Feasibility of using fNIRS to explore motor-related regional haemodynamic signal changes in patients with sensorimotor impairment and healthy controls: A pilot study.

BACKGROUND: While functional near-infrared spectroscopy (fNIRS) can provide insight into cortical brain activity during motor tasks in healthy and diseased populations, the feasibility of using fNIRS to assess haemoglobin-evoked responses to reanimated upper limb motor function in patients with tetraplegia remains unknown. OBJECTIVE: The primary objective of this pilot study is to determine the feasibility of using fNIRS to assess cortical signal intensity changes during upper limb motor tasks in individuals with surgically restored grip functions. The secondary objectives are: 1) to collect pilot data on individuals with tetraplegia to determine any trends in the cortical signal intensity changes as measured by fNIRS and 2) to compare cortical signal intensity changes in affected individuals versus age-appropriate healthy volunteers. Specifically, patients presented with tetraplegia, a type of paralysis resulting from a cervical spinal cord injury causing loss of movement and sensation in both lower and upper limbs. All patients have their grip functions restored by surgical tendon transfer, a procedure which constitutes a unique, focused stimulus for brain plasticity. METHOD: fNIRS is used to assess changes in cortical signal intensity during the performance of two motor tasks (isometric elbow and thumb flexion). Six individuals with tetraplegia and six healthy controls participate in the study. A block paradigm is utilized to assess contralateral and ipsilateral haemodynamic responses in the premotor cortex (PMC) and primary motor cortex (M1). We assess the amplitude of the optical signal and spatial features during the paradigms. The accuracy of channel locations is maximized through 3D digitizations of channel locations and co-registering these locations to template atlas brains. A general linear model approach, with short-separation regression, is used to extract haemodynamic response functions at the individual and group levels. RESULTS: Peak oxyhaemoglobin (oxy-Hb) changes in PMC appear to be particularly bilateral in nature in the tetraplegia group during both pinch and elbow trials whereas for controls, a bilateral PMC response is not especially evident. In M1 / primary sensory cortex (S1), the oxy-Hb responses to the pinch task are mainly contralateral in both groups, while for the elbow flexion task, lateralization is not particularly clear. CONCLUSIONS: This pilot study shows that the experimental setup is feasible for assessing brain activation using fNIRS during volitional upper limb motor tasks in individuals with surgically restored grip functions. Cortical signal changes in brain regions associated with upper extremity sensorimotor processing appear to be larger and more bilateral in nature in the tetraplegia group than in the control group. The bilateral hemispheric response in the tetraplegia group may reflect a signature of adaptive brain plasticity mechanisms. Larger studies than this one are needed to confirm these findings and draw reliable conclusions.

'White Cord Syndrome': A Rare Catastrophic Complication Following Anterior Cervical Discectomy and Fusion.

Background: 'White-cord syndrome' is an extremely rare entity following decompression of cervical cord in which post-operative reperfusion injury results in worsening of patient's neurology and MRI reveals signal changes in spinal cord in absence of cord compression. We wish to report a case of 'white-cord syndrome' following a 'routine' ACDF. Case Description: A 39-year-old woman with paresthesias and spastic quadriparesis was found to have C5-C6 PIVD on MRI. ACDF was performed at C5-C6, after which worsening of quadriparesis was noted, for which intravenous high-dose steroids were started. An urgent MRI was done, which revealed findings of white-cord syndrome, without compression on underlying cord. With conservative management, her ASIA grade improved from C to D and the features of white-cord syndrome disappeared on follow-up imaging. Conclusion: It is important for surgeons and patients to be aware of this rare but potentially catastrophic entity as this needs to be discussed while taking consent for surgery.

Case series on the Charcot neuroarthropathy in hands after cervical central cord syndrome.

