1/146. Thalamic hemorrhage following carotid endarterectomy-induced labile blood pressure: controlling the liability with clonidine--a case report.Carotid endarterectomy can lead to alterations in baroreceptor sensitivity. Impairment of this sensitivity can in turn lead to volatility of blood pressure (baroreflex failure syndrome--BFS). Rapid elevations in blood pressure can cause hypertensive encephalopathy in a patient with BFS. A patient is presented with hypertensive intracerebral hemorrhage associated with BFS.- - - - - - - - - - ranking = 1keywords = cerebral (Clic here for more details about this article) |
2/146. Effect of stimulation of an upper limb on motor evoked potentials in lower limb muscles to transcranial magnetic stimulation in normal subjects and patients with thalamic infarction.The effects of conditioning stimulation of an upper limb on motor evoked potentials (MEPs) of relaxed muscles in both lower limbs were studied in 7 normal subjects and two patients with left thalamic infarction. A possible mechanism for the Jendrassik maneuver (JM) is that induced proprioceptive input ascends supraspinally to facilitate the descending volleys. In order to mimic the JM with a more controlled influence, we used an electrical conditioning (C) stimulation (4 times sensory threshold) delivered to the left index finger preceding the transcranial (T) magnetic stimulation at C-T intervals of 0-200 ms. The MEP facilitation of bilateral tibialis anterior (TA) and gastrocnemius medialis (GC) was within C-T 70-110 ms. The peak facilitation was at C-T 80 ms for ipsilateral TA (309%) and GC (405%) and at C-T 90 ms for contralateral TA (207%) and GC (283%). In the two thalamic infarction patients with right-sided sensory loss, the facilitation did not occur when the conditioning stimulation was delivered to the affected index finger. Therefore, it is likely that the peripheral volley must be transmitted supraspinally to facilitate MEPs of the lower limbs. This method for studying sensory facilitation is more quantitative and reproducible than the JM and technically better than other previously described methods for somatosensory conditioning.- - - - - - - - - - ranking = 404.01766249022keywords = infarction (Clic here for more details about this article) |
3/146. A case of thalamic syndrome: somatosensory influences on visual orientation.The ability to set a straight line to the perceived gravitational vertical (subjective visual vertical, SVV) was investigated in a 21 year old woman with long standing left hemihypaesthesia due to a posterior thalamic infarct. The putative structures involved were the somatosensory and vestibular thalamus (VPL, VPM) and associative (pulvinar) thalamus. The SVV was normal when seated upright. When lying on her right side, line settings deviated about 17 degrees to the right, which is the normal A-effect. When lying on the hypaesthetic side the mean SVV remained close to true vertical-that is, the A-effect was absent, and there was a large increase in variability of the SVV settings. The findings support the view that the body tilt-induced bias of the SVV (A-effect) is largely mediated by somatosensory afferents. The finding that the A-effect was absent only when lying on the hypaesthetic side suggests that, during body tilt, the somatosensory system participates in visuogravitational orientation.- - - - - - - - - - ranking = 0.092097399608348keywords = posterior (Clic here for more details about this article) |
4/146. The stereotactic volumetric information: its role in two-step resection of brainstem and thalamic giant tumor. Report of three cases and technical note.BACKGROUND: A compact intracerebral tumoral lesion is usually considered to be completely resectable. Nevertheless, radical resection of a huge lesion located in a critical area may damage the surrounding compressed brain tissue. In cases with a good prognosis, a two-step removal appears to be a safer strategy. methods: In three cases, two with huge brain stem lesions and one with a thalamic lesion, a two-step volumetric stereotactic resection was planned. This strategy allowed us to evaluate the amount of tumor to be removed during the first procedure and to have, during the second operation, an exact definition of the reduced mass with regard to the scar tissue and postoperative adhesions. Furthermore, we avoided significant shifting of the cerebral structures during both procedures. RESULTS: There was a very good final recovery in the cases with brain stem lesions and a minimal deficit in the patient with the thalamic lesion. The patient with a mesencephalic lesion remained comatose for almost 2 days after the first procedure, confirming our fears about too radical a one-step resection. CONCLUSIONS: We think that by using current techniques, it is possible to remove a well circumscribed lesion regardless of its position. This is probably easier with giant lesions where a safe trajectory can be planned. In these cases, with lesions located in very critical areas but with a good prognosis, a two-step resection appears to be a good option.- - - - - - - - - - ranking = 2keywords = cerebral (Clic here for more details about this article) |
5/146. Pseudochoreoathetosis in four patients with hypesthetic ataxic hemiparesis in a thalamic lesion.Thalamic lesions give rise to a variety of clinical syndromes including choreoathetotic movements and ataxic hemiparesis as well as sensory deficits. We describe four patients exhibiting pseudochoreoathetosis, hypesthesia, and ataxic hemiparesis in the limbs contralateral to a thalamic lesion. Three of the four patients showed the involuntary movements within 10 days of stroke onset; the remaining patient was not seen until 4 years later. Three had infarction and the other one hemorrhage in the posterior and lateral thalamus. All the patients had both cerebellar and sensory ataxia. These cases suggest that failure to convey proprioceptive information be the basic pathophysiology of pseudochoreoathetosis.- - - - - - - - - - ranking = 67.428374481311keywords = infarction, posterior (Clic here for more details about this article) |
