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FC20.1 Sciatic neuropathy in childhood: A tertiary paediatric hospital experience
Oral Communications / Clinical Neurophysiology 117 (2006) S49–S111
Aim: The aim of our study was to investigate whether SCS obtained by chronically implanted electrodes above the dorsal columns is able to change the brain response to phasic painful cutaneous stimuli. Methods: Fourteen patients (5 men, 9 women, mean age 63.4 ± 11.2 years) with intractable cardiac syndrome X (SX) were studied. SX is characterized by angina-like chest pain episodes, mainly related to exertion and normal coronary arteries at angiography. All patients were submitted to SCS. Functional assessment of the nociceptive pathway was obtained by recording the laser evoked potentials (LEPs) with the spinal cord stimulator switched either on or off. LEPs were recorded after stimulation of both the chest (painful area) and the right hand (non-painful area). Patients were asked to rate the intensity of the laser-evoked pain along a visual analogue scale (VAS). Results: After SCS, all our patients referred a remarkable clinical improvement and a drug consumption reduction. The N2/P2 potential amplitude and the laser-evoked pain were higher with the SCS on than with the SCS off, but the difference was statistically significant only to chest stimulation. Conclusion: In SX patients submitted to SCS, the nociceptive cortex increases its excitability to phasic painful cutaneous stimuli, probably due to the removed inhibitory effect of chronic painful inputs coming from the heart. LEP recording might be useful to test the effectiveness of neuromodulation procedures in non-collaborative patients, such as those with cognitive impairment. doi:10.1016/j.clinph.2006.06.062
FC19.4 The spread of sensory symptoms outside the median territory in carpal tunnel syndrome indicates the presence of pain-related mechanisms S. Tamburin 1, S. Marani 2, A. Fiaschi 3, G. Zanette 2 1
Hospital Pederzoli, Via Monte Baldo 24, Department of Neurological Sciences and Vision, Italy 2 Sect of Neurology, Hospital Pederzoli, Department of Neurological Sciences and Vision, Verona, Italy 3 Sect of Neurological Rehabilitation, Department of Neurological Sciences and Vision, Verona, Italy Background: Patients with carpal tunnel syndrome (CTS) may complain of sensory symptoms outside the typical median nerve distribution. Objective: The study is aimed to understand which clinical features are associated with the extra-median distribution of symptoms in CTS. Methods: We recruited 241 consecutive CTS patients. After selection, 103 patients (165 hands) were included. The symptom distribution was evaluated with a self-administered hand symptoms diagram. Patients underwent objective evaluation, neurographic study, and a selfadministered questionnaire on subjective complaints.
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Results: No clinical or electrodiagnostic signs of ulnar nerve involvement were found in the 165 hands. Median distribution of symptoms was found in 60.6% of hands, glove distribution in 35.2% and ulnar distribution in 4.2%. Objective measures of median nerve lesion (tactile hypaesthesia and thenar muscles hypasthenia) and neurographic involvement were significantly more severe in median hands than in the other groups. Subjective complaints (nocturnal pain, numbness and tingling sensations) were significantly more severe in glove hands. Neurophysiological and objective measures were not correlated with subjective complaints. Conclusions: The severity of the objective examination and neurographic involvement and the intensity of sensory complaints appear to be independent factors that influence the symptoms distribution. Extra-median spread of sensory symptoms was associated with higher levels of pain and paresthesia. We suggest that central nervous system mechanisms of plasticity may underlie the spread of symptoms in CTS. doi:10.1016/j.clinph.2006.06.063
FC20.1 Sciatic neuropathy in childhood: A tertiary paediatric hospital experience R.K. Knight, M.C. Pitt Great Ormond Street Hospital for Children NHS Trust, EEG Department, UK Background: Sciatic neuropathy is a disabling condition, which has rarely been reported in children. We present the clinical and neurophysiological features of sciatic nerve injury in a series from a tertiary paediatric centre. Aim: To describe the characteristics of a series of sciatic neuropathies in children. Methods: A ‘sciatic neuropathy’ was defined as impaired sensory and/or motor nerve conduction in the sciatic nerve territory, combined with needle EMG changes of denervation in relevant muscles. Cases were identified from the Access database maintained in the department. Severity was graded based on a combination of clinical and electrophysiological findings. Results: Forty-three sciatic neuropathies were identified in 37 patients between May 1993 and December 2005. The median age at examination was 12.5 years. There were 22 boys and 15 girls, with a median duration of symptoms of 6 months. Unilateral involvement was seen in all but one child, with either side similarly affected. A congenital onset was seen in 5 (11%) 19 (44%) were iatrogenic, 13 (30%) were caused by trauma, in 4 the cause was not determined. One was a tumour compression and another postinfective plexopathy. Unilateral sciatic neuropathy was part of a radiculopathy in 6 children, and lumbar plexopathy in 3. In the others, the lesion was localised to the gluteal region in 8, and in the thigh in the remainder. Severity
