1/22. Insights into the three-dimensional structure of the oculomotor nuclear complex and fascicles.The authors report the case of a patient with an ischemic lesion in the left midbrain. The patient presented with paresis of left inferior rectus, pupil, right superior rectus, convergence and transiently, of the left medial rectus. A lesion in the left dorsal midbrain close to the oculomotor nuclear complex, selectively involving the fascicles innervating the above muscles, is proposed. Fine magnetic resonance sections showed a consistent lesion in the left paramedian dorsal midbrain. A detailed, three-dimensional, schematic computer model of the oculomotor nucleus and fascicles was constructed. Using this model, the authors topographically validate the putative site of the lesion. The medial rectus subnucleus is divided into three subgroups, A, B, and C. Subgroup C is thought to be the site of the majority of neurons controlling convergence. In the above model, the putative lesion is closer to subgroup A than to C; this suggests that subgroup A, rather than subgroup C, may have a higher concentration of neurons involved in convergence.- - - - - - - - - - ranking = 1keywords = nucleus (Clic here for more details about this article) |
2/22. Hyperacute infarction: early CT findings.The aim of our study is to determine how early and reliably ischemic brain infarcts can be detected on CT scanning. We report two cases of an early CT finding of acute ischemic infarcts where CT examination was obtained within the first 3 hours of onset of neurological symptoms. CT examination showed blurred outlines and decreased attenuation of the left lentiform nucleus, loss of the white-gray matter interface in the left insular cortex and left cortical global hypoattenuation with obliteration of left cortical sulci in one patient. In second patient CT showed the following: hyperdense left middle cerebral artery, loss of clear margins of left lentiform nucleus, subtle focal cortical hypodensity in the left fronto-parietal area with signs of mass effect in the form of ventricular compression. CT is still the first choice in the deferential diagnosis of acute stroke. Although older literature positions have suggested that CT was negative during the first 48 hours, modern CT technology can demonstrate positive findings even in the first 3 hours of onset. This is important in patients with acute stroke, as thrombolytic therapy when elected, has to be given within the first 3-6 hours after onset of symptoms. To determine how early and reliably ischemic brain infarcts can be detected on CT scanning, we report two cases of an early CT finding of acute ischemic infarcts where CT examination was obtained within the first 3 hours of onset of neurological symptoms.- - - - - - - - - - ranking = 1keywords = nucleus (Clic here for more details about this article) |
3/22. Delayed onset of hemidystonia and hemiballismus following head injury: a clinicopathological correlation. Case report.The authors report the case of a young man who suffered multiple injuries in a motor vehicle accident, the most significant of which arose in the brain, creating an unusual clinical syndrome. After experiencing an initial coma for several days, the patient was found to have a right-sided homonymous hemianopsia and a right hemiparesis, which was more marked at the shoulder and was accompanied by preservation of finger movement. Dystonic movements appeared 2 months later and progressed, along with increased spasticity on volition, to severe uncontrolled arm movements at 2 years postinjury. This motor disorder continued to worsen during the following 6 years prior to the patient's death. At autopsy, the left side of the brain was observed to have marked atrophy of the optic tract, a partial lesion of the posterior portion of the medial segment of the globus pallidus (GP), and a reduction in the size of the internal capsule at the level of the GP, suggesting impaired circulation to these areas at the time of injury. The isolated lesion of the internal segment of the GP was the presumed cause of the dystonia, acting through an alteration in thalamic inhibition. The atrophic subthalamic nucleus was the probable cause of the hemiballismus. The authors speculate that this and other delayed and progressive features of this case were the result of an active, but disordered, adaptive process that failed to compensate and, instead, caused even greater problems than the original injury.- - - - - - - - - - ranking = 0.5keywords = nucleus (Clic here for more details about this article) |
4/22. sinusitis and ischemic stroke.Acute sinusitis is a prevalent and generally uncomplicated infection that is normally resolved by medical therapy. However, severe neurological complications are known, and comprise of cerebral abscess, cavernous sinus thrombosis, meningitis, and epidural or subdural empyema. We report a case about a 10-year-old girl with a severe acute pansinusitis and ischemic stroke in the right lentiform nucleus and the anterior part of the right internal capsule. Possible explanations for this rare combination are discussed.- - - - - - - - - - ranking = 0.5keywords = nucleus (Clic here for more details about this article) |
