DEPRESSION IN PATIENTS WITH PARKINSON ’ S DISEASE WITH DEMENTIA

Introduction: Parkinson’s disease is a multisystem disorder which is characterized by a combination of motor and non-motor symptoms. Non-motor symptoms include: depression, cognitive impairment, autonomic and sensor symptoms. It is difficult to detect and treat depression symptoms in patients with Parkinson’s disease with dementia. Early identification and treatment of depression symptoms can greatly improve the quality of life in these patients, as well as facilitate the quality of caregivers’ lives. Goal of the paper: The aim of our research was to evaluate frequency of depression occurrence in patients with Parkinson’s disease with cognitive impairment. Patients and methods: We did a prospective study which included 59 PD patients, who came for a regular check-up to Neurological infirmary of the General Hospital in Niksic, in the interval from 1 st January 2016to 31 st December 2016, all of whom were previously diagnosed with Parkinson’s disease. We tested their cognitive status using the Mini Mental State Examination scale. Out of 59 patients, 32 displayed cognitive deficit and were included in further research. We gave directions about testing to guardians or caregivers of the patients who displayed moderate or distinct cognitive impairment. The testing was done on the next check-up, with Cornell’s depression scale. Results: Research showed that out of 32 patients, 5 (15.6%) didn’t suffer from depression, 8 (25%) probably suffered from major depression, while 19 (59.4%) definitely suffered from major depression. On the cognitive scale, 6 (18.8%) patients had mild, 11 (34.4%) moderate and 15 (46.9%) distinct cognitive deficit. Out of 8 patients with probable depression 3 (9.4%) had mild, 3 (9.4%) had moderate and 2 (6.2%) distinct cognitive deficit. We can also: conclude that out of 19 (59.4%) with certain depression, 1 (3.1%) had mild, 5 (15.6%) had medium severe, and 13 (40.6%) had severe cognitive deficit. Conclusion: Prevalence of depression and dementia in Parkinson’s diseasepatients is high. Our patients have moderate cognitive deficit in 34.4% of the cases, and distinct cognitive deficit in 46.9% of the cases; while 59.4% definitely suffers from major depression at some point of their illness. Their early detection is of great importance for treatment and quality of life of these patients.


INTRODUCTION
Parkinson's disease (PD) is a multisystem degenerative disorder which is characterized by a combination of motor and non-motor symptoms (1,2).Nonmotor symptoms include: depression, cognitive impairment, autonomic and sensor symptoms (2,3).It can be very complicated to identify depression in PD patients who have cognitive impairment, for known depression scales are not reliable markers to evaluate depression (4).Dementia is present in more than 30% of PD patients, especially in those over 70 years old (5,6).Depression and dementia are often connected comorbidities; however, depression can be considered a risk factor for dementia development in PD (7).Early depression identification and treatment can significantly improve the quality of life in PD patients, as well as facilitate the quality of caregivers' lives (7)(8)(9)(10).Depression may appear as one of the first symptoms of PD, but it can appear many years before the beginning of motor symptoms of the illness.Dementia in PD implies impairment of executive function, attention, slow cognitive speed, recalling learned information, and visuospatial problem (11).Dementia is also a part of neurodegenerative illnesses, including PD (12)(13)(14).Prevalence of major depression in PD patients is from 2.7% to 8.2% and from 13% to 34.5% in case of minor de-

Original article
Perovic Zlatana, Cukic Mirjana pression (14)(15)(16).Prevalence of mild cognitive impairment in PD patients is from 18.9% to 55% (17)(18)(19).PD patients with distinct cognitive deficit, who need a caregiver, form a special group.Mild cognitive deficit is present in about 35% of the patients at the beginning of motor symptoms and in about 50% of the patients after 5 years of being ill (20).Depression is a very common in dementia as part of PD.Therefore, its early identification is of the essence in order to begin early medicament therapy, which will in the long-run improve the quality of life both of the patient and the caregiver (11,16,21).

PATIENTS AND METHODS
We researched presence and degree of depression in patients with Parkinson's disease with cognitive impairment.
Patients that were tested are those who came for a regular check-up to Neurological infirmary of the General Hospital in Niksic, Montenegro, in the interval from 1 st January to 31 st December 2016, all previously diagnosed with idiopathic Parkinson's disease.We tested cognitive status in 59 patients with idiopathic Parkinson's disease, using the MMSE scale.Out of the 59 patients, 32 were included in the research, all of whom tested less than 23 points on the Mini Mental State Examination (MMSE).They were divided to three groups: with mild (20-23), moderate (11)(12)(13)(14)(15)(16)(17)(18)(19), and severe cognitive deficit (0-10 points).After the applied MMSE testing, patients or caregivers of the patients received instructions about observing the patient in the next 7 days, when the testing with the Cornell's scale for depression would be applied (13).Cornell's scale for depression was applied on patients with dementia in order to achieve a more objective assessment.The scale consists of 19 parameters which are grouped into 5 groups: mood-related signs, behavioral disturbances, physical signs, cyclic functions and ideational disturbances.Each item is rated on a scale of 0-2 (0-absent, 1-mild or intermittent, 2-severe).Score above 10 indicates probable major depression; score above 18 indicates definite major depression; score below 6 as a rule is associated with absence of significant depressive symptoms (22).
Scores are presented tabularly and in percentage.We used the Chi-square test to connect depression and cognitive impairment.
We researched the significance of the Cornell scale in detecting depression in PD patients.
Ethics Statement: The paper was approved by the Ethical committee of the hospital where we did the research, and all the patients signed the informational consent before the beginning of research.
We feel that the Cornell Scale is greatly significant in identifying depression in these patients (Table 7).The size of the impact of the 0,413 high.

DISCUSSION
Patients with Parkinson's disease, in over 50% of the cases, suffer from significant cognitive impairment at a certain stage of the illness, which is in accordance with many previous studies (17)(18)(19)(20).In case of our PD patients, with cognitive impairment, at a certain point of the illness, 25% probably suffer from major depression, and 59.4% definitely suffer from depression, which is more than in previously shown results in other studies (14-16).
Cornell's scale may help us in our daily work to early diagnose depression in PD patients with dementia, which is a prerequisite for early treatment of depression of these patients (22).
Minimizing the disability includes treating not just motor symptoms, but treating also dementia, depression and psychosis.Therefore, identification of clinically relevant screening and diagnostic tools for depression and cognitive impairment are necessary in PD patients (22)(23).

CONCLUSION
Depression and dementia are a common problem in PD patients.Their detection is highly significant to clinical practice.PD patients with cognitive impairment present a special difficulty in identifying depression.

Table 1 .
Distribution of patients with PD and cognitive impairment in relation to gender

Table 2 .
Average agepatients with PD and cognitive impairment

Table 3 .
The average length of the disease

Table 5 .
The

Table 6 .
The size of the impact of depression on cognitive impairment

Table 7 .
Cornel scale in detecting depression