Nitric-oxide triggered neurological disorders in subjects with vitamin B12 deficiency

INTRODUCTION: Nitrous oxide is frequently used for anesthesia. It may cause spinal cord toxicity. CASE REPORTS: We report two patients who presented gait disorders after nitrous oxide anesthesia. Physical examination revealed arms and legs pyramidal syndrome and abnormal proprioception, consistent with subacute combined degeneration of the spinal cord. Serum vitamin B12 level was extremely low. The patients improved with parenteral treatment with hydroxycobalamin. CONCLUSIONS: The inactivation of methionine synthase and L methylmalonylcoA mutase by nitrous oxide has been previously demonstrated. Anesthesia-related exposure to nitrous oxide may induce neurologic disorders even in patients with no preliminary vitamin B12 deficiency.     

笑气滥用导致神经功能缺损的临床特点

目的 探讨笑气滥用导致神经功能缺损的临床特点.方法 回顾性分析2例笑气滥用导致神经功能缺损患者的临床资料,并对相关文献资料进行复习.结果 1例以模拟格林-巴利综合征的症状发病,表现为四肢对称性的麻木无力,脊椎横断面T2WI显示颈髓后索倒"V"形高信号,EMG呈多发性周围神经脱髓鞘和轴索损伤.另1例以模拟急性脊髓炎症状起...     

Reversible nitrous oxide-induced myeloneuropathy with pernicious anemia: case report and literature review

A previously healthy 27-year-old woman developed a subacute myeloneuropathy after receiving nitrous oxide anesthesia for dental procedures. Neurologic evaluation revealed that she was vitamin B(12) deficient due to underlying pernicious anemia. Discontinuation of nitrous oxide and supplementation with vitamin B(12) resulted in dramatic clinical improvement, with near-complete normalization of her neurologic examination. This case and published reports reviewed here emphasize that favorable outcomes are possible following prompt recognition and treatment of vitamin B(12) deficiency.     

MR findings in subacute combined degeneration of the spinal cord caused by nitrous oxide anaesthesia – two cases

Vitamin B12 deficiency causes haematological and neurological diseases. Subacute combined degeneration (SCD) of the spinal cord is characterized by degeneration of the posterior and lateral columns. We report two cases of SCD induced by nitrous oxide (N2O) anaesthesia. In both cases magnetic resonance imaging (MRI) of the spinal cord showed symmetric, reversible changes in the posterior columns, correlating well with patients' symptoms.     

笑气滥用的神经系统损害(附1例报道并文献复习)

目的 探讨笑气(氧化亚氮)滥用中毒所致的神经系统损害的临床特点。方法 分析1例滥用笑气中毒所致的神经系统损害病例的临床特点及转归。结果 ①笑气中毒所致神经系统病变在临床易被漏诊,以青年多见; ②笑气中毒所致神经系统病变的临床表现为亚急性联合变性样的脊髓损害、以运动轴索损害为主的长度依赖性的周围神经病变以及共济失调等,并常有维生素B12水平下降、高同型半胱氨酸血症; ③磁共振可见颈髓和或胸髓后索呈不规则的白质脱髓鞘,脊髓横断面T₂WI显示颈或胸髓后索倒“V”形高信号; ④肌电图主要表现为以运动轴索损害为主的周围神经病变,多以下肢为重。结论 亚急性或慢性起病的青年患者,表现亚急性联合变样、周围神经损害等,需详细询问有无笑气接触史,行血维生素B12、同型半胱氨酸、颈髓磁共振、肌电图等检查,以明确诊断,排除笑气中毒可能。     

“笑气”中毒导致神经系统损害4例并文献复习

目的 探讨笑气中毒的临床表现、影像学特点、鉴别诊断及治疗。方法 收集本院诊治的4例笑气中毒患者的临床资料,结合国外文献报道12例,国内文献报道1例,对共计17例患者的临床表现、影像学特点、鉴别诊断及治疗等进行分析。结果 17例患者中表现为肢体麻木14例、深感觉障碍12例、肢体无力,疲倦8例,共济失调7例。影像学上表现为类似于脊髓亚急性联合变性的倒“V”字型,伴或不伴维生素B12缺乏。经过停止接触笑气,及时肌肉注射或口服维生素B12以及甲基强的松龙静脉滴注,通常可以在数周至数月内恢复正常。结论 笑气中毒导致神经系统损害的患者日益增加,临床医生要掌握其临床特点,并进行合理诊治。     

Painless aortic dissection presenting as a progressive myelopathy

We report a patient with a painless aortic dissection whose neurologic symptoms progressed over 5 days to a complete transverse myelopathy. She did not experience pain as her neurologic deficits evolved. Magnetic resonance imaging revealed a thoracic aortic dissection extending from the arch to the level of the 12th thoracic vertebra and demonstrated ischemic changes in the spinal cord and one thoracic vertebral body. Aortic dissection must be included in the differential diagnosis of spinal cord syndromes even in the absence of pain. Early recognition of aortic dissection as a cause of progressive myelopathy may become increasingly important as new therapies for central nervous system ischemia are developed.     

