Study Progress Of Subacute Combined Degeneration Of The Spinal Cord

Subacute combined degeneration of the spinal cord(SCD)is a neurological degeneration disease due to vitamin B12 deficiency.It involves the posterior and lateral columns of the spinal cord, and sometimes the peripheral nerves. The typical clinical manifestation is deep sensation disorder in extremities or both lower extremities, sensory ataxia, spastic paralysis and peripheral neuropathy such as extremity numbness.Once the diagnosis of subacute combined degeneration of the spinal cord(SCD) depended on clinical manifestation and the measurement of serum level of vitamin B12.And it's hard to make a final diagnosis to those patients with normal range of serum level of vitamin B12 or atypia clinical manifestation.It is the versatility and the non-specificity of clinical manifestation that makes the diagnosis difficult. Once be final diagnosed as SCD,the treatment is simple and effective.And in most of the time,a delayed diagnosis of SCD causes unreversible and fatal status.To make a summarize,we need to focus on making a early diagnosis,giving promptly treatment to avoid permanent nerve system disfunction. But more and more case reports in which the diagnosis had been delayed due to atypia clinical manifestation or the normal range of serum vitamin B12 cause physician to challenge the old diagnostic criteria.With the generally using of electrophysiology and magnetic resonance imaging in clinical,we have a deeper recognition in SCD which given us new sights about it. This review summarizing many literatures give a more detailed description about SCD aiming to elevate our recognition about this curable disease and help making early diagnosis.Conclusion:The SCD is not a rare clinical disease; There was no linear correlation between the severity of lesions in CNS and ferrohemoglobin level or level of serum VB12;A low serum vitamin B12 will assist us to make the diagnosis of SCD,but it is not essential; Observing the curative effect to vitamin B12 substitution treatment help us to comfirm the diagnosis; Electrophysiology,magnetic resonance imaging,new biochemical indicator such as serum homocysteic acid, the level of myelin basic protein(MBP) in cerebrospinal fluid(CSF) will assist in the early diagnosis of SCD. Evoked potential is critical for early diagnose and identification of silent cases of SCD; Lesions of SCD in spinal cord or brain can be objectively demonstrated in MRI mainly in posterior and lateral revealing columns.MRI clearly showed symmetrical iso-intense on T1 and hyper-intense on T2.Most lesions were seen at the thoracic cord. MRI help to make the diagnosis of SCD especially in those patients with normal range of serum vitamin B12. The level of MBP in CSF can reflect the severity of the lesion and prosthetic state of myelin sheath. According to many literatures, electrophysiology and magnetic resonance image can reveal the diseased region, reflect the nature and help us to observe the treatment effect. They have great value in helping making a diagnosis, revealing the diseased region and observing the treatment effect. It is essential to do electrophysiology and magnetic resonance image while you cannot tell the difference between peripheral nerve disease and myelopathy in patients with atypia clinical manifestation. Spinal cord MRI and EP could objectively show the lesions of SCD and the change before and after the treatment. These examinations and the follow-up of disease could be helpful in the diagnosis of SCD.