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Oral Communications / Clinical Neurophysiology 117 (2006) S49–S111
ranged from severe in 22 studies (51%), through moderate in 14 (32%) to mild in 6 cases (13%). The majority (68%) of the iatrogenic group were severe lesions. Two of these were related to intragluteal injections. Direct surgical injuries to the nerve, and indirect peri-operative injury, were equally represented. Conclusions: Sciatic neuropathy is infrequently seen in paediatric neurophysiological practice. Iatrogenic nerve lesions are a significant, but preventable cause of morbidity in this series. doi:10.1016/j.clinph.2006.06.064
FC20.2 Factors related to the distribution of hand symptoms in Singaporean patients with Carpal Tunnel Syndrome A. Theri Madasamy 1, R. Hay 1, E. Li 1, E.P. WilderSmith 2 1 2
National University Hospital, Neurology, Singapore Yong Loo Lin School of Medicine, Neurology, Singapore
Background: One of the core symptoms of Carpal Tunnel Syndrome (CTS) is a median nerve sensory distribution of symptoms. However, several studies have shown that symptoms in CTS frequently involve areas outside the median nerve territory. One recent study suggested that the distribution of sensory hand symptoms relates to the severity of neurophysiological abnormality. Aims/Objective: We investigated the sensory distribution of symptoms with the degree of neurophysiological CTS severity and whether symptom description may also be affected by patients’ educational level. Methods: This prospective study is being carried out at the Neurology Diagnostic Laboratory of the National University Hospital, Singapore. Inclusion is neurophysiologically confirmed CTS using the median sensory distal latency (SDL), median motor distal latency (MDL) and the 2nd Lumbrical Interossei test (2LINT). Severity grading is based on absolute values and the Bland’s scale. Patients described sensory distribution on a hand diagram. A scoring scale was developed to grade the educational level. Results: To date, we have results on 20 CTS hands. In eight hands symptoms were restricted to the median territory, in 12 hands symptoms involved both ulnar, median or other nerve sensory territories. The median territory group showed significantly longer mean median nerve neurophysiological parameters (SDL: 4.1 vs. 3.5 ms, MDL 6 vs. 4.9, 2LINT 2.8 vs. 1.5). There was no difference in the mean Bland’s score between groups. There was a clear difference in educational level between the groups, with the average educational level being higher for those with a median sensory territory distribution. Conclusion: In this ongoing study, depiction of median nerve sensory distribution of symptoms was associated
both with more severe neurophysiological alterations and higher educational levels. Knowledge of the factors influencing sensory distribution of symptoms is important for their correct interpretation. doi:10.1016/j.clinph.2006.06.065
FC20.3 Use of a nerve conduction protocol for the diagnosis of thoracic outlet syndrome: Audit of 15 year experience R.P. Kennett The Radcliffe Infirmary, UK Background: Neurogenic thoracic outlet syndrome (TOS), a chronic entrapment of the lower brachial plexus, is considered to be rare. Aims: To audit a nerve conduction protocol used to assess patients referred to me in Oxford, UK, for the electrodiagnosis (Edx) of suspected TOS over a 15 year period (1991–2005 inclusive). Method: The protocol consists of median and ulnar motor nerve conduction with F-waves, and recording of sensory nerve action potentials (SNAP) from the thumb, middle and little (DV) fingers and medial cutaneous nerve of forearm (mcnf) in both arms. Results: In total 114 patients were evaluated with the protocol, of whom a cervical rib, band or enlarged C7 spinous process was known to be present a the time of Edx in 76. Of these, 21 had changes on the protocol consistent with neurogenic TOS. Of the 38 without a known structural lesion, 17 had changes consistent with neurogenic TOS. All the patients identified as neurogenic TOS by the protocol had an abnormality of the mcnf SNAP (>50% side to side amplitude asymmetry or absent response). This was the only abnormality in 8 arms, was associated with reduction of the DV SNAP (<5 lV; 7 arms) and thenar compound muscle action potential (CMAP) amplitude (<10 mV peak to peak; 19 arms). Complete loss of the DV SNAP was seen in 6 arms. The mcnf SNAP was lost in these and 5 had reduction in thenar CMAP. Abnormality of F wave latency was seen in 3 patients and all in association with other changes. In the 48 patients with a known cervical rib or band and normal conduction findings, needle examination of the abductor pollicis brevis muscle was tested and found normal in 30. Conclusion: In this selected group of patients with symptoms suggesting TOS Edx confirmed a neurogenic lesion in a third. Testing of the medial cutaneous nerve of forearm is an essential component of the nerve conduction protocol. Loss of the DV SNAP is less sensitive and measuring F-wave latency has little value. doi:10.1016/j.clinph.2006.06.066
