- Email: [email protected]
P4.3 Single fiber electromyography in idiopathic hyperCKemia
14th ECCN / 4th ICTMS/DCS have consequences on cerebral function appreciated by conventional electroencephalogram monitoring. Methods: 12 premature newborn under 30 GA admitted in neonate ICU in CHU Lille between 2007 and 2008 were included. Patent ductus arteriosus was defined on two criteria. Continuous electroencephalographic monitoring (8-channel c-EEG) (Micromed system plus® ) starts just after indication of surgical closure of ductus arteriosus and was pursued during several days after surgery till the end of sedative treatment. Signal EEG analysis was applied including: spectral power, BSR burst suppression rate and amplitude of amplitudeintegrated electroencephalogram (a EEG);. Results: After surgical closure, signicative increase of a-EEG maxima amplitude, of 1 5 Hz biparietal and left frontotemporal spectral power and reduction in burst suppression rate were noted comparatively to presurgical values. Conclusions: Surgical closure of patent ductus arteriosus is associated with a global increase of cerebral EEG activity in very premature newborn. It appears, in this preliminary study, that large left to right shunt can significantly modify cerebral function in very premature newborn. These criteria give good arguments for surgical closure of patent ductus arteriosus in very premature newborn. P3.20 Spontaneous and odor-evoked seizures in synapsin I/II/III knockout mice: electrophysiological characterization M. Cambiaghi1 , M. Cursi1 , L. Teneud1 , E. Monzani2 , F. Minicucci1 , G. Comi1 , F. Valtorta2 , L. Leocani1 1 Neurological Department, INSPE Neuroscience Division, San Raffaele, Scientific Institute and Vita-Salute University, Milan, Italy, 2 Neuropsychopharmacology Unit; Neuroscience Division, San Raffaele, Scientific Institute and Vita-Salute University, Milan, Italy Introduction: Approximately 1% of the human population suffers from some form of epilepsy and the studies of animal models are of great advantage for the study of underlying mechanisms and new therapeutic strategies. Synapsins (SynI, SynII, SynIII) are a multigene family of synaptic vesicle (SV) phosphoproteins implicated in the regulation of synaptic transmission and plasticity. The genetic inactivation of either synapsin I and II leads to epilepsy, and the phenotype is more severe when both genes are inactivated. On the contrary, synapsin I/II/III KO (triple knockout, TKO) mice exhibit a milder epileptic phenotype, displaying only rare spontaneous seizures. Objectives: The aim of this project is to study the electrophysiological behavior of Syn-TKO mice epilepsy by video-EEG analysis. Methods: We implanted brain epidural screw electrodes in adult SynTKO and matched wt mice to record video-EEG and a wire electrode to concomitantly record EMG. We analyzed spontaneous and odor-evoked seizures and the baseline interictal EEG in awake freely-moving animals by power spectrum measures. Results: EEG seizures did not differ in duration and morphology between spontaneous and odor-evoked. In half of the recorded seizures we found a typical post-critical phase at about 4 Hz frequency, characterized by complete immobility of the animals. The power spectrum analysis of interictal EEG revealed a difference in 2 3 Hz and 7 9 Hz potency and peak-frequency between the two groups. Conclusions: These preliminary data indicate that Syn-TKO are characterized by an altered baseline EEG activity and that seizures can be followed by an absence-like phenotype. This rare-epilepsy animal model could be of great interest in studying SV relevance in spontaneous and evoked neuronal network firing.
