RESUMEN
Brain activity associated with manual stereognosis has been the focus of increasing recent research effort. However, although oral stereognosis, defined as the ability to recognize and discriminate the food bolus in the mouth, is important for mastication and swallowing, there is little information available about the neural network relating to this function. In the present study, cerebral activation associated with oral stereognosis was evaluated as compared with manual stereognosis. Brain imaging data were acquired by functional MRI (fMRI). fMRI experiments were performed on 16 healthy right-handed young adults without any history of neurological or psychiatric disorders. All subjects had all teeth without malocclusion. Ten stereognosis test shape pieces sized approximately 20 mm × 20 mm × 10 mm were fabricated for this experiment. All test pieces had a complicated form that made them difficult to recognize with ease. Subjects were instructed to assess the shape of the test piece in the mouth or hand. The ten test pieces were randomly assigned to each subject and each run. Stereognosis-specific activation was found in the primary somatosensory area, primary motor area, supramarginal gyrus, premotor area, supplementary motor area, fusiform gyrus, frontopolar area and dorsolateral prefrontal cortex. Differences in cerebral activation between oral and manual stereognosis were found in the insular cortex and visual association cortex.
Asunto(s)
Encéfalo/fisiología , Boca/fisiología , Estereognosis/fisiología , Adulto , Mapeo Encefálico , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Masculino , NeuroimagenRESUMEN
BACKGROUND CONTEXT: Although many reports have examined upper cervical rheumatoid arthritis (RA) and spinal cord disorders resulting from RA lesions, few cases of thromboembolic events in the vertebrobasilar system associated with RA lesions of the upper cervical spine have been reported. PURPOSE: We encountered a rare case of repeated vertebrobasilar thromboembolism with severe upper cervical instability resulting from RA. Furthermore, we obtained clinical images of the vertebrobasilar system just before and after the first thromboembolic event. We thus present the case of a patient with RA who recovered without surgery from repeated vertebrobasilar thromboembolism that might have been caused by severe upper cervical instability. STUDY DESIGN: Case report. METHODS: A 59-year-old man with a 14-year history of RA experienced nuchal pain because of severe atlantoaxial and vertical subluxations. While awaiting surgery, he developed left Wallenberg syndrome because of occlusion in the left vertebral artery (VA). Five days later, he displayed impaired consciousness and symptoms of right Wallenberg syndrome. Emergency magnetic resonance angiography showed occlusion in the basilar artery. After thrombolytic therapy, he gradually recovered. RESULTS: Because we presumed that the patient's recurrent thrombus formation resulted from kinking of the right VA caused by severe instability of the upper cervical spine, we planned to treat him surgically despite his impaired consciousness and tracheostomy. However, the anesthesiologist would not approve surgery because the patient had high-risk conditions. The cervical spine was thus realigned and immobilized in a halo apparatus for 3 months to achieve stability. Now, more than 5 years after these events, the patient has experienced no more thromboembolic events and his condition has remained stable, without need for surgery. CONCLUSIONS: Repeated vertebrobasilar thromboembolism in patients with RA may sometimes be caused by severe upper cervical instability that can be treated without surgery.
Asunto(s)
Artritis Reumatoide/complicaciones , Articulación Atlantoaxoidea/lesiones , Luxaciones Articulares/terapia , Inestabilidad de la Articulación/etiología , Tromboembolia/complicaciones , Tromboembolia/terapia , Artritis Reumatoide/diagnóstico por imagen , Articulación Atlantoaxoidea/diagnóstico por imagen , Humanos , Luxaciones Articulares/diagnóstico por imagen , Inestabilidad de la Articulación/diagnóstico por imagen , Inestabilidad de la Articulación/terapia , Masculino , Persona de Mediana Edad , Dispositivos de Fijación Ortopédica , Radiografía , Tromboembolia/diagnóstico por imagen , Terapia Trombolítica , Resultado del TratamientoRESUMEN
Several articles reported the association between the development of subaxial kyphosis and the hyperlordotic fixation of C1-C2. However, their patients were heterogeneous in both primary disease and operative procedure. Transarticular screw fixation has become a popular procedure for C1-C2 arthrodesis instead of wiring techniques in which C1-C2 is difficult to fix in the intended alignment. Furthermore, in rheumatoid arthritis (RA) patients, subaxial lesions play an important role in potential subaxial alignment changes. The subaxial influences after C1-C2 transarticular screw fixation in patients with RA are unclear. To investigate the radiographic features of the subaxial cervical spine after C1-C2 transarticular screw fixation for RA, we reviewed 28 cases of C1-C2 transarticular screw fixation for rheumatoid atlanto-axial subluxation. The sagittal alignment of C1-C2 and the subaxial cervical spine was measured and the factors that affect subaxial alignment were investigated. Subaxial alignment became less lordotic in the postoperative course. The C1-C2 fixation angle and subaxial alignment showed a negative linear correlation. However, no significant correlation was found between changes in the C1-C2 angle and changes in the subaxial alignment. Four patients had a postoperative kyphotic subaxial deformity. Neurologic deterioration recurred in 4 patients, because of the postoperative development of subaxial subluxation. Common radiographic changes included an increase in C1-C2 lordosis, constant inclination of C1, an anterior shift of C2, and a decrease in C2-C7 lordosis. Many factors, not only C1-C2 angle, are associated with subaxial sagittal alignment change after C1-C2 transarticular screw fixation.
