COVID-19 crítico e disfunção neurológica - uma análise comparativa direta entre o SARS-CoV-2 e outros agentes infecciosos / Critical COVID-19 and neurological dysfunction - a direct comparative analysis between SARS-CoV-2 and other infectious pathogens

RESUMO Objetivo: Avaliar se a infecção grave pelo SARS-CoV-2 está mais comumente associada a sinais de disfunção do trato corticoespinhal e outros sinais, sintomas e síndromes neurológicas, em comparação com outros agentes infecciosos. Métodos: Este foi um estudo de coorte prospectivo com inclusão consecutiva de doentes admitidos a unidades de cuidados intensivos devido a síndrome do desconforto respiratório agudo infeccioso primário, com necessidade de ventilação mecânica invasiva por > 48 horas. Os doentes incluídos foram atribuídos aleatoriamente a três investigadores para a avaliação clínica, a qual incluía a pesquisa de sinais de disfunção do trato corticoespinhal. Os dados clínicos, incluindo outras complicações neurológicas e possíveis preditores, foram obtidos independentemente a partir dos registros clínicos. Resultados: Foram incluídos consecutivamente 54 doentes com síndrome do desconforto respiratório agudo, 27 devido a SARS-CoV-2 e 27 devido a outros agentes infecciosos. Os grupos eram comparáveis na maioria das características. Os doentes com COVID-19 apresentavam risco significativamente superior de complicações neurológicas (RR = 1,98; IC95% 1,23 - 3,26). Os sinais de disfunção do trato corticoespinhal tendiam a ser mais prevalentes em doentes com COVID-19 (RR = 1,62; IC95% 0,72 - 3,44). Conclusão: Este estudo foi a primeira análise comparativa visando avaliar disfunção neurológica, entre doentes com infecção SARS-CoV-2 e outros agentes infecciosos, em um contexto de unidade de cuidados intensivos. Reportamos um risco significativamente superior de disfunção neurológica em doentes com COVID-19. Como tal, sugere-se o rastreio sistemático de complicações neurológicas em doentes com COVID-19 crítico.

ABSTRACT Objective: To evaluate whether critical SARS-CoV-2 infection is more frequently associated with signs of corticospinal tract dysfunction and other neurological signs, symptoms, and syndromes, than other infectious pathogens. Methods: This was a prospective cohort study with consecutive inclusion of patients admitted to intensive care units due to primary infectious acute respiratory distress syndrome requiring invasive mechanical ventilation > 48 hours. Eligible patients were randomly assigned to three investigators for clinical evaluation, which encompassed the examination of signs of corticospinal tract dysfunction. Clinical data, including other neurological complications and possible predictors, were independently obtained from clinical records. Results: We consecutively included 54 patients with acute respiratory distress syndrome, 27 due to SARS-CoV-2 and 27 due to other infectious pathogens. The groups were comparable in most characteristics. COVID-19 patients presented a significantly higher risk of neurological complications (RR = 1.98; 95%CI 1.23 - 3.26). Signs of corticospinal tract dysfunction tended to be more prevalent in COVID-19 patients (RR = 1.62; 95%CI 0.72 - 3.44). Conclusion: Our study is the first comparative analysis between SARS-CoV-2 and other infectious pathogens, in an intensive care unit setting, assessing neurological dysfunction. We report a significantly higher risk of neurological dysfunction among COVID-19 patients. As such, we suggest systematic screening for neurological complications in severe COVID-19 patients.