6/146. Attentional grasp in far extrapersonal space after thalamic infarction.Studies of animals and humans with focal brain damage suggest that attention in near and far extrapersonal space may be mediated by anatomically separate systems. Thalamic lesions have been associated with spatial neglect, but whether asymmetric attention specific to near or far space occur after thalamic damage has not been explored. It is also unclear if thalamic injury can induce contralesional defective response inhibition.We tested a woman with a left thalamic infarction who reported that, when driving, she had a tendency to veer towards people or objects on the right side of the road. Our patient and four controls performed a line bisection task with a laser pointer in near and far extrapersonal space. The experimenter marked each bisection either from the right of the presented line (right-distractor, RD) or the left (left-distractor, LD). RD and LD trials were pseudo-randomized.Our patient performed similarly to controls (mean -0.7 mm, controls -0.6 mm) on the line bisection task in near space. In far space she erred significantly rightward compared to her performance in near space (p<0.001). Controls performed similarly in near and far space. The experimenter position did not affect our patient's performance on near line bisections, nor did controls demonstrate a distractor effect for the near condition. In the far condition, however, our patient showed a significant distractor effect (LD -3.3 mm, RD 35.3 mm, p<0.001). Controls also demonstrated a distractor effect in the far condition (LD -6.4 mm, RD 0.7 mm, p<0.01), though of much smaller magnitude. Our results suggest that frontal-thalamic systems regulating visual attention may be disrupted by thalamic infarction. Such damage may produce an attentional grasp specific to far extrapersonal space.- - - - - - - - - - ranking = 404.01766249022keywords = infarction (Clic here for more details about this article) |
7/146. Thalamic degeneration with negative prion protein immunostaining.A 34-year-old woman presented with an insidious 5-year history of cognitive decline and apathy, associated with hypersomnia, ataxia, and dysarthria. magnetic resonance imaging of the brain showed cortical and subcortical atrophy. At autopsy we found abnormalities in the subcortical grey matter and brainstem, with a relatively preserved cerebral cortex. The thalami showed symmetrical neuronal loss and astrocytosis, particularly severe in the dorsal medial nucleus, followed by the lateral nuclei group. Prion protein immunostaining was negative, and there was no spongiform change. No mutations were detected in the prion protein gene.- - - - - - - - - - ranking = 1keywords = cerebral (Clic here for more details about this article) |
8/146. Selective loss of vergence control secondary to bilateral paramedian thalamic infarction.The supranuclear pathways for vergence eye movements are poorly understood. The authors report a 57-year-old patient who presented with selective loss of vergence control and dissociation of light and near reaction. MRI showed a symmetric paramedian thalamic infarction without midbrain lesion. The findings suggest that this syndrome is due to an interruption of supranuclear fibers to midbrain vergence neurons.- - - - - - - - - - ranking = 336.68138540851keywords = infarction (Clic here for more details about this article) |
9/146. Correlation of clinical and neuroradiological findings in down-gaze palsy.BACKGROUND: Isolated down-gaze palsy is the least common pathology of vertical gaze. patients with low-gaze palsy may consult an ophthalmologist with difficulty in reading and this may be the only ocular finding of a central nervous system lesion. methods: A 43-year-old man with isolated down-gaze palsy was examined. The medical history of the patient revealed that he had had myocardial infarction. RESULT: magnetic resonance imaging disclosed an ischemic area at the right thalamus. CONCLUSION: Down-gaze palsy may be an important sign for the diagnosis of thalamic infarctions due to embolic syndrome.- - - - - - - - - - ranking = 134.67255416341keywords = infarction (Clic here for more details about this article) |
10/146. Unilateral thalamic infarction and vertical gaze palsy: cause or coincidence?Although vertical gaze palsy (VGP) is commonly associated with lesions of the rostral mesencephalon, there is some evidence that VGP may also be caused by a unilateral thalamic lesion. The case of a 68-year-old man with persistent upward gaze palsy after a unilateral thalamic infarction, demonstrated on computed tomography and magnetic resonance imaging scans, is presented. Subsequent high-resolution magnetic resonance scanning, however, showed involvement of the rostral mesencephalon as well. The authors suggest that in previous patients with VGP ascribed to a unilateral thalamic infarction, a coexisting mesencephalic involvement may have been missed because of inappropriate imaging techniques. Strong evidence of unilateral thalamic infarction as a cause of VGP is still lacking.- - - - - - - - - - ranking = 471.35393957192keywords = infarction (Clic here for more details about this article) |
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