Poster session 4. EMG, nerve conduction, peripheral neuropathies 1 P4.1 Comparative study of prognostic value of quantitative versus conventional electromyography in Bell’s palsy D. Mohasseb1 , G. El-Tantawi1 , H. Sultan1 , R. El-Nemr1 Department of Physical Medicine, Rheumatology, and Rehabilitation, Alexandria University, Alexandria, Egypt
1
Introduction: Bell’s palsy is the most frequent cranial mononeuropathy. Prognosis is a challenging problem concerning facial palsy. The role of
S71 conventional electromyography in assessment of prognosis of acute Bell’s palsy has been determined. The use of quantitative electromyography (QEMG) for predicting outcome in acute Bell’s palsy is however still deficient. Objective: This study aimed at evaluating the prognostic value of conventional versus QEMG in acute Bell’s palsy. Methods: Twenty patients (15 women and 5 men; mean age 35.55±13.7 years) with acute unilateral Bell’s palsy were included. Fifteen healthy individuals were included as a control group. HouseBrackmann grading system (HBG) was used to grade facial paralysis. Electrophysiological examination included motor conduction study of facial nerves as well as conventional and QEMG of the nasalis muscle. Evaluations were performed 7 14 days post-paralysis and at 2 3 months thereafter. Patients were classified according to their HBG at follow up into those with satisfactory recovery and those with unsatisfactory recovery. Results: At baseline, 6 cases demonstrated reduced compound muscle action potential (CMAP) amplitude and denervation potentials at rest. Evidence of demyelination was detected in 14 patients. CMAP amplitude and denervation potentials correlated significantly with HBG at follow up (Rho = 0.81, P < 0.001; Rho = 5.098, P = 0.038 respectively). Multi-motor unit action potential analysis (MMA) revealed significantly increased area and thickness of motor units in patients with satisfactory recovery (11 patients). These parameters correlated well with facial grading at follow up (Rho = 0.514, P = 0.02; Rho = 0.454, P = 0.045 respectively). Conclusion: The role of conventional electromyography in assessment of prognosis of acute Bell’s palsy is documented. The prognostic value of QEMG can be appreciated and MMA can be of value in determining the prognosis in acute Bell’s palsy. P4.2 Lewis-Sumner syndrome: the Asian experience Y.L. Lo1 , Y.F. Dan2 , Y.E. Tan3 , T.H. Leoh2 1 Department of Neurology, National Neuroscience Institute, Singapore General Hospital, Singapore, Singapore, 2 Singapore General Hospital, Singapore, Singapore, 3 Sinagpore General Hospital, Singapore, Singapore Introduction: The Lewis-Sumner syndrome (LSS) is a rare immunemediated peripheral nerve disorder presenting with asymmetric upper limb sensory complaints and motor weakness. Asian patients with LSS have not been reported in the English literature to our knowledge. Methods: Three Asian patients with features of LSS were prospectively studied clinically and electrophysiologically. Motor root stimulation at the neck and at Erb’s point was performed. Results: Our patients tended to older, female and involve upper limbs exclusively than those in the West. They have markedly longer disease duration before diagnosis was made, which could also be due to difficulty in eliciting motor root conduction block as a sign of proximal demyelination, as observed in every patient. Patient 1 exhibited motor root conduction block at right C8 (abductor pollicis brevis and abductor digiti minimi muscles). Patient 2 exhibited motor root conduction blocks at right C8 (abductor digiti minimi), left C8 (abductor digiti minimi) and left C7 (extensor indicis). Patient 3 exhibited motor root conduction block at right C6 (biceps brachii). Pain is a universal feature, as is sensory nerve conduction abnormality. None responded well to immunotherapy, but disease stabilization was observed over the chronic course. Conclusions: Although rare, these unique observations in Asian patients with LSS differ from those reported in Western literature. Presence of motor root conduction block demonstrated for the first time is instrumental in establishing diagnosis. P4.3 Single fiber electromyography in idiopathic hyperCKemia A. Nicotra1 , V. Pavone2 , D. Restivo3 1 Department of Clinical Neurophysiology, Imperial College Healthcare NHS Trust, London, United Kingdom, 2 Department of Orthopedics, V. Emanuele Hospital, University of Catania, Catania, Italy, 3 Department of Neurology, “Nuovo Garibaldi” Hospital, Catania, Italy Introduction: Persistently raised serum creatine kinase (sCK), or hyperCKemia, is considered the biological hallmark of neuromuscular diseases. When asymptomatic or isolated hyperCKemia is found without an underlying explainable cause is referred to as “idiopathic hyperCKemia”.