Comparative study of pyramidal tract magnetic resonance diffusion tensor imaging and prognosis of hypertensive putaminal hemorrhage treated via transsylvian-transinsular and transcortical transtemporal approaches / 中国脑血管病杂志

Objectives To conduct grading comparison for the damage degree of pyramidal tracts after procedure in patients with unilateral hypertensive putamen hemorrhage via transsylvian-transinsular (TS-TI) approach and transcortical transtemporal (TC-TF) approach using magnetic resonance diffusion tensor imaging (DTI) and to evaluate the postoperative recovery of the patients according to the quality criteria of the activities of daily living (ADL),and to identify the advantages and disadvantages of both surgical approaches.Methods Sixty-three consecutive patients with first onset of unilateral hypertensive basal ganglia putamen hemorrhage admitted to Department of Neumlsurgery in Affiliated Hospital of Southwest Medical University of Traditional Chinese Medicine were enrolled prospectively.The volume of hematoma at admission was 26-45 ml.They were randomly divided into group A and group B by random number table.The patients in group A (n =31) were treated via the TS-TI approach,and those of group B (n =32) were treated via the TC-TT approach.The operator was the same surgeon.The patients of rebleeding were excluded (4 in group A,7 in group B),and 52 patients were actually included,including 27 in group A and 25 in group B.The DTI examinations were perforrned 5 to 8 d after procedure.The image data were processed by PHILIPS Extended MR Workspace 2.6.3.4 (EMW 2.6.3.4) software.The bilateral pyramidal tracts were reconstructed,the damage degree of pyramidal tract and its relationship with hematoma and surgical approach were observe respectively.The ADL quality criteria were used to evaluate the recovery at 3 months after procedure.The SPSS 17.0 software was used to conduct rank sum test for the pyramidal tract injury grade after procedure in both groups.The number of rebleeding in the operation areas and the ADL quality criteria evaluation were tested by Chi-squared test.Results There was no significant difference in the postoperative rebleeding rate between group A (12.9％,4/31) and group B (21.9％,7/32) (x2 =0.367,P =0.545).The postoperative pyramidal tract damage degree of group A was better than that of group B.There was significant difference (U =180.00,P =0.004).The comparison of ADL quality evaluation in both groups after procedure showed that the good prognosis rate (81.5％,22/27) of group A after procedure was better than that of group B (56.0％,14/25).There was significant difference (x2 =3.957,P =0.047).Conclusions The three-dimensional relationship between the hematoma lesions and the pyramidal tracts was observed by DTI,the damage degree of the pyramidal tracts were identified.The TS-TI approach was superior to the TC-TF approach in the postoperative damage degree of pyramidal tract and the quality of ADL for the treatment of hypertensive putamen hemorrhage.

Clinical Observation of Large-dose of Methylprednisolone Pulse Therapy for Acute Myelitis / 中国药房

OBJECTIVE:To investigate therapy efficacy of large-dose of methylprednisolone plus therapy for acute myelitis, and it effects on nerve function recovery,pyramidal tract conduction function and sensory disturbance. METHODS:A total of 116 patients with acute myelitis were randomly divided into observation group and control group,with 58 cases in each group. Both group received conventional treatment. Control group was additionally given Dexamethasone sodium phosphate injection 0.4 mg/(kg·d)intravenously,once a day;7 d later,they were given Methylprednisolone tablet 60 mg,orally,qd,gradually decreasing to 5 mg/d. Observation group was given Methylprednisolone sodium succinate injection 1000 mg intravenously,once a day;7 d lat-er,they were given Methylprednisolone tablet 60 mg,orally,qd,gradually decreasing to 5 mg/d. The treatment course in eaeh group was 1 month. The nerve function recovery time,pyramidal tract conduction function,sensory disturbance scores,clinical ef-ficacy and ADR were compared between 2 groups. RESULTS:After treatment,the response rate of observation group was signifi-cantly higher than that of control group(93.10% vs. 79.31%);the time of muscle strength improvement≥grade 2,walking down the ground,urination and defecation function recovery in observation group were all significantly shorter than control group,with statistical significance(P0.05). CONCLUSIONS:Based on conventional treatment,large-dose of methylprednisolone plus therapy shows good efficacy in the treatment of acute myelitis,which can helps to improve pyramidal tract conduction function of patients with acute myelitis,ease sensory disturbance,promote the nerve functional recovery with good safety.