BACKGROUND: Charcot neuroarthropathy (CNA) of the upper extremity occurs most frequently in shoulders. However, CNA in the hands is uncommon and seldom be reported. The onset of CNA is usually insidious. If this process continues undetected, it can result in joint deformity, ulceration and/or superinfection, loss of function, and amputation or even death. In this article, we are going to present three cases of CNA in the hands of individuals with cervical spinal cord injury (SCI) with central cord syndrome. CASE PRESENTATION: Three male individuals with cervical spinal stenosis contracted tetraplegia (American Spinal Injury Association Impairment Scale Grade D, D, and B) due to spinal cord contusion after a trauma and developed hand swelling without pain 2 to 3 months after their SCI. X-ray showed degenerative joint changes in the hands. CNA was considered due to the patient's history of cervical SCI, loss of motor function and sensation, symptoms of painless swelling, physical examination, and X-ray findings. The self-care sub scores of Spinal Cord Independence Measure III improved slightly only during rehabilitation and follow-up due to poor hand function. CONCLUSIONS: CNA may develop after a central or peripheral neurological disorder. Nearly every joint of the body can be affected and the lower limbs are the most frequently involved. However, CNA of the hand is rare. We present three patients with CNA in the hands after cervical SCI and review the features and early differential diagnosis of CNA. Currently there is no specific treatment available. Therefore, early identification of CNA and adequate protection to the affected joints seem important.

Rare case of real-time observation of paralytic deterioration after cervical dislocation in the hyperacute phase.

BACKGROUND: There have been no prior reports of real-time detailed records leading to complete quadriplegia immediately after fracture dislocation in high-energy trauma. Here, we report a case of cervical dislocation in which the deterioration to complete motor paralysis (modified Frankel B1) and complete recovery (Frankel E) could be monitored in real time after reduction in the hyperacute phase. CASE PRESENTATION: A 65-year-old man was involved in a car accident and sustained a dislocation at the C5/6 level (Allen-Ferguson classification: distractive flexion injury stage IV). His paralysis gradually deteriorated from Frankel D to C 2 hours after the injury and from Frankl C to B 5 hours after the injury. His final neurological status immediately before reduction was Frankel B1 (complete motor paralysis with sensation only in the perianal region). Reduction was completed within 6 h and 5 min after injury, and spinal fusion was subsequently performed. The patient exhibited rapid motor recovery immediately after surgery, and was able to walk independently on postoperative day 14. CONCLUSIONS: This case suggests that there is a mixture of cases in which the spinal cord has not been catastrophically damaged, even if the patient has complete motor paralysis. Prompt reduction has the potential to improve neurological function in such cases.

Functional magnetic resonance imaging of brain activity during hybrid assistive limb intervention in a chronic spinal cord injury patient with C4 quadriplegia.

Hybrid assistive limb (HAL) is a wearable robot, which has recently been used for the treatment of patients with movement disorders including spinal cord injury (SCI). Although several studies have indicated the effectiveness of HAL for SCI patients, changes in brain activity during the HAL intervention have not yet been fully characterized. A 19-year-old man with a chronic SCI resulting in complete C4 quadriplegia underwent five weeks of HAL training for a total of ten sessions. We evaluated his brain activity using task-induced functional MRI (fMRI) after the fourth, sixth and tenth HAL sessions. We also assessed the spasticity of this patient using the modified Ashworth scale (mAs). As controls for the task-induced fMRI, we examined the brain activity in two healthy subjects. The fMRI findings indicated an increased response to a motor imagery task in the patient's cerebral cortex compared to controls. In addition, the activation pattern in his cortex changed during the five weeks of HAL intervention. We observed increased cerebral lateralization in his primary motor cortex. We also found that the laterality index calculated for the precentral gyrus had a significant negative correlation with the total mAs score over the course of the HAL treatment. Our results indicate that the cerebral cortex of the present SCI patient was hyperactive during the imagery task, and the cortical activation was reduced with progression of the HAL treatment.

Electrical stimulation alters muscle morphological properties in denervated upper limb muscles.

