Dentato-rubral tract involvement in adult-onset adrenoleukodystrophy.

Kumar et al investigated the magnetic resonance findings of the brain and spinal cord in a large series of patients with adult-onset adrenoleukodystrophy (ALD), and described tract involvement in the corticospinal, spinothalamic, visual, and auditory pathways (1). Some authors have noticed tract demy-elination involving the cerebellar peduncles (2,3). We describe a case of adult-onset ALD with clinical symptoms of spinocer-ebellar degeneration. Lesions were found mainly in the dentate nuclei of the cerebellum, unilateral superior cerebellar pedun-cle, and red nucleus. The patient was a 24-year-old man who had been healthy until age 20, when he first complained of an unstable gait and involuntary movements in the left leg when standing. At age 21 he experienced titubation when descending stairs. Thereafter, he gradually developed dysarthria, writing disturbance, and finger tremor. He was admitted to our hospital for the investigation of these symptoms at age 24. During admission, we tested the patient's verbal and motor aptitude. The patient's verbal, performance, and total scores on a Wechsler Adult Intelligence Scale were 112, 57, and 89 respectively. We noted horizontal nystagmus and faltering speech. There was mild muscle atrophy and bilateral spasticity in his extremities, but no weakness was found. The patient's responses to the finger-to-nose, heel-to-knee, and diadochokinesis tests were most impaired on the right side. He showed tremor and dysmetria predominately in the right arm and leg when he moved. Deep tendon reflexes were exaggerated in all four limbs and the Babinski's sign was positive on the left. He had a staggering and wide gait, and he could not walk in tandem. The results of Romberg's and Mann's tests were positive. Pain and vibratory sensation was mildly elevated in the right lower extremity. The serum cortisol level was normal (10.8 g/dl, 10 min. 18.2 g/dl), suggesting a mild adrenal insufficiency. The very long chain fatty acid ratios (C26/C22, C25/C22, and C24/C22) were markedly elevated in plasma and erythrocyte membranes, a finding compatible with confirmed ALD cases. The MR image of the brain obtained during admission revealed T2 high-intensity lesions in the right dentate nucleus as well as mild atrophy of the cerebellar vermis, cerebellar hemisphere, and cerebral cortex. Six months after admission, T2 high-signal intensity was observed in both dentate nuclei and in one side of the dentate-rubral tract, extending from the right dentate nucleus through the superior cerebellar peduncle to the left red nucleus (Fig 1). Contrast-enhanced T1 weighted MR imaging revealed …