| Background and objectiveSubacute combined degeneration of the spinal cord(SCD)is a disease involving the posterior and lateral funiculus of the spinal cord and peripheral nerves caused by the vitamin B12(Vit B12)deficiency.Vit B12 plays a critical role in DNA synthesis and fatty acid degradation.Vit B12 deficiency not only reduces the activity of the essential enzymes involved in the preservation of myelin,but also causes the accumulation of methylmalonic acid and homocysteine(Hcy),which can lead to myelin toxicity,and then causes symptoms in the nervous system.SCD is often characterized by peripheral neuropathy,deep sensory loss and sensory ataxia,and untimely treatment can lead to paraplegia and even death.Therefore,early diagnosis and timely intervention of SCD are crucial.The onset of SCD is concealed and clinical manifestations are various.Some patients can have rare symptoms such as postural hypotension.Although serum Vit B12 can assist in confirming the diagnosis of SCD,some patients have Vit B12 levels within the normal range.Spinal magnetic resonance imaging(MRI)is a technique for evaluation of spinal cord abnormality in patients with SCD and has specific manifestations,which is important in the diagnosis of SCD.However,not all patients with SCD can had the lesions on spinal cord MRI.So we compared the differences between patients with lesions on spinal cord MRI and those without lesions to explore the factors affecting the manifestations of spinal cord MRI in patients with SCD.In addition,urination disorders are rarely reported in patients with SCD.And in clinical practice,urination disorders are often ignored,or diagnosis of SCD was suspected because of appearance of urination disorders.Therefore,we further compared the patients with urination disorders and those without urination disorders to explore the related factors and to deepen clinicians’ understanding of the characteristics of urination disorders in SCD.Materials and MethodsThis study retrospectively analyzed the demographic data,clinical symptoms,signs,medical history,laboratory examination,neuroelectrophysiology date and spinal cord MRI findings of 119 patients diagnosed with SCD in the Department of Neurology of the first affiliated Hospital of Zhengzhou University from August 2019 to November 2020.(1)The patients were divided into two groups according to presence of lesions on spinal cord MRI to explore the factors between two groups and neurological dysfunction score.(2)The patients were divided into two groups according to presence of urination disorders to explore the factors between two groups and neurological dysfunction score.Results1 Clinical features of SCDA total of 119 patients with SCD were collected,including 79 males(66.4%)and 40 females(33.6%).The average onset age was(56.61±14.67)years.Gastropathy was the most common medical history of patients with SCD followed by history of long-term vegetarian diet,alcoholism,diabetes and nitrous oxide inhalation.The main clinical symptoms are numbness and weakness of limbs,walking instability and dizziness.The main signs are abnormal deep and superficial sensation,positive Romberg sign,tendon reflex changes,decreased muscle strength and positive pathological reflexes.Patients with SCD may have some or all of the symptoms and signs.In this study,15 patients have sensory plane(12.6%).Among the 119 patients,hemoglobin was decreased in 68 cases(57.1%),serum Vit B12 was decreased in 43 cases(36.1%),mean corpuscular volume(MCV)was increased in 61 cases(51.3%),and Hey was increased in 71 cases(59.7%).Anti-parietal cell antibodies and anti-internal factor antibodies were tested for 47 patients,and 28 cases(59.6%)were antibody positive.Neuroelectrophysiological examination showed that the abnormal rate of sensory nerve was significantly higher than that of motor nerve(35.8%vs 26.8%,P<0.001).The abnormal rate of lower limbs nerve was significantly higher than that in upper limbs(34.9%vs 27.0%,P=0.001).The abnormal rate of P40 in somatosensory evoked potential was higher than that of N20(84.6%vs 42.2%,P<0.001).The abnormal rate of lower limbs