S72
Poster presentations: Poster session 4. EMG, nerve conduction, peripheral neuropathies
Objectives: To assess whether single-fiber electromyography (SFEMG), and specifically fiber density (FD) measurement, may detect electrophysiological abnormalities in subjects with hyperCKemia and help reveal the presence of subclinical (or pauci-or asymptomatic) muscular disorders. Methods: Nineteen subjects (13 males, 6 females; age: 26±10 years) with hyperCKemia without evident clinical muscle involvement and 15 healthy controls were studied. Electrophysiological investigations including nerve conduction studies (NCS), quantitative EMG (QEMG), SFEMG with FD measurement, and muscle biopsy were performed. Results: In the controls, all electrophysiological studies were normal. In subjects with hyperCKemia, NCS were normal but QEMG showed abnormalities in 5 (26%) subjects. SFEMG showed increased FD (>3) in a total of 12 (63%) while was normal in the remaining 7 (29%) subjects. The mean FD value was 2.6±0.5 in the control and 4±1.6 (p = 0.001) in the hyperCKemia group. In the 12 subjects with hyperCKemia and abnormal SFEMG, muscle biopsy was also abnormal. Conclusions: SFEMG revealed electrophysiological abnormalities in 63% of subjects with hyperCKemia. Our study demonstrates that SFEMG FD evaluation is able to detect the presence of muscle diseases, which are in a subclinical phase and would remain unidentified otherwise. SFEMG FD evaluation could be added to the routine examinations in the screening of idiopathic hyperCKemia. P4.4 Post-injection posterior femoral cutaneous mononeuropathy: report on clinical presentation and electrophysiological findings in 5 cases G. El Tantawi1 , H. Sultan1 1 Department of Physical Medicine, Rheumatology, and Rehabilitation; Faculty of Medicine, Alexandria, Egypt Introduction: Isolated post-injection injury of the posterior femoral cutaneous nerve (PFCN) is rarely reported. Only handful of cases has been electrophysiologically documented. The technique of Dumitru and Nelson has been developed to assess conduction along the PFCN in healthy subjects. It has thereafter been used for evaluation of PFCN neuropathy. We present 5 cases with isolated post-injection injury of PFCN who were referred for evaluation using Dumitru and Nelson technique. Objective: The aim of this work is to report on the clinical presentation and electrophysiological findings in 5 cases with post-injection PFCN injury. Methods: Five patients (4 men and a woman; mean age 52.4±13.8 years) with posterior thigh pain following intragluteal injection were evaluated. 20 healthy subjects were included as controls. Patients were assessed clinically. Sensory nerve-conduction study of the PFCN was performed in all participants. The study was bilaterally performed using the technique proposed by Dumitru and Nelson. Electrophysiological workup for exclusion of other conditions was carried out. Results: All cases presented with posterior thigh pain and paresthesia. 2 patients reported scrotal pain. Palpable swellings at injection site were identified in 2 cases. Hypesthesia along the distribution of PFCN was found in 3 patients, whereas hyperalgesia was found in 1 patient. Loss of sensation was found in 1 patient. Sensory nerve action potential (SNAP) of PFCN was bilaterally elicited in all control subjects. Unobtainable response was detected on the symptomatic side in 2 patients. Decreased SNAP amplitude by more than 50% that of the healthy side was found in 3 patients. Conclusion: Five cases with isolated post-injection PFCN injury are reported. We think that patients with this condition are seldom referred for electrophysiological evaluation. The use of the technique adopted by Dumitru and Nelson to assess PFCN is recommended in any case with post-injection posterior thigh neuralgia. P4.5 Variants of local injury of median nerve in carpal tunnel S. Nikolaev1 1 Pirogov National Medical Surgical Center, Medical Postgraduate Institute, Neurology Department, Moscow, Russian Federation The identification of the exact entrapment point of the median nerve injury in the carpal tunnel is an important consideration for further treatment. Our study was designed to determine the frequency of occurrence of median nerve injury in the carpal tunnel and detect its clinical value. One hundred and twenty (120) patients with carpal tunnel syndrome symptoms were examined. We studied 182 nerves. Based on our study of sensory orthodromic inching of carpal tunnel (Nikolaev S.,
