Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Brain Stem Infarctions”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 883 records · Page 49Linked to original sources
PubMed1984

Palatal myoclonus--its remote influence.

Four patients with palatal myoclonus were examined electromyographically. Surface EMG was recorded simultaneously from several myoclonic muscles and the correlation between their rhythmic discharges was shown. The possible existence of a remote influence of palatal myoclonus was tested by recording soleus and anterior tibial H-reflexes and seeking a correlation of their amplitudes with the rhythm of palatal myoclonus. Two cases, both with additional severe spasticity in the legs, showed rhythmic variation of the soleus H-reflex amplitude corresponding with that of their palatal myoclonus. This suggests that the neural mechanism generating the visible myoclonus has much more extensive effects.

Behcet Syndrome↗
PubMed1986

Weakness of head turning in hemiplegia: a quantitative study.

The strength of head turning was measured in normal subjects and in patients with hemiplegia of vascular origin. In normals the strength of head turning to the two sides was not significantly different. In most patients with a cortical, capsular or high brainstem lesion the strength of head turning away from the side of the lesion was reduced. In patients with a medullary lesion the strength of head turning towards the side of the lesion was reduced. The significance of these findings is discussed in relation to the cortical control of the sternocleidomastoid muscle and other muscles involved in the movement of head turning.

Adult↗
PubMed1984

Posterior fossa lesions: magnetic resonance imaging.

Studies of 40 patients with abnormalities of the posterior fossa shown on magnetic resonance (MR) imaging were reviewed and compared with CT scans. Thirteen lesions were demonstrated on MR only. Twenty-four lesions were shown on CT but MR provided more data. Three lesions were better shown on CT than on MR. MR is superior to CT because of the lack of streak artifacts and better contrast discrimination. At least two imaging sequences are required for evaluation of the lesions.

Brain Diseases↗
PubMed2002

Functional role of auditory cortex in frequency processing and pitch perception.

Microelectrode studies in nonhuman primates and other mammals have demonstrated that many neurons in auditory cortex are excited by pure tone stimulation only when the tone's frequency lies within a narrow range of the audible spectrum. However, the effects of auditory cortex lesions in animals and humans have been interpreted as evidence against the notion that neuronal frequency selectivity is functionally relevant to frequency discrimination. Here we report psychophysical and anatomical evidence in favor of the hypothesis that fine-grained frequency resolution at the perceptual level relies on neuronal frequency selectivity in auditory cortex. An adaptive procedure was used to measure difference thresholds for pure tone frequency discrimination in five humans with focal brain lesions and eight normal controls. Only the patient with bilateral lesions of primary auditory cortex and surrounding areas showed markedly elevated frequency difference thresholds: Weber fractions for frequency direction discrimination ("higher"-"lower" pitch judgments) were about eightfold higher than Weber fractions measured in patients with unilateral lesions of auditory cortex, auditory midbrain, or dorsolateral frontal cortex; Weber fractions for frequency change discrimination ("same"-"different" pitch judgments) were about seven times higher. In contrast, pure-tone detection thresholds, difference thresholds for pure tone duration discrimination centered at 500 ms, difference thresholds for vibrotactile intensity discrimination, and judgments of visual line orientation were within normal limits or only mildly impaired following bilateral auditory cortex lesions. In light of current knowledge about the physiology and anatomy of primate auditory cortex and a review of previous lesion studies, we interpret the present results as evidence that fine-grained frequency processing at the perceptual level relies on the integrity of finely tuned neurons in auditory cortex.

Acoustic Stimulation↗
PubMedDate not supplied

Dissecting aneurysms of the basilar artery in 2 patients.

An uncommon consequence of intracranial vascular disease is the intramural dissection of blood or "dissecting aneurysm". A 69-year-old man with chronic subarachnoid hemorrhage from a posterior fossa mass lesion and a 30-year-old man with migraine and a brain stem stroke illustrate the diverse etiologic, clinical, radiographic, and pathologic characteristics of this unusual lesion.

Aged↗
PubMed1994

Restricted acral sensory syndrome following minor stroke. Further observation with special reference to differential severity of symptoms among individual digits.

BACKGROUND: Restricted acral sensory syndrome (RASS) after minor stroke most often manifests as a cheiro-oral syndrome. However, recent studies have described more varied patterns of RASS and also have reported that the degree of sensory symptoms may vary among individual digits. Until recently, however, there have been no reports in which sufficient numbers of patients were studied with detailed information on the symptomatic severity among individual digits. SUMMARY OF REVIEW: In this report, I describe 30 patients presenting with RASS secondary to minor stroke. Computed tomographic scan and/or magnetic resonance imaging identified lesions in the lateral thalamus in 11, midbrain in 2, pontine tegmentum in 8, capsulo-corona radiata in 5, and frontoparietal subcortical-cortical areas in 4 patients. The patterns of RASS were cheiro-oral in 10, cheiro-oral-pedal in 8, cheiro-pedal in 4, restricted to palm and/or fingers in 7, and periotal-pedal in 1. Dominant involvement of upper lip, thumb, and index finger was frequent, especially in patients with thalamic and thalamocortical lesions. In patients with cortical-subcortical lesions, cheiro-oral or restricted finger involvements were observed, while the foot was spared. In patients with pontine lesions, bilateral RASS was occasionally observed, and the pattern of preponderant involvement of the first two digits was not apparent. CONCLUSIONS: These patterns of RASS generally agree with the previously observed sensory topography of monkeys, and they support anatomic proximity of sensory fibers from acral parts of the body. However, other mechanisms such as differential vulnerability of generation of paresthesia in different body parts or a low-threshold concept based on disproportionately large representing areas for the acral parts of the body in the human sensory system may also be required to explain some of the clinical observations.

