title: P043. Hyperechogenicity of the periaqueductal gray in chronic migraine and episodic migraine as a potential marker of progressive dysfunction: preliminary results with transcranial sonography.
authors.affiliation: Clinical Neurophysiology Unit, University of Pavia, Pavia, Italy.|Headache Science Centre, National Neurological Institute C. Mondino, Pavia, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Guaschino
authors.affiliation: Clinical Neurophysiology Unit, University of Pavia, Pavia, Italy.|Headache Science Centre, National Neurological Institute C. Mondino, Pavia, Italy.
authors.forename: Natascia
authors.initials: N
authors.lastname: Ghiotto
authors.affiliation: Headache Science Centre, National Neurological Institute C. Mondino, Pavia, Italy.|Department of Brain and Behavioural Sciences, University of Pavia, Pavia, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Tassorelli
authors.affiliation: Headache Science Centre, National Neurological Institute C. Mondino, Pavia, Italy.
authors.forename: Vito
authors.initials: V
authors.lastname: Bitetto
authors.affiliation: Headache Science Centre, National Neurological Institute C. Mondino, Pavia, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Nappi
authors.affiliation: Clinical Neurophysiology Unit, University of Pavia, Pavia, Italy.|Department of Brain and Behavioural Sciences, University of Pavia, Pavia, Italy.
authors.forename: Arrigo
authors.initials: A
authors.lastname: Moglia
authors.affiliation: Clinical Neurophysiology Unit, University of Pavia, Pavia, Italy.
authors.forename: Daniele
authors.initials: D
authors.lastname: Bosone
authors.affiliation: Headache Science Centre, National Neurological Institute C. Mondino, Pavia, Italy. grazia.sances@mondino.it.
authors.forename: Grazia
authors.initials: G
authors.lastname: Sances