Rapid Progression of Amyotrophic Lateral Sclerosis in an Acromegalic Patient After Surgical Resection of a Growth Hormone-Producing Pituitary Adenoma

Abstract

Insulin-like growth factor-1 (IGF-1) promotes the survival of neurons, mediates neuritic growth, and in 1 clinical trial human recombinant IGF-1 delayed the progression of functional impairment and decline of health-related quality of life in patients with amyotrophic lateral sclerosis (ALS). We describe a case of a 65-year-old woman with a 2-year history of symptoms and signs of acromegaly because of a pituitary microadenoma. The patient posed a challenging diagnostic dilemma because of the presence of dysarthria, which was initially considered as the consequence of acromegaly. After octreotide long-acting release (LAR) treatment, the patient underwent uneventful pituitary surgery. Although postoperative evaluation indicated a cure of acromegaly, progressive bulbar symptoms developed, which were followed by upper limb weakness and muscle atrophy. Neurologic investigations confirmed the diagnosis of ALS and riluzole therapy was given. One year after surgery growth-hormone deficiency was diagnosed, but a trial with human recombinant growth hormone failed to produce any significant improvement. Two years after surgery the patient died of a sudden respiratory arrest. Histopathologic examination of the brain and spinal cord confirmed the diagnosis of ALS. This is the first report showing a rapid progression of ALS after a surgical cure of coexisting acromegaly presumably because of cessation of high endogenous IGF-I levels.