Journal of Brain & Neuroscience Research Category: Clinical Type: Research Article

Parkinson’s Disease Research by India: A Scientometric Assessment of Publications Output for the Period 1990-2019

Gupta BM1* and Dhawan SM2
1 CSIR-NISTADS, New Delhi, India
2 CSIR-NPL, New Delhi, India

*Corresponding Author(s):
Gupta BM
CSIR-NISTADS, New Delhi, India
Email:bmgupta1@gmail.com

Received Date: Feb 16, 2021
Accepted Date: Feb 22, 2021
Published Date: Mar 01, 2021
DOI:

Abstract

The paper analyzes Parkinson’s disease research publications output by India in the global context using bibliometric indicators with the purpose to assess and evaluate the research productivity and impact of the country in the subject. The publications data for study was sourced from the Scopus database covering the 30-year period 1990-2019. The study reveals that the global research in the domain of Parkinsons’s disease is highly skewed. The top 15 most productive countries in the subject account for a 99.59% global publications share. The USA is the world leader in the subject with a 31.71% global share, followed by U.K., Germany, Italy, Japan and China (from 6.16% to 10.20%), etc. India ranks as the 13th most productive country in the world with a global publications share of 2.35% (3149 publications). India registered a 22% annual growth rate in the subject, averaged citation impact of 19.08 citations per paper, and published 21.88% of its country output as a share of international collaborative papers. The paper identifies most productive organizations, most cited organizations, most productive authors, and most cited authors. The paper also identifies the most productive journals and the most cited journals.

Keywords

Bibliometrics; Indian publications; Parkinson’s disease; Scientometrics

Introduction

Parkinson’s Disease (PD) is recognized as the most common age-related movement disorder and the second most common neurodegenerative disease [1-3].  As the PD disease worsens, non-motor symptoms begin to impact the quality of life [4,5]. The pathological features of the Parkinson disease result from the substantial cell loss or cell deaths in the substantianigra (a region of the midbrain) [4] and the concomitant loss of Dopamine (DA) neurotransmitter or not enough dopamine in this region of the brain. Though the cause of cell death is poorly understood, but it does involve the build-up or deposition of proteins within the brain as intracellular inclusions called Lewy bodies in the neurons [4,6,7]. The disease is clinically manifested after the death of ~70% of these neurons [4,6]. The symptoms usually emerge slowly [4]. Early in the disease, the most obvious symptoms are shaking, rigidity, slowness of movement, and difficulty with walking [4]. Thinking and behavioral problems may also occur [2]. Dementia becomes common in the advanced stages of the disease [7]. Depression and anxiety are also common, occurring in more than a third of people with PD [5]. Other symptoms include sensory, sleep, and emotional problems [1,2]. The main motor symptoms are collectively called "parkinsonism” or a "parkinsonian syndrome" [4,6]. 

Parkinson disease has been the subject of intense research across the world ever since it was first discovered around 200 years ago. The literature in the subject has by far grown significantly in volume. Among the bibliometric studies at international level, Xue, Hu, Lai, Cai and Wen [8] studied 100 most-cited articles (receiving 669 to 6902 citations per paper and appearing between 1996 and 2000) on Parkinson’s disease to evaluate research on metrics such as citation number, publication time, journal, impact factor, authors, original country, institution of corresponding author and study type.  Li, Ho and Li [9] assessed quantitative and qualitative global trends in Parkinson's disease literature 1991-2006 on measures such as scientific output, world collaboration, and the frequency of author keywords used. The keywords analysis helped to identify research trends and recent hot spots. Yang, Wang, Tang, Wang and Bao [10] examined publication trends in stem-cell research in the context of Parkinson's disease and studied the bibliometric characteristics of top-cited articles, published between 1999 and 2018, on metrics such as annual outputs, distribution by journals, countries/regions, and institutions. The authors also studied global collaborations between publications and tracked the growing hotspots using MeSH terms.At the national level, Gupta and Bala [11] examined the research output of India in Parkinson's Disease (PD) during 2002-2011. The bibliometric indicators used for analysis include:  Research output, research growth, country rank in global publications, citation impact, international collaboration, major collaborators and publication productivity. They also analyzed research output by subject sub-fields and described bibliometrics characteristics of the leading institutions and authors and of highly-cited papers in the subject.

