We identified eight patients with a distinct magnetic resonance imaging pattern of inhomogeneous cerebral white matter abnormalities and selective involvement of brainstem and spinal tracts. Proton magnetic resonance imaging showed increased lactate in the abnormal white matter. Clinically, the patients had slowly progressive pyramidal, cerebellar, and dorsal column dysfunction. The uniform, hi...

Very few such cases have been recorded : one by Obre, one by Athol Johnson, one by Virchow, and a case of myo-lipoma by Gowers. The paraplegia of the lower limbs, their extreme anaesthesia, the bladder weakness, the extreme contraction of both lower extremities, the increase of their tendon reflexes, need no comment. They depend partly on the compression of the cervico-dorsal cord, partly on th...

PURPOSE To determine the presence of small lesions in the pyramidal tract in patients with amyotrophic lateral sclerosis (ALS) by using magnetization-transfer (MT) measurements and MR imaging. METHODS MT ratios (MTRs) were measured in the posterior limb of the internal capsule in nine patients with ALS and in nine healthy volunteers. RESULTS The mean value of MTRs (%) in patients with ALS w...

Antidromically identified neurons projecting to the putamen (CPNs) and pyramidal tract neurons (PTNs) were recorded from motor and premotor cortex of a monkey which performed a load-bearing task with the wrist. CPNs appeared as a uniform population with very slowly conducting axons and low spontaneous activity. In contrast to PTNs, they exhibited weak, mostly insignificant correlation with grad...

The corticostriatal system is considered to be crucially involved in learning and action selection. Anatomical studies have shown that two types of corticostriatal neurons, intratelencephalic (IT) and pyramidal tract (PT) cells, preferentially project to dopamine D1 or D2 receptor-expressing striatal projection neurons, respectively. In contrast, an optogenetic study has shown that stimulation ...

Evidence is accumulating that neurons in primary motor cortex (M1) respond during action observation, a property first shown for mirror neurons in monkey premotor cortex. We now show for the first time that the discharge of a major class of M1 output neuron, the pyramidal tract neuron (PTN), is modulated during observation of precision grip by a human experimenter. We recorded 132 PTNs in the h...

The spontaneous and paroxysmal cerebral cortical synchronized activity was used as reference to study the cortical impact exerted on subcortical neurons. The sensorimotor cortical synchronized activity spread down to subcortical structures receiving direct cortical input, including neuronal populations that originate descending rubrospinal, tectospinal and reticulospinal motor axons, and to a s...

1. Intracellular recordings were made from an estimated 500 neurons in the sensorimotor cortex of barbiturate-anesthetized cats. Of those which were antidromically identified from the medullary pyramids, 70 were selected which also exhibited steady repetitive firing to steps of current injected through the recording electrode; 81% were "fast" (conduction velocity greater than 20 m/s) and 19% we...

Fig. 3: Examplary slices from TBSS / RANDOMISE results, tfce corrected cluster size p<0.05. Highlighted overlays visualize the statistical tests FA|grpX > FA|grpY; i. e. A) G1>G4 “low T2w lesion load vs. high T2w lesion load”; B) G2>G4 “low EDSS vs. high EDSS” in high T2w lesion load groups; the pyramidal tract is delineated along consecutive slices. Utility of tract based spatial statistics (T...

We examined the contribution of the motor cortex to the control of intralimb coordination during reaching in the standing cat. We recorded the activity of 151 pyramidal tract neurons (PTNs) in the forelimb representation of three cats during a task in which the cat reached forward from a standing position to press a lever. We simultaneously recorded the activity of muscles in the contralateral ...