RESUMO
BACKGROUND: Subacute combined degeneration (SCD) is a demyelinating disease characterized by vitamin B12 deficiency related segmental degeneration of the dorsal or lateral columns of the spinal cord. However, few cases have been reported as a comorbidity of SCD and neuromyelitis optica spectrum disease (NMOSD). CASE PRESENTATION: Herein, we describe a female patient (61-year-old) who had sensory deficits, paresthesia, and weakness of the distal extremities for over 2 months. She then received an initial diagnosis of SCD with typical inverted "V-sigh" hyperintensities over the posterior aspect of the spinal cord in magnetic resonance imaging (MRI - T2-weighted imaging), as well as megaloblastic anaemia in blood examinations. From the past history, there was no evidence of a dietary deficiency or gastric abnormalities. However, traditional treatment with vitamin B12 supplementation was ineffective. Hence, a demyelinating antibody examination showed that she had antibodies targeting aquaporin 4 (AQP4) in both the cerebrospinal fluid and serum, leading to the diagnosis of NMOSD. Her clinical symptoms were obviously improved after treatment with intravenous glucocorticoids. CONCLUSION: People who have nutritional deficiency or altered gastrointestinal function are more likely to develop SCD. This case raises the awareness that the poor therapeutic effects of simple vitamin B12 supplementation could be explained by immunoreactions against AQP4. A better recognition will be of great importance for the correct diagnosis of the comorbidity, as well as for essential treatment and even a better prognosis.
Assuntos
Neuromielite Óptica , Degeneração Combinada Subaguda , Aquaporina 4 , Feminino , Humanos , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Neuromielite Óptica/complicações , Neuromielite Óptica/diagnóstico , Neuromielite Óptica/tratamento farmacológico , Degeneração Combinada Subaguda/tratamento farmacológico , Degeneração Combinada Subaguda/etiologia , Vitamina B 12/uso terapêuticoRESUMO
A 17-year-old female was diagnosed with Wilson disease and commenced on oral zinc therapy. She re-presented 6 months later with a fall and had classical signs of subacute combined degeneration of the spinal cord confirmed on nerve conduction studies, as a result of zinc-induced copper deficiency. After 6 months of copper therapy, she made a complete recovery with no residual neurological deficits. Early detection of zinc-induced copper deficiency and stringent follow-up mechanisms are crucial. Early initiation of copper replacement may both limit and completely reverse neurological deficits.
Assuntos
Cobre/deficiência , Degeneração Hepatolenticular/tratamento farmacológico , Degeneração Combinada Subaguda/patologia , Zinco/efeitos adversos , Adolescente , Cobre/uso terapêutico , Feminino , Humanos , Doença Iatrogênica , Degeneração Combinada Subaguda/etiologia , Deficiência de Vitamina B 12/diagnóstico , Zinco/sangueRESUMO
BACKGROUND: Subacute combined degeneration (SCD) is a neurodegenerative disease caused by vitamin B12 deficiency. The lesions mainly involve the posterior cord, lateral cord, and peripheral nerves. Occasionally, the lesions also involve brain white matter and optic nerves in severe cases. Reports of drug-induced impaired absorption and metabolism of vitamin B12 resulting in SCD are scarce. INTRODUCTION: A patient developed SCD after long-term use of tripterygium glycoside tablets in the treatment of glomerulonephritis. However, after discontinuation and vitamin B12 treatment with tripterygium glycoside tablet, the symptoms of SCD were significantly resolved. CONCLUSION: Drug-induced SCD is a less commonly reported cause of the disease. Tripterygium glycoside tablets can induce adverse reactions in the digestive system, causing damage to absorption and metabolism of vitamin B12. Physicians should be aware of the possibility of tripterygium glycoside tablet-induced SCD after excluding more common causes such as inadequate dietary intake and impaired absorption due to gastrointestinal diseases or genetic disorders.