Materials and Methods

The data for the present study was sourced from the Scopus database.  It is one of the most reliable international multidisciplinary citation databases (http://www.scopus.com) by Elsevier Science and most widely used for bibliometric studies [12]. The Scopus has a slight edge in the coverage of health sciences, medicine and environmental science journals over the Web of Science or PubMed [13]. The strategy applied for data retrieval was as follows. Here, the keyword “Parkinson*” was suffixed to search tags --  “Key” (Keyword) and “Title” (Title of Paper)  -- and the time frame for search output was limited to -- 1990 till June, 2019. This main search strategy so formulated yielded a total of 208902 records as the world output in the subject. The global search output was refined manually to 133731 records. The final search output was further refined by country of publication (including India) to identify the top 15 most productive countries in the domain of Parkinson’s disease research. The search string (shown below) for sourcing India’s output in the subject yielded 3149 records. These records were further analyzed by document types including original articles, reviews, letters and editorials, etc [14-17]. 

(KEY(Parkinson*) or TITLE (Parkinson*)) and PUBYEAR > 1989 AND PUBYEAR < 2020 and (LIMIT-TO (AFFILCOUNTRY,"India"))

Analysis And Results

Overall publication output & growth 

As seen from Scopus database, the global research in the domain of Parkinson disease accumulated a total of 133731 publications during the 30-year period 1990-2019, with an average of 4457.7 papers per year. During the period, India contributed a 2.35% share (3139 publications) to the global publications output, with an average of 104.6 papers per year, and registered 22% annual growth compared to world average of 7.06% in the subject.  Compared to 15-year absolute growth (108.34%) registered by the world between 1990-2004 and 2005-2019, the corresponding growth by India in the subject was ten times faster (1080.08%). This sort of growth trend in the data seeks to reveal that India’s growth in the 2nd half of the study period was significantly faster compared to its 1st half. The citation impact of India averaged to 19.08 citations per paper (CPP) during 1990-2019 (Table 1, Figure 1). 

Publication Period

World

India

TP

TP

TC

CPP

TP (%)

ICP

ICP (%)

1990

1524

7

51

7.29

0.46

0

0

1991

1420

10

64

6.4

0.7

1

10

1992

1650

5

68

13.6

0.3

0

0

1993

1738

3

19

6.33

0.17

1

33.33

1994

1724

7

195

27.86

0.41

3

42.86

1995

1908

11

291

26.45

0.58

1

9.09

1996

1935

8

105

13.13

0.41

4

50

1997

2254

17

440

25.88

0.75

1

5.88

1998

2296

13

312

24

0.57

1

7.69

1999

1638

13

325

25

0.79

3

23.08

2000

2884

25

593

23.72

0.87

1

4

2001

2887

24

401

16.71

0.83

5

20.83

2002

3338

20

804

40.2

0.6

3

15

2003

3839

43

1931

44.91

1.12

6

13.95

2004

4126

40

1263

31.58

0.97

8

20

2005

4374

50

2804

56.08

1.14

14

28

2006

4739

63

2441

38.75

1.33

11

17.46

2007

5057

69

1850

26.81

1.36

12

17.39

2008

5280

76

1912

25.16

1.44

18

23.68

2009

5620

104

4597

44.2

1.85

20

19.23

2010

6149

136

4204

30.91

2.21

23

16.91

2011

6456

141

2932

20.79

2.18

28

19.86

2012

6998

174

3471

19.95

2.49

36

20.69

2013

7164

195

4467

22.91

2.72

44

22.56

2014

7009

249

5445

21.87

3.55

50

20.08

2015

7339

242

7213

29.81

3.3

54

22.31

2016

7756

317

3204

10.11

4.09

66

20.82

2017

7957

321

6002

18.7

4.03

71

22.12

2018

8149

386

1924

4.98

4.74

99

25.65

2019

8523

380

749

1.97

4.46

105

27.63

1990-2004

35161

246

6862

27.89

0.7

38

15.45

2005-2019

98570

2903

53215

18.33

2.95

651

22.43

1990-2019

133731

3149

60077

19.08

2.35

689

21.88

Table 1: India Vs World - Publication Output and Citations Count in Parkinson’s Disease Studies, 1990-2019.

