A two-year trial of oleic and erucic acids ("Lorenzo's oil") as treatment for adrenomyeloneuropathy.

BACKGROUND

Adrenomyeloneuropathy is an X-linked recessive disorder characterized by myelopathy, peripheral neuropathy, and cerebral demyelination, which develop in association with the accumulation of very-long-chain fatty acids. The administration of oleic and erucic acids inhibits the synthesis of very-long-chain fatty acids. Recently such dietary treatment has been widely publicized as a possible cure for this disease.

METHODS

We conducted an open trial in 14 men with adrenomyeloneuropathy, 5 symptomatic heterozygous women, and 5 boys (mean age, 13 years) with preclinical adrenomyeloneuropathy. The patients ate a low-fat diet and received daily doses of glycerol trioleate oil (1.7 g per kilogram of body weight) and glycerol trierucate oil (0.3 g per kilogram). Clinical manifestations, cerebral and spinal cord magnetic resonance imaging (MRI) scans, nerve conduction, and brain-stem auditory and somatosensory evoked potentials were studied prospectively over 18 to 48 months. Plasma levels of very-long-chain fatty acids and the side effects of erucic acid were monitored monthly.

RESULTS

By week 10, plasma very-long-chain fatty acid levels declined nearly to normal. Nonetheless, over a mean follow-up of 33 months none of the 14 men with adrenomyeloneuropathy improved. In nine men there was functional deterioration, coincident in four with new cerebral lesions on MRI. In a single patient there was a reduction in cerebellar demyelination, but without clinical improvement. In one of the five asymptomatic boys signs of myelopathy developed. There were no changes in the symptomatic heterozygous women. There was some improvement in peroneal-nerve conduction, but no detectable clinical improvement. Conduction to the parietal cortex (T12-P37 interpeak latency) worsened in both the symptomatic men and the boys with preclinical adrenomyeloneuropathy. There was no change in other somatosensory evoked potentials or in brain-stem auditory evoked potentials. Asymptomatic thrombocytopenia (< 100,000 cells per cubic millimeter) was noted in six patients.

CONCLUSIONS

In this open trial we found no evidence of a clinically relevant benefit from dietary treatment with oleic and erucic acids ("Lorenzo's oil") in patients with adrenomyeloneuropathy.