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At least 433 records · Page 24Linked to original sources
PubMed2006

Broadening the phenotype of childhood-onset dopa-responsive dystonia.

BACKGROUND: Dopa-responsive dystonia (DRD) may cause early-onset dystonia, with extrapyramidal or pyramidal tract dysfunction. OBJECTIVE: To broaden the phenotype of DRD. SETTING: Tertiary referral university hospital. PATIENTS: We describe 4 female siblings with genetically confirmed DRD, 3 of whom presented with "unsteadiness" and 1 with scoliosis. All had dystonia and pyramidal tract signs, 3 had additional extrapyramidal features (resting tremor, bradykinesia, or rigidity), and at least 2 had definite signs of cerebellar dysfunction. MAIN OUTCOME MEASURES: The subjective response to treatment with 62.5 mg of a combination product of levodopa and carbidopa 3 times daily was assessed at both 6- and 12-month follow-up visits with the 7-item Patient's Global Impression of Change Scale as very much improved, much improved, a little improved, no different, a little worse, much worse, or very much worse. RESULTS: All patients showed a good response to levodopa therapy 41 to 49 years after symptom onset. CONCLUSION: Cerebellar signs may be observed in patients with DRD and may improve in response to levodopa.

Dystonic Disorders↗
PubMed1984

[The pyramidal tract. Recent anatomic and physiologic findings].

The cortical origin of the pyramidal tract is first considered. Contributions of retrograde degeneration studies as well as fiber counting method following different cortical lesions are presented and discussed. The results of these classical neuro-anatomical methods are compared with those of the more recent retrograde transport tracing method. The number and the diameter spectrum of pyramidal tract fibers differ in various mammals. In more evolved species the number of pyramidal fibers increase and their diameter span becomes wider. The thickest fibers are found in man. Along their diencephalic, mesencephalic, pontine and medullary course, axonal collaterals of corticospinal axons may terminate onto cells of origin of other descending pathways, onto relay cells of ascending pathways, and onto neurons projecting to the cerebellum. At the spinal level, the rostrocaudal extent and the termination area of corticospinal fibers may differ in various mammals. In a first group of mammals, the corticospinal fibers extend only to cervical or mid-thoracic segments and terminate in the dorsal horn. In a second group of mammals, the corticospinal fibers extend throughout the spinal cord and terminate in the dorsal horn and the intermediate zone. In a third group of mammals, the corticospinal fibers extend throughout the spinal cord and terminate in the dorsal horn, the intermediate zone and the dorsolateral part of the lateral motoneuronal cell group. In a fourth group of mammals, the corticospinal fibers also extend throughout the spinal cord and terminate in the dorsal horn, the intermediate zone and the dorsolateral as well as the ventral parts of the lateral motoneuronal cell group. A comparison is made between these different types of spinal terminations and the motor capacities of these different species. The motor deficits observed after pyramidal lesions are summarized and a comparison is made between the corticospinal tract and the descending brain stem pathways. According to electrophysiological studies in conscious animals different pyramidal units can be activated during different types of movements and at different times during the preparation or execution of a movement. Recent neuro-anatomical data suggest that the pyramidal tract is composed of many structural subsystems. Recent physiological data suggest that the pyramidal tract can be involved in various aspects of the motor control.

Animals↗
PubMed1994

Pallido-pyramidal degeneration, supranuclear upgaze paresis and dementia: Kufor-Rakeb syndrome.

An unusual neurological syndrome in an Arab family with five affected siblings, is reported. Autosomal recessive inheritance is suggested by having multiple affected siblings born to phenotypically normal consanguineous parents. Similar to Davison's Pallido-pyramidal syndrome, they presented with the clinical signs and symptoms of severe parkinsonism as well as evidence of cortico-spinal tract disease. In addition, they had dementia and supranuclear upgaze paresis. MRI studies showed significant atrophy of the globus pallidus and the pyramids, as well as generalized brain atrophy in later stages. Therapy with levodopa resulted in significant improvement in the extrapyramidal dysfunction. We suggest that this probably represents a new syndrome which is closely related but not identical to the pallido-pyramidal syndrome.