Aim: The aim of our study was to investigate whether SCS obtained by chronically implanted electrodes above the dorsal columns is able to change the brain response to phasic painful cutaneous stimuli. Methods: Fourteen patients (5 men, 9 women, mean age 63.4 ± 11.2 years) with intractable cardiac syndrome X (SX) were studied. SX is characterized by angina-like chest pain episodes, mainly related to exertion and normal coronary arteries at angiography. All patients were submitted to SCS. Functional assessment of the nociceptive pathway was obtained by recording the laser evoked potentials (LEPs) with the spinal cord stimulator switched either on or off. LEPs were recorded after stimulation of both the chest (painful area) and the right hand (non-painful area). Patients were asked to rate the intensity of the laser-evoked pain along a visual analogue scale (VAS). Results: After SCS, all our patients referred a remarkable clinical improvement and a drug consumption reduction. The N2/P2 potential amplitude and the laser-evoked pain were higher with the SCS on than with the SCS off, but the difference was statistically significant only to chest stimulation. Conclusion: In SX patients submitted to SCS, the nociceptive cortex increases its excitability to phasic painful cutaneous stimuli, probably due to the removed inhibitory effect of chronic painful inputs coming from the heart. LEP recording might be useful to test the effectiveness of neuromodulation procedures in non-collaborative patients, such as those with cognitive impairment. doi:10.1016/j.clinph.2006.06.062
FC19.4 The spread of sensory symptoms outside the median territory in carpal tunnel syndrome indicates the presence of pain-related mechanisms S. Tamburin 1, S. Marani 2, A. Fiaschi 3, G. Zanette 2 1
Hospital Pederzoli, Via Monte Baldo 24, Department of Neurological Sciences and Vision, Italy 2 Sect of Neurology, Hospital Pederzoli, Department of Neurological Sciences and Vision, Verona, Italy 3 Sect of Neurological Rehabilitation, Department of Neurological Sciences and Vision, Verona, Italy Background: Patients with carpal tunnel syndrome (CTS) may complain of sensory symptoms outside the typical median nerve distribution. Objective: The study is aimed to understand which clinical features are associated with the extra-median distribution of symptoms in CTS. Methods: We recruited 241 consecutive CTS patients. After selection, 103 patients (165 hands) were included. The symptom distribution was evaluated with a self-administered hand symptoms diagram. Patients underwent objective evaluation, neurographic study, and a selfadministered questionnaire on subjective complaints.
S73
Results: No clinical or electrodiagnostic signs of ulnar nerve involvement were found in the 165 hands. Median distribution of symptoms was found in 60.6% of hands, glove distribution in 35.2% and ulnar distribution in 4.2%. Objective measures of median nerve lesion (tactile hypaesthesia and thenar muscles hypasthenia) and neurographic involvement were significantly more severe in median hands than in the other groups. Subjective complaints (nocturnal pain, numbness and tingling sensations) were significantly more severe in glove hands. Neurophysiological and objective measures were not correlated with subjective complaints. Conclusions: The severity of the objective examination and neurographic involvement and the intensity of sensory complaints appear to be independent factors that influence the symptoms distribution. Extra-median spread of sensory symptoms was associated with higher levels of pain and paresthesia. We suggest that central nervous system mechanisms of plasticity may underlie the spread of symptoms in CTS. doi:10.1016/j.clinph.2006.06.063
FC20.1 Sciatic neuropathy in childhood: A tertiary paediatric hospital experience R.K. Knight, M.C. Pitt Great Ormond Street Hospital for Children NHS Trust, EEG Department, UK Background: Sciatic neuropathy is a disabling condition, which has rarely been reported in children. We present the clinical and neurophysiological features of sciatic nerve injury in a series from a tertiary paediatric centre. Aim: To describe the characteristics of a series of sciatic neuropathies in children. Methods: A ‘sciatic neuropathy’ was defined as impaired sensory and/or motor nerve conduction in the sciatic nerve territory, combined with needle EMG changes of denervation in relevant muscles. Cases were identified from the Access database maintained in the department. Severity was graded based on a combination of clinical and electrophysiological findings. Results: Forty-three sciatic neuropathies were identified in 37 patients between May 1993 and December 2005. The median age at examination was 12.5 years. There were 22 boys and 15 girls, with a median duration of symptoms of 6 months. Unilateral involvement was seen in all but one child, with either side similarly affected. A congenital onset was seen in 5 (11%) 19 (44%) were iatrogenic, 13 (30%) were caused by trauma, in 4 the cause was not determined. One was a tumour compression and another postinfective plexopathy. Unilateral sciatic neuropathy was part of a radiculopathy in 6 children, and lumbar plexopathy in 3. In the others, the lesion was localised to the gluteal region in 8, and in the thigh in the remainder. Severity