Adult↗
PubMed1999

Brain stem MRI signal abnormalities in CADASIL.

BACKGROUND: We recently showed that the severity of MRI signal abnormalities increases with age in CADASIL, an arteriopathy due to mutations of notch 3 gene on chromosome 19. Previous results also suggest that the various hemispheric subcortical areas have a different vulnerability to ischemia in this disease. The distribution of the lesions at the brain stem level has not yet been reported. CASE DESCRIPTIONS: We reviewed the MRIs of 68 affected patients having signal abnormalities in the hemispheric white matter to assess the distribution and clinical consequences of brain stem signal abnormalities in CADASIL. We found hypersignals on T2-weighted images in the brain stem in 45% of the subjects. The pons was more frequently involved (100%) than the mesencephalon (69%) and the medulla (35%). Hyposignals on T1-weighted images, at the brain stem level, were observed only in two thirds of these subjects. The lack of signal abnormalities reaching the brain stem surface and the absence of cerebellar lesions were noteworthy. CONCLUSIONS: Brain stem signal abnormalities observed in CADASIL are found in regions irrigated only by perforating arteries. These results support parallel observations made for CADASIL-associated signal abnormalities in the cerebral hemispheres and emphasize the importance of the angioarchitecture of the cerebral vasculature to explain why a condition characterized by a systemic vessel wall pathology is manifested only as a brain disease.

Brain Stem↗
PubMed1996

[Laser Doppler flowmetry--experiences from intensive care medicine].

Laser Doppler flowmetry makes it possible to determine the status of the microcirculation with the aid of a non-invasive procedure. The present article describes the use in two ICU patients of Doppler laser flowmetry to effect a qualitative and quantitative evaluation of the side effects that may occur when using various stimulation procedures.

Adult↗
PubMedDate not supplied

Eye movements in brainstem lesions.

The eye movements of 10 patients with brainstem lesions were examined, using an electro-oculo-graphic technique. An analysis was made of the responses in the following tests: smooth pursuit, saccade, rotation, optokinetic, optovestibular and caloric. Chief interest was directed towards the peak velocity. The results were compared with the corresponding velocities in 20 normal subjects. In the same patient, one or several types of eye movements could be normal, while others were pathological. In the whole group, voluntary eye movements (smooth pursuits and voluntary saccades) were more vulnerable than reflexive ones (nystagmus). Next to the smooth pursuit test and the voluntary saccade test, the optovestibular test was the most sensitive in discriminating patients with brainstem lesions from normal subject.

Adolescent↗
PubMedDate not supplied

Extent of pyramidal tract wallerian degeneration in the brain stem on MRI and degree of motor impairment after supratentorial stroke.

The relationship between Wallerian degeneration in the brain stem and degree of motor impairment is discussed. Using MRI we studied 172 supratentorial stroke patients, whose motor impairment was graded according to Brunnstrom stage. Wallerian degeneration was represented by a T2 high-intensity area in the brain stem, and its cross-sectional extent was measured at the cerebral peduncle level. Wallerian degeneration was detected in 99 patients (57.6%). The area of T2 high intensity was significantly correlated with Brunnstrom stage. Multiple regression analysis showed that the upper extremity stage contributed most to the visualization of Wallerian degeneration. This is partly because the pyramidal tract participates in fine and precise movement. The extent of the area of Wallerian degeneration is found to be helpful in making a prognosis with respect to motor impairment in the upper extremity.

Adult↗
PubMedDate not supplied

Correlation between electromyographic reflex and MR imaging examinations of the trigeminal nerve.

BACKGROUND AND PURPOSE: Previous studies have shown that clinical localization of trigeminal nerve lesions is inaccurate as compared with MR imaging findings. The purpose of our study was to ascertain the added value of electromyographic (EMG) investigation of the trigeminal nerve reflexes for the improvement of lesion localization and for the preselection of patients for MR imaging. METHODS: We reviewed the EMG studies of the trigeminal reflexes and the MR imaging studies of 20 patients with unilateral symptoms and signs related to the trigeminal nerve (40 trigeminal nerves examined). The results of the two studies were compared to assess the value of EMG in predicting MR imaging outcome. Lesion localization as demonstrated by EMG was compared with localization at MR imaging. MR imaging was used as the standard of reference. RESULTS: Eight (40%) of 20 patients had MR imaging findings related to presenting trigeminal symptoms, including five brain stem lesions and three peripheral lesions. Fourteen (70%) of 20 patients had EMG abnormalities related to presenting symptoms and signs. For brain stem lesions, lesion localization as shown by EMG corresponded well with MR imaging findings. EMG yielded a sensitivity of 100%, a specificity of 81%, a positive predictive value of 57%, and a negative predictive value of 100% in predicting MR imaging results. Interobserver agreement was good for both the EMG reflex and MR imaging examinations. CONCLUSION: Our data suggest that EMG recordings of the trigeminal reflexes can be used to exclude structural lesions in patients with symptoms related to the trigeminal nerve. When a lesion is localized in the brain stem with EMG, a tailored MR imaging examination of this region may be sufficient.

Adult↗