P 5 Volumetric Analysis of the Hypothalamus in a Large Cohort of Patient with Amyotrophic Lateral Sclerosis

Impaired energy expenditure parallels ongoing motor neuron degeneration in patients with amyotrophic lateral sclerosis (ALS). Translational animals provide evidence that energy metabolism is associated with impaired hypothalamic function. We aimed at analyzing the hypothalamic volumes in ALS patients compared with controls. Hypothalamic volume of 281 ALS patients and 116 healthy matched controls were manually delineated based on high-resolution anatomic T1-weighted MRI images using a dedicated segmentation technique.The volume of the hypothalamus, was normalized to the intracranial volume and adjusted with age.The total hypothalmic volume was significantly decreased in ALS patients compared with controls (p<0.0001); morespecifically the posterior part of the hypothalamus was more severely atrophied compared with the anterior part. The volume loss didnotcorrelate significantly with clinical and metabolic parameters which suggests an early affection of hypothalamic function possibly preceding motor symptom onset in ALS. Volumetric alterations of the hypothalamus could be an early feature of ALS.