Exercise Study of Function and Pathology for Women With X-linked Adrenoleukodystrophy

The purpose is to see how X-linked adrenoleukodystrophy (X-ALD) is associated with strength and sensation using MRI, in women with X-ALD. The investigators will also see whether exercise can improve these symptoms for women with X-ALD.

X-linked adrenoleukodystrophy (X-ALD), a [sex-linked] progressive neurodegenerative disease, is caused by a defect in the ABCD1 gene. The disease is expressed in multiple ways, but the most common adult form is adrenomyeloneuropathy (AMN), which results in slowly progressive changes in muscle tone and weakness, sensory loss, and dysfunction of the autonomic nervous system. In a previous study the investigators linked abnormalities in the [brain/spinal cord] to lower extremity weakness in men with AMN; however, there have been no studies evaluating these relationships in women carriers (i.e., women with AMN). It is unknown, in women with AMN, how the pattern of damage in the brain and spinal cord relates to disability and if these patterns predict responsiveness to treatment. The investigators hypothesize that by using magnetization transfer (MT) and diffusion tensor imaging (DTI), two magnetic resonance imaging (MRI) modalities, to track particular changes in the brain and spinal cord will predict disability and additionally, who is likely to respond best to a training regimen. The investigators expect that these more advanced imaging techniques will be more sensitive and accurate quantitative measures of clinical motor function and women with greater loss in the spinal cord compared to the brain will benefit most from training to improve disability. To test this hypothesis, women with AMN will receive MRI scans at baseline and complete measures of global walking and lower extremity impairments of vibration sensation, spasticity, and strength at three time-points: baseline, 12 weeks, and 18 weeks after baseline. The group will participate in a resistive training program for 12 weeks. MRI data will be correlated to changes over time in measures of impairment to determine their relationships. The linking of this information will not only be important for better defining disability in women with AMN but it will also help to guide physicians and rehabilitation therapists in predicting who is likely to respond to rehabilitative interventions, as well as for optimizing the effects of future pharmacological interventions.

Female carriers as well as healthy age and gender matched individuals will participate in an exercise paradigm.

The exercise program uses a local Curves® gym to provide an individualized program of strength and cardiovascular training. The program is expected to be performed for 45 minutes 4-6 days per week.

Change in Maximal Voluntary Contraction of the Hip Flexors From Baseline to End of Training and to Post-training

Here, we will assess whether the degree of a person's white matter integrity (i.e. for tracts of interest as measured from MRI) predicts their ability to benefit from exercise. Our prediction is that those individuals with preserved white matter integrity will show the greatest improvement in hip flexor strength.

Participants are assessed at baseline (visit 1, enrollment), end of training (visit 2, week 12) and post-training (visit 3, week 18).

Inclusion Criteria: confirmed diagnosis, X-ALD heterozygote carrier no medical contraindication to participating in a strength training program able to follow complex directions as determined by a score of ≤1 on a subset of questions taken from the NIH Stroke scale (Brott et al. 1989) hip flexion strength: 6.6-15.8kg hip extension strength: up to 18.3 kg normal passive range of motion at hips/knees/ankles able to walk ≥50m Exclusion Criteria: Evidence of other neurological deficit that could interfere, such as previous stroke or muscle disease congestive heart failure cancer orthopedic conditions severe pain that precludes study participation seizures pregnancy other medical condition that precludes participation in an exercise program, e.g., unstable angina, uncontrolled diabetes, uncontrolled hypertension Healthy controls have the same age and exclusion criteria as women with AMN except that they will not be carriers for X-ALD. They must have normal neurological function.