Postoperative dementia: toxicity of nitrous oxide

INTRODUCTION: Post-operative neuropsychiatric manifestations represent a frequent situation and may be due to several aetiologies. The responsibility of vitamin B12 deficiency must be evoked, especially in case of anaesthesia with a currently used substance: nitrous oxide. CASE REPORT: A 65 year-old man with no medical history, presented problems walking and memory loss 16 days after surgery for femoral prosthesis. Neurological examination revealed paraplegia with syndrome of combined degeneration of the spinal cord. The exploration of cognitive functions showed disorientation in time with memory disorders and disturbance of executive functioning. There was no apraxia, aphasia or agnosia. There were neither psychotic symptoms nor mood changes. MMS was at 18/30. Red blood count revealed an anaemia with macrocytosis (MGV=120 3). Vitamin B12 rate was very low (less than 30 g/l). Folate blood level was normal. Brain MRI showed moderate cerebral atrophy. Other investigations led to the diagnosis of Biermer's disease (fundic atrophy at biopsy with presence in the serum of antibodies to intrinsic factor). The diagnosis of neurological attack related to a vitamin B12 deficiency secondary to Biermer's disease was established, but the appearance of disorders in the post-operative period suggested the existence of an added factor. The recovery of informations revealed that anaesthesia was maintained by nitrous oxide during two hours and the patient exhibited pre-operative anaemia with macrocytosis. The hypothesis of decompensation of latent vitamin B12 deficiency by nitrous oxide was evoked. Replacement therapy by vitamin B12 induced real improvement of the cognitive impairment. MMS increased to 25/30. DISCUSSION: Cognitive impairment due to vitamin B12 deficiency is rarely dominated by isolated memory disorders. An authentic dementia is exceptional. Our patient had a dementia diagnosed on the basis of DSM IV criteria including memory disorders, disturbance of executive functioning and significant impairment in social and occupational functioning, associated with a combined degeneration of the spinal cord, common in vitamin B12 deficiency. Furthermore, he had an unknown Biermer's disease responsible for pre-operative deficiency which was clinically latent (there was only macrocytosis anaemia). The appearance of problems in the post-operative period was due to an acute decompensation of the latent deficiency induced undoubtedly by nitrous oxide used in anaesthesia. According to Christensen, nitrous oxide causes irreversible oxidation of vitamin B12 cobalt's atom responsible for its inactivation and the appearance of clinical manifestations. Evolution under vitamin B12 replacement therapy depends on the rapidity of its founding. In our case, it led to an improvement, notably in cognitive functions. CONCLUSION: Through this observation, the authors underline the necessity to search for vitamin B12 deficiency in the case of cognitive features following general anaesthesia.     

MRI in vitamin B12 deficiency myelopathy

BACKGROUND: Little is known about vitamin B12 deficiency myelopathy's magnetic resonance imaging (MRI) manifestations and their relationship to the onset, evolution, and resolution of neurologic signs and symptoms. METHODS: We present a case and review eleven additional reported cases of subacute combined degeneration of the spinal cord detected by MRI. RESULTS: Our patient had increased T2-weighted signal and gadolinium contrast enhancement of the posterior columns in the cervical and thoracic regions and enhancement of the lateral columns in the high cervical region. This is a case with imaging evidence for lateral column lesions. Two prior reports have shown posterior column enhancement. T1-weighted images may show decreased signal in the posterior columns and sometimes demonstrate reversible spinal cord swelling. MRI abnormalities typically improve after vitamin replacement therapy. However, clinical signs may persist despite resolution of imaging abnormalities, and these abnormalities do not always resolve completely. In addition, symptoms may precede the imaging abnormality. CONCLUSIONS: Vitamin B12 deficiency may produce an increased T2-weighted signal, decreased T1-weighted signal, and contrast enhancement of the posterior and lateral columns of the spinal cord, mainly of the cervical and upper thoracic segments. Because the symptoms may precede any imaging abnormality, it is clear that spinal cord MRI may not be a highly sensitive, early test for subacute combined degeneration.     

