Authors:
Heba Mohamed Tawfik MS,
Mohamad A. Al Sadany MD*,
Shereen M. Mousa MD,
Mohamad H. El Banouby MD.

Department of Geriatrics,
Faculty of medicine, Ain Shams University

Dr. Shereen M. Mousa, Lecturer of Geriatric Medicine, Faculty of Medicine,
Ain Shams University
Prof. Mohammad H El-Banoby, Professor of neuropsychiatry and Geriatric medicine, Geriatrics Department, Faculty of Medicine, Ain Shams University.
Heba T. Mousa, Geriatric medicine resident, Faculty of Medicine, Ain Shams University.

Corresponding Author:
Dr. Mohamad A. Al Sadany, Lecturer of Geriatric Medicine, Faculty of Medicine,
Ain Shams University, Cairo, Egypt.
Tel: 0020102412671
FAX: 0020224826726
Mailing Address: Geriatric Medicine Department, Faculty of Medicine, Ain
Shams University, Cairo, Egypt.
Email: mohamadalsadany@yahoo.com

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INTRODUCTION
Mild Parkinsonian signs (MPS) or extra-pyramidal signs, including rigidity, changes in axial function, and resting tremors, occur in 15 to 40% of community-dwelling elderly and are associated with functional impairment [1]. Extra-pyramidal signs in non-demented subjects are associated with higher mortality, increased functional impairment and the subsequent development of dementia [2].

It is unclear whether the emergence of MPS reflects an age associated decline in nigrostriatal dopaminergic activity or whether these motor signs are due to the presence of emerging dementia or subcortical cerebrovascular disease [3]. Longitudinal studies have shown that MPS increase in severity over time and they are associated with incident dementia [4].

Aging is an inevitable and undeniable process that impacts all aspects of life. It is associated with a broad range of physiological and psychological changes, including a decline in cognition which contributes to loss of independence and a lower quality of life [5]. Mild Cognitive Impairment (MCI) is thought to be a transitional state between normal aging and dementia [6]. The prevalence of MCI varies between 2 and 30% in the general population and between 6 and 85% in a clinical setting (average 40%) [7].

Individuals with amnestic-MCI progress to AD at a rate of 10% to 15% per year, compared with 1% to 2% per year in normal elderly persons [8]. Also, it was found that patients with MCI when followed over time may progress to non-AD dementia, for example; patients with Parkinson's disease (PD) and MCI may be at higher risk of progressing to dementia than cognitively intact PD patients [9].

Identifying states that will predict the subsequent development of dementia has important implications for future therapeutic interventions. Much current focus is upon the entity of mild cognitive impairment [10].
Little is known about correlations of specific Parkinsonian signs with cognitive decline in AD. In some studies, the rates of change in bradykinesia, gait disorder, postural reflex impairment, and especially rigidity were strongly related to the rate of cognitive decline. In cross-sectional research on Parkinson disease, a somewhat similar pattern has been described with motor signs other than tremor showing modest correlations with cognitive function [11].

In a study on community-dwelling elderly participants aged 75 and over, abnormalities of gait including unsteadiness, frontal gait disorders and hemiparetic gaits predicted the development of non-Alzheimer dementias over a median period of 6.6 years [12].

Hence it was important to begin research reporting on such an important topic in the Egyptian elderly. The purpose of this study was to determine prevalence of Parkinsonian features specifically (bradykinesia, rigidity, tremors, changes in posture, speech and facial expressions) in non-demented community-dwelling Egyptian elderly with MCI, and to study the correlation between Parkinsonian features and cognitive functions in those MCI patients.

METHODOLOGY
Study design
A cross sectional study was conducted to assess Parkinsonian features in Egyptian elderly patients with MCI. The study was carried out in six geriatric clubs and three geriatric homes located in Cairo. Those clubs and homes were chosen randomly from a list supplied by the social workers in the geriatrics department, Ain Shams University. This list was updated regularly from the Ministry of Social Affairs. For each of those geriatric clubs and homes, lists of their elderly residents were assessed for selection in the study.

Methods
The number of MCI patients required for the study was determined as One hundred patients. To reach this required number of participants the study passed through two stages.