Motor Rehabilitation and Pyramidal Tract Remodeling after Cerebral Infarction (review) / 中国康复理论与实践

Motor dysfunction is one of the leading problems after stroke. The evidence existed that motor performance is largely affect-ed by the location and volume of white matter especially the pyramidal tract, but not the cortex. The remodeling of contralesional primary motor output tract highly correlated with motor improvement. The unaffected pyramidal tract axons regenerate and cross into the affected side after ischemia can promte motor recovery after ischemia. Exercise and other rehabilitation may play a role on remodeling of pyramidal tract subsequent after cerebral infarction.

Motor Rehabilitation and Pyramidal Tract Remodeling after Cerebral Infarction (review) / 中国康复理论与实践

@#Motor dysfunction is one of the leading problems after stroke. The evidence existed that motor performance is largely affected by the location and volume of white matter especially the pyramidal tract, but not the cortex. The remodeling of contralesional primary motor output tract highly correlated with motor improvement. The unaffected pyramidal tract axons regenerate and cross into the affected side after ischemia can promte motor recovery after ischemia. Exercise and other rehabilitation may play a role on remodeling of pyramidal tract subsequent after cerebral infarction.

Diffusion Tensor Tractography in Two Cases of Kernohan-Woltman Notch Phenomenon

Kernohan-Woltman notch phenomenon (KWP) is an ipsilateral motor weakness due to compression of the contralateral cerebral peduncle. We report two cases of KWP following traumatic brain injury. In case 1, ipsilateral hemiplegia was noted after right subdural hemorrhage. Although magnetic resonance imaging showed no abnormal signal changes on cerebral peduncle, diffusion tensor tractography (DTT) revealed interruption of corticospinal tract (CST) at lower level of the midbrain level. In case 2, there was abnormal signal change of the right cerebral peduncle contralateral to the primary lesion and we could not reconstruct right CST. Case 1 showed unsatisfactory motor recovery even after 15 months, and follow-up DTT showed no change. In case 2, follow-up DTT was not performed, but her ipsilateral hemiparesis had almost disappeared during the 15 months. DTT would be useful in detecting ipsilateral hemiparesis due to KWP and the clinical course may differ according to the lesion characteristics.

The pyramidal syndrome and the pyramidal tract: a brief historical note / A síndrome piramidal e o feixe piramidal: breve nota histórica

The discovery of the pyramidal syndrome and tract is briefly reviewed with emphasis on a few key historical aspects. The pursuit of the relationship between the lateralized deficits resulting from contralateral head trauma begins in the fourth century BC with the Hippocratic School and continues until the present day.

Os autores fazem uma breve nota histórica da síndrome piramidal e do feixe piramidal no homem. Os achados de deficiências motoras decorrentes de traumatismo craniano começam a partir do século IV AC com o pai da medicina Hipócrates (460-377) e vão até os dias atuais.

Bilateral Periodic Limb Movement Disorder Developed after Anterior Cerebral Artery Infarction

Previous reports on the lesions causing stroke-related periodic limb movement in sleep (PLMS) have involved subcortical structures such as the basal ganglia/corona radiata or pons. We report a case of an 81-year-old female patient who presented with bilateral, right-side-predominant PLMS that developed after a left cortical infarction. The right-side PLMS may be attributable to the loss of cortical inhibition following a pyramidal tract lesion, while the left-side PLMS may be caused by activation of the contralateral motor cortex due to dysfunction of interhemispheric inhibition.

The motor evoked potential in aids and HAM/TSP State of the evidence / El potencial evocado motor en SIDA y HAM/PET