Asunto(s)
Artritis Reumatoide/diagnóstico por imagen , Artritis Reumatoide/cirugía , Tornillos Óseos , Vértebras Cervicales/diagnóstico por imagen , Vértebras Cervicales/cirugía , Inestabilidad de la Articulación/diagnóstico por imagen , Inestabilidad de la Articulación/cirugía , Fusión Vertebral/instrumentación , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Implantación de Prótesis/métodos , Radiografía , Fusión Vertebral/métodos , Resultado del TratamientoRESUMEN
In vivo three-dimensional (3D) kinematics of the lumbar spine has not been well evaluated by the conventional methods because of their methodological limitations, while 3D intervertebral motions have been quantitatively determined by cadaver studies. We thus developed a novel 3D analyzing system for the relative motions of individual vertebrae using 3D magnetic resonance imaging (MRI) and analyzed in vivo 3D intervertebral motions of the lumbar spine during trunk rotation. Ten healthy volunteers underwent 3D MRI of the lumbar spine in nine positions with 15 degrees increments during trunk rotation (0 degrees , 15 degrees , 30 degrees , 45 degrees , and maximum). Relative motions of the lumbar spine were calculated by automatically superimposing a segmented 3D MRI of the vertebra in the neutral position over images of each position using the voxel-based registration method. These 3D motions were represented with 6 degrees of freedom by Euler angles and translations on the coordinate system. The mean axial rotation of ten healthy volunteers of each lumbar spinal segment in 45 degrees trunk rotation to each side ranged from 1.2 degrees to 1.7 degrees . Coupled flexion with axial rotation was observed at the segments from L1/2 to L5/S1. Coupled lateral bending of the segments from L1/2 to L4/5 was in the opposite direction of the trunk rotation, while that of T12/L1 and L5/S1 was in the same direction. The direction of the coupled lateral bending in the present study was different from that in the previous cadaver study only at L4/5. This difference might result from the non-load state of the supine position in the current study and/or the non-physiological state in the cadaver study. Our system has two limitations: (1) the study was conducted with each volunteer in the supine position, and (2) because the rotation device regulated trunk rotation, trunk rotation might not have been physiological. In vivo 3D intervertebral motions of the lumbar spine during trunk rotation were evaluated using our novel motion analysis system. These data may be useful for the optimal orthopaedic management of lumbar spinal disorders.
Asunto(s)
Imagenología Tridimensional/métodos , Vértebras Lumbares/fisiología , Imagen por Resonancia Magnética , Rotación , Adulto , Fenómenos Biomecánicos , Femenino , Humanos , MasculinoRESUMEN
Many surgeons have investigated local pain associated with posterior spine surgery for cervical or lumbar lesions. However, little information is available concerning local pain after posterior thoracic spine surgery. This prospective study was, thus, performed to investigate the frequency and clinical features of local pain after posterior spine surgery for thoracic lesions. In 29 consecutive patients undergoing posterior spine surgery for various thoracic spinal disorders, local pain was investigated before and after surgery. In all 19 patients with preoperative back pain presumably due to thoracic lesions, pain was well alleviated after surgery. In contrast, 6 patients (21%) newly developed persistent shoulder angle pain after surgery, which resembled axial pain after cervical laminoplasty. In 5 of these 6 patients surgical exposure was extended to the cervicothoracic junction, whereas persistent shoulder angle pain was independent of disease etiologies and surgical procedure, and all of the 5 patients had no other etiologies of local pain such as surgical site infections, hardware failures, pseudoarthrosis, other metastasis, and vertebral fractures. These results suggest that dissection of muscle attachments to the cervicothoracic junction would play some part in the development of persistent local pain after posterior spine surgery for thoracic lesions, although surgical exposure of the zygapophysial joints at the cervicothoracic junction might be a possible source of postoperative shoulder pain. Therefore, to minimize such surgical complications, muscle insertions into the cervicothoracic junction should be preserved as far as possible.