Stage I: A total number of 542 elderly participants (507 after exclusion) both men and women, residing in the selected geriatrics clubs and homes were randomly selected. The selected participants were ambulant at the time of assessment, not previously diagnosed as demented and had no evidence of impairment in their activities of daily living. After taking consent, they were subjected to a structured interview including demographic data, past medical history, list of medications used, physical examination, neurological examination, cognitive function assessment using Mini Mental Status Examination (MMSE) [14] and Montreal Cognitive Assessment (MoCA) [15], functional assessment using ADL (Activities of Daily Living ) [18] and IADL (Instrumental Activities of Daily Living) [19] and Screening for depression using Geriatric depression scale-15 items (GDS-15)[20].

Montreal Cognitive Assessment is a screening instrument reportedly to be capable of distinguishing MCI from age-related cognitive decline. It is a one-page 30-item point test administered in 10 minutes.

Thirty-five elderly participants were excluded from the study, and the total number of elderly participants needed for detection of MCI patients and were eligible for the study was 507 elderly participants. The exclusion criteria were: subjects with Parkinson's disease or Parkinson plus syndrome or any other clinically evident neurological disorder, subjects with severe musculoskeletal disorders, subjects who did not complete their assessment, subjects receiving neuroleptic drugs, subjects with MMSE [14] score <26, subjects who had less than 6 years of formal education, subjects with severe auditory or visual loss, and immobile subjects.

Stage II: One hundred elderly without dementia (65 men, 35 women) with a mean age 75 ±8 years were eligible for participation. The diagnosis of MCI was rendered for individuals who had cognitive impairment but who did not meet criteria for dementia. Diagnosis of mild cognitive impairment (MCI) required

(a) objective impairment in at least one of four cognitive domains (memory, executive function, language, visuospatial) based on performance on the neuropsychological test battery.
(b) a subjective complaint of memory impairment, and
(c) absence of functional impairment, according to the published criteria [13].

For specific analyses examining the subtypes of MCI, individuals who had MCI with relatively impaired episodic memory were considered amnestic-MCI, whereas individuals who had MCI with relatively spared episodic memory were considered non-amnestic MCI.

The MCI participants were assessed for detection of extra-pyramidal signs by standardized neurological examination, which included an abbreviated version [16] of the motor portion of the Unified Parkinson's Disease Rating Scale (UPDRS) [17].

The abbreviated 10 items included speech, facial expression, tremors at rest (in any body region), rigidity (rated separately in the neck, right arm, left arm, right leg, and left leg), posture, and body (axial) bradykinesia. Each of the ten items was rated from 0 to 4. A rating of 1 indicated a mild abnormality and a rating =2 indicated an abnormality of moderate severity, a rating =3 indicated severe abnormality, a rating =4 indicated marked abnormality interfering with function. A Parkinsonian sign score (range = 0 [no Parkinsonian signs] to 40 [maximum]) was calculated for each participant. Extra pyramidal signs or MPS (mild Parkinsonian symptoms) were defined as present when any one of the following conditions was met: (i) two or more UPDRS ratings >1; or (ii) one UPDRS rating >2 [1].

Statistical Analysis
The data was collected, coded and entered into a personal computer (PC). The data was analyzed with the program (SPSS) Statistical Package for Social Science under Windows version 13.0. Description of all data in the form of mean (M) and standard deviation (SD) for all quantitative variables was done. Frequency and percentage were done for all qualitative variables. Comparison of qualitative variables was done using the Chi-square test. Correlation coefficient was also used to find linear relation between different variables using r-test or Spearman correlation co-efficient. P value was always set as significant at P<0.05.

RESULTS
The results of our study showed that the mean age of our study population was 75±8 years, and 65% were men. 61% had >12 years education while the remaining 39% of study population had 6-12 years of education. Also, it shows that 63% were smokers, 57% had hypertension, 31% had diabetes, 24% had heart diseases, and 10% had other diseases, while 18% of the study population had no co-morbidity (Table 1).

Table 1: Demographic characteristics of the study population

Results revealed that 66% of the MCI participants had Parkinsonian features in any form that were distributed as follows: bradykinesia in 63% of participants, stooped posture in 49%, rigidity in 22%, speech affection in 14%, facial expression (hypomimia) in 13%, and resting tremors in only 3% of MCI participants (Table 2).

Table 2: Parkinsonian features among the studied MCI participants

We found that Parkinsonian features were significantly related to poorer performance in both MOCA and MMSE tests with a p value of (0.038) and (0.016) respectively (Table 3).

