Nerve conduction study findings of subclinical diabetic neuropathy in newly diagnosed diabetic patients

Background: Diabetes induced neuropathy is one of the most challenging complication of diabetes mellitus and is one of the major causes of non-traumatic limb amputation. The exact prevalence of diabetic neuropathy is not known and reports shows variable prevalence. There are good number of patients, who have subclinical neuropathy at the time of detection of diabetes. Aim: He aim of this study was to investigate the prevalence of subclinical neuropathy in newly diagnosed diabetic patients. Methods and Material: In this study, 104 diabetic patients and 50 healthy subjects have been studied prospectively during 2011 2012, in OPD of Department of Medicine, M.L.B. Medical college, Jhansi. All patients were clinically asymptomatic. At least one abnormal independent neurophysiological nerve parameters, which were required as the criterion of the peripheral nervous system sub clinical involvement, following results were drown. Results: The mean MNCV was significantly lower in the diabetic group (39.0 ± 5.0 m/s) when compared with nondiabetic controls (53 ± 4 m/s; P=0.0001). The mean SNCV value of case (44.05+/-11.8 m/s) and control (46+/-5 m/s) had no significant difference( p value=.37). In motor nerve conduction studies, the distal motor latency (DML) is most frequent abnormal parameter in studied nerves of upper limbs, while mean f, and MNCV is the most frequent abnormality in lower limb nerves. In all sensory nerve conduction study, the most frequent abnormal parameter was the onset of latency. Conclusion: We conclude that the percentage of abnormal electrophysiological parameter in different motor and sensory nerve were 77% in sural nerve, 66% in peroneal nerve, 63.4% in posterior tibial nerve, 57% in median motor nerve, 46.6% in ulnar motor nerve, 40% in median sensory nerve, and 47% in ulnar sensory nerve. Thus, the incidence of subclinical neuropathy is significantly higher in newly detected diabetics in this study. Key word: Nerve Conduction, Subclinical Diabetic Neuropathy Introduction Diabetic neuropathy (DN) is an important complication of diabetes mellitus, leading to the high morbidity besides huge cost involve in treatment. It invokes physical and mental trauma to patients and his nearer ones and also involve doctors of several specialties. It is also responsible for 50-75% of non-traumatic amputation. D.N. is a set of clinical syndromes that affect distinct regions of the nervous system. It may be silent and go undetected or it may present with clinical symptoms and signs that are nonspecific and insidious with slow progression. The true prevalence is not known and reports vary from 10% to 90% in diabetic patients, depending on the criteria and methods used to define neuropathy. According to Dyck PJ ET al, Twenty five percent of patients attending a diabetes clinic volunteered symptoms; 50% were found to have neuropathy after a simple clinical test such as the ankle jerk or vibration perception test; almost 90% tested positive to sophisticated tests of autonomic function or peripheral sensation. Neurological complications occur equally in type 1 and type 2 diabetes mellitus and additionally in various forms of acquired diabetes. The major morbidity associated with somatic neuropathy is foot ulceration, the precursor of gangrene and limb loss. Neuropathy increases the risk of amputation 1.7 fold; 12 fold, if there is deformity (itself a consequence of neuropathy), and 36 fold, if there is a history of previous ulceration. Ram Babu Singh et al Nerve conduction study findings of subclinical diabetic neuropathy in newly.... Indian Journal of Neurosciences, October-December, 2015;1(1):1-7 2 This study is aimed to determine the situation of the deferent nerve fiber types and the prevalence of subclinical neuropathy in type 1 & 2 diabetes mellitus, who are first time diagnosed and do not complain of any clinical symptoms. Material and Methods A total 104 random patients of newly diagnosed type-1& type-2 diabetes mellitus were studied, who were attending the OPDs of department of medicine at M.L.B. Medical College, Jhansi during 20112012. Informed consent prior study were taken from all the subjects (Group I). Control (Group II) group consist of patient’s relatives and volunteers of similar age & sex with similar nutritional status but without any obvious cause of neuropathy. Complete history and physical examination of the cases were done. In history symptoms of autonomic dysfunction and peripheral neuropathies were included such as Tingling, numbness or pain the toes, feet legs, fingers, hands and arms, wasting of the muscles of the feet or hands, indigestion, nausea or vomiting, diarrhea or constipation, Dizziness or faintness, Problem with urination and erectile dysfunction (impotence), Vaginal dryness, Weakness, weight loss or depression. During neurological examination patients were examined as per Diabetic Neuropathy Examination, a scoring system for distal polyneuropathy, for determining the presence and severity of distal symmetrical polyneuropathy. (Rochester Diabetic Neuropathy Study, 1997) DNE (Diabetic Neuropathy Examination): This is a modified form of neuropathy disability score (NDS). NDS is a widely accepted and validated physical examination scoring system, with 8 items used to diagnose neuropathy. DNE is a scoring system with 8 items. It is sensitive, fast and easy to perform in clinical practice. 1. Muscle strength: Quadriceps femoris: extension of the knee; Tibialis anterior: dorsiflexion of the foot 2. Reflex: Ankle jerk 3. Sensation index finger: Sensitivity of pinpricks 4. Sensation: big toe: Sensitivity to pin pricks, Sensitivity to touch, Vibration perception, Sensitivity to joint position Only the right limbs are tested scoring done from 0 to 2: 0 = normal 1 = mild/moderate deficit, Muscle strength: Medical Research Council scale >3-4.  Reflex: decreased but present  Sensation: decreased but present. 2 =  severely disturbed/absent  Muscle strength: Medical Research Council scale< 3-4