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P18.3 Painful diabetic neuropathies and microcirculatory alterations
S210
Posters / Clinical Neurophysiology 117 (2006) S121–S336
calculated. Ten controls and nine cases were used to develop a logistic regression model for each task. The performance of the best model was evaluated with the jack-knife method and by applying it to a second data set (four cases, four controls). Results: See Table. For typing no model could be generated. The mouse task resulted in the best model. Jackknife evaluation resulted in correct classification of 89% in cases, 90% in controls. Of the second data set, three out of four subjects were correctly classified in both groups. SD of FMEANMUAP (lower in cases) and SD of MUAP Rate across time (higher in cases) were most discriminative. Discussion: The mouse task resulted in the best model, probably since it is a standardized task at a low force level at which, according to the Cinderella hypothesis, the largest differences can be expected. The higher SD of MUAP Rate in cases may indicate a more variable activation pattern during a task, whereas the lower SD of FMEANMUAP may indicate a more homogeneous motor unit pool. This pilot study shows that a combination of surface array EMG parameters might be capable of distinguishing neck–shoulder pain cases from controls. Task
Parameters included in the model
Unilateral FMED, FMEANMUAP_SD hand task Editing task FMED_SLOPE Mouse task FMEANMUAP_SD, MUAP Rate_SD, RMS_SLOPE Stress task MUAP Rate_SD
Sensitivity
Specificity
90.0
88.9
90.0 100
66.7 100
71.4
75.0
doi:10.1016/j.clinph.2006.06.397
P18.3 Painful diabetic neuropathies and microcirculatory alterations M. Zmajevic-Schonwald University Clinic Vuk Vrhovac, Neurology Ward, Croatia Background: Hypothesis of the pathogenesis in diabetic neuropathy is heterogeneous with causative factors including microvascular insufficiency. There are also evidences that primary nociceptive afferents mediate the blood flow dysfunction in diabetic patients with peripheral neuropathy. Objective: To examine severity of neuropathy and microvascular insufficiency comparing it on patients with painful diabetic neuropathies (PDN), non-painful diabetic neuropathies (DN) and diabetes without neuropathies (D). Methods: Study conducted on 36 patients (age range 20– 60 years) using neuropathy symptom score (NSS), presence/absence of pain diagnostic codes, needle electromyography (NEMG), nerve conduction velocities (NCV),
quantitative sensory testing (CASEIV), laser doppler flowmetry (LDF). Results: 57% PDN and 30% DN patients were recorded with more impaired microvascular insufficiency than D patients. NEMG and NCV findings showed more axonal lesions in PDN compared to DN patients. Conclusion: The possible conclusion from our study is that more damaged C fibers in PDN group are cause for microcirculatory alterations leading to its insufficiency. This study offers a different method of evaluation of PDN trough microcirculatory alterations as a sensitive marker of C fiber neurovascular dysfunction. doi:10.1016/j.clinph.2006.06.398
P19.1 Impaired modulation of blink reflex in patients with benign essential blepharospasm T.V. Ilic 1, S. Milanovic 2, S. Blesic 2, S. Petkovic 3, M. Tomovic 4, V. Cedic 4 1
Military Medical Academy, Outpatients Neurological Service, Serbia and Montenegro 2 Institute for Medical Research, Serbia and Montenegro 3 Policlinical service – Ristic, Serbia and Montenegro 4 Military Medical Academy, Clinic of Neurology, Serbia and Montenegro In healthy subjects, presentation of 12 trains of low-intensity, high-frequency stimuli (HFS) to the supraorbital branch of the trigeminal nerve, concurrently with reflex blinks, potentiated subsequent blink reflex in human subjects (Mao and Evinger. J Neurosci 2001). This modulation produced by A-fiber HFS has been ascribed to synaptic changes of trigeminal neurons experiencing modified movement feedback caused by HFS, suggesting long-term potentiation (LTP)-like effects. Whereas the understanding of etiology of benign essential blepharospasm (BEB) still remains limited, there is a concept attracting considerable interest that BEB represents a form of aberrant brain plasticity. The changes in modulation of blink reflexes associated with HFS protocol of five patients with BEB were compared with those of age-matched healthy subjects. Contrary to healthy subjects, in patients with BEB, the reflex modulation after trigeminal nerve stimulation was significantly stronger during the post-interventional period of 1 h. These observations suggest that the mechanisms responsible for the potentiation of reflex size and the modulation normally seen during trigeminal nerve HFS are impaired in blepharospasm. As the feedback from the lid movement, following HFS protocol, is considered to be of critical importance for LTP-like effects, then repetitive peripheral afferent inputs in BEB patients may represent a trigger of maladaptive plasticity in susceptible individuals. doi:10.1016/j.clinph.2006.06.399
