CMT 1A and 2 in Balance control in peripheral neuropathy: Are patients equally unstable under st

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Gait Posture. 2005 May 13;

Balance control in peripheral neuropathy: Are patients equally

unstable under static and dynamic conditions?

Nardone A, Grasso M, Schieppati M.

Posture and Movement Laboratory, Division of Physical Therapy and

Rehabilitation, Scientific Institute of Veruno, Salvatore Maugeri

Foundation, Institute of Care and Research, Via Revislate 13, I-28010

Veruno (Novara), Italy.

The aim of this investigation was to assess the potentially different

effects of impaired proprioceptive input in balance control under

static and dynamic conditions in neuropathic patients. We recruited

20 normal subjects and 27 patients affected by neuropathies known to

affect to a different extent large and medium size afferent fibres.

The patients comprised 5 with Charcot-Marie-Tooth disease type 1A

(CMT1A), 8 with CMT type 2 (CMT2) and 14 with Diabetes polyneuropathy

(Diabetics).

Measurement of balance during quiet stance on a stabilometric

platform showed that sway area (SA) was larger in the CMT2 and

Diabetics than normal subjects or in CMT1A, under both eyes open and

closed conditions. The estimated conduction velocity (CV) of the

group II afferent fibres was lower in CMT2 and Diabetics than in

normal subjects and CMT1A.

Across all patients, SA increased as a function of the slowing of

group II CV. During a dynamic balance task the head A-P displacement

was only slightly increased in the patient groups with respect to

normals, despite the increased delay at which the head followed

displacement of the feet.

The unpredictably good performance of all patient groups under

dynamic condition, which was at variance with their imbalance during

quiet stance, may indicate that these patients learnt to exploit

anticipatory postural strategies.