"Whippets"-Induced Cobalamin Deficiency Manifesting as Cervical Myelopathy

BACKGROUND: Nitrous oxide (N2O) is inhaled in anesthesia and as a recreational drug from whipped cream dispensers. Its abuse reaches approximately 10% in some age groups. By inactivating cobalamin (Cbl) (vitamin B12), N2O can cause neurologic and hematologic manifestations. We present a case of N2O-induced Cbl deficiency presenting as cervical myelopathy. CASE HISTORY: After regularly inhaling N2O for many months, a 31-year-old man developed limb paresthesiae and ataxia over 3 months. Examination revealed finger pseudoathetosis, hyporeflexia, decreased sensation, and gait ataxia. Brain magnetic resonance imaging (MRI) was normal, but the posterior columns of the cervical and upper thoracic cord revealed patchy nonenhancing hyperintense lesions. Serum Cbl was 98 pg/mL (normal = 170-900 pg/mL). Cbl replacement led to recovery within 3 months. DISCUSSION: This patient presented with the symptoms and signs of Cbl deficiency. The MRI lesions in the posterior columns aided the diagnosis. Physicians need to have a high level of suspicion in cases of unexplained Cbl deficiency and myelopathy.     

Spinal cord ganglioglioma presenting as acute paraparesis

A 17-year-old male presented with acute onset paraparesis in the lower limbs. Urinary retention was present and the patient required catheterisation. Clinical examination confirmed severe bilateral lower limb weakness and a sensory level at T8. Magnetic resonance imaging (MRI) revealed a haemorrhagic intramedullary tumour extending from T8 to the conus. Microsurgical excision of the tumour was performed and the patient made a good functional recovery. The histology of the tumour demonstrated a ganglioglioma of the spinal cord. Acute paraparesis has not previously been reported with a spinal cord ganglioglioma. We discuss the clinical, diagnostic and pathological features of spinal cord gangliogliomas.     

Magnetic resonance imaging of subacute myelopathy due to cobalamin deficiency

A 77-year-old woman presented with rapidly ascending sensory ataxia. Magnetic resonance imaging (MRI) showed extensive involvement of the dorsal columns of the spinal cord. Hematological data were normal despite severe cobalamin deficiency. The contribution of magnetic resonance imaging in subacute degeneration of the spinal cord is discussed.     

Catheter Tip Granuloma Associated with Sacral Region Intrathecal Drug Administration

Spinal cord compression from catheter tip granulomatous masses following intrathecal drug administration may produce devastating permanent neurologic deficits. Some authors have advocated intrathecal catheter placement below the conus medullaris to avoid the possibility of spinal cord involvement. Multiple cases of catheter tip granulomas in the thoracolumbar region have been reported. We present a unique case of a sacral region catheter tip inflammatory mass producing permanent neurologic deficits. A 71‐year‐old white male with a diagnosis of failed back surgery syndrome was referred to the senior author for evaluation. After more extensive conservative therapy, including spinal cord stimulation, failed to yield adequate pain relief, he was offered implantation of an intrathecal pump for opioid administration. Excellent pain relief was achieved in the postoperative period; however, three years after implantation, he presented with progressive saddle anesthesia and bowel/bladder incontinence. Magnetic resonance imaging demonstrated a space occupying lesion associated with the catheter tip. The patient underwent emergent second level complete sacral laminectomy with partial resection of an intradural extra‐axial mass and removal of intrathecal catheter. At discharge, the patient had no restoration of neurologic function. Histologic examination of the mass confirmed a sterile inflammatory mass. It has been suggested that intrathecal catheters be placed below the conus medullaris to avoid the possibility of spinal cord involvement. We present an unusual case documenting devastating permanent neurologic deficits from a catheter tip granuloma in the sacral region.     

Intramedullary spinal cord metastasis as the first manifestation of a renal carcinoma

We present the case of a 69 year-old male without known antecedente who presented a clinical loss of distal force in his lower limbs during the last two months. Magnetic resonance imaging (MRI) showed an intramedullary spinal cord mass at the level of the medullaris cone. The patient was operated on; the histological diagnosis was clear cells carcinoma suggestive of metastasis from an unsuspected renal tumor that was later confirmed with an abdominal CT. When the patient's state is good, surgery can correct the neurological deficit produced by an intramedullary spinal cord lesion. The neurological state of our patient improved after the intervention, and 14 months after surgery, he has no neurological deficit in the lower limbs.     

Pernicious azotaemia? A case series of subacute combined degeneration of the cord secondary to nitrous oxide abuse

Nitrous oxide abuse is a rare cause of vitamin B12 deficiency and consequent subacute combined degeneration of the spinal cord. Worldwide and Australian statistics indicate that recreational use of nitrous oxide is increasing. We report four cases of females aged 18–24 years presenting with clinical symptoms of subacute combined degeneration of the spinal cord. MRI during admission demonstrated the classic findings of T2 hyperintensity, predominantly within the dorsal columns of the spinal cord, with variable involvement of the lateral corticospinal tracts. These cases highlight the ready availability of nitrous oxide and the fact that heavy prolonged recreational use is occurring in the community. It is important that clinicians in emergency and community settings are alerted to this unusual cause of subacute combined degeneration of the spinal cord because early aggressive vitamin B12 replacement together with behavioural change can reverse this disabling neurological syndrome.     

