Aplicación de técnicas avanzadas de neuroimágenes en rehabilitación motora / Application of advanced neuroimaging in motor rehabilitation

Introducción. La resonancia magnética funcional es una técnica no invasiva que permite el mapeo cerebral y la visualización de redes de conectividad. La hemiparesia posterior a un accidente cerebrovascular constituye un buen modelo biológico para estudiar los cambios en la conectividad cerebral. El uso de este modelo se puede expandir si se obtiene información antes y después de la rehabilitación neurológica. Objetivo. Presentar los hallazgos por neuroimágenes funcionales de un paciente con accidente cerebrovascular antes y después del tratamiento de rehabilitación neurológica. Materiales y métodos. Como parte del protocolo de rehabilitación neurológica se tomaron imágenes de resonancia antes y después del tratamiento con un equipo que operaba a 1,5 T. Se obtuvieron imágenes volumétricas potenciadas en T1, imágenes de difusión para tractografía, imágenes de resonancia funcional con el paciente en reposo y haciendo movimientos de pinza con la mano derecha. Resultados. Se obtuvieron mapas funcionales antes y después de la terapia, los cuales se presentan conjuntamente con las imágenes de conectividad estructural obtenidas mediante tractografía. Se observó que los cambios clínicos estaban acompañados de cambios en los patrones de activación obtenidos por resonancia magnética funcional. Conclusión. La versatilidad que ofrece la resonancia magnética permite conocer el estado funcional y estructural del cerebro, generando así nuevas posibilidades de diagnóstico y pronóstico en pacientes que reciben rehabilitación neurológica, con lo que se pueden cuantificar y develar ciertos procesos dinámicos de plasticidad neuronal posteriores a una lesión, que son propios del sistema nervioso central.

Introduction: Functional magnetic resonance imaging is a noninvasive technique that allows mapping and visualizing of brain connectivity networks. The hemiparesis after a stroke is a good biological model to study changes in brain connectivity. This model can be expanded if information is obtained before and after neurorehabilitation therapy. Objective: To present the functional neuroimaging findings in a patient with stroke before and after performing neurorehabilitation therapy. Materials and methods: As part of the neurorehabilitation protocol, resonance imaging was performed before and after treatment with an equipment operating at 1.5 T. Volumetric T1-weighted images, diffusion images for tractography, functional resonance images with the patient at rest and with the patient performing pincer movement with the right hand were obtained. Results: Functional maps before and after therapy were obtained, which are presented together with structural connectivity images obtained by tractography. Clinical changes can be seen accompanied by changes in activation patterns obtained by functional magnetic resonance imaging. Conclusion: The versatility of magnetic resonance imaging allows further knowledge of the structural and functional state of the brain generating new possibilities for diagnosis and prognosis in patients undergoing neurorehabilitation therapy. Neurological rehabilitation processes can be quantified and they can reveal certain postlesional neuroplasticity dynamic processes that the central nervous system possesses.

Magnetic resonance diffusion tensor imaging for diagnosis of pyramidal tract damage in rats / 法医学杂志

OBJECTIVE@#To explore the applicability of magnetic resonance diffusion tensor imaging (DTI) for diagnosis of pyramidal tract damage in rats.@*METHODS@#Marmarou's model was set up, followed by DTI scanning at 3, 12, 24 and 72 h post trauma to acquire the dispersion parameter of bilateral pyramidal tracts. Moreover, axonal varicosities per square millimeter and the percentage of positive area of axons demonstrated by beta-amyloid precursor protein (beta-APP) immunostaining were obtained, as well as the mean density and sum density of neurofilament (NF) 68 immunostaining.@*RESULTS@#Axial diffusivity (AD), fraction anisotropy (FA) and relative anisotropy (RA) in the pyramidal tract were significantly and continuously reduced and reached to the bottom at 72h post trauma (P < 0.05) in accord with the gradient of axonal damage verified by beta-APP and NF68 immunostaining. Furthermore, the changes of AD, FA and RA showed a significant negative correlation with the beta-APP immunohistochemical results.@*CONCLUSION@#DTI has important value for early diagnosis in pyramidal tract damage.

Relação entre degeneração do trato córtico-espinhal através de ressonância magnética e escala funcional (ALSFRS) em pacientes com esclerose lateral amiotrófica / Correlation between corticospinal tract degeneration through magnetic resonance imaging, and functional scale (ALSFRS) in patients whit amyotrophic lateral sclerosis

