Parkinson's Disease (IPD) is a chronic neurodegenerative disease that has
profound motor and non-motor symptoms and effects on quality of life, health
care and personal costs1.
refers to a multi-system function that works to keep the body upright while
sitting, standing and during changing posture. Postural instability is commonly
observed in severe cases of IPD2. A single, objective measure of
this later finding is impossible due to the integrated nature of postural
In the year 2000
posturography was introduced as a tool for documentation of disability and
impairment4. Computerized dynamic posturography (CDP) is an
objective, non-invasive specialized clinical assessment technique5.
Different examination protocols examine movement coordination and sensory
organization of visual, somatosensory and vestibular information relevant to
The aim of this
study is to evaluate and analyze objectively dynamic balance during functional
activity performance in patients with Parkinson’s Disease (PD).
This study is a
case control study performed in the department of Neurology, Cairo University.
It included 20 Egyptian patients with PD and 20 control healthy subjects. Both
patients and control were matched for age, sex, height and weight (p>0.05).
The mean age, weight and height in PD patients group were 51±7.42 yrs,
68.2±18.11 kg and 162.55±6.97cm respectively. Inclusion criteria were: Duration
of disease from 5-8 years with no cognitive dysfunction (Mini Mental State
Examination (MMSE) score mean value was 28.3±0.47) and patients who are able to
walk without any assistive devices or physical assistance (disease severity
ranged from stage 2.5-3 according to the modified Hoen and Yahr scale7.
excluded if they had cognitive dysfunction, peripheral neuropathy, ear
problems, visual problems, cardiovascular disease that could affect locomotion,
or require assistive device, physical assistance.
dynamic posturography (Smart balance master® and Balance master system®)
was used. The testing protocols included: (1) Sensory organization test that
measure the equilibrium score parameter; it evaluates the different sensory
systems (somatosensory, visual and vestibular) on postural stability, (2) Sit
to stand (STS) measured the weight transfer, rising index and center of gravity
(COG) sway velocity parameters, (3) Tandem walk (TW) measures the step width,
speed and end sway parameters, (4) Step/Quick turn (SQT) measures turn time and
turn sway parameters.
were presented as mean ± standard deviation (SD). The paired t-test was used to
examine the difference between posturographic scores of both patients and
controls. SPSS (version 12 windows) and graph Pad Instat (version 3.05) were
used for data analysis. P value <0.05 was considered statistically
significant and >0.05 was considered statistically non-significant.
organization test (equilibrium score)
scores (ES) were measured during different situation corresponding to the six sensory
conditions. Comparison of patients and control scores showed a statistically
significant difference (p<0.01) in all tests as shown in Table (1)
to Stand test (STS)
Comparison of both
groups showed highly significant statistical difference (p<0.01) in weight
transfer time being higher in patients. A significant statistical difference
also was found in rising index and COG sway being decreased in patients
compared to control group as shown in Table (2).
There was a
statistically significant increase in step width and end sway and statistically
significant decrease in speed in patients compared to controls as shown in Table
(3). The increase in step width was explained by patient lack of good dynamic
balance control if the base of support (BOS) is narrow.
and quick turn (SQT) test
Comparison of the
turn time and turn sway to the left and right directions showed a significant
increase in patient group compared to control group. This difference were more
on turning to the right side as shown in Table (4)
The results of this
study proved that there was a significant affection of postural stability in
Parkinson Disease (PD) patients compared to age, sex, weight and height matched
controls and this instability was due to abnormality of sensory system.
deficit in the sensory organization tests was observed as it was previously
demonstrated in different studies2,8. This reflects breakdown in the
central hierarchy of postural control which can be explained by dysfunction of
the basal ganglia (BG) as one of its function is somatosensory integration.
Somatosensory deficit produce an abnormally constructed body scheme and explain
stooped posture of PD patients9-11.
result of the present study showed that there was an increase in postural sway
when visual information was deprived which means that PD patients has a visual
dependence for the regulation of postural control. This agrees with many
studies (2, 8, 12) that postulate
that presence of inaccurate visual information overrides the ability to reweigh
sensory feedback sources and prioritize accurate information. Other studies
rejected this finding like Beuter et al.13 and Roujier14,
who stated eye closure was compensated by increase excitatory drive to postural
Also the role of
basal ganglia (BG) in sensory organization was demonstrated when the PD
patients postural instability became accentuated with moving surrounding
experiments. This was explained as a difficult initial posture adjustment. This
was proved by Vaugoyeau et al.15.
The study showed
that patients were unable to use vestibular input in the presence of impaired
visual and proprioceptive input to maintain balance which agree with
Bronte-Stewart et al.2. Later this finding was disapproved by
Nallegowda et al.12, but this is may be due to the fact that they
measured only the vestibulospinal reflex.
Lack of proper
rising of patients may be attributed to their rigidity and bradykinesia as well
as restricted range of motions at the level of ankle, knee, hip and/or spine
In this study, the
PD patients were unable to walk on a narrow base of support (BOS). This was
explained by poor ability of patients to alter postural synergies for changes
in initial stance posture to reduce ability to use proprioceptive information
to select postural muscle activation patterns based on the specific pattern of
displacements as a result of impaired proprioceptive guidance of movement16-18.
