Spine MR imaging features of subacute combined degeneration patients

Subacute Combined Degeneration of the Spine: A Case Study of Delayed Diagnosis in the Emergency Department

Subacute combined degeneration of the spine (SCDS) is a well-known disease that classically presents with progressive sensory and motor deficits and characteristic magnetic resonance imaging (MRI) findings, leading to its use as a key diagnostic tool. However, clinical and MRI findings in SCDS may be diverse, and thus, a high index of suspicion should be maintained for this disease, which can cause irreversible neurological damage if left untreated. In this article, we report the case of a 29-year-old female with significant recent life stressors and otherwise unremarkable medical history who presented with progressive weakness of the bilateral lower extremities who previously had unremarkable computed tomography (CT) and MRI completed at an outside hospital for the same symptoms, which had since continued to worsen. Her presentation at our emergency department (ED) prompted urgent evaluation with an MR cord compression study and neurology consultation. This workup resulted in an unremarkable preliminary MR read, and she was without anemia in laboratory studies. Given this, she was ultimately discharged with high suspicion for conversion disorder. After an addendum report from radiology with concern for subacute combined degeneration of the spine, she was called back to the ED where further workup revealed pernicious anemia leading to SCDS. This case highlights the importance of maintaining suspicion and avoiding premature closure in patients with reported neurological deficits.

Magnetic resonance imaging in a patient with nitrous oxide-induced subacute combined degeneration of the spinal cord

INTRODUCTION

Chronic nitrous oxide use can lead to neurological findings that are clinically and radiographically identical to those found in patients with pernicious anemia, specifically subacute combined degeneration of the spinal cord and peripheral neuropathy.

CASE SUMMARY

A 22-year-old man presented with lower extremity weakness and ataxia in the setting of inhaling 250 nitrous oxide cartridges two to three times weekly for two years.

IMAGES

Magnetic resonance imaging showed T2 hyperenhancement of the dorsal columns of the cervical spine from the first to the sixth vertebrae, which helped to establish a diagnosis of nitrous oxide-induced subacute combined degeneration of the spinal cord.

CONCLUSIONS

Chronic nitrous oxide use should be included in the differential diagnosis of any patient with otherwise unexplained neurological complaints that localize to the dorsal columns and has the changes on magnetic resonance imaging described here.

Imaging Aspects of Toxic and Metabolic Myelopathies

Metabolic and toxic myelopathies usually occurs due to several different causes. Metabolic myelopathy usually occurs due to deficiency of a nutrient, such as vitamin B12. Toxic myelopathy occurs secondary to the exposure to an external toxic agent. Although they may have a difficult diagnosis, determination of the specific cause of myelopathy is of utmost importance, because many causes are amenable to treatment. Although they have many clinical, electrophysiologic, and neuropathologic similarities, imaging may aid in the suspicion of toxic or metabolic myelopathy. The aim of this article, is to review the imaging features of the main toxic and metabolic myelopathies.

Spinal muscular atrophy-like phenotype in a mouse model of acid ceramidase deficiency

Mutations in ASAH1 have been linked to two allegedly distinct disorders: Farber disease (FD) and spinal muscular atrophy with progressive myoclonic epilepsy (SMA-PME). We have previously reported FD-like phenotypes in mice harboring a single amino acid substitution in acid ceramidase (ACDase), P361R, known to be pathogenic in humans (P361R-Farber). Here we describe a mouse model with an SMA-PME-like phenotype (P361R-SMA). P361R-SMA mice live 2-3-times longer than P361R-Farber mice and have different phenotypes including progressive ataxia and bladder dysfunction, which suggests neurological dysfunction. We found profound demyelination, loss of axons, and altered sphingolipid levels in P361R-SMA spinal cords; severe pathology was restricted to the white matter. Our model can serve as a tool to study the pathological effects of ACDase deficiency on the central nervous system and to evaluate potential therapies for SMA-PME.

A Diagnostic Approach to Spastic ataxia Syndromes

Spastic ataxia is characterized by the combination of cerebellar ataxia with spasticity and other pyramidal features. It is the hallmark of some hereditary ataxias, but it can also occur in some spastic paraplegias and acquired conditions. It often presents with heterogenous clinical features with other neurologic and non-neurological symptoms, resulting in complex phenotypes. In this review, the differential diagnosis of spastic ataxias are discussed and classified in accordance with inheritance. Establishing an organized classification method based on mode inheritance is fundamental for the approach to patients with these syndromes. For each differential, the clinical features, neuroimaging and genetic aspects are reviewed. A diagnostic approach for spastic ataxias is then proposed.

