It is characterized by Lhermitte's sign, an electric shock-like sensation that radiates into various parts of the body when the neck is flexed. The symptoms resolve spontaneously. Late Delayed Brain Injury Late delayed radiation injury appears months to years after radiation therapy and may affect any part of the nervous system. The disorder is characterized by dementia, sometimes with gait apraxia and incontinence. There is no treatment.
Some patients respond temporarily to ventricular shunting.
Focal radiation damage affects patients who receive either focal brain irradiation for the treatment of extracranial neoplasms or whole brain irradiation for the treatment of intracranial neoplasms. Neurologic signs suggest that a mass is present and include headache, focal or generalized seizures, and hemiparesis. MRI reveals a hypointense mass that sometimes exhibits contrast enhancement. The clinical and MRI findings in patients with focal radiation damage cannot be distinguished from those in patients with brain tumors, and diagnosis can be made only by biopsy. Corticosteroids may ameliorate symptoms.