OBJECTIVE: We aimed to better understand the involvement of the corticospinal tract, assessed by non-invasive transcranial stimulation, in order to determine the actual involvement of the motor system in patients with HAM/TSP and AIDS. METHOD: An exhaustive MEDLINE search for the period of 1985 to 2008 for all articles cross-referenced for "HTLV-I, HTLV-II, HTLV-III and HIV, HIV1, HIV2, evoked potential, motor evoked potential, high voltage electrical stimulation, transcranial magnetic stimulation, magnetic stimulation, corticomotor physiology, motor pathways, acquired immunodeficiency syndrome, AIDS, SIDA, tropical spastic paraparesis, HTLV-I-associated myelopathy, HAM, TSP, and HAM/TSP" were selected and analysed. RESULTS: Eighteen papers published in English, Spanish, Portuguese, French and Japanese were identified. Only the central motor conduction time has been analyzed in seropositive patients to human retroviruses. The investigations done on HAM/TSP support the involvement of the pyramidal tract mainly at lower levels, following a centripetal pattern; in AIDS, such an involvement seems to be more prominent at brain levels following a centrifugal pattern. CONCLUSION: The central motor conduction time abnormalities and involvement differences of the corticospinal tract of patients with AIDS and HAM/TSP dissected here would allow to re-orient early neurorehabilitation measures in these retroviruses-associated neurodegenerative disorders. Besides this, more sophisticated and sensitive non-invasive corticospinal stimulation measures that detect early changes in thalamocortical-basal ganglia circuitry will be needed in both clinically established as well as asymptomatic patients at times when the fastest corticospinal fibers remain uninvolved.

OBJETIVO: Investigar el compromiso del tracto piramidal, evaluado por estimulación trascranial no invasiva, en pacientes afectados por SIDA y HAM/TSP. MÉTODO: Se realizó una búsqueda en la base de datos MEDLINE, que abarcó el período de 1985 a 2008; se incluyeron los términos "HTLV-I, HTLV-II, HTLV-III and HIV, HIV1, HIV2, evoked potential, motor evoked potential, high voltage electrical stimulation, transcranial magnetic stimulation, magnetic stimulation, corticomotor physiology, motor pathways, acquired immunodeficiency syndrome, AIDS, SIDA, tropical spastic paraparesis, HTLV-I-associated myelopathy, HAM, TSP, and HAM/TSP". RESULTADOS: Se obtuvieron 18 artículos publicados en inglés, español, portugués, francés y japonés. El tiempo de conducción central es el único parámetro que se ha estudiado en individuos seropositivos a retrovirus humanos. Las investigaciones hechas en HAM/PET apoyan el compromiso del tracto piramidal, principalmente a nivel dorso-lumbar, de manera centrípeta. En SIDA, el compromiso parece ser mas prominente a nivel cortical, siguiendo un patrón centrifugo. CONCLUSION: El conocer las diferencias en el compromiso y anormalidades del tracto corticoespinal de los pacientes con SIDA y HAM/TSP podrán ser útiles para reorientar la neurorehabilitación temprana en estos desórdenes neurodegenerativos asociados a retrovirus. De otro lado, evaluaciones mas sensibles y sofisticadas del sistema piramidal, que permitan detectar cambios tempranos en los circuitos talamocorticoganglionicos serán mandatarios de realizar a partir de la fecha, bien sea que los individuos estén asintomáticos o no, en estadios clínicos donde las fibras corticoespinales rápidas no estén aun comprometidas.

Imaging measurement of brain function when ankle dorsiflexion and planter flexion / 中国康复理论与实践

@#ObjectiveTo measure cortical areas involved ankle dorsiflexion and planter flexion.MethodsSix-health subjects performed ankle dorsiflexion and planter flexion. While, functional MRI at 1.5 T was made.ResultsWhen ankle dorsiflexion, the excited cortical areas included bilateral primary motor cortex (MⅠ) and primary somatosensory cortex (SⅠ), but area on contralateral side bigger than that on ipsilateral side, as well as chief visual cortexes and vermis of cerebellum. Inhibited areas included area 19, area 20 and area 39. When ankle planter flexion, the excited areas included contralateral secondary motor area (MⅡ) and striate body, ipsilateral supplementary motor area (SMA) and limbic system. Inhibited areas included bilateral upper middle precentral gyrus and postcentral gyrus, superior parietal lobule, inferior parietal lobule and prefrontal cortex.ConclusionThere is a great difference in the brain function images respectively in ankle dorsiflexion and planter flexion.