Posters / Clinical Neurophysiology 117 (2006) S121–S336
calculated. Ten controls and nine cases were used to develop a logistic regression model for each task. The performance of the best model was evaluated with the jack-knife method and by applying it to a second data set (four cases, four controls). Results: See Table. For typing no model could be generated. The mouse task resulted in the best model. Jackknife evaluation resulted in correct classification of 89% in cases, 90% in controls. Of the second data set, three out of four subjects were correctly classified in both groups. SD of FMEANMUAP (lower in cases) and SD of MUAP Rate across time (higher in cases) were most discriminative. Discussion: The mouse task resulted in the best model, probably since it is a standardized task at a low force level at which, according to the Cinderella hypothesis, the largest differences can be expected. The higher SD of MUAP Rate in cases may indicate a more variable activation pattern during a task, whereas the lower SD of FMEANMUAP may indicate a more homogeneous motor unit pool. This pilot study shows that a combination of surface array EMG parameters might be capable of distinguishing neck–shoulder pain cases from controls. Task
Parameters included in the model
Unilateral FMED, FMEANMUAP_SD hand task Editing task FMED_SLOPE Mouse task FMEANMUAP_SD, MUAP Rate_SD, RMS_SLOPE Stress task MUAP Rate_SD
Sensitivity
Specificity
90.0
88.9
90.0 100
66.7 100
71.4
75.0
doi:10.1016/j.clinph.2006.06.397
P18.3 Painful diabetic neuropathies and microcirculatory alterations M. Zmajevic-Schonwald University Clinic Vuk Vrhovac, Neurology Ward, Croatia Background: Hypothesis of the pathogenesis in diabetic neuropathy is heterogeneous with causative factors including microvascular insufficiency. There are also evidences that primary nociceptive afferents mediate the blood flow dysfunction in diabetic patients with peripheral neuropathy. Objective: To examine severity of neuropathy and microvascular insufficiency comparing it on patients with painful diabetic neuropathies (PDN), non-painful diabetic neuropathies (DN) and diabetes without neuropathies (D). Methods: Study conducted on 36 patients (age range 20– 60 years) using neuropathy symptom score (NSS), presence/absence of pain diagnostic codes, needle electromyography (NEMG), nerve conduction velocities (NCV),
quantitative sensory testing (CASEIV), laser doppler flowmetry (LDF). Results: 57% PDN and 30% DN patients were recorded with more impaired microvascular insufficiency than D patients. NEMG and NCV findings showed more axonal lesions in PDN compared to DN patients. Conclusion: The possible conclusion from our study is that more damaged C fibers in PDN group are cause for microcirculatory alterations leading to its insufficiency. This study offers a different method of evaluation of PDN trough microcirculatory alterations as a sensitive marker of C fiber neurovascular dysfunction. doi:10.1016/j.clinph.2006.06.398
P19.1 Impaired modulation of blink reflex in patients with benign essential blepharospasm T.V. Ilic 1, S. Milanovic 2, S. Blesic 2, S. Petkovic 3, M. Tomovic 4, V. Cedic 4 1
Military Medical Academy, Outpatients Neurological Service, Serbia and Montenegro 2 Institute for Medical Research, Serbia and Montenegro 3 Policlinical service – Ristic, Serbia and Montenegro 4 Military Medical Academy, Clinic of Neurology, Serbia and Montenegro In healthy subjects, presentation of 12 trains of low-intensity, high-frequency stimuli (HFS) to the supraorbital branch of the trigeminal nerve, concurrently with reflex blinks, potentiated subsequent blink reflex in human subjects (Mao and Evinger. J Neurosci 2001). This modulation produced by A-fiber HFS has been ascribed to synaptic changes of trigeminal neurons experiencing modified movement feedback caused by HFS, suggesting long-term potentiation (LTP)-like effects. Whereas the understanding of etiology of benign essential blepharospasm (BEB) still remains limited, there is a concept attracting considerable interest that BEB represents a form of aberrant brain plasticity. The changes in modulation of blink reflexes associated with HFS protocol of five patients with BEB were compared with those of age-matched healthy subjects. Contrary to healthy subjects, in patients with BEB, the reflex modulation after trigeminal nerve stimulation was significantly stronger during the post-interventional period of 1 h. These observations suggest that the mechanisms responsible for the potentiation of reflex size and the modulation normally seen during trigeminal nerve HFS are impaired in blepharospasm. As the feedback from the lid movement, following HFS protocol, is considered to be of critical importance for LTP-like effects, then repetitive peripheral afferent inputs in BEB patients may represent a trigger of maladaptive plasticity in susceptible individuals. doi:10.1016/j.clinph.2006.06.399