1
2008) we assigned four most common levels of tunnel injury. The injury at the carpal tunnel entrance, at the joint line and at 1 cm below the joint line, occurred in 50% of cases. The injury at the carpal tunnel exit and at 2 3 cm below the joint line, was observed in 23.1% cases. The injury in the middle of the carpal tunnel and at 1 2 cm below the joint line, was obtained in 25.3% cases. The injury along the tunnel where there was no clear localization of nerve injury occurred in 1.7%. Based on clinical observations, the best operative results were obtained in patients with nerve injury at the tunnel entrance. In case of nerve injury at the tunnel exit, surgical treatment gave no improvement. The nerve injuries in the middle of the carpal tunnel and along the tunnel were observed in patients with endocrine abnormalities and inflammatory lesions of connective tissue. Conclusions: When studying the carpal tunnel it is recommended to detect the exact site of nerve injury. This is important to select the surgery technique and perform further treatment. P4.6 Detection of early neuropathy in type 2 diabetes mellitus R. Remli1 , H.J. Tan2 , M.Z. Zaleha3 , M.R. Shahrul Azmin2 , W.Y. Wan Nur Nafisah2 , M.I. Norlinah2 , A.A. Raymond2 1 Neurology Unit, Department of Medicine, National University of Malaysia, Kuala Lumpur, Malaysia, 2 Department of Medicine, 3 Department of Community Health, Universiti Kebangsaan, Malaysia Introduction: Diabetes mellitus is associated with a broad spectrum of microvascular complications, including diabetic peripheral neuropathy (DPN). It is important to identify neuropathy even in the asymptomatic patients because the disease process predictably produces significant morbidity from late-stage consequences of infection, ulceration, and amputation. The nerve conduction study is a simple and non-invasive tool to detect early changes in asymptomatic DPN. There is a lack of population based studies of asymptomatic DPN in the Asian population. Objective: To determine the frequency and predictors of asymptomatic lower limb neuropathy amongst type 2 diabetic patients in University Kebangsaan Malaysia Medical Centre (UKMMC). Methods: This was a cross sectional study involving all type 2 diabetic patients from the endocrine clinic and medical wards UKMMC. All patients were subjected to a neurological examination to ascertain their neuropathy disability score and nerve conduction studies. Result: Ninety patients who were asymptomatic for neuropathy were recruited. Of these, 81 patients (90%) had abnormal NCS and 9 patients (10%) had normal NCS. From 81 asymptomatic neuropathy patients, 14 (15.6%) had pure motor neuropathy, 12 (12.2%) had pure sensory neuropathy and 56 (62%) had mixed sensory-motor neuropathy. Duration of diabetes, age of diabetic patients and presence of retinopathy were found to be significantly associated with the presence of asymptomatic neuropathy. Using multivariate analysis only the duration of diabetes more than 4 years was found to be an independent risk factor for neuropathy. Conclusion: The frequency of asymptomatic neuropathy in type 2 DM in this study was high. This study highlights the importance of the NCS in determining the presence of asymptomatic neuropathy in type 2 diabetes mellitus patients. The early detection of DPN in type 2 DM patients who had diabetes for more than 4 years may reduce the detrimental consequences associated with it. P4.7 Botulism in humans: time course of the neurophysiological abnormalities A. Petrucci1 , L. Lispi1 1 Unit of Neurology and Neurophysiology, S. Camillo Hospital, Rome, Italy Introduction: The typical neurophysiological abnormalities in botulism are small amplitude muscle action potential (cMAP) and increased jitter with blocking on single fiber electromyography (SFEMG) (Sanders DB et al. 2003); moreover, we have previously reported lacking of facilitation on repetitive nerve stimulation (RNS) (Lispi L et al 2009). An explanation for the reduced cMAP amplitude and for the absence of facilitation is the structural blockage induced by botulinum toxins at the neuromuscular junctions. On the other hand, the jitter abnormalities could be related either to the synaptic blocking or to the formation of new synapses, that have been documented in experimental botulism by means of immunocytochemical studies (Pestronk A. 1988).
