Athetosis-dystonia in intramedullary lesions of spinal cord

Athetosis and dystonia are well known clinical signs, described in disorders of basal ganglia. As opposed to pseudoathetosis, true athetosis was hitherto not reported in cord lesions. We here report three patients with athetosis and dystonia of hands due to intramedullary lesions of cervical cord: two patients with syringomyelia and one with glioma. Even though pseudoathetosis can be produced by lesions of posterior columns and likely to be confused with the involuntary movements of our patients, they had clinical and EMG findings consistent with true athetosis. A possible explanation for the athetosis and dystonia due to cord lesion is being postulated.     

Diagnostic imaging of spinal cord lesions

Magnetic resonance imaging (MRI) has greatly facilitated morphologic evaluation of spinal cord lesions. Eleven cases representative of inflammatory, demyelinating, neoplastic and vascular diseases, are presented which illustrate and summarize important abnormal features in spinal cord imaging, particularly MR findings. Recently, specialised techniques such as MR angiography, fat-inhibiting methods, dynamic MRI and functional imaging have been developed. These methods have facilitated not only lesion diagnosis but also qualitative assessment, and are being used to analyze pathophysiology. Comprehensive diagnoses based on such modalities may be important in determining indications for surgery or defining the extent of surgery or the intensity of other treatments.     

Intramedullary mass lesions of the spinal cord

Intramedullary tumors form 10% of all the spinal cord tumors. Majority of them are gliomas and rarely benign tumors are encountered. Twenty five cases of intramedullary mass lesions are studied regarding their clinical presentation, radiological features, surgical aspects and outcome following the surgery and radiotherapy. There were six benign lesions where the outcome was excellent. There were 11 patients with astrocytoma and 8 cases with ependymoma. In all, arrest of the disease or improvement could be achieved in 20 cases. Extent of surgical resection and role of radiotherapy, which are still controversial, are discussed.     

Cutaneous silent periods in intramedullary spinal cord lesions

OBJECTIVE: The neurophysiological assessment of intramedullary spinal cord lesions has been unsatisfactory. Previous studies in patients with syringomyelia suggest that testing of cutaneous silent periods (CSPs) may be useful to assess centromedullary lesions. METHODS: The authors studied nine patients with intramedullary spinal cord lesions of different etiologies. Eight patients with cervical lesions presented with hypalgesia, hypothermesthesia, or pain in at least one upper extremity; five of them had also upper limb weakness or sensory impairment. One patient with a thoracic lesion had normal upper limb function. The authors recorded CSPs in abductor pollicis brevis muscle following digit II and digit V stimulation. Somatosensory evoked potentials (SEPs) were obtained following median and tibial nerve stimulation. Motor evoked potentials (MEPs) were obtained in biceps brachii, abductor digiti minimi and tibialis anterior muscles following transcranial magnetic or electrical stimulation. RESULTS: CSP abnormalities were found in all patients with cervical lesions, but not in the patient with a thoracic lesion. Cortical median nerve SEPs had normal latencies in all patients, while tibial nerve SEPs, upper limb MEPs, and lower limb MEPs were delayed in five patients each. In one patient, abnormal CSP were the only neurophysiological finding. CSP abnormalities were associated with hypalgesia and hypothermesthesia in 95% of the studies. CONCLUSION: Upper extremity CSP testing is a sensitive neurophysiological technique for the assessment of cervical intramedullary lesions. In particular, abnormal CSPs are highly associated with spinothalamic dysfunction.     

Unusual spinal cord lesions in late-onset non-ketotic hyperglycinemia

Non-ketotic hyperglycinemia is a disorder of glycine metabolism with severe neurologic regression in the infantile stage, while late-onset non-ketotic hyperglycinemia is a rare form characterized by variable clinical, biochemical, and imaging features. This report describes a boy of late-onset non-ketotic hyperglycinemia presenting with an unusual long tract-like lesion of the spinal cord aside by magnetic resonance imaging. This is the first reported child of non-ketotic hyperglycinemia with abnormal imaging features of spinal cord.     

