The Experts below are selected from a list of 93 Experts worldwide ranked by ideXlab platform

Smi Choikwon - One of the best experts on this subject based on the ideXlab platform.

  • sensory sequelae of Medullary infarction differences between lateral and Medial Medullary Syndrome
    Stroke, 1999
    Co-Authors: Smi Choikwon
    Abstract:

    Background and Purpose—A comparison between long-term sensory sequelae of lateral Medullary infarction (LMI) and Medial Medullary infarction (MMI) has never been made. Methods—We studied 55 patients with Medullary infarction (41 with LMI and 14 with MMI) who were followed up for >6 months. We examined and interviewed the patients with the use of a structured format regarding the most important complaints, functional disabilities, and the presence of sensory symptoms. The nature and the intensity of sensory symptoms were assessed with the modified McGill-Melzack Pain Questionnaire and the visual analog scale, respectively. Results—There were 43 men and 12 women, with an average age of 59 years. Mean follow-up period was 21 months. The sensory symptoms were the most important residual sequelae in LMI patients and the second most important in MMI patients. In LMI patients, the severity of residual sensory symptoms was significantly related to the initial severity of objective sensory deficits (P<0.05). Senso...

Teruo Shimizu - One of the best experts on this subject based on the ideXlab platform.

  • preserved widespread n18 and progressive loss of p13 14 of median nerve seps in a patient with unilateral Medial Medullary Syndrome
    Electroencephalography and Clinical Neurophysiology, 1996
    Co-Authors: Masahiro Sonoo, Hiroki Hagiwara, Yasufumi Motoyoshi, Teruo Shimizu
    Abstract:

    Median nerve somatosensory evoked potentials (SEPs) in a patient with unilateral Medial Medullary Syndrome of recent onset having an MRI-confirmed lesion at upper medulla were investigated. Cortical N20 following stimulation of the affected limb was extremely depressed and delayed, whereas widespread N18, which was best manifested by the CPi-C2S lead (CPi is centroparietal electrode ipsilateral to the stimulation), showed no significant difference regarding amplitude and duration between affected and non-affected sides. The result supported our previous opinion that the principal part of N18, the broad negativity lasting around 20 ms, originates from the cuneate nucleus at the Medullary level. Less steep onset of N18 on the affected side suggested that some structures rostral to the cuneate nucleus, possibly the termination of the overall ascending volley, may contribute to the earliest part of N18. P13/14 on the affected side normally preserved at the first examination progressively declined and finally disappeared after 4 months, which suggested that the major part of P13/14 is generated within caudalmost Medial lemniscus, as well as the occurrence of retrograde degeneration of lemniscal fibers.

  • Preserved widespread N18 and progressive loss of P13/14 of median nerve SEPs in a patient with unilateral Medial Medullary Syndrome.
    Electroencephalography and Clinical Neurophysiology, 1996
    Co-Authors: Masahiro Sonoo, Hiroki Hagiwara, Yasufumi Motoyoshi, Teruo Shimizu
    Abstract:

    Median nerve somatosensory evoked potentials (SEPs) in a patient with unilateral Medial Medullary Syndrome of recent onset having an MRI-confirmed lesion at upper medulla were investigated. Cortical N20 following stimulation of the affected limb was extremely depressed and delayed, whereas widespread N18, which was best manifested by the CPi-C2S lead (CPi is centroparietal electrode ipsilateral to the stimulation), showed no significant difference regarding amplitude and duration between affected and non-affected sides. The result supported our previous opinion that the principal part of N18, the broad negativity lasting around 20 ms, originates from the cuneate nucleus at the Medullary level. Less steep onset of N18 on the affected side suggested that some structures rostral to the cuneate nucleus, possibly the termination of the overall ascending volley, may contribute to the earliest part of N18. P13/14 on the affected side normally preserved at the first examination progressively declined and finally disappeared after 4 months, which suggested that the major part of P13/14 is generated within caudalmost Medial lemniscus, as well as the occurrence of retrograde degeneration of lemniscal fibers.

A. Noronha - One of the best experts on this subject based on the ideXlab platform.

  • The Medullary vascular Syndromes revisited
    Journal of Neurology, 1995
    Co-Authors: A. Noronha
    Abstract:

    There are two major vascular Syndromes of the medulla oblongata: the Medial and the lateral. The Medial Medullary Syndrome is characterized by the triad of ipsilateral hypoglossal nerve palsy with contralateral hemiparesis and loss of deep sensation. Lateral Medullary infarction commonly presents with Homer's Syndrome, ataxia, alternating thermoanalgesia, nystagmus, vertigo and hoarseness. Combinations of the two major Syndromes occur as bilateral Medial Medullary, hemi-Medullary and bilateral lateral Medullary Syndromes. Each of these Syndromes frequently manifests with incomplete or atypical findings depending on the extent of the lesion. Magnetic resonance imaging has been useful in the clinical diagnosis of Medullary infarctions. The site of the lesion may help predict the arteries involved.

