title: Pallidal stimulation in dystonia affects cortical but not spinal inhibitory mechanisms.
abstract: BACKGROUND
  Deep brain stimulation (DBS) of the globus pallidus interna is an effective tool for the treatment of dystonia with possible distant effects reaching beyond the basal ganglia network.
  
  
  OBJECTIVE
  We analyzed the cortical silent period (CoSP) to test inhibitory circuits at the cortical level, and the cutaneous silent period (CuSP) and the H-reflex to test inhibitory circuits at the spinal level.
  
  
  METHODS
  The upper limb muscles of 16 patients (9F, aged 54±(SD)16years) with generalized (N=9) and cervical (N=7) dystonia treated with DBS bilaterally were examined by the CoSP, CuSP and H-reflex in two states with random order: (i) in DBS ON and (ii) in DBS OFF condition two hours later, and compared with healthy controls.
  
  
  RESULTS
  While the CuSP and H-Reflex did not differ between groups and remained unaffected by DBS, the CoSP was influenced significantly in dystonia. The CoSP onset latency was shortened (p<0.05 corrected) and the CoSP duration prolonged (p<0.01 corrected) in ON versus OFF condition. This effect was especially larger in generalized or phasic type of dystonia. Compared to healthy controls, the CoSP latency and duration became shorter in patients during the OFF condition only.
  
  
  CONCLUSIONS
  The pallidal DBS did not affect the spinal inhibitory circuitry in dystonia. However, the abnormally low cortical inhibition was normalized after DBS possibly offering more efficient suppression of aberrant dystonic movements.
authors.affiliation: Department of Neurology, Charles University, Third Faculty of Medicine, Charles University in Prague and Faculty Hospital Kralovske Vinohrady, Czech Republic.
authors.forename: Václav
authors.initials: V
authors.lastname: Boček
authors.affiliation: Department of Neurology, Charles University, Third Faculty of Medicine, Charles University in Prague and Faculty Hospital Kralovske Vinohrady, Czech Republic. Electronic address: ivana.stetkarova@fnkv.cz.
authors.forename: Ivana
authors.initials: I
authors.lastname: Štětkářová
authors.affiliation: Department of Neurology and Center of Clinical Neuroscience, Charles University in Prague, 1(st) Faculty of Medicine and General University Hospital in Prague, Czech Republic.
authors.forename: Anna
authors.initials: A
authors.lastname: Fečíková
authors.affiliation: Department of Neurology and Center of Clinical Neuroscience, Charles University in Prague, 1(st) Faculty of Medicine and General University Hospital in Prague, Czech Republic.
authors.forename: Václav
authors.initials: V
authors.lastname: Čejka
authors.affiliation: Department of Stereotactic and Radiation Neurosurgery, Na Homolce Hospital, Prague, Czech Republic.
authors.forename: Dušan
authors.initials: D
authors.lastname: Urgošík
authors.affiliation: Department of Neurology and Center of Clinical Neuroscience, Charles University in Prague, 1(st) Faculty of Medicine and General University Hospital in Prague, Czech Republic.
authors.forename: Robert
authors.initials: R
authors.lastname: Jech
mesh_terms: D000328:Adult; D000368:Aged; D002540:Cerebral Cortex / Q000503:physiopathology*; D013181:Cortical Spreading Depression / Q000502:physiology*; D046690:Deep Brain Stimulation / Q000379:methods*; D004421:Dystonia / Q000628:therapy*; D019054:Evoked Potentials, Motor / Q000502:physiology; D005260:Female; D005917:Globus Pallidus / Q000502:physiology*; D006181:H-Reflex / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009433:Neural Inhibition / Q000502:physiology*; D012720:Severity of Illness Index; D013116:Spinal Cord / Q000503:physiopathology*; D055815:Young Adult
keywords: Cortical inhibition; Cortical silent period; Cutaneous silent period; Deep brain stimulation; Dystonia; Globus pallidus; H-reflex; Spinal inhibition