Stimulus artifact removal to detect trigeminal sensory evoked potentials.

Objective: Large stimulus and myogenic artifacts usually prevent detection of sensory evoked potentials to electrical stimulation in trigeminal sensory territory (t-SEP). Stimulus Artifact (SA) removal can be obtained by means of two stimulating modes (Dual Mode Stimulation - DMS) having in common a fixed cathode alternatingly referred to opposed anodes, resulting in SAs of opposite polarity. Opposite SAs progressively cancel each other out during averaging, without interaction with the underlying bio-electrical events.

Focal hole versus screw stimulation to prevent false negative results in detecting pedicle breaches during spinal instrumentation.

Objective: We describe a stimulus-evoked EMG approach to minimize false negative results in detecting pedicle breaches during lumbosacral spinal instrumentation.

Methods: In 36 patients receiving 176 lumbosacral pedicle screws, EMG threshold to nerve root activation was determined using a focal probe inserted into the pilot hole at a depth, customized to the individual patients, suitable to position the stimulating tip at the point closest to the tested nerve root. Threshold to screw stimulation was also determined.

Normative Values for Intertrial Variability of Motor Responses to Nerve Root and Transcranial Stimulation: A Condition for Follow-Up Studies in Individual Subjects.

Objective: Intertrial variability (ITV) of motor responses to peripheral (CMAP) and transcranial (MEP) stimulation prevents their use in follow-up studies. Our purpose was to develop strategies to reduce and measure CMAP and MEP ITV to guide long-term monitoring of conduction slowing and conduction failure of peripheral and central motor pathway in the individual patient.

Methods: Maximal compound muscle action potentials to High Voltage Electrical Stimulation (HVES) of lumbo-sacral nerve roots (r-CMAP) and activated, averaged motor evoked potentials (MEPs) to Transcranial Magnetic Stimulation (TMS) using double cone coil were recorded from 10 proximal and distal muscle districts of lower limbs.

Double-Cone Coil TMS Stimulation of the Medial Cortex Inhibits Central Pain Habituation.

Objective: The aim of this study was to investigate whether Transcranial Magnetic Stimulation (TMS) applied over the medial line of the scalp affects the subjective perception of continuous pain induced by means of electric stimulation. In addition, we wanted to identify the point of stimulation where this effect was maximum.

Methods: Superficial electrical stimulation was used to induce continuous pain on the dominant hand.

Behavioral and neuroplastic effects of low-frequency rTMS of the unaffected hemisphere in a chronic stroke patient: a concomitant TMS and fMRI study.

Repetitive Transcranial Magnetic Stimulation (rTMS) ameliorates motor and neuropsychological deficits following stroke, but little is known about the underlying neuroplasticity. We investigated neuroplastic changes following 5 days of low-frequency rTMS on the intact motor cortex to promote motor recovery in a chronic patient with subcortical stroke. The feasibility of administering multiple treatments was also assessed 6 months later by applying the same protocol over the patient's parietal cortex to improve visuospatial disorders.

A new neurophysiological approach to assess central motor conduction damage to proximal and distal muscles of lower limbs.

Objective: To develop a neurophysiological method to explore central motor pathways to proximal and distal muscles of lower limbs.

Methods: MEPs to transcranial magnetic stimulation using the double cone coil were bilaterally and simultaneously recorded from vastus medialis, tibialis anterior and flexor hallucis brevis. Voluntary facilitation was controlled using a predefined sequence of movements of constant amplitude.

Non-invasive high voltage electrical stimulation as a monitoring tool of nerve root function in lumbosacral surgery.

Objective: To verify the safety and clinical use of non-invasive high-voltage electrical stimulation (HVES) in patients with compressive radiculopathy. To test the feasibility of HVES to survey nerve root function during lumbosacral surgery.

Methods: In 20 patients undergoing lumbosacral surgery for degenerative spinal diseases, compound muscle action potentials (CMAPs) evoked by maximal HVES were bilaterally recorded throughout surgery from L3 to S2 radicular territories.

A methodological reappraisal of non invasive high voltage electrical stimulation of lumbosacral nerve roots.

Objective: To describe a neurophysiological method to locate the optimal stimulation site (OSS) over the vertebral column, customized to the individual subject, to achieve maximal activation of lumbosacral roots by means of non-invasive high voltage electrical stimulation (HVES).

Methods: OSS was located in 30 volunteers by testing different stimulation points of a surface multi-electrode array placed over the dorso-lumbar junction of the vertebral column. The dorso-ventral stimulating montage was used (Troni et al.

Segmental analysis of motor conduction velocity in distal tracts of tibial nerve: a coaxial needle electrode study.

Objective: To describe a new method of segmental analysis of motor nerve conduction velocity (mCV) in the tibial nerve (Tn) tract distal to the upper margin of the tarsal tunnel (TT).

Methods: Compound muscle action potentials (CMAPs) were recorded with a coaxial needle electrode from the flexor hallucis brevis muscle (FHB), to test the medial plantar nerve (MPn), and from the flexor digiti quinti brevis (FDQB) and the first dorsal interosseous (FDI) muscles, to test the superficial and deep branches of the lateral plantar nerve (sLPn and dLPn, respectively). CMAPs were elicited by stimulating at three sites located above (S1) and below (S2) the TT and at the sole of the foot (S3 for MPn and S4 for LPn).

Sporadic bulbospinal muscle atrophy with facial-onset sensory neuropathy.

We report a case of idiopathic severe facial-onset sensorimotor neuropathy with no evidence of Kennedy's disease, familial amyotrophic lateral sclerosis, amyloidosis, Tangier disease, sarcoidosis, chronic basilar meningitis, or Sjögren's syndrome. Clinical and neurophysiological features of this patient resemble those of four recently reported patients who were affected with facial-onset sensorimotor neuropathy (FOSMN), a probably novel disease. The present report provides information about a further patient with FOSMN in order to better characterize the clinical and laboratory features of this disease.