Asunto(s)
Dolor de Espalda/fisiopatología , Procedimientos Neuroquirúrgicos/efectos adversos , Dolor Intratable/fisiopatología , Complicaciones Posoperatorias/fisiopatología , Vértebras Torácicas/cirugía , Adulto , Anciano , Anciano de 80 o más Años , Dolor de Espalda/etiología , Vértebras Cervicales/anatomía & histología , Vértebras Cervicales/fisiopatología , Vértebras Cervicales/cirugía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Músculo Esquelético/lesiones , Músculo Esquelético/fisiopatología , Músculo Esquelético/cirugía , Nociceptores/fisiología , Dolor Intratable/etiología , Complicaciones Posoperatorias/etiología , Estudios Prospectivos , Dolor de Hombro/etiología , Dolor de Hombro/fisiopatología , Vértebras Torácicas/anatomía & histología , Vértebras Torácicas/fisiopatología , Articulación Cigapofisaria/fisiopatología , Articulación Cigapofisaria/cirugíaRESUMEN
STUDY DESIGN: A prospective study. OBJECTIVE: To examine the prevalence and clinical manifestations of segmental motor paralysis after cervical laminoplasty and to investigate the presence of intramedullary high-signal intensity area (HIA) on postoperative T2-weighted magnetic resonance imaging (MRI). SUMMARY OF BACKGROUND DATA: Almost all previous studies had been retrospectively conducted, and MRIs of all subjects, including a control population, have never been investigated. METHODS: In the 79 patients of the prospective group, the sole examiner evaluated muscle strengths daily for perioperative 3 weeks and MRI scans were performed before and after surgery. Medical records of the 79 consecutive patients before this study were also investigated (control group). RESULTS: Ten patients from the prospective group developed segmental motor paralysis (proximal in 5, distal in 2, and diffuse in 3), whereas paralysis occurred in only 4 patients from the control group (proximal in 3 and diffuse in 1). On postoperative MRI, a linear HIA corresponded to the paralyzed segment more frequently than a focal or no HIA. CONCLUSION: In the prospective cases, distal or diffuse paralysis was found more frequently than in the retrospective control group. Linear HIAs were significantly more likely to present in the paralyzed segments.
Asunto(s)
Brazo , Vértebras Cervicales/cirugía , Procedimientos Ortopédicos/efectos adversos , Parálisis/etiología , Adulto , Anciano , Anciano de 80 o más Años , Vértebras Cervicales/patología , Estudios de Cohortes , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Debilidad Muscular/etiología , Debilidad Muscular/fisiopatología , Músculo Esquelético/fisiopatología , Dolor/etiología , Dolor/fisiopatología , Parálisis/diagnóstico , Parálisis/epidemiología , Parálisis/fisiopatología , Periodo Posoperatorio , Prevalencia , Estudios Prospectivos , Trastornos de la Sensación/etiología , Trastornos de la Sensación/fisiopatología , Índice de Severidad de la EnfermedadAsunto(s)
Artroplastia de Reemplazo de Rodilla , Fracturas del Fémur/cirugía , Fracturas no Consolidadas/cirugía , Prótesis e Implantes , Terapia Recuperativa , Anciano , Artritis Reumatoide/cirugía , Femenino , Humanos , Articulación de la Rodilla/fisiopatología , Rango del Movimiento Articular , ReoperaciónRESUMEN
BACKGROUND CONTEXT: Recent reports have described the long-term efficacy and safety of infliximab as a treatment for ankylosing spondylitis (AS). The most important adverse effects of infliximab are infections, malignancies, autoimmunities, and hypersensitivity reactions. There has never been a reported case of paraparesis after infliximab therapy for AS. PURPOSE: To describe a case with paraparesis caused by rapid exacerbation of preexisting spinal pseudoarthrosis after infliximab therapy for advanced AS. STUDY DESIGN/SETTING: Case report/Osaka University Graduate School of Medicine, Suita, Japan. PATIENT SAMPLE: A 55-year-old man with a 27-year history of AS. OUTCOME MEASURES: Case report. METHODS: A 55-year-old man with a 27-year history of AS was treated with infliximab, which provided considerable pain relief and improvement of activities of daily living. However, as the patient resumed vigorous daily activity, he felt back pain and subsequently developed paraparesis. Radiographs showed rapid exacerbation of preexisting spinal pseudoarthrosis at the T11-T12 level after infliximab therapy. RESULTS: After laminectomy and posterolateral fusion, the back pain and paraparesis improved sufficiently to allow independent walking, but moderate bladder dysfunction persisted. CONCLUSIONS: Although this patient could have certainly become myelopathic over time without undergoing infliximab therapy, the patient's history and radiographic course suggest that suppression of inflammation by infliximab improved his activities of daily living, which paradoxically exacerbated preexisting spinal pseudoarthrosis and quickened the onset of subsequent myelopathy.
