Contribution of central neuropathy to postural instability in IDDM patients with peripheral neuropathy.
OBJECTIVE
To evaluate the contribution of central neuropathy on postural impairment observed in diabetic patients with peripheral neuropathy.


METHODS
Central sensory and motor nervous propagation, nerve conduction velocity, and static posturography were assessed in the following age-matched subjects: 7 IDDM patients with peripheral neuropathy (group DN), 18 IDDM patients without peripheral neuropathy (group D), and 31 control subjects (group C). Somatosensory-evoked potentials (SEPs) during tibial nerve stimulation were recorded, and the spine-to-scalp sensory central conduction time (SCCT) was evaluated. Motor-evoked potentials (MEPs) were recorded from leg muscles during magnetic transcranial brain stimulation, and the scalp-to-spine motor central conduction time (MCCT) was evaluated. The following posturographic parameters were calculated from the statokinesigram: trace length, trace surface, velocity of body sway with its standard deviation, and VFY (a parameter derived from the velocity variance and the anteroposterior mean position of the body).


RESULTS
SCCT was significantly higher in the DN group than in the C and D groups (P < 0.001). MCCT was similar in all groups. Posturographic parameters were all significantly impaired in the DN group (P < 0.01). While posturographic parameters showed a direct relationship with some parameters of peripheral nerve conduction, no correlations were observed with SEP and MEP central conduction time. These results were also confirmed by logistic regression, which indicates peripheral neuropathy as the only implicating factor in postural instability (odds ratio 0.22, 95% CI 0.07-0.75) after data reduction by means of factor analysis.


CONCLUSIONS
Although diabetic patients with peripheral neuropathy show a delay in central sensory conduction, postural instability may be fully explained by the presence of peripheral neuropathy.
Uccioli
L
L
Department of Endocrinology, University of Rome Tor Vergata, Italy.
Giacomini
P G
PG
Pasqualetti
P
P
Di Girolamo
S
S
Ferrigno
P
P
Monticone
G
G
Bruno
E
E
Boccasena
P
P
Magrini
A
A
Parisi
L
L
Menzinger
G
G
Rossini
P M
PM
D000328:Adult; D001921:Brain / Q000503:physiopathology; D002493:Central Nervous System Diseases / Q000503:physiopathology; D003922:Diabetes Mellitus, Type 1 / Q000503:physiopathology*; D003929:Diabetic Neuropathies / Q000503:physiopathology*; D003930:Diabetic Retinopathy; D019054:Evoked Potentials, Motor; D005073:Evoked Potentials, Somatosensory; D005260:Female; D006801:Humans; D007866:Leg; D008297:Male; D009046:Motor Neurons / Q000502:physiology; D018482:Muscle, Skeletal / Q000294:innervation; D009431:Neural Conduction; D009475:Neurons, Afferent / Q000502:physiology; D010523:Peripheral Nervous System Diseases / Q000503:physiopathology; D010543:Peroneal Nerve / Q000503:physiopathology; D011187:Posture; D011507:Proteinuria; D013497:Sural Nerve / Q000503:physiopathology; D013979:Tibial Nerve / Q000503:physiopathology