Objective: To gain insight into the natural history of arrested cerebral adrenoleukodystrophy (CALD), we quantified the change in Neurologic Function Score (NFS) and Loes Score (LS) over time in patients whose cerebral lesions spontaneously stopped progressing.

Methods: We retrospectively reviewed a series of 22 patients with arrested CALD followed longitudinally over a median time of 2.4 years (0.7 – 17.0). Primary outcomes were change in radiographic disease burden (measured by LS) and clinical symptoms (measured by NFS) between patients who never developed a contrast-enhancing lesion (GdE- subgroup), and those who did (GdE+ subgroup). Secondary analyses comparing patterns of neuroanatomical involvement and lesion number, and prevalence estimates, were performed.

Results: Cerebral lesions were first detected at a median age of 23.3 years old (8.0 – 67.6), with an initial LS of 4 (0.5 – 9).  NFS was 0.5 (0 – 6). Overall change in NFS or LS per year did not differ between subgroups. No patients who remained GdE- converted to a progressive CALD phenotype. The presence of contrast enhancement was associated with disease progression (r_s = 0.559, p < 0.001). Four patients (18.2%) underwent step-wise progression, followed by spontaneous resolution of contrast enhancement, and re-arrest of disease.  Three patients (13.6%) converted to progressive CALD.  Nineteen patients (86.4%) have arrested CALD at most recent follow-up. The prevalence of arrested CALD is 12.4%.

Conclusion: Arrested CALD lesions can begin in childhood, and patients are often asymptomatic early in disease. The majority of patients remain stable.  However, clinical and MRI surveillance is recommended as a minority of patients undergo step-wise progression, or conversion to progressive CALD.