Asunto(s)
Anticuerpos Monoclonales/efectos adversos , Antirreumáticos/efectos adversos , Paraparesia/etiología , Seudoartrosis/fisiopatología , Espondilitis Anquilosante/complicaciones , Vértebras Torácicas/patología , Proteína C-Reactiva/análisis , Proteína C-Reactiva/efectos de los fármacos , Comorbilidad , Humanos , Infliximab , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Seudoartrosis/cirugía , Compresión de la Médula Espinal/etiología , Compresión de la Médula Espinal/cirugía , Fusión Vertebral , Espondilitis Anquilosante/tratamiento farmacológico , Vértebras Torácicas/cirugíaRESUMEN
STUDY DESIGN: Kinematics of the cervical spine during lateral bending were investigated using a novel system of three-dimensional motion analysis. OBJECTIVES: To demonstrate in vivo intervertebral coupled motions of the cervical spine during lateral bending of the neck. SUMMARY OF BACKGROUND DATA: No previous studies have successfully documented in vivo three-dimensional intervertebral motions of the cervical spine during lateral bending. METHODS: Twelve healthy volunteers underwent three-dimensional magnetic resonance imaging (MRI) of the cervical spine in 7 positions with 10 degrees increments of lateral bending. Relative motions of the cervical spine were calculated automatically by superimposing a segmented three-dimensional-MRI of the vertebra in the neutral position over images of each position using volume registration. RESULTS: Mean maximum lateral bending of the cervical spine to one side was 1.6 degrees to 5.7 degrees at each level. Coupled axial rotation opposite to lateral bending was observed in the upper cervical levels (Oc-C1, 0.2 degrees ; C1-C2, 17.1 degrees ), while in the subaxial cervical levels, it was observed in the same direction as lateral bending except for at C7-T1. Coupled flexion-extension motion was small at all vertebral levels (<1.1 degrees). CONCLUSIONS: We succeeded in identifying in vivo coupled motions of the cervical spine in lateral bending for the first time.
Asunto(s)
Vértebras Cervicales/diagnóstico por imagen , Vértebras Cervicales/fisiología , Movimientos de la Cabeza/fisiología , Imagenología Tridimensional/métodos , Adulto , Fenómenos Biomecánicos/instrumentación , Fenómenos Biomecánicos/métodos , Femenino , Humanos , Imagenología Tridimensional/instrumentación , Imagen por Resonancia Magnética/instrumentación , Imagen por Resonancia Magnética/métodos , Masculino , Docilidad , RadiografíaRESUMEN
STUDY DESIGN: Three-dimensional intervertebral motions of the subaxial cervical spine during head rotation were investigated in healthy volunteers using three-dimensional magnetic resonance imaging (MRI). OBJECTIVES: To document intervertebral coupled motions of the subaxial cervical spine during rotation. SUMMARY OF BACKGROUND DATA: In vivo three-dimensional kinematics of the subaxial cervical spine in rotation have not previously been well described, since they are too complicated to follow using conventional radiography or computed tomography techniques. METHODS: Ten healthy volunteers underwent three-dimensional MRI of the cervical spine in 11 positions with 15 degrees increments during head rotation using a 1.0-T imager. Relative motions of the subaxial cervical spine were calculated by automatically superimposing a segmented three-dimensional MRI of the vertebra in the neutral position over images of each position using volume registration. Three-dimensional motions of adjacent vertebrae were represented with 6 df (6 degrees of freedoms) by Euler angles and translations on the coordinate system defined by Panjabi, then visualized in animations using surface bone models. RESULTS: Mean axial rotation of the subaxial cervical spine in maximum head rotation (69.5 degrees ) was 2.2 degrees at C2-C3, 4.5 degrees at C3-C4, 4.6 degrees at C4-C5, 4.0 degrees at C5-C6, 1.6 degrees at C6-C7, and 1.5 degrees at C7-T1. Coupled lateral bending with axial rotation was observed in the same direction as axial rotation at all levels (C2-C3, 3.6 degrees ; C3-C4, 5.4 degrees; C4-C5, 5.0 degrees ; C5-C6, 5.3 degrees ; C6-C7, 4.9 degrees ; C7-T1, 1.2 degrees ). Coupled extension with axial rotation occurred in the middle cervical region (C2-C3, 1.4 degrees ; C3-C4, 2.3 degrees ; C4-C5, 1.5 degrees ), while in the lower cervical region, flexion was coupled with axial rotation (C5-C6, 0.9 degrees ; C6-C7, 2.4 degrees ; C7-T1, 3.0 degrees ). CONCLUSIONS: We investigated intervertebral motions of the subaxial cervical spine during head rotation using a three-dimensional imaging system, and obtained the first accurate depictions of in vivo coupled motion. These findings will be helpful as the basis for understanding abnormal conditions.