BACKGROUND: Damage to lower motor neuron causes denervation and degeneration of the muscles affected. Experimental and clinical studies of muscle denervation in lower extremities demonstrated that direct electrical stimulation (ES) of muscle can prevent denervation atrophy and restore contractility. The aim of this study was to identify possible myogenic effect of ES on denervated forearm and hand muscles in persons with spinal cord injury (SCI) and tetraplegia. METHODS: This prospective interventional study with repeated measurement design included 22 patients aged 48·6 (± 15·7), 0·25 (0·1/46) years after spinal cord lesion, AIS A-D. In each patient, two electrophysiologically-confirmed denervated muscles in the hand and forearm were analyzed - one extrinsic (Extensor Carpi Ulnaris - ECU) and one intrinsic (1st Dorsal Interosseus - IOD1). Muscles were stimulated for 33 min, five times per week over a 12-weeks period. Using ultrasonography (USG), muscle thickness (MT) and pennation angle (PA) of these muscles were determined at start and end of the stimulation period. FINDINGS: MT of IOD1 increased from 6·3 mm (± 3·2 mm) to 9·2 mm (± 2·4 mm) (p = 0·004) and the PA from 5·5° (± 3·0°) to 11° (± 2·2°) (p = 0·001). The corresponding values for the ECU were 5·5 mm (± 2·5 mm) to 7·0 mm (± 2·2 mm) (p = 0·039) and 5·5° (± 3·4°) to 9·4° (± 3·8°) (p = 0·005), respectively. The correlation of MT between baseline and completion was r = 0·58 (p = 0·037) for the ECU and r = 0·63 (p = 0·008) for the IOD1. INTERPRETATION: 12 weeks of direct muscle stimulation increases the MT and PA of the denervated intrinsic and extrinsic hand muscles studied. FUNDING: Swiss Paraplegic Centre, Switzerland.

Beware the Wandering Needle: Inadvertent Intramedullary Injection During an Attempted Cervical Medial Branch Block.

A 27-year-old man developed sudden neck pain, severe quadriparesis, and right shoulder allodynia during an outpatient cervical medial branch block procedure. Cervical spine imaging revealed evidence of an interlaminar needle trajectory with abnormal signal in the right hemicord at the level of C4, consistent with intramedullary injection and contusion. Following a 48-hour stay in the intensive care unit, during which hemodynamic vasopressor support was administered to optimize spinal cord perfusion, the patient exhibited almost complete neurologic recovery with resolution of the neuropathic pain. He was eventually discharged home and underwent outpatient physical therapy for a mild residual right hemiparesis.

Comprehensive genotype-phenotype correlation in AP-4 deficiency syndrome; Adding data from a large cohort of Iranian patients.

Mutations in adaptor protein complex-4 (AP-4) genes have first been identified in 2009, causing a phenotype termed as AP-4 deficiency syndrome. Since then several patients with overlapping phenotypes, comprised of intellectual disability (ID) and spastic tetraplegia have been reported. To delineate the genotype-phenotype correlation of the AP-4 deficiency syndrome, we add the data from 30 affected individuals from 12 out of 640 Iranian families with ID in whom we detected disease-causing variants in AP-4 complex subunits, using next-generation sequencing. Furthermore, by comparing genotype-phenotype findings of those affected individuals with previously reported patients, we further refine the genotype-phenotype correlation in this syndrome. The most frequent reported clinical findings in the 101 cases consist of ID and/or global developmental delay (97%), speech disorders (92.1%), inability to walk (90.1%), spasticity (77.2%), and microcephaly (75.2%). Spastic tetraplegia has been reported in 72.3% of the investigated patients. The major brain imaging findings are abnormal corpus callosum morphology (63.4%) followed by ventriculomegaly (44.5%). Our result might suggest the AP-4 deficiency syndrome as a major differential diagnostic for unknown hereditary neurodegenerative disorders.

Delayed quadriparesis after posterior spinal fusion for scoliosis: a case series.

STUDY DESIGN: A multicenter retrospective IRB exempt case series analyzing clinical and radiographical data of patients treated by three surgeons over the past two decades was conducted. OBJECTIVE: To examine the factors involved in the development of quadriparesis in patients who underwent posterior spinal fusion for scoliosis. Delayed spinal cord infarcts usually present at the region of instrumentation according to reports from the Scoliosis Research Society. Nonetheless, there is a lack of data regarding factors associated with delayed quadriparesis following posterior spinal fusion METHODS: Evaluated variables were age, Cobb angle, blood loss, and curve correction percentage. Postoperative imaging was also evaluated to determine factors indicative of the etiology of the quadriparesis. RESULTS: Eight patients presented delayed postoperative quadriparesis. All patients had a postoperative examination equal to that of baseline. The first patient deteriorated at 6 h postoperatively and the most delayed patient presented 4 days postoperatively. Six patients had neuromuscular disorders and 2 had adolescent idiopathic scoliosis. Mean age was 13.7, mean curve magnitude was 78.7°, mean percent curve correction was 71% and the mean estimated blood loss was 1185 cc. Seven of eight patients had documented peri- or postoperative hypotension. CONCLUSIONS: Cervical infarction is the likely cause of delayed quadriparesis after posterior spinal fusion. Even though the underlying etiology continues to be unclear, postoperative hypotension, curve magnitude, percent curve correction, and the presence of cervical kyphosis/stenosis may be contributory and need to be closely evaluated. LEVEL OF EVIDENCE: IV, Case Series.

