Brain Damage Newsroom

Brain Damage Considered To Be A New Clinical And Pathological Entity Are Described

Three cases of postirradiation brain damage considered to be a new clinical and pathological entity are described. Three women were irradiated for tumors in and around the left middle ear. Treatment plans and isodose distributions show that a maximum tissue dose of about 5500 rad of Co/sup 60/ gamma radiation was delivered to each patient.

The treatment time was approximates 1 month, but the fractionation was different. In the first case there were 20, the second 27, and the third 16 fractions. The clinical course was similar. Clinical examination showed gross cerebellar ataxia, horizontal nystagmus, and Romberg's sign. In the first case there was also paralysis of the 6th cranial nerve and an extensor plantar response. The first patient died four weeks after the onset of symptoms, while the other two started to show signs of recovery after four weeks, made a complete recovery in about 8-8 weeks, and are alive and well six years later.

An autopsy on the first patient showed disseminsted demyelination in a patchy fashion. Plaques were found in the white matter of the cerebrum, cerebellum, and brain stem, where the dose was highest, but there were lesions on the opposite side also where the dose was much lower. There was only a minor degree of blood vessel change, and it was of an early kind, unlike the more commonly seen fibrinoid necrosis of arterial walls. Secondiy, passing through the areas of demyelination were normal neurons and axons.

Around the plaques, astrocytic proliferation and clasmatodendrosis were seen, and around this a wall of microglial cells. It was considered that radiation might have invoked an allergic or autoimmune response. In view of the very marked similarity, it is not unreasonable to assume that all 3 patients had similar pathological processes and that some, as yet unknown, factor permitted two to live and allowed one to die.

The points of difference from previously defined syndrome are as follows: the latent period between radiation and onset is measured in weeks instead of months; the onset is acute instead of gradual; recovery may take place; the pathological picture is of demyelination rather than blood vessel damage. The possibility that damage to myelin sheaths or cytoplasmic enzyme systems is involved is discussed. (BBB