to have obvious changes in their fibers, i. e., extensive vacuolization and destruction of fasciculi fibers. In 48 hours, the myelin might be granular, the nodes swollen with spireme-like isotropic threads above and below the cementing discs, and the neurokeratin framework might be prominent around the axis cylinder. The nerve fibers of animals that received virus in enteric toxin were always involved and almost completely destroyed in some sections within 48 hours. The animals that received virus intracerebrally did not show comparable changes, even though 10 or more days had elapsed between the time of inoculation and the time the animals were sacrificed.