Spinal cord injury in infancy: activity-based therapy impact on health, function, and quality of life in chronic injury.

INTRODUCTION: Spinal cord injury (SCI) in infancy magnifies the complexity of a devastating diagnosis. Children injured so young have high incidences of scoliosis, hip dysplasia, and respiratory complications leading to poor health and outcomes. We report the medical history, progression of rehabilitation, usual care and activity-based therapy, and outcomes for a child injured in infancy. Activity-based therapy (ABT) aims to activate the neuromuscular system above and below the lesion through daily, task-specific training to improve the neuromuscular capacity, and outcomes for children with acquired SCI. CASE PRESENTATION: A 3-month-old infant suffered a cervical SCI from a surgical complication with resultant tetraplegia. Until age 3, her medical complications included scoliosis, kyphosis, and pneumonia. Even with extensive physical and occupational therapy, she was fully dependent on caregivers for mobility and unable to roll, come to sit, sit, stand or walk. She initiated ABT at ~3 years old, participating for 8 months. The child's overall neuromuscular capacity improved significantly, especially for head and trunk control, contributing to major advances in respiratory health, novel engagement with her environment, and improved physical abilities. DISCUSSION: From injury during infancy until 3 years old, this child's health, abilities, and complications were consistent with the predicted path of early-onset SCI. Due to her age at injury, severity and chronicity of injury, she demonstrated unexpected, meaningful changes in her neuromuscular capacity during and post-ABT associated with improved health, function and quality of life for herself and her caregivers.

[Untreated os odontoideum may cause tetraplegia].

This review summarises the present, limited, knowledge of os odontoideum (OO). The prevalence is unknown, and the aetiology is widely debated, though irrelevant to management of the disease. Surgery of symptomatic patients is advocated, as there is more uncertainty about the treatment of asymptomatic patients. Diagnosis is obtained with plain X-ray. However, nowadays MRI and CT scanning are recommended for further clarification and judgement of the severity. Knowledge of OO is important to minimise misjudgement and consequently inappropriate treatment. It is recommended, that patients are examined by highly specialised spine doctors before further cervical manipulation due to the high risk of instability with potentially severe consequences.

Cortical and Subcortical Effects of Transcutaneous Spinal Cord Stimulation in Humans with Tetraplegia.

An increasing number of studies supports the view that transcutaneous electrical stimulation of the spinal cord (TESS) promotes functional recovery in humans with spinal cord injury (SCI). However, the neural mechanisms contributing to these effects remain poorly understood. Here we examined motor-evoked potentials in arm muscles elicited by cortical and subcortical stimulation of corticospinal axons before and after 20 min of TESS (30 Hz pulses with a 5 kHz carrier frequency) and sham-TESS applied between C5 and C6 spinous processes in males and females with and without chronic incomplete cervical SCI. The amplitude of subcortical, but not cortical, motor-evoked potentials increased in proximal and distal arm muscles for 75 min after TESS, but not sham-TESS, in control subjects and SCI participants, suggesting a subcortical origin for these effects. Intracortical inhibition, elicited by paired stimuli, increased after TESS in both groups. When TESS was applied without the 5 kHz carrier frequency both subcortical and cortical motor-evoked potentials were facilitated without changing intracortical inhibition, suggesting that the 5 kHz carrier frequency contributed to the cortical inhibitory effects. Hand and arm function improved largely when TESS was used with, compared with without, the 5 kHz carrier frequency. These novel observations demonstrate that TESS influences cortical and spinal networks, having an excitatory effect at the spinal level and an inhibitory effect at the cortical level. We hypothesized that these parallel effects contribute to further the recovery of limb function following SCI.SIGNIFICANCE STATEMENT Accumulating evidence supports the view that transcutaneous electrical stimulation of the spinal cord (TESS) promotes recovery of function in humans with spinal cord injury (SCI). Here, we show that a single session of TESS over the cervical spinal cord in individuals with incomplete chronic cervical SCI influenced in parallel the excitability cortical and spinal networks, having an excitatory effect at the spinal level and an inhibitory effect at the cortical level. Importantly, these parallel physiological effects had an impact on the magnitude of improvements in voluntary motor output.