Table 3: Comparison between participants with and without Parkinsonian features as regards their MOCA and MMSE tests scores

The most affected cognitive domain of MoCA test was language (P value = 0.005), while other cognitive domains such as executive, attention, calculation, abstraction, and delayed recall did not show such significance (Table 4).

Table 4: Comparison between participants with and without Parkinsonian features as regards the score of different cognitive domains of the MOCA test

A statistically significant negative correlation was found between both total MOCA score (P = 0.045) and its sub-item (language) score (P = 0.001) and UPDRS score of the studied Parkinsonian features (Table 5). Finally presence of Parkinsonian features were significantly related to vascular risk factors such as smoking (P value =0.018), hypertension (P value =0.007), and ischemic heart disease (P value =0.04) (Table 6).

Table 5: Correlation between UPDRS score and the MOCA total and sub-items cognitive domains scores

Table 6: Relation between presence of Parkinsonian Features and different
co-morbidities

DISCUSSION
Mild Parkinsonian signs (MPS) include gait and balance changes, rigidity, bradykinesia, and tremor which can occur commonly during the clinical examination of older people who do not have known neurological disease, with prevalence estimates for MPS as a whole ranging from 15% to 95%. MPS are generally progressive and they are coupled with functional difficulties, impaired gait and balance, and increased risks of mild cognitive impairment, dementia, and mortality [21].
The aim of the current study was to assess the prevalence of Parkinsonian features among individuals with MCI and to find any correlation between the presence and severity of Parkinsonian features and the degree of MCI. Our results revealed that 66% of the study population has Parkinsonian features. The wide range of MPS among normal elderly and the fact that such signs are coupled with MCI and dementia patients may explain the high prevalence that was observed in our population.

Boyle and colleague [22] found that among individuals with MCI, lower levels of cognitive function particularly in perceptual speed, were associated with higher levels of Parkinsonian signs which are related to the severity and type of cognitive impairment. Our study revealed almost the same results; there was a statistical significant relation between MCI and Parkinsonian features with a mean score of MOCA being higher in patients without Parkinsonian features (23.74±1.831), than those with Parkinsonian features (22.73± 2.459). Also the severity of MCI was closely related to the presence and the severity of Parkinsonian features and this was obvious by the statistically significant negative correlation between total MCI score and UPRD score.

The most common Parkinsonian features that were observed in our population are bradykinesia and stooped posture; they affected almost 50% of our study population. This agrees with Boyle et al. [22] who found that MCI is associated with multiple Parkinsonian signs, including bradykinesia, gait disturbance and rigidity but disagrees with Louis et al., [1] who found that rigidity rather than tremor or bradykinesia was most strongly associated with MCI (amnestic type). This may be due to the fact that they did not include the assessment of appendicular bradykinesia so it is possible that they may have underestimated the correlates of Parkinsonian signs, and both of the previously mentioned studies included patients without MCI, which is lacking in our study.

The most affected cognitive function in our sample was language which was found to be significantly related to Parkinsonian features. Critchley [23] in a study of speech disorders in Parkinsonism reported that it is a paradigm of the integration of phonation, articulation, and language in production of speech, and as language is considered one of the deficiencies and diagnostic criteria of MCI so it was expected to be one of the most affected functions in our patients. Other cognitive function did not show such significant correlation.

Finally it was observed that Parkinsonian features were significantly related to the presence of smoking, hypertension and ischemic heart disease. Being risk factors for cerebrovascular disease, the three previously mentioned conditions could represent the relation between MCI and Parkinsonian features and cerebrovascular disease. This association was reported in a lot of the literature, such as Bennett et al., [24] who reported that cerebrovascular involvement in mild cognitive impairment is intermediate between that seen in ageing and early Alzheimer's disease. Also, Louis et al., [1] found that Parkinsonian features were associated with vascular risk factors like hypertension, as well as there being an association between vascular risk factors and MCI, and both suggest that cerebrovascular disease may be contributing to both Parkinsonian features and MCI.

ACKNOWLEDGMENTS
We acknowledge the social workers of Geriatrics and Gerontology department, Faculty of Medicine, Ain Shams University, Cairo, Egypt for their help in providing lists for geriatric clubs and homes in Cairo.

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