Lemniscus Medialis

A few months after the operation, hyperactive neurons were recorded from the thalamic nuclei and lemniscus medialis.  

We think that these patients' lesions were localized in the lemniscus medialis.  

From these animals, hyperactive neurons were recorded from the contralateral thalamic nuclei, lemniscus medialis.  

Selective involvement of the corticospinal tract, the solitary tract, and the lemniscus medialis also has been found..  

However, the neurons in the pars compacta of the substantia nigra, paranigral nucleus, parabrachial pigmental nucleus, tegmental pedunculopontine nucleus, supratrocheal nucleus, cuneiform nucleus, subcuneiform nucleus and lemniscus medialis, which were positive in other diseases and in non-neurological controls, were not stained by these antibodies in PD brains.  

One to three months after the operation, cellular activity was recorded from the contralateral thalamic nuclei (VP, zona incerta), lemniscus medialis and striatum. Hyperactive neurons were recorded from the thalamic nuclei and lemniscus medialis.  

There is evidence that rostral and caudal parts of the P14 generator (lemniscus medialis) are differently affected in brain death, resulting in an abolition of the rostral part, while occasionally leaving intact for some time the caudal part.  

In addition, a large number of immunoreactive fibers was found in the lemniscus medialis and a scarce number in the stria medullaris.  

One to three months after the operation, hyperactive neurons were examined in the contra-lateral thalamic nuclei (VP, zona incerta), and lemniscus medialis.  

No correlation was found between the duration of aphagia and adipsia and the size of damage to zona incerta, fields of Forel, capsula interna, lemniscus medialis, ventral tegmental area and substantia nigra.  

A much lower voltage, positive-negative-positive triphasic SEP showed peak latencies of the initial positivity and the major negativity of 13.3 msec and 16.0 msec, respectively, and had maximal voltage (16 microV) in the ventralmost parts of the nucleus ventro-intermedius (V.im) and radiatio praelemniscalis (Ra.prl), and substantial potentials in the lemniscus medialis (L.m) and nucleus ventro-oralis posterior (V.o.p).  

A single shock stimulation of the lemniscus medialis elicited a series of SDs, each without being preceded by a phasic hyperpolarizing potential.  

Other than the raphe system, serotonin-immunoreactive perikarya were seen in the following regions: the reticular formation (18.9%), the lemniscus medialis (8.5%), the nucleus interpeduncularis (1.5%), the subpyramidal region (4.0%) and the periaqueductal gray (0.2%)..  

The SEPs were recorded in the lemniscus medialis (LM), the centrum medianum (CM), and over the anterior suprasylvian gyrus (ASSG).  

In each case could be found an alteration or damage of functionally relevant structures of the ventrocaudal--lateral Thalamus, the intralaminar and intralaminar-reticular nuclei, of the Pulvinar thalami, the lemniscus medialis and the striopallidar nuclei formation by tumuorcellinfiltration and oedema.  

Somatosensory evoked potentials after stimulation of the right median nerve demonstrated only lemniscus medialis response.  

The positive components 1 and 2 of the averaged field response induced in the somesthetic S1 cortex by submaximal stimulation of cortical radiation and supramaximal stimulation of lemniscus medialis showed non-existent amplitude variability whereas the dispersion was significant for components 3, 4 and 5.  

Stimulation, with concentric bipolar electrodes, of several brainstem structures overlapping monoaminergic regions such as the nucleus raphe magnus, the nucleus raphe pallidus, the lemniscus medialis, the ventrolateral reticular formation, the locus coeruleus and the nucleus commissuralis, induced an inhibition of the laryngeal-initiated swallowing.  

Large accumulations of grains were seen in the hypothalamus, the amygdala, in the fasciculus medialis prosencephali, in the fasciculus longitudinalis medialis, in the ventrolateral part of the periventricular gray matter, in the lemniscus medialis and in the raphe nuclei.  

Furthermore, proctolin immunoreactive peptide was found to be contained in certain fiber systems (lemniscus medialis and fiber tracts near the Raphe)..  

Ten patients with intractable pain of central origin were operated on for pain relief by implanting the chronic stimulating electrode (Medtronic Co.) in the posterior limb of the internal capsule, thalamic sensory nuclei or mesencephalic lemniscus medialis, and the results were briefly described. Consequently a lesion was stereotaxically made in the most medial portion of the lemniscus medialis of the rostral mesencephalon. Stimulation of the mesencephalic lemniscus medialis of the right side elicited comfortable warm sensation in contralateral upper half of the body including hand, fingers and face with simultaneous diminution of pain. These two cases were suggestive of the role of lemniscus medialis in pain modulation. Blockade of the lemniscus medialis elicited, and its facilitation inhibited the pain.  

Changes in the concentrations of these substances were determined before and after giving stimulations (2-5 V, 0.2-0.5 msec, 40-50 Hz, 20-sec duration) to 6 patients through electrodes implanted in deep brain structures (DBS; posterior limb of the internal capsule in 5 patients and rostral mesencephalic lemniscus medialis in one patient), and to 2 other patients through electrodes implanted in the spinal dorsal column (DCS).  

Specific points emphasized are the presence of a mild pyramidal syndrome as a permanent finding in 2 of these patients, and the anomalies of visual (longer lag period) and somesthetic (slowed conduction rate in the lemniscus medialis) evoked potentials probably the result of extension into other pathways than the cerebellar system.  

An antinociceptive response was consistently produced after NT injection into the nucleus amygdaloideus centralis, rostral area praeoptica medialis, the ventral thalamus dorsomedial and medial to the lemniscus medialis, rostral mesencephalic periventricular gray, and medial pontine formatio reticularis.  

Our results in 32 cases (March 31, 1979) with lemniscus medialis stimulation, including the specific and nonspecific somatosensory nuclei or periaqueductal gray matter show in 53% of our cases, a reduction of pain of over 50%. Mesencephalic lemniscus medialis DBS, introduced by one of the authors (Mundinger), leads to a functional blockade of spinothalamic, lemniscus medialis and spino-reticular systems.  

region B 9 (dorsal of the lemniscus medialis) a few positive cells; 4.  

Stimulation of the ipsilateral brain stem including lemniscus medialis, mesencephalic reticular formation and some other structures, produces short latency excitation of the pallidal cells..  

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