80. Small fiber neuropathy in Amyotrophic Lateral Sclerosis: Contribution of laser-evoked potentials and skin biopsy

• Published in: Clinical neurophysiology 2017-12, Vol.128 (12), p.e434-e434
• Main Authors: Maccora, S., Donadio, V., Pagliarani, E., Infante, R., Incensi, A., Di Stasi, V., Liguori, R.
• Format: Article
• Language: English
• ISSN: 1388-2457; 1872-8952
• DOI: 10.1016/j.clinph.2017.09.087

Increasing evidence suggests that amyotrophic lateral sclerosis (ALS) is a multisystem neurodegenerative disorder, also determining a small fiber neuropathy (SFN) as recognized by skin biopsy studies in distal legs, irrespective of the disease duration. This study aimed at evaluating the performance of a battery of neurophysiological and morphological tests assessing the small fiber loss occurring in ALS. We recruited 10 consecutive ALS patients (5M, age 64.9±7.3, duration of symptoms 29.1±20.7months). All patients had undergone skin biopsy (from thigh and lower leg) and LEPs using a Nd-YAP laser (1340nm) by stimulating hand, foot and face skin surface. Intraepidermal nerve fiber density was altered in 100% of patients. 80% of ALS patients showed abnormalities in LEPs. Comparing face, hand and foot, Aδ-LEPs were more often abnormal recording from foot. Interestingly, C fibers in the trigeminal territory showed the highest abnormalities (40% of patients). Our study has confirmed a small fiber involvement in ALS patients. To our knowledge this is the first study using Nd:YAG LEPs and skin biopsy in a ALS cohort. However, our findings need to be extended to a larger number of patients in order to evaluate the possibility of a higher involvement of C fibers rather than A-δ in SFN associated to ALS.