Poster session 4. EMG, nerve conduction, peripheral neuropathies 1 P4.1 Comparative study of prognostic value of quantitative versus conventional electromyography in Bell’s palsy D. Mohasseb1 , G. El-Tantawi1 , H. Sultan1 , R. El-Nemr1 Department of Physical Medicine, Rheumatology, and Rehabilitation, Alexandria University, Alexandria, Egypt
1
Introduction: Bell’s palsy is the most frequent cranial mononeuropathy. Prognosis is a challenging problem concerning facial palsy. The role of
S71 conventional electromyography in assessment of prognosis of acute Bell’s palsy has been determined. The use of quantitative electromyography (QEMG) for predicting outcome in acute Bell’s palsy is however still deficient. Objective: This study aimed at evaluating the prognostic value of conventional versus QEMG in acute Bell’s palsy. Methods: Twenty patients (15 women and 5 men; mean age 35.55±13.7 years) with acute unilateral Bell’s palsy were included. Fifteen healthy individuals were included as a control group. HouseBrackmann grading system (HBG) was used to grade facial paralysis. Electrophysiological examination included motor conduction study of facial nerves as well as conventional and QEMG of the nasalis muscle. Evaluations were performed 7 14 days post-paralysis and at 2 3 months thereafter. Patients were classified according to their HBG at follow up into those with satisfactory recovery and those with unsatisfactory recovery. Results: At baseline, 6 cases demonstrated reduced compound muscle action potential (CMAP) amplitude and denervation potentials at rest. Evidence of demyelination was detected in 14 patients. CMAP amplitude and denervation potentials correlated significantly with HBG at follow up (Rho = 0.81, P < 0.001; Rho = 5.098, P = 0.038 respectively). Multi-motor unit action potential analysis (MMA) revealed significantly increased area and thickness of motor units in patients with satisfactory recovery (11 patients). These parameters correlated well with facial grading at follow up (Rho = 0.514, P = 0.02; Rho = 0.454, P = 0.045 respectively). Conclusion: The role of conventional electromyography in assessment of prognosis of acute Bell’s palsy is documented. The prognostic value of QEMG can be appreciated and MMA can be of value in determining the prognosis in acute Bell’s palsy. P4.2 Lewis-Sumner syndrome: the Asian experience Y.L. Lo1 , Y.F. Dan2 , Y.E. Tan3 , T.H. Leoh2 1 Department of Neurology, National Neuroscience Institute, Singapore General Hospital, Singapore, Singapore, 2 Singapore General Hospital, Singapore, Singapore, 3 Sinagpore General Hospital, Singapore, Singapore Introduction: The Lewis-Sumner syndrome (LSS) is a rare immunemediated peripheral nerve disorder presenting with asymmetric upper limb sensory complaints and motor weakness. Asian patients with LSS have not been reported in the English literature to our knowledge. Methods: Three Asian patients with features of LSS were prospectively studied clinically and electrophysiologically. Motor root stimulation at the neck and at Erb’s point was performed. Results: Our patients tended to older, female and involve upper limbs exclusively than those in the West. They have markedly longer disease duration before diagnosis was made, which could also be due to difficulty in eliciting motor root conduction block as a sign of proximal demyelination, as observed in every patient. Patient 1 exhibited motor root conduction block at right C8 (abductor pollicis brevis and abductor digiti minimi muscles). Patient 2 exhibited motor root conduction blocks at right C8 (abductor digiti minimi), left C8 (abductor digiti minimi) and left C7 (extensor indicis). Patient 3 exhibited motor root conduction block at right C6 (biceps brachii). Pain is a universal feature, as is sensory nerve conduction abnormality. None responded well to immunotherapy, but disease stabilization was observed over the chronic course. Conclusions: Although rare, these unique observations in Asian patients with LSS differ from those reported in Western literature. Presence of motor root conduction block demonstrated for the first time is instrumental in establishing diagnosis. P4.3 Single fiber electromyography in idiopathic hyperCKemia A. Nicotra1 , V. Pavone2 , D. Restivo3 1 Department of Clinical Neurophysiology, Imperial College Healthcare NHS Trust, London, United Kingdom, 2 Department of Orthopedics, V. Emanuele Hospital, University of Catania, Catania, Italy, 3 Department of Neurology, “Nuovo Garibaldi” Hospital, Catania, Italy Introduction: Persistently raised serum creatine kinase (sCK), or hyperCKemia, is considered the biological hallmark of neuromuscular diseases. When asymptomatic or isolated hyperCKemia is found without an underlying explainable cause is referred to as “idiopathic hyperCKemia”.
