title: Post-ganglionic autonomic neuropathy associated with anti-glutamic acid decarboxylase antibodies.
abstract: Antibodies to glutamic acid decarboxylase (GAD-Abs) have been associated with several conditions, rarely involving the autonomic nervous system. Here, we describe two patients complaining of autonomic symptoms in whom a post-ganglionic autonomic neuropathy has been demonstrated in association with significantly elevated serum and CSF GAD-Abs levels.
  
  
  
  Patients underwent nerve conduction studies, sympathetic skin response testing, evaluation of autonomic control of the cardiovascular system and skin biopsy. Also, serum screening to exclude predisposing causes of peripheral neuropathy was performed. Anti-GAD65 antibodies were evaluated in serum and CSF.
  
  
  
  GAD-Abs titer was increased in both serum and CSF in both patients. Sympathetic skin response was absent and skin biopsy revealed a non-length-dependent small-fiber neuropathy with sympathetic cholinergic and adrenergic post-ganglionic damage in both patients. Nerve conduction studies and evaluation of autonomic control of the cardiovascular system were normal in both patients. Both patients were treated with steroids with good, but partial, (patient 2) recovery of the autonomic dysfunctions.
  
  
  
  Although the pathophysiological mechanisms involved are not fully defined, GAD-abs positivity in serum and CSF should be searched in patients with autonomic neuropathy when no other acquired causes are evident. This positivity may help to clarify autoimmune etiology and, subsequently, to consider immunomodulatory treatment.
authors.affiliation: Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy. enricofileccia@gmail.com.
authors.forename: E
authors.identifier: 0000-0002-3943-7539
authors.initials: E
authors.lastname: Fileccia
authors.affiliation: Neurology Unit, S. Orsola-Malpighi Hospital, Bologna, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Rinaldi
authors.affiliation: Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy.|IRCCS Institute of Neurological Sciences of Bologna, Bologna, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Liguori
authors.affiliation: IRCCS Institute of Neurological Sciences of Bologna, Bologna, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Incensi
authors.affiliation: Neurology Unit, S. Orsola-Malpighi Hospital, Bologna, Italy.
authors.forename: R
authors.initials: R
authors.lastname: D'Angelo
authors.affiliation: Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy.
authors.forename: M P
authors.initials: MP
authors.lastname: Giannoccaro
authors.affiliation: IRCCS Institute of Neurological Sciences of Bologna, Bologna, Italy.
authors.forename: V
authors.initials: V
authors.lastname: Donadio
mesh_terms: D001323:Autoantibodies / Q000097:blood*; D001338:Autonomic Fibers, Postganglionic / Q000473:pathology*; D001342:Autonomic Nervous System Diseases / Q000097:blood* / Q000134:cerebrospinal fluid / Q000175:diagnosis*; D005968:Glutamate Decarboxylase / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009431:Neural Conduction / Q000502:physiology
chemical_list: D001323:Autoantibodies; D005968:Glutamate Decarboxylase
keywords: Anti-GAD antibodies; Anti-glutamic acid decarboxylase antibodies; Autonomic neuropathy; Post-ganglionic autonomic neuropathy; Skin biopsy