Carolina Kachramanoglou

Low myo-inositol indicating astrocytic damage in a case series of neuromyelitis optica.

Astrocytic necrosis is a prominent pathological feature of neuromyelitis optica (NMO) lesions and is clinically relevant. We report 5 NMO‐related cases, all with longitudinally extensive lesions in the upper cervical cord, who underwent cervical cord 1H‐magnetic resonance spectroscopy. Lower myo‐inositol/creatine values, suggesting astrocytic damage, were consistently found within the NMO lesions when compared with healthy controls and patients with multiple sclerosis (MS), who showed at least 1 demyelinating lesion at the same cord level. Therefore, the in vivo quantification of myo‐inositol may distinguish NMO from MS. This is an important step toward developing imaging markers for clinical trials in NMO. Ann Neurol 2013;74:301–305

Novel strategies in brachial plexus repair after traumatic avulsion

Clinical trials in spinal cord injury (SCI) can be affected by many confounding variables including spontaneous recovery, variation in the lesion type and extend. However, the clinical need and the paucity of effective therapies has spawned a large number of animal studies and clinical trials for SCI. In this review, we suggest that brachial plexus avulsion injury, a longitudinal spinal cord lesion, is a simpler model to test methods of spinal cord repair. We explore reconstructive techniques currently explored for the repair of brachial plexus avulsion and focus on the use of olfactory ensheathing cell transplantation as an adjunct treatment in brachial plexus repair.

Metabolic Changes in the Spinal Cord After Brachial Plexus Root Re-implantation

Objective. To investigate metabolic changes within the spinal cord using proton magnetic resonance spectroscopy (1H-MRS) and determine their relationship with clinical function in patients with complete brachial plexus avulsion who underwent reimplantation of the ventral roots. Methods. Single-voxel 1H-MRS of the cord between C1 and C3 was performed in 10 patients with normal spinal cord on MRI, who underwent reimplantation of C5 to T1 ventral roots on average 5.5 years earlier, and 19 healthy controls. The ratios of the concentrations of the following main metabolites, with respect to total creatine levels, were obtained: total N-acetyl-aspartate, choline-containing compounds, creatine and phosphocreatine (Cr), and myo-inositol (m-Ins). Patient disability was assessed using upper limb scales. Differences in metabolite concentration ratios and their correlations with disability were investigated. Results. Patients showed increased m-Ins/Cr ratio compared with controls, which was associated with the level of function of the affected arm and time from injury. Conclusions. The finding of increased m-Ins/Cr in patients suggests that reactive gliosis, perhaps in response to the degeneration of avulsed fibers, may occur in the spinal cord above the site of injury and be relevant to motor dysfunction. However, this pathological process appears to diminish with time. These insights underline the need to integrate metabolic imaging with structural and functional magnetic resonance imaging to obtain a complete view of spinal cord plasticity. Last, this study provides the first steps toward identifying markers to serve as outcome measures for trials comparing strategies of plexus repair following avulsion injury.

Tissue- and column-specific measurements from multi-parameter mapping of the human cervical spinal cord at 3 T

The aim of this study was to quantify a range of MR parameters [apparent proton density, longitudinal relaxation time T1, magnetisation transfer (MT) ratio, MT saturation (which represents the additional percentage MT saturation of the longitudinal magnetisation caused by a single MT pulse) and apparent transverse relaxation rate R2*] in the white matter columns and grey matter of the healthy cervical spinal cord. The cervical cords of 13 healthy volunteers were scanned at 3 T using a protocol optimised for multi‐parameter mapping. Intra‐subject co‐registration was performed using linear registration, and tissue‐ and column‐specific parameter values were calculated. Cervical cord parameter values measured from levels C1–C5 in 13 subjects are: apparent proton density, 4822 ± 718 a.u.; MT ratio, 40.4 ± 1.53 p.u.; MT saturation, 1.40 ± 0.12 p.u.; T1 = 1848 ± 143 ms; R2* = 22.6 ± 1.53 s–1. Inter‐subject coefficients of variation were low in both the cervical cord and tissue‐ and column‐specific measurements, illustrating the potential of this method for the investigation of changes in these parameters caused by pathology. In summary, an optimised cervical cord multi‐parameter mapping protocol was developed, enabling tissue‐ and column‐specific measurements to be made. This technique has the potential to provide insight into the pathological processes occurring in the cervical cord affected by neurological disorders.