S72
Poster presentations: Poster session 4. EMG, nerve conduction, peripheral neuropathies
Objectives: To assess whether single-fiber electromyography (SFEMG), and specifically fiber density (FD) measurement, may detect electrophysiological abnormalities in subjects with hyperCKemia and help reveal the presence of subclinical (or pauci-or asymptomatic) muscular disorders. Methods: Nineteen subjects (13 males, 6 females; age: 26±10 years) with hyperCKemia without evident clinical muscle involvement and 15 healthy controls were studied. Electrophysiological investigations including nerve conduction studies (NCS), quantitative EMG (QEMG), SFEMG with FD measurement, and muscle biopsy were performed. Results: In the controls, all electrophysiological studies were normal. In subjects with hyperCKemia, NCS were normal but QEMG showed abnormalities in 5 (26%) subjects. SFEMG showed increased FD (>3) in a total of 12 (63%) while was normal in the remaining 7 (29%) subjects. The mean FD value was 2.6±0.5 in the control and 4±1.6 (p = 0.001) in the hyperCKemia group. In the 12 subjects with hyperCKemia and abnormal SFEMG, muscle biopsy was also abnormal. Conclusions: SFEMG revealed electrophysiological abnormalities in 63% of subjects with hyperCKemia. Our study demonstrates that SFEMG FD evaluation is able to detect the presence of muscle diseases, which are in a subclinical phase and would remain unidentified otherwise. SFEMG FD evaluation could be added to the routine examinations in the screening of idiopathic hyperCKemia. P4.4 Post-injection posterior femoral cutaneous mononeuropathy: report on clinical presentation and electrophysiological findings in 5 cases G. El Tantawi1 , H. Sultan1 1 Department of Physical Medicine, Rheumatology, and Rehabilitation; Faculty of Medicine, Alexandria, Egypt Introduction: Isolated post-injection injury of the posterior femoral cutaneous nerve (PFCN) is rarely reported. Only handful of cases has been electrophysiologically documented. The technique of Dumitru and Nelson has been developed to assess conduction along the PFCN in healthy subjects. It has thereafter been used for evaluation of PFCN neuropathy. We present 5 cases with isolated post-injection injury of PFCN who were referred for evaluation using Dumitru and Nelson technique. Objective: The aim of this work is to report on the clinical presentation and electrophysiological findings in 5 cases with post-injection PFCN injury. Methods: Five patients (4 men and a woman; mean age 52.4±13.8 years) with posterior thigh pain following intragluteal injection were evaluated. 20 healthy subjects were included as controls. Patients were assessed clinically. Sensory nerve-conduction study of the PFCN was performed in all participants. The study was bilaterally performed using the technique proposed by Dumitru and Nelson. Electrophysiological workup for exclusion of other conditions was carried out. Results: All cases presented with posterior thigh pain and paresthesia. 2 patients reported scrotal pain. Palpable swellings at injection site were identified in 2 cases. Hypesthesia along the distribution of PFCN was found in 3 patients, whereas hyperalgesia was found in 1 patient. Loss of sensation was found in 1 patient. Sensory nerve action potential (SNAP) of PFCN was bilaterally elicited in all control subjects. Unobtainable response was detected on the symptomatic side in 2 patients. Decreased SNAP amplitude by more than 50% that of the healthy side was found in 3 patients. Conclusion: Five cases with isolated post-injection PFCN injury are reported. We think that patients with this condition are seldom referred for electrophysiological evaluation. The use of the technique adopted by Dumitru and Nelson to assess PFCN is recommended in any case with post-injection posterior thigh neuralgia. P4.5 Variants of local injury of median nerve in carpal tunnel S. Nikolaev1 1 Pirogov National Medical Surgical Center, Medical Postgraduate Institute, Neurology Department, Moscow, Russian Federation The identification of the exact entrapment point of the median nerve injury in the carpal tunnel is an important consideration for further treatment. Our study was designed to determine the frequency of occurrence of median nerve injury in the carpal tunnel and detect its clinical value. One hundred and twenty (120) patients with carpal tunnel syndrome symptoms were examined. We studied 182 nerves. Based on our study of sensory orthodromic inching of carpal tunnel (Nikolaev S.,