Delayed radiation lesions of the human spinal cord

Summary A report is given on patho-anatomical findings in five adult patients with cervical myelopathy following X-irradiation of hypopharyngeal cancer. The findings were largely consistent with those of earlier reports; however, telangiectases were found in all cases. The pathogenesis of the damage is briefly discussed in relation to experimental work on postirradiation lesions of the central nervous system. A vascular lesion is held to be the most important pathogenetic factor.

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Zusammenfassung Es wird über die pathologischen Befunde bei fünf Erwachsenen mit cervicaler Myelopathie nach Röntgenbestrahlung von Hypopharynx-Carcinomen berichtet. Die Befunde zeigten weitgehende Übereinstimmung mit jenen früherer Beobachtungen, doch wurden in allen Fällen Teleangiektasien angetroffen. Die Pathogenese der Röntgenspätschädigung des Rückenmarks wird unter Berücksichtigung experimenteller Befunde diskutiert. Eine Gefäßschädigung — vorwiegend durch Schädigung der Gefäßendothelzellen — wird als wichtigster pathogenetischer Faktor angenommen.

     

脊髓髓内病变的显微外科治疗

目的分析脊髓髓内占位性病变的手术特点,探讨手术时机、手术方式及预后。方法回顾性分析2002年7月-2008年4月经手术和病理证实的25例脊髓髓内占位性病变,随访患者术后神经功能状态。结果病变全切20例,次全切除3例,大部切除2例。术后病理证实室管膜瘤15例,星形细胞瘤2例,海绵状血管瘤2例,脂肪瘤2例,神经鞘瘤1例,血管畸形1例,结核瘤1例,炎性肉芽肿1例。术后神经功能好转20例,无变化3例,加重2例。结论对脊髓髓内病变应早期诊断,应在发生明显神经功能障碍之前实施手术。沿着确切的瘤一髓界面分离、切除病变,是肿瘤一级切除的基本保证,重建蛛网膜下腔能有效防止脊髓粘连;采用椎板成型解剖学复位技术可提高术后脊柱稳定性。     

Development of serotonin immunoreactivity in the rat spinal cord and its plasticity after neonatal spinal cord lesions

The postnatal maturation of spinal pathways may account for the gradual time course of postnatal development of behavior and also account for the greater anatomical reorganization which often follows damage to the developing CNS compared to the mature CNS. The purpose of the current study was to examine (1) the prenatal and postnatal development of the descending serotonergic (5-HT) projection to the spinal cord and (2) the effects of a neonatal spinal cord lesion on this development. In addition, we wished to determine (3) whether transplants of fetal spinal cord tissue placed into the neonatal lesion site alter the plasticity of the 5-HT projection to the cord. Peroxidase-antiperoxidase immunocytochemical techniques were used. At embryonic day 14 (E14), no 5-HT immunoreactive fibers could be identified at any spinal cord level. By E18 the first axons were identified in the white matter only at all spinal cord levels. At birth, 5-HT immunoreactive fibers were present both in the white matter and in the gray matter at all cord levels. The projection within the gray matter was diffuse and considerably less dense than in the adult. The postnatal maturation of the 5-HT projection within the gray matter of the spinal cord followed rostral to caudal and ventral to dorsal gradients. During the first weeks postnatal, the 5-HT immunoreactivity within the cord increased to attain an adult pattern and density by 14 days in the cervical cord and 21 days in the thoracic and lumbar cord. The effect of a spinal cord hemisection at birth on the anatomical reorganization of the descending serotonergic innervation of the cord was compared with the effect of the same lesion in the adult. In the adult animal, mid-thoracic hemisection decreased the 5-HT content of the ventral horn of the lumbar spinal cord caudal and ipsilateral to the lesion to 8% of that on the intact side. When this same lesion was made in the newborn animal, the innervation was 43% of that on the intact side. When a transplant of fetal spinal cord tissue was inserted into the lesion site in the newborn animals, there was even greater 5-HT innervation caudal to the lesion, 83% of that on the intact side. These results indicate that there is considerable postnatal development and plasticity of the descending serotonergic projection to the spinal cord, and this plasticity is enhanced by the presence of a spinal cord transplant at the site of the lesion.     

