title: Serotonin impairment in CSF of PD patients, without an apparent clinical counterpart.
abstract: In Parkinson's disease (PD), several studies have detected an impaired serotonin (5-HT) pathway, likely affecting both motor and non-motor domains. However, the precise impact of 5-HT impairment is far from established. Here, we have used a HPLC chromatographic method, in a homogenous cohort (n = 35) of non fluctuating, non dyskinetic PD patients, to assess the concentration of 5-HT and its metabolite 5-HIAA in peripheral cerebrospinal fluid (CSF) obtained from lumbar puncture (LP). LP was performed following three days of therapy withdrawal, in order to vanish the effects of prolonged released dopamine agonists (DA), and in absence of any serotonergic agent. The PD patient group showed a significantly reduced CSF level of both 5-HT and 5-HIAA compared to either age-matched control subjects (n = 18), or Alzheimer's disease patients (n = 20). However, no correlation emerged between 5-HT/5-HIAA concentrations and UPDRS-III (r = -0.12), disease duration (r = -0.1), age (r = -0.27) and MMSE (r = 0.11). Intriguingly, low CSF 5-HT levels did not differ for gender or for motor phenotype (in terms of non-tremor dominant subtype and tremor dominant subtype). Further, low CSF 5-HT levels did not correlate with the presence of depression, apathy or sleep disturbance. Our findings support the contention that 5-HT impairment is a cardinal feature of stable PD, probably representing a hallmark of diffuse Lewy bodies deposition in the brainstem. However, clinical relevance remains uncertain. Given these findings, an add-on therapy with serotonergic agents seems questionable in PD patients, or should be individually tailored, unless severe depression is present.
authors.affiliation: Department of Systems Medicine c/o Movement Disorder Centre, University of Tor Vergata, Rome, Italy.
authors.forename: Enrica
authors.initials: E
authors.lastname: Olivola
authors.affiliation: Department of Systems Medicine c/o Movement Disorder Centre, University of Tor Vergata, Rome, Italy.
authors.forename: Mariangela
authors.initials: M
authors.lastname: Pierantozzi
authors.affiliation: Department of Systems Medicine c/o Movement Disorder Centre, University of Tor Vergata, Rome, Italy; IRCCS Fondazione S. Lucia, Rome, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Imbriani
authors.affiliation: Department of Systems Medicine c/o Neurophysiopathology Unit, University of Tor Vergata, Rome, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Liguori
authors.affiliation: Department of Systems Medicine c/o Movement Disorder Centre, University of Tor Vergata, Rome, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Stampanoni Bassi
authors.affiliation: Department of Systems Medicine c/o Movement Disorder Centre, University of Tor Vergata, Rome, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Conti
authors.affiliation: Department of Systems Medicine c/o Movement Disorder Centre, University of Tor Vergata, Rome, Italy.
authors.forename: Vincenza
authors.initials: V
authors.lastname: D'Angelo
authors.affiliation: IRCCS Fondazione S. Lucia, Rome, Italy; Department of Systems Medicine c/o Neurophysiopathology Unit, University of Tor Vergata, Rome, Italy.
authors.forename: Nicola Biagio
authors.initials: NB
authors.lastname: Mercuri
authors.affiliation: Department of Systems Medicine c/o Movement Disorder Centre, University of Tor Vergata, Rome, Italy; IRCCS Fondazione S. Lucia, Rome, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Stefani
mesh_terms: D000368:Aged; D015331:Cohort Studies; D003863:Depression / Q000150:complications; D005260:Female; D006801:Humans; D006897:Hydroxyindoleacetic Acid / Q000134:cerebrospinal fluid / Q000378:metabolism; D008297:Male; D010300:Parkinson Disease / Q000134:cerebrospinal fluid* / Q000175:diagnosis / Q000378:metabolism / Q000523:psychology; D012701:Serotonin / Q000134:cerebrospinal fluid* / Q000378:metabolism; D013129:Spinal Puncture
chemical_list: D012701:Serotonin; D006897:Hydroxyindoleacetic Acid