Neurophysiologic follow-up of long-term dietary treatment in adult-onset adrenoleukodystrophy

Objective: to monitor the effects of dietary treatment in adult-onset adrenoleukodystrophy (ALD) by means of somatosensory evoked potentials (SEPs) and motor evoked potentials (MEPs). Background: SEPs and MEPs have proved useful in revealing signs of progressively severe, central dying-back axonopathy in early stages of adult-onset ALD. Methods: eight patients with adult-onset ALD underwent clinical examination, brain and spine MRI, and SEP and MEP studies before and after 3 years of Lorenzo's oil dietary therapy. Results: before treatment, brain MRI was normal in five patients. Three of these patients had pure spinal SEP abnormalities and in the remaining two patients SEPs showed signs of involvement of both the spinal and cerebral somatosensory tracts. After treatment, the three patients with pure spinal abnormalities showed clinical and neurophysiologic worsening, whereas the two patients with a more advanced stage of disease (exhibited by SEPs) showed substantially unchanged clinical and neurophysiologic features. The patients with abnormal brain MRI at the onset of treatment showed clinical and neurophysiologic worsening. Conclusions: Lorenzo's oil therapy had no effect on patients with evidence of inflammatory brain lesions. Moreover, in patients without clear signs of inflammatory damage, this treatment does not modify significantly the natural course of the disease. However, because effective treatments should begin before the onset of severe neurologic symptoms, SEPs and MEPs should be considered to evaluate the effectiveness of other experimental treatments in the patient with a negative brain MRI.