5/22. Reorganization of somatic sensory function in the human thalamus after stroke.A patient with thalamic stroke underwent microelectrode-guided stereotactic thalamic exploration during surgery for control of tremor. The results of somatic sensory mapping in this patient were compared with explorations carried out during stereotactic surgery for the control of essential tremor (70 patients). There was evidence both of somatotopic reorganization and of anatomic reorganization of the representation of deep structures in the principal somatic sensory nucleus of the thalamus and the nuclei located anterior to it. This case demonstrates that thalamic reorganization can occur after a thalamic stroke and may play a role in recovery from such a stroke.- - - - - - - - - - ranking = 0.5keywords = nucleus (Clic here for more details about this article) |
6/22. The clinical and MRI correlate of ischaemia in the ventromedial midbrain: Claude's syndrome.The eponymous syndrome of Claude is caused by a lesion of the red nucleus and adjacent third nerve nucleus, resulting in the combination of an ipsilateral oculomotor palsy and contralateral ataxia. The MRI correlate of this syndrome has only occasionally been described. We present three cases with MRI findings which confirm the association of this clinical syndrome with infarction of the ventromedial midbrain. The coexistence of hypertension and small vessel ischaemia in two cases suggests this type of infarct may arise as a result of small vessel disease.- - - - - - - - - - ranking = 1keywords = nucleus (Clic here for more details about this article) |
7/22. Eyelid tremor in a patient with a unilateral paramedian thalamic lesion.A patient with a circumscribed infarction of the right paramedian thalamus developed a tremor of both eyelids on voluntary eye closure. Co-registration of the magnetic resonance image to a stereotactic atlas of the human thalamus revealed that the lesion was confined to a small subgroup of paramedian nuclei, including the parvocellular part of the mediodorsal nucleus. It is concluded that this region provides inhibitory input to cortical and/or subcortical regions controlling eyelid movements. Voluntary eye closure may involve direct cortico-nuclear connections and indirect pathways through the paramedian thalamus, most probably through the mediodorsal nucleus.- - - - - - - - - - ranking = 1keywords = nucleus (Clic here for more details about this article) |
8/22. Visualization of ischaemic penumbra using a computed tomography perfusion method.A computed tomography (CT) perfusion imaging and a diffusion/perfusion magnetic resonance imaging (MRI) were performed in a 51-year-old man at 15 and 15.5 h of onset of left middle cerebral artery infarction, respectively. The established infarct, as revealed by the diffusion-weighted MRI, had low values of cerebral blood flow (CBF) and cerebral blood volume (CBV) on the CT perfusion study. The ischaemic penumbra, as reflected by the perfusion-diffusion mismatch on MRI, had reduced CBF, prolonged mean transit time (MTT) and compensated CBV. Spontaneous bleeding occurred in the medial part of the left lentiform nucleus, immediately following decompressive craniectomy. CT measurements of CBF, CBV and MTT may visualize the ischaemic penumbra and explain the site of bleeding after surgical decompression.- - - - - - - - - - ranking = 0.5keywords = nucleus (Clic here for more details about this article) |
9/22. Hemiballismus following general anesthesia. A case report.Hemiballismus is characterized by the abrupt onset of violent proximal flinging movements, affecting the limbs, neck and trunk on one side of the body. It is caused by the lesion in the region of the contralateral subthalamic nucleus of the Luys. Usually it is a self-limiting disease, lasting 6-8 weeks. A 49-year-old man has been admitted to the hospital after flinging movements of his right arm and the right side of the trunk occurred. A few days earlier he had undergone general anesthesia prior to a dental procedure. There was trouble in waking the patient afterwards. The movements lasted a few days. MRI of the brain revealed ischemic lesions areas in T2-weighted images localized in the region of globus pallidus bilaterally. EEG was abnormal, and showed slowed background activity with slow waves in left temporal lobe. He was treated with haloperidol, clonazepam and vasoactive medications. In spite of administered treatment, hemiballic movements reappeared occasionally. Due to increased frequency of the movements the patient was hospitalized again two years later. The second MRI revealed changes described earlier and a new ischaemic focus in left parietal lobe. Continuation of treatment with haloperidol was administered.- - - - - - - - - - ranking = 0.5keywords = nucleus (Clic here for more details about this article) |
10/22. Clinically evidenced unilateral dissociation of saccades and pursuit eye movements.A patient affected by an ischaemic lesion of the right medial thalamic nucleus presented with a uniocular dissociation of upward vertical saccades and pursuit movement, with absent upward vertical saccades in the left eye. Clinical observations were confirmed by magnetic field scleral search coils analysis. During the vertical eye movement the patient denied any diplopia, thus suggesting a transient visual suppression in the left eye.- - - - - - - - - - ranking = 0.5keywords = nucleus (Clic here for more details about this article) |
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