S74
Oral Communications / Clinical Neurophysiology 117 (2006) S49–S111
ranged from severe in 22 studies (51%), through moderate in 14 (32%) to mild in 6 cases (13%). The majority (68%) of the iatrogenic group were severe lesions. Two of these were related to intragluteal injections. Direct surgical injuries to the nerve, and indirect peri-operative injury, were equally represented. Conclusions: Sciatic neuropathy is infrequently seen in paediatric neurophysiological practice. Iatrogenic nerve lesions are a significant, but preventable cause of morbidity in this series. doi:10.1016/j.clinph.2006.06.064
FC20.2 Factors related to the distribution of hand symptoms in Singaporean patients with Carpal Tunnel Syndrome A. Theri Madasamy 1, R. Hay 1, E. Li 1, E.P. WilderSmith 2 1 2
National University Hospital, Neurology, Singapore Yong Loo Lin School of Medicine, Neurology, Singapore
Background: One of the core symptoms of Carpal Tunnel Syndrome (CTS) is a median nerve sensory distribution of symptoms. However, several studies have shown that symptoms in CTS frequently involve areas outside the median nerve territory. One recent study suggested that the distribution of sensory hand symptoms relates to the severity of neurophysiological abnormality. Aims/Objective: We investigated the sensory distribution of symptoms with the degree of neurophysiological CTS severity and whether symptom description may also be affected by patients’ educational level. Methods: This prospective study is being carried out at the Neurology Diagnostic Laboratory of the National University Hospital, Singapore. Inclusion is neurophysiologically confirmed CTS using the median sensory distal latency (SDL), median motor distal latency (MDL) and the 2nd Lumbrical Interossei test (2LINT). Severity grading is based on absolute values and the Bland’s scale. Patients described sensory distribution on a hand diagram. A scoring scale was developed to grade the educational level. Results: To date, we have results on 20 CTS hands. In eight hands symptoms were restricted to the median territory, in 12 hands symptoms involved both ulnar, median or other nerve sensory territories. The median territory group showed significantly longer mean median nerve neurophysiological parameters (SDL: 4.1 vs. 3.5 ms, MDL 6 vs. 4.9, 2LINT 2.8 vs. 1.5). There was no difference in the mean Bland’s score between groups. There was a clear difference in educational level between the groups, with the average educational level being higher for those with a median sensory territory distribution. Conclusion: In this ongoing study, depiction of median nerve sensory distribution of symptoms was associated
both with more severe neurophysiological alterations and higher educational levels. Knowledge of the factors influencing sensory distribution of symptoms is important for their correct interpretation. doi:10.1016/j.clinph.2006.06.065
FC20.3 Use of a nerve conduction protocol for the diagnosis of thoracic outlet syndrome: Audit of 15 year experience R.P. Kennett The Radcliffe Infirmary, UK Background: Neurogenic thoracic outlet syndrome (TOS), a chronic entrapment of the lower brachial plexus, is considered to be rare. Aims: To audit a nerve conduction protocol used to assess patients referred to me in Oxford, UK, for the electrodiagnosis (Edx) of suspected TOS over a 15 year period (1991–2005 inclusive). Method: The protocol consists of median and ulnar motor nerve conduction with F-waves, and recording of sensory nerve action potentials (SNAP) from the thumb, middle and little (DV) fingers and medial cutaneous nerve of forearm (mcnf) in both arms. Results: In total 114 patients were evaluated with the protocol, of whom a cervical rib, band or enlarged C7 spinous process was known to be present a the time of Edx in 76. Of these, 21 had changes on the protocol consistent with neurogenic TOS. Of the 38 without a known structural lesion, 17 had changes consistent with neurogenic TOS. All the patients identified as neurogenic TOS by the protocol had an abnormality of the mcnf SNAP (>50% side to side amplitude asymmetry or absent response). This was the only abnormality in 8 arms, was associated with reduction of the DV SNAP (<5 lV; 7 arms) and thenar compound muscle action potential (CMAP) amplitude (<10 mV peak to peak; 19 arms). Complete loss of the DV SNAP was seen in 6 arms. The mcnf SNAP was lost in these and 5 had reduction in thenar CMAP. Abnormality of F wave latency was seen in 3 patients and all in association with other changes. In the 48 patients with a known cervical rib or band and normal conduction findings, needle examination of the abductor pollicis brevis muscle was tested and found normal in 30. Conclusion: In this selected group of patients with symptoms suggesting TOS Edx confirmed a neurogenic lesion in a third. Testing of the medial cutaneous nerve of forearm is an essential component of the nerve conduction protocol. Loss of the DV SNAP is less sensitive and measuring F-wave latency has little value. doi:10.1016/j.clinph.2006.06.066