Assuntos
Medicamentos de Ervas Chinesas/uso terapêutico , Glicosídeos/uso terapêutico , Degeneração Combinada Subaguda/etiologia , Tripterygium/química , Medicamentos de Ervas Chinesas/efeitos adversos , Glomerulonefrite/tratamento farmacológico , Glicosídeos/efeitos adversos , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Degeneração Combinada Subaguda/diagnóstico por imagem , Degeneração Combinada Subaguda/tratamento farmacológico , Comprimidos , Vitamina B 12/uso terapêutico , Complexo Vitamínico B/uso terapêuticoAssuntos
Óxido Nitroso , Humanos , Óxido Nitroso/efeitos adversos , Óxido Nitroso/administração & dosagem , Degeneração Combinada Subaguda/etiologia , Degeneração Combinada Subaguda/induzido quimicamente , Masculino , Doenças da Medula Espinal/induzido quimicamente , Doenças da Medula Espinal/etiologia , Doenças da Medula Espinal/diagnóstico por imagemAssuntos
Doenças da Medula Espinal , Degeneração Combinada Subaguda , Deficiência de Vitamina B 12 , Humanos , Imageamento por Ressonância Magnética , Óxido Nitroso/efeitos adversos , Medula Espinal , Doenças da Medula Espinal/diagnóstico por imagem , Doenças da Medula Espinal/etiologia , Degeneração Combinada Subaguda/etiologiaAssuntos
Anemia Perniciosa , Degeneração Combinada Subaguda , Deficiência de Vitamina B 12 , Anemia Perniciosa/complicações , Anemia Perniciosa/diagnóstico , Humanos , Degeneração Combinada Subaguda/diagnóstico por imagem , Degeneração Combinada Subaguda/etiologia , Deficiência de Vitamina B 12/complicações , Deficiência de Vitamina B 12/diagnósticoRESUMO
Avoidant/restrictive food intake disorder (ARFID) is a potentially lethal eating disorder. This case example of a male, G, aged 17 years with ARFID illustrates the multiplicity of health problems related to nutritional deficiencies which may develop in an adolescent of normal weight. Of particular concern was the diagnosis of subacute combined degeneration (SCD) of the spinal cord and the real possibility that G may have irreversible damage to his spinal cord. To our knowledge, this is the first reported case of a patient with SCD of the spinal cord due to ARFID. The adolescent was found to be deficient in Vitamin A, E, K, D, B12, and folate. Management required vitamin replacement, initial nasogastric feeding and the slow introduction of a varied diet. This patient will require long term rehabilitation. Medical practitioners need to be attuned to abnormal eating patterns in children and adolescents and refer for specialist care early.
Assuntos
Ingestão de Alimentos/psicologia , Transtornos da Alimentação e da Ingestão de Alimentos/complicações , Degeneração Combinada Subaguda/etiologia , Adolescente , Deficiência de Vitaminas/psicologia , Humanos , Masculino , Degeneração Combinada Subaguda/psicologiaRESUMO
BACKGROUND: It is believed that Pernicious anaemia (PA) is more common in the West. We postulate however that in India PA is probably an important aetiological factor as a cause of Vitamin B12 deficiency in patients having neurological disease. OBJECTIVE: To investigate the aetiological factors resulting in Vitamin B12 (Vit B12) deficiency in patients with subacute combined degeneration (SACD) and other neurological manifestations. METHODS: We undertook a prospective study of 50 patients, all clinically suspected to have Vit B12 deficiency; they were investigated clinically, haematologically, biochemically and radiologically. RESULTS: There was a dominance of males (41 of 50) with the majority in the age group of more than 40 years of age. There was no correlation between the socio-economic and dietary status on the one hand and the clinical manifestation on the other. Anti intrinsic factor antibodies (AIFAB) were positive in 19 of 50 patients (38%) and anti parietal cell antibodies (APCAB) were positive in 28 of 50 (56%) patients. CONCLUSION: We conclude that Pernicious anaemia is an important cause of various neurological manifestations including SACD in the Vitamin B12 deficient population in the age group of more than 40 years, irrespective of the socio-economic and dietary status in the Indian subcontinent. It is supported by the presence of AIFAB or APCAB in this group.