S. Gomez-llata - One of the best experts on this subject based on the ideXlab platform.

  • Microsurgical considerations of the anterior spinal and the anterior-ventral spinal arteries
    Acta Neurochirurgica, 2006
    Co-Authors: J. A. Santos-franco, E. De Oliveira, R. Mercado, R. I. Ortiz-velazquez, R. Revuelta-gutierrez, S. Gomez-llata
    Abstract:

    Background. There are few data describing the microanatomy of the anterior-ventral spinal (AVSA) and anterior spinal arteries (ASA) and discussing their clinical and surgical implications. We describe the anatomical features of this arterial complex, and highlight their use when planning and performing surgical approaches to lesions involving the ventral aspect of the medulla and the foramen magnum. Method. The microsurgical anatomy and branching pattern of the AVSA and the ASA from fifty human cadaver brain stems is described using a surgical microscope. Results. We found one anterior-ventral spinal artery at each side in 30 of the brain stems (60%). The ASA was a direct branch emerging from the left vertebral artery (VA) in 15 (30%), from the right VA in 4 (8%), and from the basilar artery (BA) in one brain stem (2%). The previously described as “typical pattern” of the junction of the AVS arteries from both sides, was observed only in 9 brain stems (18%). The anterior communicating spinal artery (ACoSA) was observed in 15 brain stems (30%). Also multiple ACoS arteries were described in one brain stem. Both, the AVSA and the ASA were observed to send long circumferential branches that supplied irrigation to the olive in 42 (84%) brain stems. Conclusions. This anatomical study gives important information for a better understanding of the clinical picture of ischemic lesions of the brain stem, such as the Medial Medullary Syndrome, and highlights the remarkable role of the AVSA and ASA as anatomical landmarks during the surgical approaches to lesions involving the ventral aspect of the medulla and the foramen magnum.

  • Surgical Microanatomy Microsurgical considerations of the anterior spinal and the anterior-ventral spinal arteries
    2006
    Co-Authors: J. A. Santos-franco, E. De Oliveira, R. Mercado, R. I. Ortiz-velazquez, R. Revuelta-gutierrez, S. Gomez-llata
    Abstract:

    Summary Background. There are few data describing the microanatomy of the anterior-ventral spinal (AVSA) and anterior spinal arteries (ASA) and discussing their clinical and surgical implications. We describe the anatomical features of this arterial complex, and highlight their use when planning and performing surgical approaches to lesions involving the ventral aspect of the medulla and the foramen magnum. Method. The microsurgical anatomy and branching pattern of the AVSA and the ASA from fifty human cadaver brain stems is described using a surgical microscope. Results. We found one anterior-ventral spinal artery at each side in 30 of the brain stems (60%). The ASA was a direct branch emerging from the left vertebral artery (VA) in 15 (30%), from the right VA in 4 (8%), and from the basilar artery (BA) in one brain stem (2%). The previously described as ‘‘typical pattern’’ of the junction of the AVS arteries from both sides, was observed only in 9 brain stems (18%). The anterior communicating spinal artery (ACoSA) was observed in 15 brain stems (30%). Also multiple ACoS arteries were described in one brain stem. Both, the AVSA and the ASA were observed to send long circumferential branches that supplied irrigation to the olive in 42 (84%) brain stems. Conclusions. This anatomical study gives important information for a better understanding of the clinical picture of ischemic lesions of the brain stem, such as the Medial Medullary Syndrome, and highlights the remarkable role of the AVSA and ASA as anatomical landmarks during the surgical approaches to lesions involving the ventral aspect of the medulla and the foramen magnum.

Masahiro Sonoo - One of the best experts on this subject based on the ideXlab platform.

  • preserved widespread n18 and progressive loss of p13 14 of median nerve seps in a patient with unilateral Medial Medullary Syndrome
    Electroencephalography and Clinical Neurophysiology, 1996
    Co-Authors: Masahiro Sonoo, Hiroki Hagiwara, Yasufumi Motoyoshi, Teruo Shimizu
    Abstract:

    Median nerve somatosensory evoked potentials (SEPs) in a patient with unilateral Medial Medullary Syndrome of recent onset having an MRI-confirmed lesion at upper medulla were investigated. Cortical N20 following stimulation of the affected limb was extremely depressed and delayed, whereas widespread N18, which was best manifested by the CPi-C2S lead (CPi is centroparietal electrode ipsilateral to the stimulation), showed no significant difference regarding amplitude and duration between affected and non-affected sides. The result supported our previous opinion that the principal part of N18, the broad negativity lasting around 20 ms, originates from the cuneate nucleus at the Medullary level. Less steep onset of N18 on the affected side suggested that some structures rostral to the cuneate nucleus, possibly the termination of the overall ascending volley, may contribute to the earliest part of N18. P13/14 on the affected side normally preserved at the first examination progressively declined and finally disappeared after 4 months, which suggested that the major part of P13/14 is generated within caudalmost Medial lemniscus, as well as the occurrence of retrograde degeneration of lemniscal fibers.

  • Preserved widespread N18 and progressive loss of P13/14 of median nerve SEPs in a patient with unilateral Medial Medullary Syndrome.
    Electroencephalography and Clinical Neurophysiology, 1996
    Co-Authors: Masahiro Sonoo, Hiroki Hagiwara, Yasufumi Motoyoshi, Teruo Shimizu
    Abstract:

    Median nerve somatosensory evoked potentials (SEPs) in a patient with unilateral Medial Medullary Syndrome of recent onset having an MRI-confirmed lesion at upper medulla were investigated. Cortical N20 following stimulation of the affected limb was extremely depressed and delayed, whereas widespread N18, which was best manifested by the CPi-C2S lead (CPi is centroparietal electrode ipsilateral to the stimulation), showed no significant difference regarding amplitude and duration between affected and non-affected sides. The result supported our previous opinion that the principal part of N18, the broad negativity lasting around 20 ms, originates from the cuneate nucleus at the Medullary level. Less steep onset of N18 on the affected side suggested that some structures rostral to the cuneate nucleus, possibly the termination of the overall ascending volley, may contribute to the earliest part of N18. P13/14 on the affected side normally preserved at the first examination progressively declined and finally disappeared after 4 months, which suggested that the major part of P13/14 is generated within caudalmost Medial lemniscus, as well as the occurrence of retrograde degeneration of lemniscal fibers.