Neurophysiological evaluation of motor corticospinal pathways by TMS in idiopathic early-onset Parkinson's disease.
OBJECTIVE
In a previous study we found altered motor corticospinal conduction in patients with early-onset Parkinson's disease (EOPD) and parkin gene mutations (PARK2). Aim of the present study was to evaluate central motor conduction in patients with EOPD, negative for parkin mutations to establish if prolonged CMCT is specific of PARK2 or it may be present in other EOPD patients.


METHODS
Eleven patients with non-PARK2 EOPD underwent transcranial magnetic stimulation (TMS) to evaluate central motor conduction time (CMCT). Motor threshold (MT), motor evoked potential (MEP) amplitude, central silent period threshold (cSPT), and duration were also determined.


RESULTS
All patients but one showed normal CMCT. CMCT and the other electrophysiological data did not differ significantly between patients and healthy controls, except for cSPT mean value which was higher in patients than in controls (p=0.008). No significant correlation was found between electrophysiological and clinical data in EOPD patients. CMCT was significantly prolonged in six PARK2 patients compared to non-PARK2 patients.


CONCLUSIONS
We conclude that CMCT is usually normal in idiopathic EOPD: we suggest that in presence of a prolonged CMCT the diagnosis of PARK2 should be considered.


CONCLUSIONS
CMCT may represent a simple electrophysiological test that could be utilized in an early phase of diagnosis to differentiate PARK2 patients from those with idiopathic EOPD.
Perretti
Anna
A
Department of Neurological Sciences, "Federico II" University of Naples, Italy. Electronic address: anperret@unina.it.
De Rosa
Anna
A
Department of Neurological Sciences, "Federico II" University of Naples, Italy.
Marcantonio
Lucia
L
Department of Neurological Sciences, "Federico II" University of Naples, Italy.
Iodice
Valeria
V
Department of Neurological Sciences, "Federico II" University of Naples, Italy.
Estraneo
Anna
A
Salvatore Maugeri Foundation, IRCSS, Telese Terme (BN), Italy.
Manganelli
Fiore
F
Department of Neurological Sciences, "Federico II" University of Naples, Italy.
Garavaglia
Barbara
B
Unit of Molecular Neurogenetics, Neurological Institute C. Besta Foundation IRCCS, Milan, Italy.
Filla
Alessandro
A
Department of Neurological Sciences, "Federico II" University of Naples, Italy.
Santoro
Lucio
L
Department of Neurological Sciences, "Federico II" University of Naples, Italy.
De Michele
Giuseppe
G
Department of Neurological Sciences, "Federico II" University of Naples, Italy.
D000328:Adult; D017668:Age of Onset; D004247:DNA / Q000235:genetics; D003937:Diagnosis, Differential; D004525:Efferent Pathways / Q000503:physiopathology*; D055724:Electrophysiological Phenomena; D019054:Evoked Potentials, Motor / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000503:physiopathology*; D009154:Mutation / Q000235:genetics; D009431:Neural Conduction / Q000502:physiology; D010300:Parkinson Disease / Q000175:diagnosis* / Q000235:genetics; D018807:Polymorphism, Single-Stranded Conformational; D011712:Pyramidal Tracts / Q000503:physiopathology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013116:Spinal Cord / Q000503:physiopathology*; D050781:Transcranial Magnetic Stimulation; D044767:Ubiquitin-Protein Ligases / Q000235:genetics
D004247:DNA; D044767:Ubiquitin-Protein Ligases; C111567:parkin protein