Biomaterial Database

Generator mechanisms of giant somatosensory evoked potentials in cortical reflex myoclonus. 1987

R Kakigi, and H Shibasaki

Department of Internal Medicine, Saga Medical School, Japan.

In order to clarify the generator mechanisms for giant cortical evoked potentials, scalp topographies of somatosensory evoked potentials (SEPs) following various types of stimulation, including electrical nerve trunk and finger stimulation and mechanical stimulation, were investigated in 5 patients with cortical reflex myoclonus. For SEPs evoked by median nerve stimulation, not only the P25 and N34 components in central and parietal regions but also N25 in the frontal region were markedly enlarged in each patient. Their scalp distributions were not significantly different from those of normal subjects. P25 and N25, but not N34, were considerably attenuated by interfering tactile stimulation applied to the hand. The components corresponding to P25, N25 and N34 following electrical stimulation of the digital nerves as well as mechanical stimulation of the finger were also remarkably large and showed scalp distributions similar to those for median nerve SEPs. It is therefore concluded that the giant cortical SEPs of cortical reflex myoclonus are generated in those areas of the primary sensory cortex which generate normal SEPs, in response to an input, at least in part, from cutaneous afferents on the basis of an extremely enhanced cortical excitability.

UI	MeSH Term	Description	Entries
D008475	Median Nerve	A major nerve of the upper extremity. In humans, the fibers of the median nerve originate in the lower cervical and upper thoracic spinal cord (usually C6 to T1), travel via the brachial plexus, and supply sensory and motor innervation to parts of the forearm and hand.	Median Nerves,Nerve, Median,Nerves, Median
D009207	Myoclonus	Involuntary shock-like contractions, irregular in rhythm and amplitude, followed by relaxation, of a muscle or a group of muscles. This condition may be a feature of some CENTRAL NERVOUS SYSTEM DISEASES; (e.g., EPILEPSY, MYOCLONIC). Nocturnal myoclonus is the principal feature of the NOCTURNAL MYOCLONUS SYNDROME. (From Adams et al., Principles of Neurology, 6th ed, pp102-3).	Myoclonus, Action,Myoclonus, Nocturnal,Myoclonus, Palatal,Polymyoclonus,Myoclonic Jerk,Myoclonic Jerking,Myoclonus Simplex,Myoclonus, Eyelid,Myoclonus, Intention,Myoclonus, Lower Extremity,Myoclonus, Oculopalatal,Myoclonus, Segmental,Myoclonus, Sleep,Myoclonus, Upper Extremity,Action Myoclonus,Extremity Myoclonus, Lower,Extremity Myoclonus, Upper,Eyelid Myoclonus,Intention Myoclonus,Jerk, Myoclonic,Jerking, Myoclonic,Jerks, Myoclonic,Lower Extremity Myoclonus,Myoclonic Jerks,Nocturnal Myoclonus,Oculopalatal Myoclonus,Palatal Myoclonus,Segmental Myoclonus,Simplex, Myoclonus,Sleep Myoclonus,Upper Extremity Myoclonus
D010812	Physical Stimulation	Act of eliciting a response from a person or organism through physical contact.	Stimulation, Physical,Physical Stimulations,Stimulations, Physical
D012018	Reflex	An involuntary movement or exercise of function in a part, excited in response to a stimulus applied to the periphery and transmitted to the brain or spinal cord.
D002540	Cerebral Cortex	The thin layer of GRAY MATTER on the surface of the CEREBRAL HEMISPHERES that develops from the TELENCEPHALON and folds into gyri and sulci. It reaches its highest development in humans and is responsible for intellectual faculties and higher mental functions.	Allocortex,Archipallium,Cortex Cerebri,Cortical Plate,Paleocortex,Periallocortex,Allocortices,Archipalliums,Cerebral Cortices,Cortex Cerebrus,Cortex, Cerebral,Cortical Plates,Paleocortices,Periallocortices,Plate, Cortical
D004558	Electric Stimulation	Use of electric potential or currents to elicit biological responses.	Stimulation, Electric,Electrical Stimulation,Electric Stimulations,Electrical Stimulations,Stimulation, Electrical,Stimulations, Electric,Stimulations, Electrical
D004560	Electricity	The physical effects involving the presence of electric charges at rest and in motion.
D005073	Evoked Potentials, Somatosensory	The electric response evoked in the CEREBRAL CORTEX by stimulation along AFFERENT PATHWAYS from PERIPHERAL NERVES to CEREBRUM.	Somatosensory Evoked Potentials,Evoked Potential, Somatosensory,Somatosensory Evoked Potential
D005385	Fingers	Four or five slender jointed digits in humans and primates, attached to each HAND.	Finger
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man