Postural instability in Charcot-Marie-Tooth type 1A patients is strongly associated with reduced somatosensation.

In order to determine the influence of somatosensory impairments, due to the loss of large myelinated fibres, on the postural stability of Charcot-Marie-Tooth 1A (CMT) patients, a cross-sectional balance assessment was done. Nine CMT patients were compared with eight patients with a distal type of Spinal Muscular Atrophy (SMA), and 11 healthy control subjects. The balance assessment consisted of four tasks: quiet barefoot standing on a stable versus compliant surface, with eyes opened or closed. Force plate signals were used to calculate the velocity of the centre of pressure of the ground reaction forces. The patients' distal muscle force (MRC scale), vibration detection threshold (Rydel-Seiffer tuning fork) and superficial tactile sensation (Semmes-Weinstein monofilaments) were clinically assessed. Compared to the healthy subjects, postural stability of both patient groups was seriously impaired, however, increased visual dependency was only found in the CMT patients. The postural instability of the CMT patients correlated significantly with decreased vibration sense only. The strength of the correlation increased with task complexity. It is concluded that somatosensory deficits substantially contribute to impaired postural stability and increased visual dependency in CMT patients.

[1]  J. Collins,et al.  Vibrating insoles and balance control in elderly people , 2003, The Lancet.

[2]  Suzanne G. Leveille,et al.  Independent effects of peripheral nerve dysfunction on lower-extremity physical function in old age: the Women's Health and Aging Study. , 2000, Diabetes care.

[3]  P. Schmitz,et al.  Measuring vibration threshold with a graduated tuning fork in normal aging and in patients with polyneuropathy , 1998, Journal of neurology, neurosurgery, and psychiatry.

[4]  P. Thoumie,et al.  Changes in motor activity and biomechanics during balance recovery following cutaneous and muscular deafferentation , 1996, Experimental Brain Research.

[5]  A. Geurts,et al.  Postural organization in patients with hereditary motor and sensory neuropathy. , 1992, Archives of physical medicine and rehabilitation.

[6]  A. Bronstein,et al.  Body sway and vibration perception thresholds in normal aging and in patients with polyneuropathy. , 1995, Journal of neurology, neurosurgery, and psychiatry.

[7]  Marco Schieppati,et al.  Balance control in peripheral neuropathy: are patients equally unstable under static and dynamic conditions? , 2006, Gait & posture.

[8]  R W Simmons,et al.  Postural stability of diabetic patients with and without cutaneous sensory deficit in the foot. , 1997, Diabetes research and clinical practice.

[9]  J. Lupski,et al.  Charcot‐Marie‐Tooth disease and related neuropathies: Mutation distribution and genotype‐phenotype correlation , 2002, Annals of neurology.

[10]  K. Stansberry,et al.  Diabetes, peripheral neuropathy, and old age disability , 2002, Muscle & nerve.

[11]  P. E. Sullivan,et al.  Balance and physical impairments after stroke. , 1999, Archives of physical medicine and rehabilitation.

[12]  S. Lord,et al.  Postural stability and associated physiological factors in a population of aged persons. , 1991, Journal of gerontology.

[13]  Marco Schieppati,et al.  Loss of large-diameter spindle afferent fibres is not detrimental to the control of body sway during upright stance: evidence from neuropathy , 2000, Experimental Brain Research.

[14]  F. Schlösser,et al.  The Semmes Weinstein monofilament examination as a screening tool for diabetic peripheral neuropathy. , 2009, Journal of vascular surgery.

[15]  J. J. Collins,et al.  Age-related changes in open-loop and closed-loop postural control mechanisms , 2004, Experimental Brain Research.

[16]  R. Abresch,et al.  Design of the Protocol , 1995 .

[17]  M. Morris,et al.  Foot and ankle characteristics associated with impaired balance and functional ability in older people. , 2005, The journals of gerontology. Series A, Biological sciences and medical sciences.

[18]  Craig W. Newman,et al.  Handbook of Balance Function Testing , 1993 .

[19]  François Curtin,et al.  Multiple correlations and bonferroni’s correction , 1998, Biological Psychiatry.

[20]  J. Derr,et al.  Postural Instability in Patients with Diabetic Sensory Neuropathy , 1994, Diabetes Care.

[21]  P. Fransson,et al.  Changes in postural control in healthy elderly subjects are related to vibration sensation, vision and vestibular asymmetry. , 2001, Acta oto-laryngologica.

[22]  A. Geurts,et al.  Intrasubject variability of selected force-platform parameters in the quantification of postural control. , 1993, Archives of physical medicine and rehabilitation.

[23]  M A Hughes,et al.  The relationship of postural sway to sensorimotor function, functional performance, and disability in the elderly. , 1996, Archives of physical medicine and rehabilitation.