Culture of Olfactory Ensheathing Cells for Central Nerve Repair: The Limitations and Potential of Endoscopic Olfactory Mucosal Biopsy

BACKGROUND Autotransplantation of olfactory ensheathing cells (OECs) into the damaged central nervous system is a potential therapeutic strategy for spinal cord and root cord injuries. One limiting factor has been the poor OEC yields from human mucosal biopsies. Previous studies have only commented on their success in obtaining mucosal specimens containing olfactory mucosa, but have not commented on the yield of OECs from those specimens. OBJECTIVE To describe a reproducible and safe surgical technique for obtaining human olfactory mucosa and identify patient factors that possibly affect the yield of OEC cultures from the human olfactory mucosa. METHODS We obtained mucosal biopsies from 43 consecutive patients by using a novel reproducible surgical technique and our laboratory culture protocol. The Spearman rank correlation coefficient was used to assess the relationship between OECs and fibroblast yield with patient characteristics and specimen factors. RESULTS A greater yield of OECs was obtained from patients of younger age. In addition, patients with worse mucosal disease yielded poorer cell cultures. Greatest yields were found in patients with absence of mucosal disease. Furthermore, a higher yield of OECs was obtained from specimens harvested from the more caudal portions of the superior turbinate, and OEC yield did not correlate with the ventroposterior location of the biopsy. CONCLUSION We have provided evidence that biopsies closer to the cribriform plate can produce larger yields of OECs, and that patient factors like age and mucosal disease adversely affect the culture yield.

Anatomy and Cellular Constituents of the Human Olfactory Mucosa: A Review

Studies using animal models have recently suggested that the olfactory mucosa may be a source of cells capable of stimulating and contributing to complex neurologic regeneration. Several groups have already transplanted cell derivatives from the olfactory mucosa into injury models, and the results so far have been promising. To fully appreciate the meaning of these experiments, a better understanding of the cellular biology and physiology of the olfactory system is necessary. It is therefore of utmost importance for us to first identify and understand its constituents.

Rosai-Dorfman disease presenting as a thoracic intradural extramedullary spinal tumor but without extraspinal manifestations

Dear editor, Rosai-Dorfman disease (RDD), also known as sinus histiocytosis with massive lymphadenopathy, was first reported by Destombes in 1965 as adenitis with lipid excess. Four years later, it was more fully described by Rosai and Dorfman. It is traditionally characterized by massive lymphadenopathy, lymphocytosis, constitutional symptoms, and varying organ system involvement [1], including the skin, paranasal sinuses, soft tissues, bone, salivary glands, oral cavity, kidney, lower respiratory tract, larynx, and very rarely other locations. Central nervous system (CNS) involvement is extremely rare; to date, only 16 cases of spinal cord involvement have been described. The disease can have a protracted course lasting months or even years, often accompanied by phases of exacerbation and remission, with an overall mortality of 7% [3]. We describe here, to the best extent of our knowledge, the first case of RDD with a lesion in the thoracic intradural extramedullary space causing acute paraparesis. A 16-year-old Afro-Caribbean girl developed severe right leg cramps and weakness and progressive numbness of both legs while on vacation. Upon returning to home, her symptoms rapidly progressed, and she presented to the Accident and Emergency Department unable to walk, almost paraplegic, with urinary incontinence. Neurological examination revealed bilateral leg weakness (MRC grade 1 in ankles and knees; grade 2 in hips), and brisk reflexes and extensor plantar responses bilaterally. Emergent MRI showed severe spinal cord compression at T4/5. The lesion was of intermediate T2and T1-weighted signal intensity and displaced the cord to the left (Fig. 1). Intracranial appearances were normal. Laboratory investigations were unremarkable except for a white blood cell count of 17× 10/l. Computed tomography of the chest, abdomen, and pelvis showed no significant lymphadenopathy. The patient was immediately started on dexamethasone and transferred to the neurosurgical unit. A T4/5 costotransversectomy approach was performed, allowing complete resection of the mass without manipulation of the spinal cord. Histological examination of the excised mass showed histiocytic cells and engulfing lymphocytes, a phenomenon known as emperipolesis. This is characteristic of RDD. There were no complications from surgery. The patient recovered quickly; within 7 days, her coordination, strength, and gait had all returned to normal. Since a complete resection of the mass was performed and lymphadenopathy was not observed, radiation and chemotherapy were not performed. The patient has been kept under follow-up and has not had a recurrence 2 years after surgery. The rarity of RDD and the variance in presentation render a definitive management protocol impractical. But among patients with CNS involvement, surgical resection appears to offer the best outcome, and total excision is This work has been carried out at UCL/UCLH which receive funding from the National Institute for Health Research Comprehensive Biomedical Research Centre. C. W. R. Chen : C. Kachramanoglou :D. Choi Department of Neurosurgery, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG UK