Clinical features of different stage subacute combined degeneration of the spinal cord

Subacute combined degeneration (SCD), caused by vitamin B12 disorders, leads to severe degeneration of the spinal cord. Thus, it is significant to make timely diagnosis and treatment options of SCD. The objectives were to summarize clinical features of different sate SCD. Clinical data of 42 SCD patients of spinal cord were retrospectively analyzed, which were classified into early stage, middle stage and late stage SCD. Among the patients, 9 were classified into early stage, 22 into middle stage, and 11 into late stage SCD. Total cholesterol and hemoglobin levels were relatively higher in late stage SCD. In contrast, mean corpusular volume (MCV) level was higher in early stage SCD. There were typical abnormalities only in 8 patients on magnetic resonance imaging (MRI), and a dynamia was a common neurological abnormality in all patients. Importantly, the differences in abnormal findings in anti-nuclear antibodies (ANA) testing, visual acuity and fundus testing were statistically significant in different stage SCD (P < .05). There were correlation between most variances with SCD stage. Strikingly, there existed close relationship between enhanced levels of blood glucose (r = -0.289, P = .066), glycated hemoglobin (GHB) (r = -0.288, P = .068) and homocysteine (r = -0.563, P = .000), abnormal visual findings (r = 0.309, P = .049) and megaloblastic anemia (r = -0.295, P = .061) with different SCD stage, among which abnormal visual findings were closely associated with middle stage SCD. Moreover, levels of total cholesterol, blood glucose, homocysteine and abnormal finding of visual acuity were significant in diagnosis and clinical staging of SCD (P < .05). Although MRI scanning and serum vitamin B12 level were widely used for SCD diagnosis, neurological examination and homocysteine level may be more potentially valuable indexes for SCD diagnosis and staging.

An unusual case of subacute combined degeneration due to nitrous oxide abuse, which relapsed after bariatric surgery: A case report

RATIONALE

Several studies have reported subacute combined degeneration (SCD) induced by nitrous oxide (N2O) abuse. However, few studies have reported that N2O-induced SCD recurred because of sleeve gastrectomy after neurological symptoms improved.

PATIENT CONCERNS

We report the case of an 18-year-old woman who developed paresthesia, weakness in 4 limbs, and an unstable gait after frequent, excessive N2O inhalation.

DIAGNOSIS

The patient was diagnosed as having SCD.

INTERVENTIONS AND OUTCOMES

Nineteen days after intravenous mecobalamin and supplementation with other kinds of vitamin B, her weakness and paresthesia resolved. However, 7 months after discharge, the patient experienced recurrence following sleeve gastrectomy. Blood biochemistry revealed low vitamin B12 levels. After a 22-day treatment, similar to the first hospitalization, her residual numbness and unsteady gait improved.

LESSONS

This case highlights that patients, especially those at high risk of vitamin B12 deficiency, undergoing sleeve gastrectomy require careful nutritional follow-up and routine monitoring of micronutrients such as vitamin B12 and homocysteine. Continuous vigilance is essential for patients with common and rare neurological complications.

Metabolic and Toxic Myelopathies

Metabolic and toxic causes of myelopathy form a heterogeneous group of disorders. In this review, we discuss the causes of metabolic and toxic myelopathies with respect to clinical presentation, pathophysiology, diagnostic testing, treatment, and prognosis. This review is organized by temporal course (hyperacute, acute, subacute, and chronic) and etiology (e.g., nutritional deficiency, toxic exposure). Broadly, the myelopathies associated with dietary toxins (neurolathyrism, konzo) and decompression sickness present suddenly (hyperacute). The myelopathies associated with heroin use and electrical injury present over hours to days (acutely). Most nutritional deficiencies (cobalamin, folate, copper) and toxic substances (nitrous oxide, zinc, organophosphates, clioquinol) cause a myelopathy of subacute onset. Vitamin E deficiency and hepatic myelopathy cause a chronic myelopathy. Radiation- and intrathecal chemotherapy-induced myelopathy can cause a transient and/or a progressive syndrome. For many metabolic and toxic causes of myelopathy, clinical deficits may stabilize or improve with rapid identification and treatment. Familiarity with these disorders is therefore essential.

