PMID- 18596185
OWN - NLM
STAT- MEDLINE
DCOM- 20081212
LR  - 20080909
IS  - 0022-3077 (Print)
IS  - 0022-3077 (Linking)
VI  - 100
IP  - 3
DP  - 2008 Sep
TI  - Subcortical interactions between somatosensory stimuli of different modalities 
      and their temporal profile.
PG  - 1610-21
LID - 10.1152/jn.90412.2008 [doi]
AB  - Interactions between inputs of different sensory modality occur along the sensory 
      pathway, including the thalamus. However, the temporal profile of such 
      interaction has not been fully studied. In eight patients who had been implanted 
      an intrathalamic electrode for deep brain stimulation as symptomatic treatment of 
      tremor, we investigated the interactions between mechanical taps and electrical 
      nerve stimuli. Somatosensory evoked potentials (SEPs) were recorded from Erb's 
      point, cervical spinal cord, nucleus ventrointermedialis of the thalamus, and 
      parietal cortex. A handheld electronic reflex hammer was used to deliver a 
      mechanical tap to the skin overlying the first dorsal interosseous muscle and to 
      trigger an ipsilateral digital median nerve electrical stimulus time-locked to 
      the mechanical tap with a variable delay of 0 to 50 ms. There were significant 
      time-dependent interactions between the two sensory volleys at the subcortical 
      level. Thalamic SEPs were decreased in amplitude at interstimulus intervals 
      (ISIs) from 10 to 40 ms with maximum effect at 20 ms (-42.8 +/- 10.5%; P < 
      0.001). A similar decrease was also seen in the number and frequency of the 
      high-frequency components of thalamic SEPs (-25 +/- 4%). A smaller reduction 
      (-18.1 +/- 5.8%; P < 0.001) was present in upper cervical response at ISI = 20 
      ms. There were no changes in peripheral responses. Cortical SEPs were almost 
      completely absent in some subjects at ISIs from 20 to 50 ms. There were no 
      changes in SEP latencies. Our results indicate that significant time-dependent 
      interactions between sensory volleys occur at the subcortical level. These 
      observations provide further insight into the physiological mechanisms underlying 
      afferent gating between sensory volleys of different modality.
FAU - Costa, Joao
AU  - Costa J
AD  - Electromyography and Motor Control Unit, Neurology Department, Institut 
      d'Investigacio Biomedica August Pi i Sunyer, Hospital Clinic, Universitat de 
      Barcelona, Barcelona, Spain.
FAU - Valls-Sole, Josep
AU  - Valls-Sole J
FAU - Valldeoriola, Francesc
AU  - Valldeoriola F
FAU - Rumia, Jordi
AU  - Rumia J
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20080702
PL  - United States
TA  - J Neurophysiol
JT  - Journal of neurophysiology
JID - 0375404
SB  - IM
MH  - Afferent Pathways/*physiopathology
MH  - Aged
MH  - Analysis of Variance
MH  - *Brain Mapping
MH  - Deep Brain Stimulation/methods
MH  - Evoked Potentials, Somatosensory/*physiology
MH  - Female
MH  - Humans
MH  - Male
MH  - Median Nerve/physiopathology/radiation effects
MH  - Middle Aged
MH  - Parkinson Disease/pathology/physiopathology
MH  - Physical Stimulation
MH  - Reaction Time/physiology
MH  - Skin/innervation
MH  - Thalamus/pathology/*physiopathology
MH  - Time Factors
MH  - Tremor/pathology/physiopathology
EDAT- 2008/07/04 09:00
MHDA- 2008/12/17 09:00
CRDT- 2008/07/04 09:00
PHST- 2008/07/04 09:00 [pubmed]
PHST- 2008/12/17 09:00 [medline]
PHST- 2008/07/04 09:00 [entrez]
AID - 90412.2008 [pii]
AID - 10.1152/jn.90412.2008 [doi]
PST - ppublish
SO  - J Neurophysiol. 2008 Sep;100(3):1610-21. doi: 10.1152/jn.90412.2008. Epub 2008 
      Jul 2.