Assuntos
Anemia Perniciosa/complicações , Doenças do Sistema Nervoso/diagnóstico , Doenças do Sistema Nervoso/etiologia , Exame Neurológico , Degeneração Combinada Subaguda/diagnóstico , Degeneração Combinada Subaguda/etiologia , Deficiência de Vitamina B 12/diagnóstico , Deficiência de Vitamina B 12/etiologia , Adulto , Idoso , Anemia Perniciosa/diagnóstico , Anemia Perniciosa/epidemiologia , Anemia Perniciosa/imunologia , Autoanticorpos/sangue , Estudos Transversais , Dieta Vegetariana , Feminino , Humanos , Índia , Fator Intrínseco/imunologia , Masculino , Pessoa de Meia-Idade , Doenças do Sistema Nervoso/epidemiologia , Doenças do Sistema Nervoso/imunologia , Células Parietais Gástricas/imunologia , Fatores de Risco , Degeneração Combinada Subaguda/epidemiologia , Degeneração Combinada Subaguda/imunologia , Deficiência de Vitamina B 12/epidemiologia , Deficiência de Vitamina B 12/imunologiaRESUMO
RATIONALE: Subacute combined degeneration of the spinal cord is a degenerative disease of the central and peripheral nervous systems caused by vitamin B12 deficiency, mainly involving the spinal cord posterior, lateral, and peripheral nerves, but rarely involving the cerebellum. PATIENT CONCERNS: A 41-year-old woman presented with a 2-year history of walking unsteadily. Her hematologic examination revealed megaloblastic anemia and vitamin B12 deficiency. Electromyography showed multiple peripheral nerve damage (sensory fibers and motor fibers were involved). Imaging examination showed long T2 signal in the cervical, thoracic and lumbar spinal cord and cerebellum. Gastroscopy revealed autoimmune gastritis. DIAGNOSES: Subacute combined degeneration of the spinal cord. INTERVENTIONS: By supplementing with vitamin B12. OUTCOMES: The patient's symptoms of limb weakness, diet, and consciousness were improved, and the muscle strength of both lower limbs recovered to grade IV. LESSONS: The symptomatic people should seek medical treatment in time to avoid further deterioration of the disease. When esophagogastroduodenoscopy is performed as part of routine physical examination in asymptomatic people, it should be checked for the presence of autoimmune gastritis. Early diagnosis can prevent irreversible neuropathy.
Assuntos
Degeneração Combinada Subaguda , Humanos , Feminino , Adulto , Degeneração Combinada Subaguda/etiologia , Degeneração Combinada Subaguda/diagnóstico , Deficiência de Vitamina B 12/complicações , Deficiência de Vitamina B 12/diagnóstico , Gastrite/diagnóstico , Vitamina B 12/uso terapêutico , Vitamina B 12/administração & dosagem , Cerebelo/patologia , Cerebelo/diagnóstico por imagem , Imageamento por Ressonância MagnéticaAssuntos
Óxido Nitroso/efeitos adversos , Degeneração Combinada Subaguda/etiologia , Transtornos Relacionados ao Uso de Substâncias/complicações , Administração por Inalação , Adulto , Anestésicos/efeitos adversos , Anestésicos/uso terapêutico , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Óxido Nitroso/uso terapêutico , Transtornos Relacionados ao Uso de Substâncias/etiologia , Vitamina B 12 , Deficiência de Vitamina B 12/etiologiaRESUMO
Cobalamin C (CblC) deficiency is a rare inborn error in cobalamin (vitamin B12) metabolism which results in impaired intracellular processing of dietary vitamin B12. This leads to a wide range of clinical manifestations including cognitive impairment, psychiatric symptoms, myelopathy, thrombotic events, glomerulonephritis, and pulmonary arterial hypertension. CblC deficiency typically presents in the pediatric population but can also present in adulthood. Diagnosis in adults can be challenging due to the rarity of this condition and its myriad clinical presentations. CblC deficiency is treatable, so early diagnosis is important in preventing permanent neurologic damage. Although CblC deficiency results from a defect in vitamin B12 metabolism, B12 levels remain normal. Diagnosis depends on testing metabolites altered by vitamin B12 dysfunction such as methylmalonic acid (MMA) and homocysteine. We presented a case of a 20-year-old woman who presented with chronic progressive lower extremity weakness and sensory changes. She was eventually diagnosed with subacute combined degeneration because of CblC deficiency and effectively treated. This case highlights the importance of considering inborn errors of metabolism in adult patients and including testing of metabolites such as MMA and homocysteine when suspecting vitamin B12 dysfunction.