Note: TP-Total papers; TC-Total citations; CPP-Citations per paper; ICP-International collaborative papers. 

Figure 1: Parkinson disease research studies- Global Vs India 1990 -2019. 

During the period under study, the bulk of the publications output by India appeared as articles and reviews (61.19% and 22.61% share), and the rest was distributed across other publication types: conference papers, letters, book chapters, editorials, notes, short surveys, erratum etc. 

India collaborated with a total of 160 foreign countries in its research pursuits in Parkinson disease. It published 21.88% of its output (689) as a share of International Collaborative Publications (ICP). The citation impact of the ICP publications by India was 35.12 citations per paper, nearly twice that of the country average (19.08) during the period. The USA was the largest collaborating partner with India with a 46.08% share of total ICP publications by the country, followed by U.K. (13.21%), Australia (9.72%), Saudi Arabia (9.43%) and others. 

Of the 3198 publications by India on Parkinson’s disease during 1990-2019, 3108 (98.70%) were the outcome from research projects supported by funding from 140 Indian and foreign funding agencies.  CSIR funded for the largest number of papers (116), followed by ICMR (102 papers), Kerala, DST, India (95 papers), etc. Among the foreign funding agencies, Bangladesh Council of Scientific & Industrial Research funded 132 papers, National Institute of Health, USA (48 papers), etc. 

On  classifying India’s Parkinson’s disease research output by age groups of target population, it was found that “Adults” constituted the largest research category of target population, followed by “Middle Aged” (13.02%), “Aged” (12.70%), “Adolescents” (3.24%) and Children’s (2.41%) during 1990-2019 (Table 2). 

S.No

Target Population Age Group

Number of Papers

Share of Papers

1990-2004

2005-2019

1990-2019

1990-2004

2005-2019

1990-2019

1

Adults

90

624

714

36.59

21.50

22.67

2

Middle Aged

48

362

410

19.51

12.47

13.02

3

Aged

41

359

400

16.67

12.37

12.70

4

Adolescents

20

82

102

8.13

2.82

3.24

5

Children’s

15

61

76

6.10

2.10

2.41

6*

TOTAL

246

2903

3149

100.00

100.00

100.00

7*

ACTUAL TOTAL

214

1488

1702

87

51.26

54.04

Table 2: Break-up of Research Papers by Age Groups of Target Population.

Top 10 countries in research studies on Parkinson ’s disease 

More than 100 countries participated in global research in the domain of Parkinson’s disease (133731 papers). Of these, the top 15 countries contributed a 99.59% share to the global output in 30-year during 1990-2019.  The USA contributed a 31.71% global share, followed by U.K., Germany, Italy, Japan and China (from 6.16% to 10.20%), Canada, France and Spain (from 4.59% to 5.24%), Australia, Netherlands, Sweden, India, South Korea and Brazil (from 1.82% to 2.95%) during 1990-2019. During the 15-year study period (1990-2004 and 2005-2019), 11 of top 15 countries (namely China, India, South Korea, Brazil, Italy, Australia, Spain, Netherlands, Germany, Canada and Sweden) witnessed marginal jump in their global share by 0.23% to 6.40%, where as 4 other countries (namely U.K., USA, France and Japan) witnessed marginal dip in their global share by 0.46% to 3.47%. (Table 3, Fugure 2). 

S.No

Name of the Country

Number of Papers

Share of Papers

1990-2004

2005-2019

1990-2019

1990-2004

2005-2019

1990-2019

1

USA

11476

30936

42412

32.64

31.38

31.71

2

U.K.

3708

9939

13647

10.55

10.08

10.2

3

Germany

2863

8356

11219

8.14

8.48

8.39

4

Italy

2111

7537

9648

6

7.65

7.21

5

Japan

3114

5313

8427

8.86

5.39

6.3

6

China

505

7728

8233

1.44

7.84

6.16

7

Canada

1776

5237

7013

5.05

5.31

5.24

8

France

2161

4737

6898

6.15

4.81

5.16

9

Spain

1318

4819

6137

3.75

4.89

4.59

10

Australia

682

3259

3941

1.94

3.31

2.95

11

Netherlands

886

2961

3847

2.52

3

2.88

12

Sweden

807

2489

3296

2.3

2.53

2.46

13

India

246

2903

3149

0.7

2.95

2.35

14

South Korea

214

2665

2879

0.61

2.7

2.15

15

Brazil

210

2230

2440

0.6

2.26

1.82

 

Total of top 15 countries

32077

101109

133186

91.23

102.58

99.59

 

Total of world

35161

98570

133731

     

Table 3: Top 15 Most Productive Countries on Parkinson’s disease during 1990-2019.