Spinal Epidural Hematoma Associated with Epidural Metastasis After Minor Trauma.

BACKGROUND: Spinal epidural hematoma associated with epidural metastasis is very rare. Epidural hematoma is unusual in itself, and metastatic epidural tumors do not commonly occur. CASE DESCRIPTION: A 76-year-old man with a medical history of untreated stage III rectal cancer and chronic obstructive pulmonary disease underwent emergency spine surgery for acute development of severe quadriplegia due to cervical epidural hematoma after minor indirect trauma. Hemorrhagic lesions, such as yellow ligaments, were accompanied by hematomas that adhered to the dura mater and were confirmed on pathology to be small cell carcinoma. Some nodules were detected in the right pulmonary hilar lesion and pleural lesion on computed tomography, and stage IV small cell carcinoma was diagnosed. CONCLUSIONS: To our knowledge, spinal epidural hematoma accompanied by epidural metastasis has not previously been reported. We hypothesized that tissue invasion of malignant neoplasms may cause hemorrhagic conditions. The presence of a tumor should therefore be considered in the differential diagnosis of cases of epidural hematoma.

Severe Spinal Cord Compression by Anomalous Vertebral Arteries Treated with Gore-Tex Tape Transposition Technique.

Rare anomalous courses of vertebral arteries in the craniovertebral junction may compress the spinal cord causing myelopathy. We report here the severest form of this pathologic condition successfully treated with transposition of bilateral vertebral artery using Gore-Tex tapes. A 73-year-old man presented with progressive tetraparesis and gait disturbance. Imaging studies showed bilateral atresia of the C1 transverse foramina and the both vertebral arteries penetrating the dura below the C1 lamina. Pinched by the vertebral artery loops on both sides, the spinal cord was severely deformed. Through the standard midline approach, we carefully transposed both vertebral arteries off the spinal cord, placing them at the optimal position using Tanaka et al's Gore-Tex tape technique originally reported for microvascular decompression. The Gore-Tex tape transposition technique proved to be versatile and useful for safe transposition of the vertebral artery in this challenging case.

Bilateral Accessory C1 and C2 Facet Joints; Clinical, Neuroradiological and Peroperative Findings in an Adult with Quadriparesis

Objectives Accessory C1 and C2 facet joints are very rare. Only few cases were reported in the literature.We report a case of bilateral accessory facets in an adult with special attention to clinical, neuroradiological, as well as peroperative findings. Case report A 37-year-old male presented with progressive quadriparesis. Radiology revealed bilateral posterior accessory C1 and C2 facet joints compressing the spinal cord with craniovertebral junction (CVJ) instability. Both accessory C1 and C2 facets with the posterior arch of the C1 were removed. Lateral mass screws and plates fixation at the C1 and C2 level, as well as fusion, were performed. Postoperatively, the patient recovered well. Conclusion In accessory C1 and C2 facet joints, when symptomatic, neuroradiological findings can guide to the proper diagnosis, to pathological understanding, and, ultimately, to management strategy.

Iatrogenic spinal cord injury with tetraplegia after an elective non-spine surgery with underlying undiagnosed cervical spondylotic myelopathy: Literature review and case report.

Cervical spondylotic myelopathy (CSM) can predispose to acute spinal cord injury and post-operative quadriparesis during non-spine procedures, although few accounts of this phenomenon exist within the literature. To the best of our knowledge, there are only 18 cases reported in the literature including ours with spinal cord injury following elective non-spine surgery with undiagnosed CSM. Due to multifactorial pathophysiology, the maintenance of cervical cord neutrality is not sufficient to ensure that these patients will not sustain cord injury intraoperatively as this solely addresses the role of static factors. Vigilance to factors affecting cord perfusion and vascular compromise, such as the mean arterial pressure (MAP), is imperative. Additionally, further studies should evaluate the role of positioning in the myelopathic patient and whether the steep Trendelenburg position, commonly used in robotic surgeries, contributes to spinal cord venous congestion and resultant cord ischemia in these patients given their baseline stenotic canal. This review illustrates the importance of having a heightened awareness of this common degenerative condition in our aging patient population, often a forgotten underlying medical comorbidity.