Assuntos
Erros Inatos do Metabolismo dos Aminoácidos , Doenças da Medula Espinal , Degeneração Combinada Subaguda , Deficiência de Vitamina B 12 , Adulto , Feminino , Humanos , Criança , Adulto Jovem , Degeneração Combinada Subaguda/etiologia , Deficiência de Vitamina B 12/complicações , Deficiência de Vitamina B 12/diagnóstico , Vitamina B 12/metabolismo , Erros Inatos do Metabolismo dos Aminoácidos/complicações , Erros Inatos do Metabolismo dos Aminoácidos/diagnóstico , Ácido MetilmalônicoRESUMO
Nitrous oxide is among the most common drugs used by adolescents and young adults, and its neuropsychiatric sequelae are severe but reversible with timely treatment. The causal mechanism relates to impaired metabolism of vitamin B12, which is necessary for the development and maintenance of the myelin sheath. Individuals most susceptible to neuropsychiatric manifestations are those with a secondary cause of vitamin B12 deficiency, including nutritional deficiency and impaired absorption, or an alternative cause of impaired metaboclism. We describe the case of a man in his thirties who developed subacute combined degeneration of the spinal cord and polyneuropathy in the setting of recreational nitrous oxide use and autoimmune atrophic gastritis. Our case highlights clinical pearls for diagnosis and treatment, differential diagnosis, common concomitant aetiologies and the importance of screening for substance use disorder and psychiatric comorbidities.
Assuntos
Gastrite Atrófica , Gastrite , Degeneração Combinada Subaguda , Deficiência de Vitamina B 12 , Humanos , Masculino , Atrofia/patologia , Gastrite/induzido quimicamente , Gastrite/diagnóstico , Gastrite/tratamento farmacológico , Gastrite Atrófica/complicações , Óxido Nitroso/efeitos adversos , Medula Espinal/diagnóstico por imagem , Medula Espinal/patologia , Degeneração Combinada Subaguda/tratamento farmacológico , Degeneração Combinada Subaguda/etiologia , Vitamina B 12/metabolismo , Deficiência de Vitamina B 12/induzido quimicamente , Deficiência de Vitamina B 12/complicações , Deficiência de Vitamina B 12/diagnóstico , AdultoRESUMO
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.
Assuntos
Oxibato de Sódio , Degeneração Combinada Subaguda , Glicemia , Colesterol , Hemoglobinas Glicadas , Homocisteína , Humanos , Estudos Retrospectivos , Oxibato de Sódio/uso terapêutico , Degeneração Combinada Subaguda/etiologia , Vitamina B 12/uso terapêuticoRESUMO
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.
Assuntos
Cirurgia Bariátrica , Transtornos Neurológicos da Marcha , Degeneração Combinada Subaguda , Complexo Vitamínico B , Adolescente , Cirurgia Bariátrica/efeitos adversos , Feminino , Homocisteína , Humanos , Óxido Nitroso/efeitos adversos , Parestesia , Degeneração Combinada Subaguda/induzido quimicamente , Degeneração Combinada Subaguda/etiologia , Vitamina B 12/efeitos adversos , Complexo Vitamínico B/farmacologia , Complexo Vitamínico B/uso terapêuticoRESUMO
Background: Autoimmune gastritis (AIG) and Primary Sjögren's syndrome (pSS) are both autoimmune diseases with low prevalence in China. Subacute combined degeneration (SCD) of the spinal cord is the most common neurological manifestation of vitamin B12 deficiency. Until now, a patient with pSS and complications of AIG including SCD has not been reported. Case Presentation: A 69-year-old woman presented with palpitations and symmetrical and progressive numbness in her hands and feet. The patient had a sense of stepping on cotton and could not write or walk without help. We reviewed the patient's history and analyzed her blood tests, imaging, gastroscopic findings, and pathological results. The patient fulfilled the criteria of AIG, pSS, spinal cord SCD and early pernicious anemia (PA) simultaneously. Although pSS can lead to reduction of vitamin B12, this is the first overlapping case of pSS with spinal cord SCD. After symptomatic treatment, the patient returned to a normal life. Conclusions: This first report about the coexistence of pSS and complications of AIG including SCD and PA will promote a better understanding of the relationship between these diseases.