Value of studying spinal evoked potentials in patients with thoracolumbar spinal cord lesions

31 control subjects and 14 patients with dorso-lumbar spinal cord lesions were studied using the spEP (spinal evoked response). The presented responses were recorded by subcutaneous needle electrodes following stimulation of the peroneal nerve. Results from control subjects are presented first (triphasic negative potential, latency increasing with level of recording). The 14 patients were grouped according to their clinical symptoms. The prognostic value of the spEP response was considered. Results were as follow: flaccid paraplegia with no motor response to stimulation: no spEP was recorded; complete anatomoclinical paraplegia: the spEP was normal caudal to the lesion and negative rostral to the lesion; complete paraplegia with minor anatomical lesions: prognosis was good when spEP rostral to the lesion was recorded and poor when no response was detected; motor paraplegia: the spEPs rostral and caudal to the lesion were normal. In all cases, the levels of the lesions were in accordance with the upper level at which changes in spEPs were observed.     

Embryonic radial glia bridge spinal cord lesions and promote functional recovery following spinal cord injury

Radial glial cells are neural stem cells (NSC) that are transiently found in the developing CNS. To study radial glia, we isolated clones following immortalization of E13.5 GFP rat neurospheres with v-myc. Clone RG3.6 exhibits polarized morphology and expresses the radial glial markers nestin and brain lipid binding protein. Both NSC and RG3.6 cells migrated extensively in the adult spinal cord. However, RG3.6 cells differentiated into astroglia slower than NSC, suggesting that immortalization can delay differentiation of radial glia. Following spinal cord contusion, implanted RG3.6 cells migrated widely in the contusion site and into spared white matter where they exhibited a highly polarized morphology. When injected immediately after injury, RG3.6 cells formed cellular bridges surrounding spinal cord lesion sites and extending into spared white matter regions in contrast to GFP fibroblasts that remained in the lesion site. Behavioral analysis indicated higher BBB scores in rats injected with RG3.6 cells than rats injected with fibroblasts or medium as early as 1 week after injury. Spinal cords transplanted with RG3.6 cells or dermal fibroblasts exhibited little accumulation of chondroitin sulfate proteoglycans (CSPG) including NG2 proteoglycans that are known to inhibit axonal growth. Reduced levels of CSPG were accompanied by little accumulation in the injury site of activated macrophages, which are a major source of CSPG. However, increased staining and organization of neurofilaments were found in injured rats transplanted with RG3.6 cells suggesting neuroprotection or regrowth. The combined results indicate that acutely transplanted radial glia can migrate to form bridges across spinal cord lesions in vivo and promote functional recovery following spinal cord injury by protecting against macrophages and secondary damage.     

Recovery of locomotion in the cat following spinal cord lesions

In most species, locomotor function beneath the level of a spinal cord lesion can be restored even if the cord is completely transected. This suggests that there is, within the spinal cord, an autonomous network of neurons capable of generating a locomotor pattern independently of supraspinal inputs. Recent studies suggest that several physiological and neurochemical changes have to occur in the neuronal networks located caudally to the lesion to allow the expression of spinal locomotion. Some evidence of this plasticity will be addressed in this review. In addition, original data on the functional organisation of the lumbar spinal cord will also be presented. Recent works in our lab show that segmental responsiveness of the spinal cord of the cat to locally micro-injected drugs in different lumbar segments, in combination with complete lesions at various level of the spinal cord, suggest a rostro-caudal organisation of spinal locomotor control. Moreover, the integrity of midlumbar segments seems to be crucial for the expression of spinal locomotion. These data suggest that the regions of critical importance for locomotion can be confined to a restricted portion of the spinal cord. Later, these midlumbar segments could be targeted by electrical stimulation or grafts to improve recovery of function. Understanding the changes in spinal cord neurophysiology and neurochemistry after a lesion is of critical importance to the improvement of treatments for locomotor rehabilitation in spinal-cord-injured patients.