Spastic paraparesia — a condition that involves weakness in the lower limbs and difficulty moving them — can be the only symptom of adult-onset adrenoleukodystrophy (ALD), a case report suggests.
The study, “X-linked adrenoleukodystrophy presenting as isolated spastic paraparesia,” was published in the journal Acta Neurologica Belgica.
People with ALD have mutations in the ABCD1 gene, which provides instructions for producing the adrenoleukodystrophy protein (ALDP). The manifestations of this disorder can vary, even among people with the same mutation.
With adult-onset ALD, also known as adrenomyeloneuropathy (AMN), patients usually show the first signs of the disease in their late 20s. These first symptoms tend to be stiff gait and weakness in the legs, along with problems with control over the bowel and bladder, and cognitive and adrenal involvement.
Now, researchers at Pamukkale University, in Turkey, presented the case of a 34-year-old man who had spastic paraparesia as the only symptom of AMN.
The man went to the emergency room because his legs had become progressively weaker over the previous five years. He had not been able to run for the past year, but could walk without assistance.
A neurological examination showed spasticity, or muscle stiffness, and increased reflexes in the man’s legs. He was unable to perform the heel-to-shin test due to spasticity. In contrast, the results in his upper limbs were normal, and he had no trouble performing the finger-to-nose test.
No cognitive impairment, changes in behavior, or difficulty controlling bowel and bladder movements were reported.
His lab exams, including full blood count, thyroid function, sex hormones, pituitary hormones, and liver and kidney function all were normal.
The doctors performed imagining exams of the brain and spinal cord, and observed no injuries or relevant findings. Studies assessing the nerve signals and brain and nerve function also were normal.
The man had a 48-year-old sister who also presented gait disorders that had started in her 30s. The symptoms had progressed slowly, and she walked assisted by a walking stick. She had problems with control over her bowel and bladder.
A genetic analysis showed that both siblings had the same mutation in the ABCD1 gene. Notably, the patients had two nephews from another sister who had died at an early age due to childhood ALD.
The researchers emphasized that the different ALD manifestations seen in this family showed that “ALD could cause different [symptoms] even in the same family, and such patients should be closely followed up for conversion to the cerebral form and the development of other systemic findings.”
This study presented a case of “adult-onset isolated spastic paraparesia without any endocrine or cognitive abnormalities,” the researchers said.
As the patient had no “cognitive or adrenal involvement, this case once more reminded us that AMN should be kept in mind in the differential diagnosis of patients with isolated spastic paraparesia,” the team added.