 Figure 2: Distribution of Parkinson's Disease by Country of Publication 1990-19.

Subject-wise distribution of research output 

In all, Parkinson’s disease research studies by India are distributed by the Scopus classification across nine subject areas. Of these, medicine accounted for the largest publication share (45.47%), followed by neuroscience (30.84%), biochemistry, genetics & molecular biology (26.42% share), pharmacology, toxicology & pharmaceutics (25.69% share) and the other five subjects (computer science, engineering, chemistry, agricultural & biological Sciences and immunology & microbiology) contributed between 1.97% to 6.80% sharerespectivelys of the country output. 

The research activity index of each subject, computed for two select periods viz 1990-2004 and 2005-2019, was found to differ quantitatively. The world average AI for a given subject is always 100. With reference to the world average index, the activity index in three subject areas (medicine, neuroscience, agriculture & biological science) dipped from a high level between (110.78 - 148.39) in 1990-2004 to a level below the world average between (95.9 - 99.09) in 2005-2019. In 6 other areas, their activity index spiked from a low-end level between (5.98 - 87.68) in 1990-2004 to a level well above the world average between (101-04 -107.97) in 2005-2019. This shows that research activity in all of the nine subject areas has been dynamic and changing with the changing times. The 5-yearly average growth was the lowest in engineering discipline (95.47%) and the highest in computer science (275.10%) (Figures 3 and 4).

 Figure 3: Parkinson's Disease Research - Change in Activity Index between 1990-2004 & 2005-2019.

Figure 4: Parkinson Disease Research - 5-Yearly Growth in Related Subject Areas 1990-2019. 

Distribution of research output by Types of Parkinson’s disease: Parkinson’s disease has been classified as primary and secondary.  The primary Idiopathic disease yielded only 75 records and the main emphasis was on Secondary Atypical disease in India. A break-up of India’s publication on various types of Parkinson’s disease is shown in Figure 5.

 Figure 5: Distribution of Parkinson Disease Research by Parkinson Disease Type - 1990-2019.

Significant keywords 

As seen from the Scopus database, a total of 269 keywords seem to define and identify India’s literature on Parkinson’s disease as well as give some idea about the broad research trends in the treatment and investigation of the disease (Table 4, Figure 6). These keywords have been classified   under broad subject headings along with the frequency of keyword occurrence. 

Broad Term

Neuroprotection (453), Neurodegenerative Diseases (357), Degenerative Disease (294) Neurologic Disease (166) Neuroprotective Agent (164) Neurotoxicity (183) Neurodegeneration (124), Parkinsonism (560), Parkinsonian Disorders (190)

Specific  to Parkinson’s disease

Parkinson Disease (2118), Parkinson's Disease (1106)

Oxidation Related

Oxidative Stress (547) Anti-oxidants(250), Anti-oxidant Activity (243) Reactive Oxygen Metabolite (182)

Pahology Related

Pathophysiology (277) Pathogenesis (165)) Neuropathology (85)

Protein Related

Protein Expression (276), Alpha Synuclein (276), Protein Aggregation (153)

Enzyme Related

Enzyme Activity (235) Glutathione (220), Superoxide Dismutase (189) Enzyme Inhibition (84), Catalase (169)

Medications

Levodopa (408) Carbidopa Plus Levodopa (88) Rotenone (107) Oxidopamine (108) Haloperidol (107) Carbidopa (74) Monoamine Oxidase Inhibitor (37) Bromocriptine (71) Pramipexole (77) Ropinirole (82) Apomorphine (52), Selegiline(85) Rasagiline (47) Amantadine (82)

Genetic Related

Genetics (221) Gene Expression (124) Gene Mutation(115), Gene Expression Regulation (58), Single Nucleotide Polymorphism (56) Genetic Association (50), Messenger RNA (50), Genetic Predisposition (49) Genotype (45), Genetic Variability (44)