Sequestered disc fragment mimicking a psoas abscess

BACKGROUND CONTEXT If a herniated lumbar disc fragment extrudes and migrates away from the spinal column, the radiographic appearances can be confusing. STUDY DESIGN In this article, we report a rare case of a sequestrated disc fragment in the psoas muscle, discrete from the adjacent disc space, which presented with features similar to a psoas abscess on imaging studies. CONCLUSIONS It is vital that in such cases the correct diagnosis is made to avoid unnecessary treatments and inappropriate management.

Long-Term Outcome of Brachial Plexus Reimplantation After Complete Brachial Plexus Avulsion Injury

Background Complete brachial plexus avulsion injury is a severe disabling injury due to traction to the brachial plexus. Brachial plexus reimplantation is an emerging surgical technique for the management of complete brachial plexus avulsion injury. Objective We assessed the functional recovery in 15 patients who underwent brachial plexus reimplantation surgery after complete brachial plexus avulsion injury with clinical examination and electrophysiological testing. Methods We included all patients who underwent brachial plexus reimplantation in our institution between 1997 and 2010. Patients were assessed with detailed motor and sensory clinical examination and motor and sensory electrophysiological tests. Results We found that patients who had reimplantation surgery demonstrated an improvement in Medical Research Council power in the deltoid, pectoralis, and infraspinatous muscles and global Medical Research Council score. Eight patients achieved at least grade 3 MRC power in at least one muscle group of the arm. Improved reinnervation by electromyelography criteria was found in infraspinatous, biceps, and triceps muscles. There was evidence of ongoing innervation in 3 patients. Sensory testing in affected dermatomes also showed better recovery at C5, C6, and T1 dermatomes. The best recovery was seen in the C5 dermatome. Conclusions Our results demonstrate a definite but limited improvement in motor and sensory recovery after reimplantation surgery in patients with complete brachial plexus injury. We hypothesize that further improvement may be achieved by using regenerative cell technologies at the time of repair.

Self-Mutilation in Patients After Nerve Injury May Not Be Due to Deafferentation Pain: A Case Report

OBJECTIVE Animals with transected nerves may develop self-mutilating behavior (autotomy) directed at the denervated body part. Autotomy is often thought to be a response to deafferentation pain produced by pathological changes in the dorsal horn, and self-mutilation after dorsal rhizotomy has consequently been used as an outcome measure for the investigation of chronic pain in animal models. A less recognized hypothesis suggests that autotomy is simply an animals efforts to remove the useless part. We report a case of self-mutilation of the thumb and fingers in a patient with loss of all sensory modalities in the arm after brachial plexus avulsion. CONCLUSION Asking the patient about the reasons for his self-mutilation provides insights into the cause of autotomy which cannot be established from animal studies. We suggest that autotomy may not be a result of chronic pain, and discuss the human experience and alternative underlying pathological processes.