Assuntos
Anemia Perniciosa , Gastrite , Síndrome de Sjogren , Degeneração Combinada Subaguda , Idoso , Anemia Perniciosa/complicações , Anemia Perniciosa/diagnóstico , Feminino , Gastrite/complicações , Gastrite/diagnóstico , Humanos , Síndrome de Sjogren/complicações , Síndrome de Sjogren/diagnóstico , Degeneração Combinada Subaguda/complicações , Degeneração Combinada Subaguda/etiologiaRESUMO
We report a case of subacute combined spinal cord degeneration (SCD) caused by vegetarianism and autoimmune gastritis, which is rarely reported in Japan, and which showed improvement in symptoms and imaging findings after vitamin B12 administration. As delayed treatment can lead to irreversible damage, we suggest that patients with characteristic abnormal signals in the posterior cervical cord should be examined while considering the possibility that SCD may occur even in the absence of a history of gastrectomy or heavy drinking. We also describe the patient's reversible abnormal signals in the cerebral white matter on magnetic resonance imaging, indicative of an early sign of leukoencephalopathy associated with vitamin B12 deficiency. J. Med. Invest. 69 : 299-301, August, 2022.
Assuntos
Leucoencefalopatias , Degeneração Combinada Subaguda , Deficiência de Vitamina B 12 , Humanos , Leucoencefalopatias/complicações , Imageamento por Ressonância Magnética , Degeneração Combinada Subaguda/diagnóstico por imagem , Degeneração Combinada Subaguda/tratamento farmacológico , Degeneração Combinada Subaguda/etiologia , Vitamina B 12/uso terapêutico , Deficiência de Vitamina B 12/complicações , Deficiência de Vitamina B 12/diagnóstico por imagem , Deficiência de Vitamina B 12/tratamento farmacológico , VitaminasRESUMO
INTRODUCTION: Autoimmune gastritis causing both subacute combined degeneration of the spinal cord and pernicious anemia is rare in clinical practice. Here, we report a case of subacute combined degeneration of the spinal cord and pernicious anemia resulting from vitamin B12 deficiency due to autoimmune gastritis. PATIENT CONCERNS: A 66-year-old woman presented with a 2-month history of numbness in her extremities. DIAGNOSES: The diagnoses were (1) autoimmune gastritis (2) subacute combined degeneration of the spinal cord (3) pernicious anemia (4) hypergastrinemia (5) chronic lymphocytic thyroiditis. INTERVENTIONS: The patient received intramuscular methylcobalamin treatment for 5 days, followed by oral methylcobalamin daily.Outcomes: Symptoms improved, and anemia recovered in the second month after discharge. She discontinued her medication afterward, and the neurological symptoms recurred. CONCLUSIONS: Autoimmune gastritis can lead to several diseases if not intervened in the early course. Neuropathy and hematopathy recur with treatment discontinuity. Methylcobalamin and adenosylcobalamin are unlikely to be more effective than vitamin B12.