Imaging

Nuclear Magnetic Resonance Imaging (210) Magnetic Resonance Imaging (90) Neuroimaging (99) Positron-Emission Tomography (36) Single Photon Emission Computed Tomography (21) Computer Assisted Tomography (67)

Brain & Parts

Dopamine (398), Brain (253), Dopaminergic Nerve Cell (245) Nerve Degeneration (186) SubstantiaNigra (213) Neurons (151) Dopaminergic Neurons (110) Nerve Cell (117) Basal Ganglion (71)

Other related Diseases

Alzheimer Disease (593) Diabetes Mellitus (152) Schizophrenia (152), Epilepsy (134) Multiple Sclerosis (124) Amyotrophic Lateral Sclerosis (173) Cerebrovascular Accident (93)

Motor Dyfunctions

Motor Dysfunction (203), Motor Activity (106) Bradykinesia (119), Dyskinesia (116) Cognitive Defect (146) Tremor (169) Muscular Dystrophy (16) Spinal Muscular Atrophy (10) Postural Balance(9)

Non-Motor Dyfunctions

Dementia (120), Dystonia (118) Olfactory Bulb (12) Speech Disorder (27) Restless Legs Syndrome(22) Impulse Control Disorder (15) Memory Disorder (43) Respiratory Chain (18) Autonomic Dysfunction (22) Mental Disease (32) Depression (226) Anxiety (56) Sleep Disorder (62) Psychosis (75) Orthostatic Hypotension (9)

Surgery

Brain Depth Stimulation (104) Neurosurgery (34)

Others

Apoptosis (203) Corpus Striatum (197) Signal Transduction (172) Mitochondria (137) Drug Delivery System (128) Tyrosine 3 Monooxygenase (128) Mitochondrion (124) Hypertension(120) Risk Factor (113) Catalase (169) Animal Model (152)

Table 4: Significant Keywords Distributed by Broad Categories defining Parkinson’s disease Literature from India during 1990-2019.

 Figure 6: Parkinson's Disease Research - Top 25 Keywords for Literature Retrieval 1990-2019.

Top 10 most productive & cited organizations in India 

The scientometric profile of top 10 most productive and top 10 most cited organization is presented in Table 5.  In all, a total of 700 organizations from India participated in Parkinson’s disease research during 1990-2019. The top 50 most productive organizations contributed 62.95% share (1982) to the country output in the subject. Their productivity varied from 16 to 210 publications per organization. 

S.No

Name of the Organization

TP

TC

CPP

HI

ICP

ICP (%)

RCI

Top 10 Most Productive Organizations

1

National Institute of Mental Health & Neurosciences (NIMHANS), Bangalore

210

3870

18.43

36

44

20.95

0.97

2

All India Institute of Medical Sciences (AIIMS), New Delhi

162

9032

55.75

26

24

14.81

2.92

3

Indian Instiyute of Toxicologi, Lucknowcal Research (IITR)

101

5903

58.45

31

17

16.83

3.06

4

Postgraduate Institute of Medical Education & Research (PGIMER), Chandiagrh

75

7597

101.3

16

12

16

5.31

5

Indian Institute of Chemical Biology (IICB), Kolkata

75

2037

27.16

24

23

30.67

1.42

6

JamiaHamdard University, Delhi

69

2692

39.01

27

27

39.13

2.04

7

Annamalia University

61

1335

21.89

21

31

50.82

1.15

8

Central Drug Research Institute (CDRI), Lucknow

58

1180

20.34

20

9

15.52

1.07

9

Panjab University, Chandigarh

57

4881

85.63

19

6

10.53

4.49

10

SreeChitraTirunal Institute of Medical Science & Technology (SCTIMST), Trivandrum