1
2008) we assigned four most common levels of tunnel injury. The injury at the carpal tunnel entrance, at the joint line and at 1 cm below the joint line, occurred in 50% of cases. The injury at the carpal tunnel exit and at 2 3 cm below the joint line, was observed in 23.1% cases. The injury in the middle of the carpal tunnel and at 1 2 cm below the joint line, was obtained in 25.3% cases. The injury along the tunnel where there was no clear localization of nerve injury occurred in 1.7%. Based on clinical observations, the best operative results were obtained in patients with nerve injury at the tunnel entrance. In case of nerve injury at the tunnel exit, surgical treatment gave no improvement. The nerve injuries in the middle of the carpal tunnel and along the tunnel were observed in patients with endocrine abnormalities and inflammatory lesions of connective tissue. Conclusions: When studying the carpal tunnel it is recommended to detect the exact site of nerve injury. This is important to select the surgery technique and perform further treatment. P4.6 Detection of early neuropathy in type 2 diabetes mellitus R. Remli1 , H.J. Tan2 , M.Z. Zaleha3 , M.R. Shahrul Azmin2 , W.Y. Wan Nur Nafisah2 , M.I. Norlinah2 , A.A. Raymond2 1 Neurology Unit, Department of Medicine, National University of Malaysia, Kuala Lumpur, Malaysia, 2 Department of Medicine, 3 Department of Community Health, Universiti Kebangsaan, Malaysia Introduction: Diabetes mellitus is associated with a broad spectrum of microvascular complications, including diabetic peripheral neuropathy (DPN). It is important to identify neuropathy even in the asymptomatic patients because the disease process predictably produces significant morbidity from late-stage consequences of infection, ulceration, and amputation. The nerve conduction study is a simple and non-invasive tool to detect early changes in asymptomatic DPN. There is a lack of population based studies of asymptomatic DPN in the Asian population. Objective: To determine the frequency and predictors of asymptomatic lower limb neuropathy amongst type 2 diabetic patients in University Kebangsaan Malaysia Medical Centre (UKMMC). Methods: This was a cross sectional study involving all type 2 diabetic patients from the endocrine clinic and medical wards UKMMC. All patients were subjected to a neurological examination to ascertain their neuropathy disability score and nerve conduction studies. Result: Ninety patients who were asymptomatic for neuropathy were recruited. Of these, 81 patients (90%) had abnormal NCS and 9 patients (10%) had normal NCS. From 81 asymptomatic neuropathy patients, 14 (15.6%) had pure motor neuropathy, 12 (12.2%) had pure sensory neuropathy and 56 (62%) had mixed sensory-motor neuropathy. Duration of diabetes, age of diabetic patients and presence of retinopathy were found to be significantly associated with the presence of asymptomatic neuropathy. Using multivariate analysis only the duration of diabetes more than 4 years was found to be an independent risk factor for neuropathy. Conclusion: The frequency of asymptomatic neuropathy in type 2 DM in this study was high. This study highlights the importance of the NCS in determining the presence of asymptomatic neuropathy in type 2 diabetes mellitus patients. The early detection of DPN in type 2 DM patients who had diabetes for more than 4 years may reduce the detrimental consequences associated with it. P4.7 Botulism in humans: time course of the neurophysiological abnormalities A. Petrucci1 , L. Lispi1 1 Unit of Neurology and Neurophysiology, S. Camillo Hospital, Rome, Italy Introduction: The typical neurophysiological abnormalities in botulism are small amplitude muscle action potential (cMAP) and increased jitter with blocking on single fiber electromyography (SFEMG) (Sanders DB et al. 2003); moreover, we have previously reported lacking of facilitation on repetitive nerve stimulation (RNS) (Lispi L et al 2009). An explanation for the reduced cMAP amplitude and for the absence of facilitation is the structural blockage induced by botulinum toxins at the neuromuscular junctions. On the other hand, the jitter abnormalities could be related either to the synaptic blocking or to the formation of new synapses, that have been documented in experimental botulism by means of immunocytochemical studies (Pestronk A. 1988).