Disseminated necrotizing leukoencephalopathy

An 11-year-old boy had a relapse of acute lymphoblastic leukemia involving the CNS. He was treated with whole brain radiotherapy and intrathecal methotrexate. One week after the whole brain radiotherapy, he developed personality changes and right facial weakness. Brain MRI was obtained ([Figure 1]).

Figure 1 Initial brain MRI. Axial T2-weighted brain MRI shows extensive regions of subcortical hyperintensity with small internal foci of low signal (A). Post-contrast T1-weighted axial MRI shows a necrotic-appearing subcortical enhancement pattern within the anterior temporal and inferior frontal lobes bilaterally (B).

Disseminated necrotizing leukoencephalopathy is an uncommon neurotoxicity syndrome associated with whole brain radiotherapy and methotrexate. Personality change is commonly reported[1]. Disseminated necrotizing leukoencephalopathy is characterized by subcortical T2-hyperintensities with low-signal foci and corresponding contrast-enhancing areas[1],[2]. Early cessation of inciting therapies may prevent progression ([Figure 2]). Our patient returned to his neurologic baseline and at 14-month follow-up remained without further deterioration.

Figure 2 Follow-up brain MRI. Imaging four months after initial recognition of disseminated necrotizing leukoencephalopathy and cessation of inciting therapies demonstrates interval improvement in edema (A) and reduced extent of contrast enhancement (B).

• References

• 1 Oka M, Terae S, Kobayashai R, Sawamura Y, Kudoh K, Tha KK et al. MRI in methotrexate-related leukoencephalopathy: disseminated necrotizing leukoencephalopathy in comparison with mild leukoencephalopathy. Neuroradiology. 2003;45(7):493-7.
• 2 Laxmi SN, Takahashi S, Matsumoto K, Higan S, Kurihara N, Imaizumi M et al. Treatment-related disseminated necrotizing leukoencephalopathy with characteristic contrast enhancement of the white matter. Radiat Med. 1996 Nov-Dec;14(6):303-7.