Assuntos
Anemia Perniciosa , Gastrite , Degeneração Combinada Subaguda , Deficiência de Vitamina B 12 , Idoso , Anemia Perniciosa/complicações , Anemia Perniciosa/diagnóstico , Anemia Perniciosa/tratamento farmacológico , Feminino , Gastrite/complicações , Gastrite/diagnóstico , Gastrite/tratamento farmacológico , Humanos , Degeneração Combinada Subaguda/diagnóstico , Degeneração Combinada Subaguda/tratamento farmacológico , Degeneração Combinada Subaguda/etiologia , Deficiência de Vitamina B 12/complicações , Deficiência de Vitamina B 12/diagnóstico , Deficiência de Vitamina B 12/tratamento farmacológicoRESUMO
Subacute combined degeneration of the spinal cord (SACD), a condition resulting from vitamin B12 deficiency, generally affects elderly people. We present a 12-year-old girl, who, despite a non-vegetarian diet and no obvious etiological factors, developed SACD.
Assuntos
Medula Espinal/patologia , Degeneração Combinada Subaguda/patologia , Deficiência de Vitamina B 12/complicações , Criança , Dieta , Feminino , Humanos , Injeções Intramusculares , Imageamento por Ressonância Magnética , Degeneração Combinada Subaguda/tratamento farmacológico , Degeneração Combinada Subaguda/etiologia , Resultado do Tratamento , Vitamina B 12/uso terapêutico , Deficiência de Vitamina B 12/tratamento farmacológicoRESUMO
A 68-year-old woman presented with a 2-year history of worsening unsteady gait. Her neurological examination revealed peripheral neuropathy with lower limb sensory dominance. T2-weighted imaging revealed a disorder of the posterior cervical cord. Blood test findings revealed vitamin B12 deficiency, and gastroscopy revealed typical findings of autoimmune gastritis. She received vitamin B12 supplementation, but some peripheral neuropathy symptoms persisted due to longstanding vitamin B12 deficiency. Asymptomatic patients should undergo gastroscopy to detect autoimmune gastritis, as chronic vitamin B12 deficiency causes irreversible peripheral neuropathy.
Assuntos
Doenças Autoimunes/complicações , Gastrite/complicações , Gastrite/imunologia , Doenças do Sistema Nervoso Periférico/etiologia , Doenças do Sistema Nervoso Periférico/fisiopatologia , Degeneração Combinada Subaguda/etiologia , Degeneração Combinada Subaguda/fisiopatologia , Deficiência de Vitamina B 12/fisiopatologia , Idoso , Feminino , Humanos , Japão , Degeneração Combinada Subaguda/diagnóstico por imagem , Deficiência de Vitamina B 12/sangueRESUMO
BACKGROUND: To determine the prevalence of subacute combined degeneration (SCD) patients with normal or elevated serum vitamin B12 level and to identify clinical characteristics of these patients. METHODS: We searched PubMed, EMBASE, and Cochrane library, without language restriction up to June 2019 and included studies with SCD patients who were diagnosed with normal or elevated serum vitamin B12 levels. Meta-analysis was performed to estimate the prevalence of SCD in patients with normal or elevated serum vitamin B12 levels and compare the differences of clinical data between patients with low and no-low serum vitamin B12 level. RESULTS: Six studies were included in our analysis, with a total number of 181 patients involved. The pooled proportion in patients with no-low serum vitamin B12 level was 31.0% (95% confidence interval [CI]: 22.5-40.8). There was no significant difference in the level of hemoglobin (Mean difference (MD): -3.05, 95% CI: -12.42 to 6.33. Pâ=â0.52) and erythrocyte mean corpuscular volume (MD: -2.37, 95% CI: -11.17 to 6.43, Pâ=â0.60) between SCD patients with no-low and those with low serum vitamin B12 levels. The meta-analysis showed that the functional disability rating scale on admission in patients with low serum vitamin B12 level was no worse than that with normal or elevated serum vitamin B12 level (MD:â0.29, 95% CI: -0.58 to 1.16, Pâ=â0.51). CONCLUSION: Decreased level of serum vitamin B12 may not be a necessity for the diagnosis of SCD. Approximately one third of the SCD patients have normal or elevated serum vitamin B12 level. No differences were found in clinical severity between patients with normal or elevated serum vitamin B12 level and those with low level of serum vitamin B12 on admission.