Key Characteristics of Nitrous Oxide-Induced Neurological Disorders and Differences Between Populations

Background: Nitrous oxide (N₂O), commonly known as laughing gas, is inhaled recreationally because it produces the feelings of euphoria and freedom from pain. The risk of neurological dysfunction secondary to N₂O abuse and its clinical diagnosis are, however, not yet sufficiently recognized, especially in China. Here, we have summarized the key clinical characteristics of N₂O-induced neurological disorders.

Materials and Methods: We recruited 20 patients with N₂O-induced neurological disorders and analyzed their clinical features, laboratory data, magnetic resonance imaging and electromyography. We also carried out a literature review and compared 99 previously reported patients with our case series to confirm our results. Subgroup analysis was performed to explore the difference in demographical and clinical characteristics of N₂O abuse between Asian and non-Asian patients.

Results: The most common initial symptoms of N₂O-induced neurological disorders were weakness and/or paresthesia. Most patients presented with myelopathy and/or peripheral neuropathy. The most commonly involved segment of the spinal cord was the cervical spinal cord, extending over 4–6 vertebral levels, but more than half of the patients with myelopathy had no sensory change at the corresponding spinal level. Homocysteine was found to be the most sensitive and practical indicator for diagnosis. Subgroup analysis showed that the Asian patients (median: 22.0 years old, Q1–Q3:19.0–26.0 years old) with N₂O abuse were younger than non-Asian patients [26.0 (22.3–31.0) years old, P = 2.8 × 10⁻⁴]. The incidence of myelopathy combined with peripheral neuropathy was significantly higher in Asian patients than in non-Asian patients, who had myelopathy or peripheral neuropathy (P = 2 × 10⁻⁵).

Conclusions: Key clinical characteristics of N₂O abuse are longitudinally extensive cervical myelopathy and peripheral neuropathy. Recognition of these traits in young people in the age group of 20–30 years will provide important guidance for accurate diagnosis of neurological disease associated with N₂O abuse. The clinical manifestations differ in Asian patients and non-Asian patients.

Subacute combined degeneration of the cervical and dorsal spinal cord in a 40-year-old male patient: A case report

Subacute combined degeneration of the spinal cord is a neurologic complication of vitamin B12 deficiency. It presents as a potentially reversible demyelination of the posterior and lateral columns of the cervical and dorsal spinal cord. We present the case of a 40-year-old male with progressive sensory and motor deficit from the lower extremities ascending to the mid-thoracic region. A combination of laboratory tests and magnetic resonance imaging confirmed the diagnosis of subacute degeneration of the spinal cord due to vitamin B12 deficiency.

Correlation between anemia and clinical severity in subacute combined degeneration patients

OBJECTIVES

Subacute combined degeneration (SCD) is a demyelinating disease commonly caused by vitamin B12 deficiency. Several studies have been reported SCD could be accompanied by anemia. However, the correlation between anemia and clinical severity of SCD patients is unclear. In this study, we aim to analyze the clinical characteristics of SCD concomitant with anemia, and investigate the effect of anemia in predicting the severity of SCD.

METHODS

A total 42 patients were included in the study. Clinical, laboratory, radiological findings, and outcomes from the patients were analyzed. All patients were treated with vitamin B12 for no less than 6 months and a functional disability rating scale was used to evaluate severity of neurological impairment at the time of admission and 3 and 6 months after admission in our study.

RESULTS

85.7% patients had macrocytosis. Decreased serum vitamin B12 levels were found in 27 patients (64.3%). MRI showed long-segment abnormality on the spinal cord in 22 patients. No differences in rating score were found in patients grouped by sex, age, clinical course, serum vitamin B12, or MRI manifestations at the time of admission or at the follow-up visits. Negative correlation was seen between hemoglobin levels and the clinical severity scores on admission.

CONCLUSION

Not all patients with SCD concomitant with anemia had decreased serum vitamin B12 level. The inverse correlation between hemoglobin level and clinical severity suggests the degree of anemia can help in evaluating the extent of neurologic impairment.

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.

Nutritional neuropathies

Neuropathies associated with nutritional deficiencies are routinely encountered by the practicing neurologist. Although these neuropathies assume different patterns, most are length-dependent, sensory axonopathies. Cobalamin deficiency neuropathy is the exception, often presenting with a non-length-dependent sensory neuropathy. Patients with cobalamin and copper deficiency neuropathy characteristically have concomitant myelopathy, whereas vitamin E deficiency is uniquely associated with a spinocerebellar syndrome. In contrast to those nutrients for which deficiencies produce neuropathies, pyridoxine toxicity results in a non-length-dependent sensory neuronopathy. Deficiencies occur in the context of malnutrition, malabsorption, increased nutrient loss (such as with dialysis), autoimmune conditions such as pernicious anemia, and with certain drugs that inhibit nutrient absorption. When promptly identified, therapeutic nutrient supplementation may result in stabilization or improvement of these neuropathies.

