title: Autonomic Function Tests and MIBG in Parkinson's Disease: Correlation to Disease Duration and Motor Symptoms.
abstract: OBJECTIVE
  Disorders of the autonomic nervous system (ANS) have a variable degree of clinical relevance in patients with Parkinson's disease (PD). Here, we assessed whether subclinical autonomic dysfunction, as evaluated by a complete battery of autonomic function tests (AFTs), correlates with PD progression.
  
  
  METHODS
  A series of 27 consecutive patients with PD underwent extensive ANS investigations including the head-up tilt test (HUTT), Valsalva maneuver, deep-breathing test, and handgrip test (HG); further, they performed 123I-meta-iodobenzylguanidine (MIBG) scintigraphy.
  
  
  RESULTS
  Seven of the 27 patients showed orthostatic hypotension (OH) at HUTT and pathological responses to the deep-breathing and HG test and Valsalva maneuver. The majority of the remaining 20 patients with PD showed pathological responses to deep-breathing (n = 13) and/or HG (n = 11). Only 3 of 27 suffered relevant OH. MIBG uptake of myocardium was decreased in 19 patients with PD (H/M ratio 1.3 ± 0.2). Prolonged clinical observation (>3 years), persistent response to levodopa, and MIBG repetition allowed us to exclude negative MIBG as attributable to atypical Parkinsonism. MIBG uptake did not correlate with OH and other AFTs. Both HG test response and MIBG did correlate with the Unified Parkinson's Disease Rating Scale (UPDRS) motor score and disease duration. A positive correlation emerged between diastolic blood pressure (DBP) response to HG test and MIBG and with systolic blood pressure (SBP) response at tilt test.
  
  
  CONCLUSIONS
  Our investigation suggests that ANS impairment affects the majority of patients with PD, even those PD patients showing negative MIBG, irrespective of clinical neurovegetative symptoms. The strict correlation that has been revealed with disease progression supports the routine utilization of AFTs as a reliable and inexpensive tool for monitoring peripheral sympathetic dysfunction in PD and optimizing therapy.
authors.affiliation: Department of System Medicine, Neurology, University of Rome "Tor Vergata", Rome, Italy.
authors.forename: Camilla
authors.initials: C
authors.lastname: Rocchi
authors.affiliation: Department of System Medicine, Neurology, University of Rome "Tor Vergata", Rome, Italy.
authors.forename: Mariangela
authors.initials: M
authors.lastname: Pierantozzi
authors.affiliation: Neurocenter of Southern Switzerland, Lugano, Switzerland.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Galati
authors.affiliation: Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy.
authors.forename: Agostino
authors.initials: A
authors.lastname: Chiaravalloti
authors.affiliation: IRCCS Fondazione S. Lucia, Rome, Italy.
authors.forename: Valerio
authors.initials: V
authors.lastname: Pisani
authors.affiliation: Neurocenter of Southern Switzerland, Lugano, Switzerland.
authors.forename: Chiara
authors.initials: C
authors.lastname: Prosperetti
authors.affiliation: Department of System Medicine, Neurology, University of Rome "Tor Vergata", Rome, Italy.
authors.forename: Benedetta
authors.initials: B
authors.lastname: Lauretti
authors.affiliation: Department of System Medicine, Neurology, University of Rome "Tor Vergata", Rome, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Stampanoni Bassi
authors.affiliation: Department of System Medicine, Neurology, University of Rome "Tor Vergata", Rome, Italy.
authors.forename: Enrica
authors.initials: E
authors.lastname: Olivola
authors.affiliation: Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy.
authors.forename: Orazio
authors.initials: O
authors.lastname: Schillaci
authors.affiliation: Department of System Medicine, Neurology, University of Rome "Tor Vergata", Rome, Italy.|IRCCS Fondazione S. Lucia, Rome, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Stefani
mesh_terms: D019797:3-Iodobenzylguanidine; D000328:Adult; D000368:Aged; D000978:Antiparkinson Agents / Q000627:therapeutic use; D001341:Autonomic Nervous System / Q000503:physiopathology*; D001794:Blood Pressure / Q000502:physiology; D005260:Female; D018737:Hand Strength; D006321:Heart / Q000000981:diagnostic imaging; D006801:Humans; D007980:Levodopa / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging; D009460:Neurologic Examination; D010300:Parkinson Disease / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000503:physiopathology*; D019275:Radiopharmaceuticals; D012720:Severity of Illness Index; D013997:Time Factors
chemical_list: D000978:Antiparkinson Agents; D019275:Radiopharmaceuticals; D019797:3-Iodobenzylguanidine; D007980:Levodopa
keywords: Autonomic function test; MIBG; Orthostatic hypotension; Parkinson's disease