Damage to oligodendroglial supporting cells with demyelination, reactive gliosis, and coagulation necrosis also may occur. The breakdown of white matter may induce marked edema and mass effect. Clinicians may suspect recurrence since the symptoms of focal necrosis frequently recapitulate those of tumor. Decreased intellectual functioning has been observed in adults after cranial irradiation. Certain cognitive functions such as memory may be more susceptible to decline than others, and may prevent patients from returning to their premorbid occupation.
Clinical features range from mild lassitude or personality change to incapacitating dementia.
Some patients with cerebral atrophy may have gait disturbance and urinary incontinence similar to the syndrome of normal pressure hydrocephalus. The nervous system of the child has many sites vulnerable to radiation damage. The diagnosis of RIN may be difficult to confirm. MRI may show a contrast-enhancing mass with extensive white matter alterations and hyperintensity of the periventricular white matter. Cerebral cortical atrophy is manifest as enlarged cerebral sulci and ventricular dilatation.