56

2252

40.21

19

16

28.57

2.11

Top 10 Most Impactful organizations

1

Sri Ramachandra Institute of Higher Education & Research (SRIHER), Madras

21

6988

332.8

9

8

38.1

17.4

2

Christian Medical College (CMC), Vellore

17

3355

197.4

9

7

41.18

10.3

3

Institute of Genome & Integrated Biology (IGIB), Delhi

20

3525

176.3

13

8

40

9.24

4

King George’s Medical University (KGMU), Lucknow

48

5321

110.9

16

15

31.25

5.81

5

Sanjay Gandhi Postgraduate Institute of Medical Sciences (SGPGIMS), Lucknow

35

3763

107.5

13

5

14.29

5.63

6

Postgraduate Institute of Medical Education & Research (PGIMER), Chandiagrh

75

7597

101.3

16

12

16

5.31

7

Panjab University, Chandigarh

57

4881

85.63

19

6

10.53

4.49

8

University of Delhi

56

3951

70.55

19

16

28.57

3.7

9

Indian Instiyute of Toxicologi, Lucknowcal Research (IITR)

101

5903

58.45

31

17

16.83

3.06

10

All India Institute of Medical Sciences (AIIMS), New Delhi

162

9032

55.75

26

24

14.81

2.92

Table 5: Top 10 Most Productive/Cited Organizations in Parkinson’s Disease Research during 1982-2019. 

Note: *TP-Total publications; TC -Total citations; CPP-Citations per paper; ICP-International collaborative papers; RCI-Relative citation index 

Institutional Collaboration among Top 15 Indian Organizations: On studying collaborative linkages among top 15 organizations, it was noticed that organizations having highest number of linkages were: IITR-Lucknow, AIIMS-New Delhi and NIMHANS-Bangalore) (51, 35 and 29) and having least linkages were: Annamalia University, AMU –Aligarh and CFTRI – Mysore (3, 3 and 1). Across top 15 organizations, the largest number of collaborative linkages (16) is between AIIMS - New Delhi and University of Delhi, followed by IITR-Lucknow and BHU – Varanasi (14 linkages), IITR-Lucknow and KGMU – Lucknow (11 linkages), NIMHANS - Bangalore - AIIMS - New Delhi (9 linkages), etc (Figure 7). 

Figure 7: Collaborative Network of Top 15 Organizations in Parkinson’s disease Research during 1990-2019. 

Top 10 most productive & cited authors

The scientometric profile of top 10 most productive and top 10 most cited authors are presented in Table 6.  In all, 871 authors from India participated in Parkinson’s disease research during 1990-2019. The top 50 authors contributed a 36.042% share to the total country output in the subject. Their research productivity varied from 13 to 79 publications per author. 

S.No

Name of  the Author

Affiliation of the Author

TP

TC

CPP

HI

ICP

ICP (%)

RCI

Top 10 Most Productive Authors

1

P.K. Pal

NIMHANS-Bangalore

79

833

10.54

17

10

12.66

0.55

2

M.Behari

AIIMS – New Delhi

73

1587

21.74

20

7

9.59

1.14

3

K.P.Mohanakumar

IICB-Kolkata

56

1857

33.16

24

18

32.14

1.74

4

V.Goyal

AIIMS – New Delhi

42

317

7.55

10

5

11.90

0.40

5

T.Manivasagam

Annamalai University

41

959

23.39

20

29

70.73

1.23

6

M.P.Singh

IITR-Lucknow

41

974

23.76

21

2

4.88

1.25

7

R.Yadav

NIMHANS-Bangalore

39

278

7.13

9

2

5.13

0.37

8

A.Kishore

SCTIMST-Trivandrum

33

836

25.33

16

13

39.39

1.33

9

U.B.Muthana

NIMHANS-Bangalore

33

645

19.55

16

10

30.30

1.02

10

A.Borah

Assam University

30

578

19.27

14

7

23.33

1.01

Top 10 Most Impactful Authors

1

R.B.Mythri

NIMHANS-Bangalore

13

762

58.62

11

5

38.46

3.07

2

R.K.Chaturvedi

IITR-Lucknow

19

1041

54.79

15

4

21.05

2.87

3

K.S.Saravanan

IICB-Kolkata

13

639

49.15

11

4

30.77

2.58

4

A.K.Agrawal

IITR-Lucknow

13

526

40.46

11

4

30.77

2.12

5

V.Ravindranath

NBRI-Gurgaon

17

677

39.82

13

3

17.65

2.09

6

S.K.Shankar

NIMHANS-Bangalore

13

488

37.54

9

4

30.77

1.97

7

J. Ali

JamiaHamdard-Delhi

22

824

37.45

14

10

45.45

1.96

8

S.Baboota

JamiaHamdard-Delhi

22

824

37.45

14

10

45.45

1.96

9

S.Chakrabarti

IPGMER-Kolkata

13

437

33.62

10

6

46.15

1.76

10

K.P.Mohanakumar

IICB-Kolkata

56

1857

33.16

24

18

32.14

1.74

Table 6: Publication Profile of Top 10 Indian Most Productive and 10 Most Impactful Authors in Parkinson’s disease Research during 1990-2019.