The patients were
unable to turn around during functional activity of daily living. This agrees
with many studies19-21, which attributed this finding to loss of
intersegmental axial coordination which correspond to the well-known phenomenon
of “en bloc” turning of Parkinson’s Disease.
The result of this
study concludes that many functional systems are involved as a cause of the
postural instability in PD patients (somatosensory, visual, vestibular and
motor) and that posturography has an essential role in evaluation of such
[Disclosure: Authors report no conflict of
P. The importance of non-motor disturbances to quality of life in Parkinson's
disease. J Neurol Sci. 2011; 310(1-2): 12-6.
HM, Minn AY, Rodrigues K, Buckley EL, Nashner LM. Postural instability in
idiopathic Parkinson's disease: the role of medication and unilateral
pallidotomy. Brain. 2002;125(Pt 9): 2100-14.
3. Brusse KJ, Zimdars S, Zalewski KR, Steffen TM.
Testing functional performance in people with Parkinson disease. Phys Ther.
2005; 85(2): 134-41.
4. Cocchiarella L,
Turk MA, Andersson G. Improving the evaluation of permanent impairment. JAMA.
2000; 283(4): 532-3.
NT, Solomon D. Practical issues in the management of the dizzy and balance
disorder patient. Philadelphia; London: W.B. Saunders; 2000.
6. Gouveris H,
Stripf T, Victor A, Mann W. Dynamic posturography findings predict balance
status in vestibular schwannoma patients. Otol Neurotol. 2007; 28(3): 372-5.
7. O'Sullivan SB, Schmitz TJ. Physical
rehabilitation. 5th ed. ed. Philadelphia: F.A. Davis; 2007.
8. Ickenstein GW,
Ambach H, Klöditz A, Koch H, Isenmann S, Reichmann H, et al. Static
posturography in aging and Parkinson's disease. Front Aging Neurosci. 2012; 4: 20.
9. Valkovic P, Krafczyk S, Saling M, Benetin J,
Bötzel K. Postural reactions to neck vibration in Parkinson's disease. Mov
Disord. 2006; 21(1): 59-65.
10. Valkovic P, Krafczyk S, Bötzel K. Postural
reactions to soleus muscle vibration in Parkinson's disease: scaling
deteriorates as disease progresses. Neurosci Lett. 2006; 401(1-2): 92-6.
11. Kamata N, Matsuo
Y, Yoneda T, Shinohara H, Inoue S, Abe K. Overestimation of stability limits
leads to a high frequency of falls in patients with Parkinson's disease. Clin
Rehabil. 2007; 21(4): 357-61.
12. Nallegowda M, Singh U, Handa G, Khanna M, Wadhwa
S, Yadav SL, et al. Role of sensory input and muscle strength in maintenance of
balance, gait, and posture in Parkinson's disease: a pilot study. Am J Phys Med
Rehabil. 2004; 83(12): 898-908.
13. Beuter A,
Hernández R, Rigal R, Modolo J, Blanchet PJ. Postural sway and effect of
levodopa in early Parkinson's disease. Can J Neurol Sci. 2008; 35(1): 65-8.
14. Rougier P. The
influence of having the eyelids open or closed on undisturbed postural control.
Neurosci Res. 2003; 47(1): 73-83.
15. Vaugoyeau M, Viel
S, Assaiante C, Amblard B, Azulay JP. Impaired vertical postural control and
proprioceptive integration deficits in Parkinson's disease. Neuroscience. 2007;
16. Chong RK, Horak
FB, Woollacott MH. Parkinson's disease impairs the ability to change set
quickly. J Neurol Sci. 2000; 175(1): 57-70.
17. Dimitrova D, Nutt
J, Horak FB. Abnormal force patterns for multidirectional postural responses in
patients with Parkinson's disease. Exp Brain Res. 2004; 156(2): 183-95.
18. Dimitrova D, Horak
FB, Nutt JG. Postural muscle responses to multidirectional translations in
patients with Parkinson's disease. J Neurophysiol. 2004; 91(1): 489-501.
19. Crenna P,
Carpinella I, Rabuffetti M, Calabrese E, Mazzoleni P, Nemni R, et al. The
association between impaired turning and normal straight walking in Parkinson's
disease. Gait Posture. 2007; 26(2): 172-8.
20. Willems AM,
Nieuwboer A, Chavret F, Desloovere K, Dom R, Rochester L, et al. Turning in
Parkinson's disease patients and controls: the effect of auditory cues. Mov
Disord. 2007; 22(13): 1871-8.
21. Baltadjieva R,
Giladi N, Gruendlinger L, Peretz C, Hausdorff JM. Marked alterations in the
gait timing and rhythmicity of patients with de novo Parkinson's disease. Eur J
Neurosci. 2006; 24(6): 1815-20.