Adolescent↗
PubMed1998

Conduction pathways of motor evoked potentials following transcranial magnetic stimulation: a rodent study using a "figure-8" coil.

We have examined the conduction pathways of motor evoked potentials (MEPs) elicited by transcranial magnetic stimulation, and their correlation with locomotor function in rats. MEPs were concomitantly recorded from the spinal cord (sMEPs) and the limb muscles (mMEPs) before and after various spinal tract ablations. Motor function was also examined using an inclined plane test. sMEPs were composed of four negative peaks (N1-N4) and mMEPs of high-voltage, biphasic waves. Ventral funiculus transection reduced the N1-N3 peaks and abolished mMEPs. Contrarily, dorsal funiculus transection including the pyramidal tract did not alter these MEPs. Motor performance on an inclined plane was worse after ventral funiculus transection than after other transections. These findings indicate that, in rats, the N1-N3 peaks of magnetic sMEPs conduct ventral funiculus activity, and that magnetic mMEPs mainly reflect extrapyramidal activities and are correlated with locomotor function.

Animals↗
PubMed1986

The adult organization and development of the rubrospinal tract. An experimental study using the orthograde transport of WGA-HRP in the North-American opossum.

We have employed the orthograde transport of wheat germ agglutinin conjugated to horseradish peroxidase to study the organization of rubrospinal connections in adult and pouch young opossums. Our results suggest that: in the adult opossum rubrospinal axons are distributed more widely than suggested by previous studies; rubrospinal projections are formed postnatally in the opossum, but much earlier than corticospinal connections; rubrospinal axons do not grow synchronously, as a massive bundle following a few leading axons, but by addition of axons over a protracted period of time; and the growth of rubral axons into the spinal gray matter follows a predictable rostral to caudal gradient as well as a proximal to distal one relative to the tract. Rubrospinal development is discussed in light of the growth of cerebellar and cortical axons into the red nucleus and the development of motor function.

Animals↗
PubMed2005

'Importance sampling' in MS: use of diffusion tensor tractography to quantify pathology related to specific impairment.

Specific neurological impairments in multiple sclerosis (MS) are dependent on the pathology in clinically eloquent areas of the central nervous system. We aimed to use diffusion tensor fiber tracking to identify the pyramidal tracts and corpus callosum in MS patients, measure the apparent diffusivity within the tracts, and evaluate whether this would correlate with relevant disability scores. Dual-echo and diffusion tensor magnetic resonance imaging (DT-MRI) brain scans were obtained from 29 patients with relapsing remitting MS, and 13 age and gender matched normal controls. Voxels from pyramidal tracts and corpus callosum were automatically identified using a tractography based algorithm. Mean apparent diffusion coefficient (ADC(av)) was measured for these tracts. Scores of Expanded Disability Status Scale (EDSS) and Paced Auditory Serial Addition Test (PASAT) were obtained. The median EDSS score was 2.5 (inter-quartile range 2-3.25). The ADC(av) in the pyramidal tracts (p=0.02) and corpus callosum (p=0.0004) in patients was significantly higher than in controls. Pyramidal tracts ADC(av) was correlated with pyramidal FSS (r=0.5, p=0.008). Corpus callosum ADC(av) was correlated with PASAT (r=-0.58, p=0.001). Global T2 lesion volume did not correlate with the EDSS, but correlated with ADC(av) of the pyramidal tracts (r=0.6, p=0.0007) and corpus callosum (r=0.8, p<0.0001). T2 lesion volume within the pyramidal tracts and corpus callosum correlated with ADC(av) in the pyramidal tracts (r=0.6, p=0.0009) and corpus callosum (r=0.65, p=0.0002) respectively, but not with pyramidal FSS or PASAT score. DT-MRI quantifies pathology in specific white matter tracts and may increase the specificity of MRI in monitoring progression of motor and cognitive deficits in MS.

Acoustic Stimulation↗