Study In Sporadic Amyotrophic Lateral Sclerosis Patients With Abnormal Sensory Nerve

Objective:To analysis the finding of sensory nerve conduction test (SNCT) and the causes of abnormal sensory nerve in patients with SALS and study the clinical significance of SNCT.Methods:We collected the patients with sporadic amyotrophic lateral sclerosis in outpatient and inpatient department of the second hospital affiliated to Zhejiang University Medical College from January2010to October2014. The information about their gender, age, handedness, onset, occupation, disease duration, past history of disease, trauma history, symptoms, signs, laboratory examination, imaging examination and so on were recorded. Keypoint.Net was applied to estimate the sensory nerve conduction velocities (SCV) and sensory nerve action potential (SNAP) amplitude of median nerve, ulnar nerve, sural nerve and superficial peroneal nerve in163patients. SNCT contained at least two sensory nerves of both upper limb and lower limb. Electromyography(EMG) and motor nerve conduction test(MNCT) examination were also observed. Each of SNCT results compared with our normal value, below the lower line was abnormal. The ALS patients were divided into two groups according to age:<55y group and>55y group. At the same time,100healthy people which matched with age and sex were selected for control. Furthermore, all the indexes were compared among groups.Results:1. Clinical date:A total of163patients with SALS were recruited in our study, male101cases and female62cases, the ratio of male:female was1.6:1.54cases in <45y group and109cases in>55y group. The mean age of onset was56.5±10.9years. The time duration between onset and diagnosis was14.3±8.9months on average. Many of patients came from Zhejiang. The top2profession of ALS patients were agriculture, forestry, fishery workers and factory workers. The most common onset site of disease was cervical segments. Some ALS patients had subjective feeling obstacle such as numb, pain, cold, acid bilges feeling etc, most common of that is numbness.2. Diffuse neurogenic changes on EMG presented in all patients. MCV of all patients roughly normal. CMAP amplitudes in a few patients of obvious muscle atrophy moderately reduced.3. Compared to control group, a significant difference was noted in SCV and SNAP amplitude of all tested sensory nerves except SNAP of median nerve, ulnar nerve and sural nerve in<55y ALS group. SCV and SNAP amplitude of median nerve, ulnar nerve, sural nerve and superficial peroneal nerve was a significant difference in>55y ALS group (P<0.05)4.10abnormal median nerves,12abnormal ulnar nerves,9abnormal sural nerves and16abnormal superficial peroneal nerves respectively were found in<55y ALS group. While28abnormal median nerves,41abnormal ulnar nerves,27abnormal sural nerves and81abnormal superficial peroneal nerves respectively were found in≥55y ALS group. The constituent ratio of three parameters changes include SCV, SNAP amplitude, SCV and SNAP amplitude among two groups didn’t reach statistical significance (P>0.05) 5. We checked out four nerves were abnormal in1case, three nerves were abnormal in5case, two nerves were abnormal in7case, one nerves were abnormal in14cases among<55y ALS group. While five nerves were abnormal in2case, four nerves were abnormal in13case, three nerves were abnormal in14case, two nerves were abnormal in20case, one nerves were abnormal in33case among>55y ALS group. The number of abnormal case between two groups of ALS patients was no statistically significant (P>0.05).6. Main cause of abnormal sensory nerve conduction in ALS:Injury and trauma fracture were the main reasons in<55y ALS group while peripheral nerve crush lesion, trauma, some occupational factors, lack of nutrition, diabetes are the main reasons in≥55y ALS group.Conclusions:1. ALS patients might have peripheral sensory nerve obstacle. So when sensory conduction test showing abnormal, the diagnosis of ALS could not be eliminated. However, the sensory conduction test in ALS was normal except few. There are many reasons cause the abnormality of sensory nerve conduction of ALS, such as diabetes, peripheral nerve crush lesion, trauma, some occupational factors and so on.2. The main complains of ALS patients were unrelated to the change of electrophysiological examination, unless combined with definite peripheral neuropathy.3. The parameters changes of sensory nerve conduction test in ALS included SCV slowed and/or SNAP amplitude decreased. In different age group, the constituent ratio of three parameters changes showed no difference.4.The purpose of sensory nerve conduction test is to exclude peripheral neuropathy, not to exclude ALS. But generally, the SNCT in ALS is normal.