Note: *TP-Total publications; TC -Total citations; CPP-Citations per paper; ICP-International collaborative papers; RCI-Relative citation index 

Collaboration among top 15 authors: On studying collaborative linkages among top 15 authors, it was noticed that authors having highest linkages were: P.K. Paul, A. Lenka, M.Behari and V.Goyal (62, 40, 39 and 27) and having least linkages were: A.Kishore, T.Manivasagam and K.P. Mohanakuma (1, 4 and 8). Across top 15 authors, the largest number of collaborative linkages (33) is between P.K. Paul – R.Yadav, P.K.Paul – A.Lenka (26), M.Behari and V.Goyal (23) and J.Ali and S.Baboota (22), R.Yadav and A. Lenka (14), M.Behari and U.B.Muthana (11), etc. (Table 7, Figure 8). 

S.No

Name of the Journal

Number of Papers (TP)

TC

CPP

1982-00

2001-19

1982-19

1982-19

Top 10 Most Productive Journals

1

Neurology India

30

87

117

838

7.16

2

Annals of the Indian Academy of Neurology

0

64

64

260

4.06

3

Parkinsonism & Related Disorders

4

56

60

1043

17.38

4

Molecular Neurobiology

0

40

40

560

14.00

5

CNS aand Neurological Disorders Drug Targets

0

39

39

560

14.36

6

Movement Disorders

10

28

38

1337

35.18

7

Journal of the Neurological Sciences

5

26

31

622

20.06

8

Neurochemical Research

0

30

30

698

23.27

9

Asian Journal of Pharmacological & Clinical Research

0

29

29

127

4.38

10

Neurochemistry International

1

28

29

649

22.38

Top  10  Most Impactful Journals

1

Brain Research

5

18

23

1190

51.74

2

Movement Disorders

10

28

38

1337

35.18

3

Current Pharmaceutical Design

0

18

18

463

25.72

4

Neurochemical Research

0

30

30

698

23.27

5

Neurochemistry International

1

28

29

649

22.38

6

Journal of the Neurological Sciences

5

26

31

622

20.06

7

PLOS One

0

18

18

325

18.06

8

Parkinsonism & Related Disorders

4

56

60

1043

17.38

9

Neurotoxicity Research

2

22

24

409

17.04

10

Neuroscience Letters

3

26

29

491

16.93

Table 7: Most Productive Journals in which India Published Parkinson’s disease research 1990-2019.

 Figure 8: Collaborative Network of Top 15 Authors in Parkinson’s disease Research during 1990-2019.

Medium of research communication 

The bulk of publications output by India in Parkinson’s disease research (92.44%, 2911) appeared in journals, and the remaining appeared in conference proceedings, book series and books (3.81%, 2.29% and 1.46%).  Of the 563 journals partcipitated in India’s Parkinson’s disease output: 460 published 1-5 papers each, 60 published 6-10 papers each, 22 published 11-20 papers each, 18 published 21-50 papers each, 2 each published 51-100 papers each and 1 published 117 papers during 1990-2019. 

The top 50 most productive journals published 15 to 117 papers and together they account for a 30.47% (887) share of total output by India in Parkinson’s disease research output during 1990-2019. The most productive journals in the subject are Neurology India (117 papers), Annals of the Indian Academy of Neurology (64 papers), Parkinsonism & Related Disorders (60 papers) and Molecular Neurobiology (40 papers).The Brain Researchjournal tops on citations per item 51.74, followed by Movement Disorders (35.18), Current Pharmaceutical Design (25.72) and Neurochemical Research (23.27), during 1990-2019. Top 10 most productive and most impactful journals are listed in Table 7. 