亚急性脊髓混合变性的17例临床特征和诊断

目的评价亚急性脊髓混合变性（ＳＣＤ）的临床特征及电生理和磁共振成像的诊断价值。方法回顾分析了１７例ＳＣＤ患者的临床表现。结果发现全部ＳＣＤ患者发病由维生素Ｂ１２缺乏引起，胃大部切除术是一个主要病因，肢体感觉异常和深感觉减退是ＳＣＤ最常见的症状和体征，１２例合并周围神经损害，５例合并植物神经损害，体感诱发电位有极高的敏感性，磁共振成像可以明确脱髓鞘的部位。结论电生理和磁共振检查对ＳＣＤ的诊断和治疗起重要作用     

An infant with an intradural lipoma of the cervical spine extending into the posterior fossa.

BACKGROUND: Intradural lipomas of the cervical spine are very rare. These tumours show no association with spinal dysraphism. We describe an infant with cervical spinal cord lipoma. Surgical decompression of the cord resolved all neurologic deficits. CASE DESCRIPTION: An 8 month old female infant presented with retarded development of motor function in the limbs, in addition to dysphagia. Computed tomography identified a tumour of fat density that extended from the medulla to C7. Magnetic resonance imaging showed hyperintensity on both T1- and T2-weighted images. A fat-suppression sequence demonstrated an area of signal enhancement in the dorsal portion of the tumour following administration of gadolinium. The adjacent spinal cord was normal. Partial removal of the tumour was performed together with decompressive laminoplasty. The enhancing region proved to be fibrous tissue. Motor development resumed in the week following operation. CONCLUSION: Retarded motor development was the main manifestation of this infant's rare spinal tumour. Neuroimaging was of considerable diagnostic value; in particular, fat-suppression magnetic resonance imaging demonstrated details of the tumour and surrounding structures. Decompressive laminoplasty and laminectomy with partial removal of the tumour was effective in reversing clinical deficits.     

Leukoencephalopathy with brain stem and spinal cord involvement and high lactate: a genetically proven case without elevated white matter lactate

A 17-year-old Indian boy with gradually progressive ataxia with onset at 12 years of age is described. Magnetic resonance imaging (MRI) of the brain revealed extensive, inhomogeneous signal abnormalities in the cerebral white matter, with involvement of selected tracts in the brain stem and spinal cord. The imaging findings were characteristic of leukoencephalopathy with brain stem and spinal cord involvement and high lactate, a recently described leukodystrophy. Interestingly, magnetic resonance spectroscopy of the abnormal white matter did not reveal elevated lactate. The patient was compound heterozygous for 2 new mutations in DARS2, genetically confirming the diagnosis.     

A case of subacute combined degeneration of the spinal cord due to folic acid and copper deficiency

Subacute combined degeneration of the spinal cord (SACD) is a rare neurologic disorder manifesting progressive symptoms of paresthesia and spastic paralysis. Herein we present an autopsy case of SACD caused by folic acid and copper deficiency. A 16-year-old male presented with gradually worsening unsteady gait, and bladder and rectal dysfunction. He had a medical history of T-cell acute lymphoblastic leukemia (T-ALL), diagnosed 1.5?years previously. The patient had undergone chemotherapy, including methotrexate, as well as allogeneic bone mallow transplantation. Laboratory tests revealed normal vitamin B₁₂ and methylmalonic acid concentration, but reduced serum copper, ceruloplasmin and folic acid concentrations. Magnetic resonance imaging revealed symmetrical T2 signal hyperintensities in the posterior and lateral spinal cord. The patient was treated with oral copper, oral folate, and intravenous vitamin B₁₂. A month after this treatment, the patient’s symptoms were unchanged, and 2?months later he died of acute adrenal insufficiency. The pathological findings of the spinal cord were compatible with SACD. Because SACD is usually reversible with early treatment, it should be suspected in high-risk patients undergoing chemotherapy or those who are malnourished with characteristic symptoms of SACD, even in young patients.     

Cluster headache and TACs: rationale for central and peripheral neuromodulation

Vitamin B12 deficiency causes haematological, gastrointestinal and neurological diseases. Subacute combined degeneration (SCD) of the spinal cord is characterised by degeneration of the posterior and lateral columns. We report a case of SCD associated with nitrous oxide anaesthesia.