TY - JOUR
T1 - Balance control in Sensory Neuron Disease
AU - Nardone, Antonio
AU - Galante, Massimo
AU - Pareyson, Davide
AU - Schieppati, Marco
N1 - Funding Information:
We thank Dr Angelo Sghirlanzoni for referral of patients affected by Sensory Neuron Disease and Dr Margherita Grasso for technical assistance. This study was supported by a ‘Ricerca Finalizzata 2002’ Grant No. 174 from the Italian Ministry of Health and by a ‘FIRB 2001’ Grant No. RBNE01FJ4J from the Italian Ministry of Education University and Research.
PY - 2007/3
Y1 - 2007/3
N2 - Objective: Balance control under static and dynamic conditions was assessed in patients with Sensory Neuron Disease (SND) in order to shed further light on the pathophysiology of ataxia. Methods: Fourteen patients with diabetic polyneuropathy and 11 with SND underwent clinical and neurophysiological evaluation, stabilometric recording of body sway during quiet stance with and without vision, stereometric analysis of body segment displacement while riding a platform translating in anterior-posterior direction with and without vision (dynamic condition), and EMG recording of leg muscle responses to abrupt stance perturbation produced by rotation of a supporting platform. The findings were compared to those of age matched normal subjects. Results: Clinical and neurophysiological evaluation revealed a more severe motor impairment in patients with diabetes than SND, while sensory impairment was superimposable. Some patients with SND had vestibular dysfunction of diverse severity. Body sway during stance was larger in patients with SND than diabetes with and without vision. In the stance perturbation condition, the latency of the long-loop EMG response to platform rotation was disproportionately increased with respect to the spinal response in the SND but not in diabetic patients. Under dynamic condition, patients with SND oscillated more than diabetic patients and several of them easily lost balance with eyes closed. Conclusions: Patients with SND show severe unsteadiness under both static and dynamic conditions, particularly with eyes closed. The patchy sensory loss of SND, disrupting sensation from territories other than the lower limbs and possibly including the vestibular nerve, could be responsible for this instability. Ataxia is correlated to the abnormal latency of the muscle responses to stance perturbation. Since increased response latencies cannot be attributed to a vestibular deficit, the deterioration of equilibrium control would be ascribed mainly to the degeneration of the central branch of the afferent fibres. Significance: Measures of body balance under quiet stance and dynamic conditions can provide relevant diagnostic information as to the pathophysiology and severity of ataxia and viability of the central branch of the sensory fibres, and help in separating patients with peripheral neuropathy from patients with loss of sensory neurones.
AB - Objective: Balance control under static and dynamic conditions was assessed in patients with Sensory Neuron Disease (SND) in order to shed further light on the pathophysiology of ataxia. Methods: Fourteen patients with diabetic polyneuropathy and 11 with SND underwent clinical and neurophysiological evaluation, stabilometric recording of body sway during quiet stance with and without vision, stereometric analysis of body segment displacement while riding a platform translating in anterior-posterior direction with and without vision (dynamic condition), and EMG recording of leg muscle responses to abrupt stance perturbation produced by rotation of a supporting platform. The findings were compared to those of age matched normal subjects. Results: Clinical and neurophysiological evaluation revealed a more severe motor impairment in patients with diabetes than SND, while sensory impairment was superimposable. Some patients with SND had vestibular dysfunction of diverse severity. Body sway during stance was larger in patients with SND than diabetes with and without vision. In the stance perturbation condition, the latency of the long-loop EMG response to platform rotation was disproportionately increased with respect to the spinal response in the SND but not in diabetic patients. Under dynamic condition, patients with SND oscillated more than diabetic patients and several of them easily lost balance with eyes closed. Conclusions: Patients with SND show severe unsteadiness under both static and dynamic conditions, particularly with eyes closed. The patchy sensory loss of SND, disrupting sensation from territories other than the lower limbs and possibly including the vestibular nerve, could be responsible for this instability. Ataxia is correlated to the abnormal latency of the muscle responses to stance perturbation. Since increased response latencies cannot be attributed to a vestibular deficit, the deterioration of equilibrium control would be ascribed mainly to the degeneration of the central branch of the afferent fibres. Significance: Measures of body balance under quiet stance and dynamic conditions can provide relevant diagnostic information as to the pathophysiology and severity of ataxia and viability of the central branch of the sensory fibres, and help in separating patients with peripheral neuropathy from patients with loss of sensory neurones.
KW - Body sway
KW - Dynamic equilibrium
KW - Long-loop reflex
KW - Postural perturbation
KW - Sensory Neuron Disease
KW - Stretch reflex
UR - http://www.scopus.com/inward/record.url?scp=33846839388&partnerID=8YFLogxK
U2 - 10.1016/j.clinph.2006.11.012
DO - 10.1016/j.clinph.2006.11.012
M3 - Article
SN - 1388-2457
VL - 118
SP - 538
EP - 550
JO - Clinical Neurophysiology
JF - Clinical Neurophysiology
IS - 3
ER -