Study on motor evoked potential of Arnoid Chiari malformation / 中国康复理论与实践

@# Objective To study the electrical stimulation motor evoked potentials in Arnoid Chiari malformation.Methods Electrical stimulation motor evoked potentials were recorded in 30 cases with Arnoid Chiari malformation proved by MRI.Results Abnormality rate of MEP was 96.7%,and the abnormal patterns mainly consisted of the delay of latency and the delay of central motor conduction time(CMCT). The change of MEP was connected with myodynamia and the type of Arnoid Chiari malformation .Conclusions The change of MEP is more sensitive than clinical change, and can indicate the damage of the motor function objectively and quantitatively, and MEP can be used as an objective criterion for surgical effect, and can predict the recovery of motor function.

Monitoring of Pyramidal Motor Evoked Potentials in the Rat

Pyramidal motor evoked potential (PMEP) was recored in rat using the specially designed stimulating electrode for preferential activation of a pyramidal cell layer of the motor cortex. The PMEPs, recorded in the upper levels of a neural axis (medulla and C7), were composed of short latency complex waves and a long latency positive wave with a large amplitude and prolonged duration. However, the PMEP recorded at the lower level of a neural axis (T8) only showed the long latency a large positive wave. Conduction velocity of the short latency wave was approximately 11.1m/sec. Judging by the conduction velocities of these waves, it appeared that the short latency-wave complex originated from direct activation of pyramidal cells in the motor cortex (D-wave). The long latency-wave seemed to be evoked by indirect activation of the pyramidal cells (I-wave). This view was further supported by the serial depth recordings of PMEPs in the medulla as well as by the field mapping of PMEPs in the T4 spinal cord. PMEPs completely disappeared following the acute lesion of an internal capsule, indicating that these waves originated from the motor cortex rather than the brain stem nuclei such as the reticular nuclei.

The Characteristic and Origin of Motor Evoked Potential in Rats

Motor evoked potential(MEP) produced by cortical surface or transcranial stimulation has evolved as a new clinical and experimental tool to monitor the integrity of motor pathways and to map motor cortex. Clinical assessment of motor system using MEP has further advanced with recent development of the magnetic stimulator. The primary concept using MEPs for test of motor pathways was based on the assumption that pyramidal neurons in the motor cortex are activated by electrical stimulation applied on the cerebral cortex and synchronized compound action potentials are conducted mainly along the corticospinal tracts in the spinal cord. However,recent studies indicated that the origins of the Meps in non primates may differ from those previously believed. In order to use MEPs as a clinical or experimental tool, it is essential to clarify the origin of MEPs. Therefore, goals of this study were : (1) to investigate the origin of MEPs, and (2) to design the most reliable but simple method to evoke and monitor MEPs. In a total of fifteen rats, MEPs were produced by cortex to cortex stimulation and were monitored using a pair of epidural electrodes. Using varying stimulus intensities, the amplitudes and latencies of MEPs were statistically analyzed. The latencies and amplitudes of the MEPs in these animals showed surprisingly large standard deviations, which were partially resulted in these animals showed surprisingly large standard deviations, which were partially resulted from convergence of neighboring waves during high stimulation intensities. Wave forms of MEPs were also varied greatly depending on the position of recording electordes. At low stimulus intensities, most consisten MEPs were obtained when the stimulating electrodes were placed on the hard palate and the temporal muscle, not on the motor cortex. This observation indicates that the primary source of MEPs is not the motor cortex in the rat. When the potentials generated by direct stimulation of motor cortex and those generated by reticular nuclei were monitored epidurally in the same preparation using the same electrodes, these potentials generated by different sources actually identical in their latencies and wave forms. However, the threshold stimulus intensities evoking these potentials were quite different in the two metholds. The threshold was much lower to evoke potentails by reticular nuclei stimulation. It suggests that MEPs are geneated by the reticular nuclei or brain structure located in the brain stem. The observation that the motor cortex play no major roles in generating MEPs was confirmed by sequential sections of neural axis from the motor cortex to brain stem in three rats. All these findings suggested that neither direct motor cortex stimulation not transcranial stimulation did evoke MEPs originating from the motor cortex in rat. These stimulating methods activate reticular nuclei by stimulus current spread to the brain stem. Since the reticular formation plays an important role in motor function in rats, MEP originated from reticular nucleus can be an important testing of the motor function in rats. Moreover, transcranial stimulation of the brain is technically easy. This technique producing MEPs originated from reticular nucleus can be useful to monitor the integrity of motor pathways.

