Adrenomyeloneuropathy Presenting With Adrenal Insufficiency
In January 2012, a 33-year-old man visited the Department of Rehabilitation Medicine in Seoul Medical Center with complaints of a 13-year history for bilateral, progressive weakness and spasticity in his lower extremities as well as gait disturbance, urge incontinence and impotence. He showed scissoring gait and dragged his feet during walking. He had no family history of neurological or autoimmune disorders and absences of any trauma to the spine. At the age of 15, he was diagnosed with primary adrenal insufficiency so-called Addison disease and has been taking daily Prednisolone of 5 mg.\nPhysical examinations showed hyperpigmentation, especially in gingiva, tongue, creases of hand, and areolae (). The respiratory, cardiovascular, and abdominal examinations were unremarkable but the muscle bulk in his lower extremities was diminished. On neurologic examination, there was decreased vibratory, pain and temperature sensation below the nipple. In a manual muscle test, flexion and extension of the hip and knee joint each showed 4/4, the ankle dorsiflexion III/III, and the ankle plantarflexion IV/IV under the Medical Research Council classification. He showed spastic gait pattern, with hyperactive deep tendon reflexes and positive Babinski sign. Each degree of spasticity of knees and ankles measured with Modified Ashworth Scale was grade 1. Intellectual and memory functions were within the normal range.\nIn laboratory findings, adrenocorticotropic hormone (ACTH) level was above 1,500 pg/mL (normally 10.60 pg/mL) and a short synacthen test showed adrenal failures with a baseline cortisol 0.9 µg/dL (normally 2.9.19.4 µg/dL), 0.7 µg/dL at 30 minutes and 0.6 µg/dL at 60 minutes. The serum testosterone level was 2.40 ng/mL (normally 2.41.8.17 ng/mL). VLCFAs were measured in the plasma. C26:0 levels were 2.969 µmol/L (normally <1.31 µmol/L), the C26:0/C22:0 was 0.083 µmol/L (normally <0.023 µmol/L), and the C24:0/C22:0 was 1.727 µmol/L (normally <1.39 µmol/L) ().\nIn electophysiologic studies, somatosensory evoked potentials (SEPs) showed no responses in posterior tibial nerve but normal in median nerve. Brainstem auditory evoked potentials (BAEPs) and visual evoked potentials (VEPs) did not demonstrate definite abnormal findings. Nerve conduction studies (NCS) and needle electromyographic examinations were within normal range.\nMagnetic resonance imaging showed intramedullary signal changes along entire thoracic cord, which were suggestive of myelopathy (). The diagnosis of AMN was confirmed by raising circulating concentrations of VLCFA.