A esclerose lateral amiotrófica (ELA) é doença neurodegenerativa que afeta o trato córtico-espinhal. A escala funcional de avaliação em ELA (ALSFRS) é um questionário que quantifica clinicamente as perdas motoras, enquanto a imagem por tensor de difusão (DTI) avalia a integridade das fibras através da fração de anisiotropia (FA). No presente estudo, sete pacientes com ELA definida foram avaliados pela ALSFRS e imediatamente submetidos à DTI, obtendo valores de FA nas regiões: pedúnculo cerebral (PC), cápsula interna (CI) e substância barnca subjacente às áreas motora primária (M1), motora secundária (M2) e somestésica (SI). Um grupo controle foi constituído de doze indivíduos saudáveis. Os pacientes apresentaram valores de FA significativamente menores que os controles, com tendência à maior redução à direita e nas regiões mais caudais. Curiosamente, os valores de FA estavam reduzidos na área somestésica. Não foi observada correlação entre a duração dos sintomas e os valores de FA. Apesar da correlação entre os valores da ALSFRS e a degeneração em PC e CI, nossos resultados sugerem que essa escala subjetiva não é um bom parâmetro para a avaliação do dano estrutural nas porções encefálicas do trato corticoespinhal.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease that affects the corticospinal tract. ALS functional rating scale (ALSFRS) is a questionnaire that quantifies motor deficits, while diffusion tensor imaging (DTI) evaluates the integrity of fibers through the fractional anisotropy (FA). In the present study, seven ALS patients were evaluated by ALSFRS and immediately submitted to DTI, getting FA values in the following regions: cerebral peduncle (PC), internal capsule (CI) and the white matter under the primary motor cortex (M1), secondary motor cortex (M2) and somestetic cortex (SI). A control group was constituted by twelve healthy individuals. FA values in patients were significantly lower when compared with controls, with a tendency to higher reductions in the right hemisphere and more inferior regions. Interestingly, FA values were reduced in somestetic area. No correlation was observed between symptoms duration and FA values. Despite the correlation observed between ALSFRS scores and degeneration in PC and CI, our results suggest that this subjective scale is not a good parameter for the evaluation of the structural damage in encephalic portions of the corticospinal tract.

Corticospinal Tract Compression by Hematoma in a Patient with Intracerebral Hemorrhage: A Diffusion Tensor Tractography and Functional MRI Study

The purpose of this study was to demonstrate corticospinal tract compression that was due to a hematoma by using diffusion tensor tractography (DTT) and functional MRI (fMRI) in a patient with an intracerebral hemorrhage (ICH). A 23-year-old right-handed woman presented with severe paralysis of her right extremities at the onset of a spontaneous ICH. Over the first three days from onset, the motor function of the affected upper and lower extremities rapidly recovered to the extent that she was able to overcome applied resistance to the affected limbs, and her limbs regained normal function 3 weeks after onset. The tract of the right hemisphere originated from the primary sensori-motor cortex (SM1) and it passed through the known corticospinal tract pathway. However, the tract of the left hemisphere was similar to that of the right hemisphere except that it was displaced to the antero-medial side by the hematoma at the cerebral peduncle. Only the contralateral SM1 area centered on the precentral knob was activated during affected (right) or unaffected (left) hand movements, respectively. In conclusion, fMRI and DTT demonstrated a corticospinal tract compression due to hematoma in this patient. We conclude that the combined use of these two modalities appears to improve the accuracy of investigating the state of the corticospinal tract.

Olivopontocerebellar atrophy presenting with stridor.

The spectrum of degenerative ataxia includes the symptomatic degenerative ataxias and the primary degenerative ataxias. The later may be sporadic and idiopathic or hereditary, being genetically determined. When an individual ataxic patient presents with an adult-onset degenerative ataxia and has a negative family history, the physician is faced with a diagnosis of pure idiopathic sporadic degenerative ataxia or one of the hereditary ataxias. The clinical spectrum of olivopontocerebellar atrophy (OPCA) usually consists of pancerebellar signs with pyramidal and abnormal eye movements. Although Stridor is more commonly found in multisystem atrophy, it is rarely seen in OPCA. We, here report a case of third decade onset of ataxia presenting with stridor.

Magnetic resonance findings in amyotrophic lateral sclerosis using a spin echo magnetization transfer sequence: preliminary report

We present the magnetic resonance (MR) findings of five patients with anytrophic lateral sclerosis (ALS) using a spin-echo sequence with an additional magnetization transfer (MT) pulse on T1-weighted images (T1 SE/MT). These findings were absent in the control group and consisted of hyperintensity of the corticospinal tract. Moreover we discuss the principles and the use of this fast but simple MR technique in the diagnosis of ALS.

Neuropatias associadas à infecçäo pelo protovírus T-linfotrópico humano (HTLV-I): aspectos clínicos / Neuropathies associated to infection by human T-lymphotropic virus (HTLV-I): clinical aspects

Säo revistas as principais alteraçöes clínicas encontradas nas neuropatias associadas à infecçäo pelo protovírus T-linfotrópico humano (HTLV-I)

Locked in state. A clinicopathological study.

Two patients developed the locked-in state characterised by quadriplegia and mutism with an alert sensorium. Initially they had mild dysarthria and uncrossed hemisensory or hemimotor deficits involving the face and ipsilateral extremities. Both patients died. Rostral brainstem infarctions were found at autopsy in them. Acute onset of uncrossed hemisensory and hemimotor deficits with dysarthria may be caused by infarction of the pons which may predispose to locked-in state.

Subacute combined degeneration of the spinal cord in acute monoblastic leukemia.

A 54-year-old man who had acute monoblastic leukemia and manifestations of subacute combined degeneration (SCD) of the spinal cord is described clinically and pathologically. Infiltration of the wall of the stomach by leukemic cells may produce impairment in gastric absorption of vitamin B12 and leukemia itself may cause deficiency of folic acid. Decreased level of vitamin B12 or folic acid or both may have evoked symptoms of SCD of the spinal cord in this patient.