The Intraspinal Pathways Conducting Motor Evoked Potentials in Rats

Recently, motor evoked potential(MEP) using cortical surface of transcranial stimulation have been used to monitor the integrity of motor pathways and map motor cortex in human and animal. The primary concept using motor evoked potentials(MEPs) for test of motor pathways was based on the assumtion that pyramidal neurons in the motor cortex are activated by electrical stimulation applied on the cerebral cortex and synchronized compound action potentials are conducted mainly along the corticospinal tracts in the spinal cord. However, the origins and the descending pathways of these MEPs in small animals may be different from those of potentials evoked by intracortical microstimulation because of current spread. Our previous study revealed that the origns of the MEPs in rats differed from those previously believed and may be reticular nuclei. To further clarify those results and localize the intraspinal pathways conduction MEPs, consecutive vertical and/or horizontal sections of the spinal cord were performed at T9 cord level in twelve rats. MEPs were recorded at T2/3 and L2/3 before and after each section and sequential alterations of MEPs were observed. In six rats, the stimulation was alternated between the right and left cortex and the lateralities of conduction pathways were compared. All six cases showed no differences of MEPs and pattern of wave abolition after each section between right and left brain stimulation. The alteration of MEPs after each consecutive section was categorized by analyzing latency shift, amplitude change, and disappearance of waves. We divided a cross section of T9 spinal cord into forty-six squares. If one of the categorized changes occurrd after cutting an area, the appropriate score was given for the area since more change of waves meant more significant contribution of the cut area to conduction of MEPs. The score of twelev rats were summed in each forty-six spots and map showing the distribution of MEPs was constructed. The map revealed that MEPs were conducted along the wide area of ventral and lateral funiculus of the spinal cord but mainly along the medial portion of the ventral funiculus of the spinal cord but mainly along the medial portion of the ventral funiculus and ventral portion of the larteral funiculus through which reticulospinal and vestibulospinal tracts pass. No conduction of MEPs along the corticospinal tracts was confirmed. This finding supports the result of our previous study. However, this extrapyramidal MEP conducted along ventral spinal cord in addition to somatosensory evoked potential(SSEP) which is conducted along posterior funiculus can be useful to monitor the integrity of the whole spinal cord. Moreover, the extrapyramidal MEP can be more useful than pyramidal MEP in rats because the reticular formation plays a more important role in motor function and pyramidal tract is located in posterior funiculus.

OBSERVATION ON THE ARTERIES OF THE HUMAN MEDULLA OBLONGATA / 解剖学报

The origin, distribution, anastomoses and variations of the arteries of medulla oblongata were observed on 110 Chinese adult brains. The internal arteries and their territories were observed on 20 brains by artereography and clearing method (Spalteholz's technic). The results were as follows: The arteries of medulla oblongata could be divided into four groups according to their distribution. The arteries of the anteromedian and anterolateral groups arose from the anterior spinal artery, and also from the vertebral artery and basilar artery. The arteries of the lateral group contained a series of small arterial rami, which arose from the vertebral artery, posterior inferior cerebellar artery, anterior inferior cerebellar artery and basilar artery. The arteries of the posterior group arose from the posterior spinal artery and posterior inferior cerebellar artery. The arteries of each group branched and penetrated into the medulla, they ramify into fine branches, and the capillary network was formed. The internal anteromedian arteries supplied the hypoglossal nucleus, medial lemniseus etc. The internal anterolateral arteries supplied chiefly pyramidal tract. The internal posterior arteries supplied the gracile and cuneate nuclei. The internal lateral arteries supplied the rest of the areas which include reticular formation, dorsal nucleus of the vagus nerve etc.. The arterial supply of the medullary lateral area and the endartery were discussed.