An exoskeleton controlled by an epidural wireless brain-machine interface in a tetraplegic patient: a proof-of-concept demonstration.

BACKGROUND: Approximately 20% of traumatic cervical spinal cord injuries result in tetraplegia. Neuroprosthetics are being developed to manage this condition and thus improve the lives of patients. We aimed to test the feasibility of a semi-invasive technique that uses brain signals to drive an exoskeleton. METHODS: We recruited two participants at Clinatec research centre, associated with Grenoble University Hospital, Grenoble, France, into our ongoing clinical trial. Inclusion criteria were age 18-45 years, stability of neurological deficits, a need for additional mobility expressed by the patient, ambulatory or hospitalised monitoring, registration in the French social security system, and signed informed consent. The exclusion criteria were previous brain surgery, anticoagulant treatments, neuropsychological sequelae, depression, substance dependence or misuse, and contraindications to magnetoencephalography (MEG), EEG, or MRI. One participant was excluded because of a technical problem with the implants. The remaining participant was a 28-year-old man, who had tetraplegia following a C4-C5 spinal cord injury. Two bilateral wireless epidural recorders, each with 64 electrodes, were implanted over the upper limb sensorimotor areas of the brain. Epidural electrocorticographic (ECoG) signals were processed online by an adaptive decoding algorithm to send commands to effectors (virtual avatar or exoskeleton). Throughout the 24 months of the study, the patient did various mental tasks to progressively increase the number of degrees of freedom. FINDINGS: Between June 12, 2017, and July 21, 2019, the patient cortically controlled a programme that simulated walking and made bimanual, multi-joint, upper-limb movements with eight degrees of freedom during various reach-and-touch tasks and wrist rotations, using a virtual avatar at home (64·0% [SD 5·1] success) or an exoskeleton in the laboratory (70·9% [11·6] success). Compared with microelectrodes, epidural ECoG is semi-invasive and has similar efficiency. The decoding models were reusable for up to approximately 7 weeks without recalibration. INTERPRETATION: These results showed long-term (24-month) activation of a four-limb neuroprosthetic exoskeleton by a complete brain-machine interface system using continuous, online epidural ECoG to decode brain activity in a tetraplegic patient. Up to eight degrees of freedom could be simultaneously controlled using a unique model, which was reusable without recalibration for up to about 7 weeks. FUNDING: French Atomic Energy Commission, French Ministry of Health, Edmond J Safra Philanthropic Foundation, Fondation Motrice, Fondation Nanosciences, Institut Carnot, Fonds de Dotation Clinatec.

Cervical epidural hematoma after spinal manipulation therapy: a case report.

BACKGROUND: Cervical spinal manipulation therapy is a common non-invasive treatment for neck pain and stiffness, and has been widely used in the population. However, most people do not pay attention to the potential risks of neck manipulation, such as ligament damage, fractures, and spinal cord injuries. Epidural hematoma is a disease in which blood accumulates in the epidural space of the vertebral body. This disease is usually caused by trauma or iatrogenic surgery, and may be associated with blood coagulopathies, neoplasms, or degenerative spinal disease. Reports of epidural hematoma caused by cervical spinal manipulation are rare. CASE PRESENTATION: We present the case of a patient with tetraplegia and spinal shock after neck manipulation. A physical examination of the patient on admission found tenderness in the neck and increased muscle tension in both upper limbs. The superficial sensation of the upper limb disappeared, but the deep sensation still remained. The lower extremity had 0/5 power on both sides. The sensation below the T2 level completely disappeared. A cervical magnetic resonance imaging scan showed an acute posterior epidural hematoma from the C3-T3 vertebrae. Ultimately, the patient underwent emergency hematoma removal and showed partial improvement in symptoms of paralysis during follow-up. CONCLUSIONS: Although spinal manipulation is simple and neck pain is common and recurrent in the general population, the basic condition and disease history of patients should be determined before manipulation. For high-risk patients, caution should be applied for cervical spinal manipulation or it should be prohibited. For a suspected hematoma, MRI should be used at an early stage to diagnose and locate the hematoma.