Perry S. Gerard

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Between attacks, migraine patients are characterized by potentiation instead of habituation of stimulation-evoked cortical responses. It is debated whether this is due to increased or decreased cortical excitability. We have studied the changes in visual cortex excitability by recording pattern-reversal visual evoked potentials (PR-VEP) after low- and(More)
We performed transcranial magnetic stimulations of the motor and visual cortices in healthy controls (n = 27) and in patients suffering from migraine without (n = 33) or with (n = 25) aura between attacks. By using a 13-cm circular coil placed over the vertex and recordings of the first dorsal interosseus muscle, we measured thresholds (at rest and during(More)
BACKGROUND AND PURPOSE Prevalence and characteristics of ipsilateral upper limb motor-evoked potentials (MEPs) elicited by focal transcranial magnetic stimulation (TMS) were compared in healthy subjects and patients with acute stroke. METHODS Sixteen healthy subjects and 25 patients with acute stroke underwent focal TMS at maximum stimulator output over(More)
Pressure pain thresholds were assessed with an algometer (Somedic Inc.), over the forehead, temple and suboccipital region as well as over the Achilles tendon. A group of 32 patients suffering from chronic tension-type headache was compared to 20 healthy controls and to 10 migraineurs without aura. Although individual values were widely scattered, pressure(More)
Between attacks, migraineurs lack habituation in standard visual evoked potentials (VEPs). Visual stimuli also evoke high-frequency oscillations in the gamma band range (GBOs, 20-35 Hz) assumed to be generated both at subcortical (early GBOs) and cortical levels (late GBOs). The consecutive peaks of GBOs were analysed regarding amplitude and habituation in(More)
The effects of noxious and non-noxious limb stimulations on the second exteroceptive suppression of voluntary temporalis muscle activity (ES2) were studied in healthy human volunteers. Duration of temporalis ES2 was measured on averaged rectified responses obtained after stimulating the labial commissure at an intensity of 25 mA. Single peripheral(More)
In order to determine the mono- or oligosynaptic character of connections between pyramidal axons and individual spinal motor neurons, we constructed peri-stimulus time histograms (PSTHs) of the firing probability of voluntarily activated single motor units (SMUs) of various upper and lower limb muscles upon slightly suprathreshold transcranial anodal(More)
Bilateral multifocal renal oncocytomas are very rare disorders with only 6 previously reported cases in the world literature, of which only 3 have had pathologic confirmation. We present the first reported case of diffuse, bilateral, multifocal renal oncocytomatosis in a patient with end-stage renal disease requiring hemodialysis. Our patient was found to(More)
Major breakthroughs in catheter, guidewire, and other angiographic equipment currently allow interventional radiologists to diagnose massive life-threatening upper and lower GI hemorrhage and to stop the bleeding safely and effectively using superselective catheterization and microcoil embolization. Similarly, the interventional radiologist can treat acute(More)