Highly-cited papers 

Only 84 (2.67% share) out of 3149 publications in Parkinson’s disease registered 100 to 3730 citations per paper and together received 23435 citations, with an average of 278.99 citations per paper. Among 84 highly-cited papers by citations count: 62 had registered citations in the range 100-199 per paper, 9 were in the citation range 200-299, 3 the in citation range 300-399, 5 in the citation range 400-699, 4 in the citation range 1001-1673 and 1 with 3730 citations. 

Of the 84 highly-cited papers (43 articles, 40 reviews and 1 editorial), 42 were non-collaborative among rest: 8 and 34 were national and international collaborative papers.Among the India’s 34 international collaborative papers, USA participated in 25 papers, followed by Italy , Japan (11 papers) and UK (10-12 papers), Australia, Canada, Germany, Spain, Singapore and the Netherlands (9 papers each), A

Discussion

This paper seeks to examine the status of Parkinson’s disease research in India in the global context covering publications for the period 1990-2019. India registered a faster 22% annual research growth compared to 7.06% by the world in the subject. Its research growth was comparatively faster in the 2nd half of the study period (2005-2019) compared to its 1st half (1990-2004). However, despite its faster research growth, India is weak in terms research productivity and far behind compared to the top most productive countries in the world, such as the USA, the UK, and Germany. Currently, India ranks as the 13th most productive country in the world accounting for as little share to the world as 2.35%. The low-level research productivity in India may be attributed to poor research productivity at the institutional level. For instance, top 50 institutes in India had merely contributed 16-210 papers, an average of average 39.64 papers per institute in the 30-year period.  It seems that research in the domain of Parkinson’s disease is still not a priority research area in the country. The other probable reason for low-level research productivity could be lack of project funding options Parkinson’s disease research. 

India published 21.88% of its output as a share of international collaborative papers. The citation impact of such collaborative papers has been nearly twice (35.19 CPP) that of the country average (19.08 CPP).  The USA was its single largest collaborating partner in international research projects, followed by the U.K. and Germany. The data here indicates that India should pursue more and more international collaborative projects in order to improve the visibility and impact of its research in the domain Parkinson’s disease research at international level. 

Further, a close study of the citation life cycle of top 10 most cited papers reveals the citation peak period for the most recent papers published between 2015-17 is three-four years, whereas for the other papers published between 2003-10, it is 10-14 years. This implies that the quality and impact of recent research in the subject is far more impressive and visible, getting far more national and international attention than the other research papers in the subject. The data here highlights the view that has talent in the domain of Parkinson’s disease research and such a talent must be nurtured. 

The pockets of excellence in Parkinson’s disease research  are centered around top 10 institutes - Panjab University, Chandigarh, All India Institute of Medical Sciences (AIIMS), New Delhi, Central Drug Research Institute (CDRI), Lucknow, Postgraduate Institute of Medical Education & Research (PGIMER), Chandiagrh, Indian Instiyute of Toxicologi, Lucknowcal Research (IITR), National Institute of Mental Health & Neurosciences  (NIMHANS), Bangalore, SreeChitraTirunal Institute of Medical Science & Technology (SCTIMST), Trivandrum,  Indian Institute of Chemical Biology (IICB), Kolkata, JamiaHamdard University, Delh, and Annamalia University. Their research output as a share of international collaborative papers ranged between 10.53% and 50.82%.

Conclusion

The global research in the domain of Parkinson’s disease is dominated by top 15 most productive countries as they account for 99.59% share of the world output. India ranks as the 13th largest most productive country in the world. India is very weak in terms of research productivity. But its performance in terms of citation impact is moderately high. Further, the study observes that weak research productivity by India in the domain Parkinson’s disease  may due to lack of adequate research project funding or due to the fact that Parkinson’s disease research is not a top priority area of the country.  Given the fact, the potential to improve research productivity and impact in the subject is great, it is important that stakeholders at national and state level in the country should draw up plans to support, advance, and encourage in-house as well as collaborative national and international research in the domain of Parkinson’s disease research.

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Citation:  Gupta BM, Dhawan SM (2021) Parkinson’s Disease Research by India: A Scientometric Assessment of Publications Output for the Period 1990-2019. J Brain Neursci 5: 017.

Copyright: © 2021  Gupta BM, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

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