Rare anterior funiculus lesions in subacute combined degeneration of the spinal cord: a case report and literature review

Objective: Anterior funiculus lesion is uncommon in subacute combined degeneration of the spinal cord with few data available. Aim of the study was to describe a case with the rare manifestation and summarize existing literatures.Methods: We report a case of a 42-year-old woman with anterior and lateral funiculus lesions on cervicothoracic spine magnetic resonance imaging, who presented with unsteady gait, sensory level and weakness of lower limbs. Besides, we reviewed and analyzed literatures about subacute combined degeneration of the spinal cord with anterior funiculus lesions published during the past two decades.Results: The diagnosis of subacute combined degeneration of the spinal cord was considered due to her presence of low serum vitamin B12 levels, pernicious anemia and gastric carcinoid.Conclusion: Physicians should consider subacute combined degeneration of the spinal cord as a possible differential diagnosis when faced with atypical lesions distributed in the anterior funiculus.

Intramedullary spinal tumor-like lesions

The development of magnetic resonance imaging (MRI) has led to an increasingly frequent detection of changes in the spinal cord. The most common intramedullary lesions are: demyelinating; vascular; inflammatory; infectious; and congenital, largely called tumor-like lesions. Spinal cord tumors are relatively rare, as compared with brain tumors. The hardest task is to conclude whether the spinal cord lesion is a tumor or a tumor-like lesion. This review is intended to help evaluate the spinal cord and gives an overview of the tumor-like lesions occurring in the spinal cord along with their characteristic.

The Role of Vitamin B12 in the Management and Optimization of Treatment in Patients With Degenerative Cervical Myelopathy

STUDY DESIGN

Narrative review.

OBJECTIVES

To discuss the relationship between degenerative cervical myelopathy (DCM) and vitamin B12 deficiency. Specifically, it is the aim to outline the rational for future research into assessment and therapeutic optimization of vitamin B12 in the treatment of DCM.

METHODS

Literature review.

RESULTS

DCM is the commonest cause of spinal cord impairment, with an average age of presentation in the sixth decade. Patients at this age have also been reported to have a high prevalence of vitamin B12 deficiency, with estimates of up to 20% in the elderly. Vitamin B12 deficiency can result in subacute combined degeneration of the spinal cord (SACD), and several case reports have pointed to patients with both DCM and SACD. Both SACD and reversible compressive injury due to DCM necessitate remyelination in the spinal cord, a process that requires adequate vitamin B12 levels. Basic science research on nerve crush injuries have shown that vitamin B12 levels are altered after nerve injury and that vitamin B12 along with dexamethasone or nonsteroidal anti-inflammatory drugs can reduce Wallerian degeneration. Furthermore, it has been suggested that a combination of B-vitamins can reduce glutamate-induced neurotoxicity.

CONCLUSIONS

Given the high prevalence of clinical and subclinical vitamin B12 deficiency in the elderly, the role of vitamin B12 in myelination, and vitamin B12 deficiency as a differential diagnosis of DCM, it is important to investigate what role vitamin B12 levels play in patients with DCM in terms of baseline neurological function and whether optimization of vitamin B12 levels can improve surgical outcome. Furthermore, the routine assessment of vitamin B12 levels in patients considered for DCM surgery should be considered.