was higher than that of upper limbs in motor evoked potential(54.3%vs 16.0%,P<0.001).Spinal cord MRI examination was performed in 119 patients.36 patients(30.3%)had lesions in the spinal cord,mainly involving the cervical spinal cord,followed by the thoracic spinal cord,and a few of them could involve the lumbar spinal cord.Head MRI examination was performed in 65 patients,and 50 patients(76.9%)showed white matter demyelination.2 The related factors and neurological dysfunction scores between patients with lesions on spinal cord MRI and those without lesionsCompared with the patients without lesions on spinal cord MRI,the patients with lesions had a higher proportion of disease course less than or equal to 3 months(58.3%vs 38.6%,P=0.046),a higher proportion of nitrous oxide inhalation history(8.3%vs 0,P=0.026).And the patients with lesions on spinal cord MRI more prone to increased MCV(75.0%vs 41.0%,P=0.001),increased Hey(75.0%vs 53.0%,P=0.025)and megaloblastic anemia(63.9%vs 32.5%,P=0.001).The age of onset in the patients with lesions on spinal cord MRI was significantly younger than those without lesions(47.39 ±15.79 vs 60.60 ±12.25,P<0.001).The detection rate of MRI lesions in patients who were<45 years old(68.4%)was higher than that in patients who were 45-64 years(30.0%)and≥65 years old(12.5%)(P<0.001).3 The related factors and neurological dysfunction scores between patients with urination disorders and those without urination disordersThere were 18 patients with urination disorders.There was no significant difference in age at onset,disease course,gastropathy,long-term vegetarian diet,alcoholism,diabetes,nitrous oxide inhalation,hemoglobin,MCV,Hey,Vit B12 and folic acid between patients with urination disorders and those without urination disorders.Compared with the patients without urination disorders,the patients with urination disorders had higher positioning score(2.56±0.62 vs 1.62±0.80,P<0.001),higher gait disorder score(2.89±0.96 vs 1.47±1.25,P<0.001),higher pyramidal tract involvement score(1.06±1.11 vs 0.29±0,62,P<0.001)and higher neurological dysfunction score(6.78 ±2.60 vs 4.42±2.15,P=0.001).Compared with the patients without urination disorders,the patients with urination disorders was more likely to have limb weakness(83.3%vs 51.5%,P=0.012),decreased muscle strength(83.3%vs 33.7%,P<0.001)and positive pathological reflexes(44.4%vs 18.8%,P=0.037).In the patients with urination disorders,the abnormal rate of motor nerve(48.1%vs 23.4%,P<0.001),sensory nerve(45.7%vs 34.2%,P=0.033),P40(97.1%vs 82.5%,P=0.030)and pyramidal tract conduction of upper and lower extremities(54.2%vs 10.8%,P<0.001;70.6%vs 51.5%,P=0.039)were higher than patients without urination disorders.Conclusion1.The decrease of serum Vit B12 level is not a necessary standard for SCD diagnosis.Neuroelectrophysiology and spinal cord MRI are important auxiliary examinations,which can indicate the lesion site of patients with SCD.The neuroelectrophysiological examination shows that the posterior funiculus is more likely to be affected.The sensation nerves more severely affected than motor nerve,and the lower limb more severely affected than the upper limb.Spinal cord MRI predominantly showed that abnormal signal posterior to the spinal cord.Cervical spinal cord is the most common site of involvement,followed by thoracic spinal cord,and a few are lumbar spinal cord.2.The detection rate of spinal cord MRI lesions in SCD was 30.3%,and the detection rate of MRI lesions in patients who were less than 45 years old was higher,which may be related to the stronger immuno-inflammatory response in the young patients.The abnormality of spinal cord MRI in patients with SCD may be related to younger age of onset,shorter disease course of SCD,nitrous oxide inhalation,increased MCV and increased Hey.3.The occurrence of urination disorders has nothing to do with the disease course of SCD patients,not only in the late stage.SCD patients with urination disorders have more severe neurological dysfunction and often have symptoms of lateral cord involvement. |
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