Spinal cord involvement in adult-onset metabolic and genetic diseases

In adulthood, spinal cord MRI abnormalities such as T2-weighted hyperintensities and atrophy are commonly associated with a large variety of causes (inflammation, infections, neoplasms, vascular and spondylotic diseases). Occasionally, they can be due to rare metabolic or genetic diseases, in which the spinal cord involvement can be a prominent or even predominant feature, or a secondary one. This review focuses on these rare diseases and associated spinal cord abnormalities, which can provide important but over-ridden clues for the diagnosis. The review was based on a PubMed search (search terms: 'spinal cord' AND 'leukoencephalopathy' OR 'leukodystrophy'; 'spinal cord' AND 'vitamin'), further integrated according to the authors' personal experience and knowledge. The genetic and metabolic diseases of adulthood causing spinal cord signal alterations were identified and classified into four groups: (1) leukodystrophies; (2) deficiency-related metabolic diseases; (3) genetic and acquired toxic/metabolic causes; and (4) mitochondrial diseases. A number of genetic and metabolic diseases of adulthood causing spinal cord atrophy without signal alterations were also identified. Finally, a classification based on spinal MRI findings is presented, as well as indications about the diagnostic work-up and differential diagnosis. Some of these diseases are potentially treatable (especially if promptly recognised), while others are inherited as autosomal dominant trait. Therefore, a timely diagnosis is needed for a timely therapy and genetic counselling. In addition, spinal cord may be the main site of pathology in many of these diseases, suggesting a tempting role for spinal cord abnormalities as surrogate MRI biomarkers.

Spinal Manifestations of Systemic Disease

The spine is frequently involved in systemic diseases, including those with neuropathic, infectious, inflammatory, rheumatologic, metabolic, and neoplastic etiologies. This article provides an overview of systemic disorders that may affect the spine, which can be subdivided into disorders predominantly involving the musculoskeletal system (including bones, joints, disks, muscles, and tendons) versus those predominantly involving the nervous system. By identifying the predominant pattern of spine involvement, a succinct, appropriate differential diagnosis can be generated. The importance of reviewing the medical record, as well as prior medical imaging (including nonspine imaging), which may confer greater specificity to the differential diagnosis, is stressed.

Clinical and imaging characteristics of subacute combined degeneration complicated with white matter lesions in the brain: a report of five cases

PURPOSE

To report five cases of subacute combined degeneration (SCD) with brain involvement and explore its clinical and imaging characteristics.

METHODS

A retrospective study was performed on the clinical data and brain MRI of five patients with subacute combined degeneration with brain involvement (out of 107 cases with SCD in total). White matter lesions (WML) assessment was performed qualitatively using Fazekas scale score.

RESULTS

The main symptoms in four patients were weakness in both lower extremities and unstable walking (limb weakness in three patients, dizziness in three patients, and blurred vision in one patient). One patient had memory loss and cognitive dysfunction. The MMSE scale indicated mild dementia in one patient. On head MRI (Magnetic Resonance Imaging), multifocal and symmetrical high signals of T2WI and FLAIR were observed in the frontal lobe and periventricular white matter in four patients, while another patient showed preferential atrophy in frontal regions. Fazekas scale scores ranged from 1-6.

CONCLUSION

Adult subacute combined degeneration seldom involves the brain. Multifocal and symmetrical high signal white matter lesions can be found on FLAIR and T2WI, as well as frontal atrophy on head MRI.

Three-point sign in subacute combined degeneration of the spinal cord: A case report

RATIONALE

Subacute combined degeneration (SCD) of the spinal cord has been reported to have distinctive characteristics on magnetic resonance imaging (MRI), such as an "inverted V sign", a "pair of binoculars sign", and a "dot sign". We report a 3-point sign as a novel MRI characteristic, expanding the spectrum of imaging signs for SCD.

PATIENT CONCERNS

A 64-year-old female vegetarian presented with a 3-month history of progressive numbness and weakness in the lower extremities.

DIAGNOSIS

Laboratory examination showed a reduced serum vitamin B12 level. Spinal MRI showed hyperintensity within the posterior and lateral columns (appearing as a three-point sign) on T2-weighted imaging. Thus, the patient was diagnosed with SCD.

INTERVENTIONS

The patient was treated with intravenous cyanocobalamin and oral vitamin B12.

OUTCOMES

After a follow-up period of 5 months, the symptoms were significantly improved.

LESSONS

Clinicians should be aware of this atypical MRI pattern, which may facilitate an early diagnosis.

Differential diagnosis of multiple sclerosis in Latin America

Improvement of multiple sclerosis (MS) diagnoses leads to earlier and correct disease management. The differential diagnostic workup for MS comprises a large variety of medical conditions. There are general guidelines and criteria for diagnosing MS worldwide, but awareness of regional differences needs to be kept in mind. Latin American patients who are screened for MS diagnoses may require an approach that is not exactly the same as that used for patients in North America, western Europe or Asia. In the present review, the conditions that are important for the differential diagnoses of MS in Latin America are reviewed. They include infections, metabolic diseases, nutritional deficits and other autoimmune conditions that physicians in charge of these patients need to be familiar with.