Highlights 
● Lavender essential oil can improve the symptoms of stroke including motor function, speech and delirium.
● Using Lavender essential oil is associated with decrease in malondialdehyde level and an increase in the level of antioxidants.
Introduction
Stroke is an acute brain injury caused by impairment in blood supply to one part of the brain tissue due to cerebrovascular blockage by a blood clot or rupture of arteries supplying that part [1]. Stroke is the third leading cause of mortality and morbidity in industrial countries, and a surviving patient will suffer complications such as paralysis, memory, thinking, speech, and psychological problems. Delirium, another complication of stroke, is a common impairment in consciousness and cognition that occurs acutely with characteristics such as altered consciousness, reduced focus and memory, impaired orientation, with rapid onset in a few hours or a few days and acute and notable fluctuations in inpatients [2]. Post-stroke delirium can increase mortality and morbidity, hospital costs, time consumed, and ultimately many problems for the family and community [3]. 
Following the above problems and subsequent disorders in swallowing, bladder and bowel control, respiratory muscle functioning, muscle movement, blood pressure changes, and many other complications, these measures are taken for the patients: inserting NG tube, physiotherapy, frequent draining of secretions from lungs and airways, tracheal intubation, urinary catheterization, using air mattresses, and even medication-therapy with antibiotics, anticoagulants, and antibiotic [4-8]. 
In conjunction with the routine care and treatment techniques, other methods have been suggested to provide care for patients with inflammation, wounds, neurological disorders, and muscular problems [9]. One of these methods is aromatherapy, in which aromatic oils are used in a controlled manner to maintain and promote physical and mental health. These oils are the essences extracted from aromatic plants with anti-inflammatory, antimicrobial, and stress-reducing and pain reducing properties [9,10]. 
Lavandula angustifolia, commonly known in Iran as Ostokhodoos (Lavender), is widely available as an aromatic plant. The flower and essence of lavender are used in the cosmetic and perfume industries [11]. Many compounds have been identified in this plant, including geraniol, linalool, linalyl acetate, cineol, borneol, α-pinene, and camphor, which produce sedative and analgesic effects probably by affecting different regions of the CNS [12]. Of all different plants, aromatherapy with lavender is of much interest to researchers because it is safe and has no known contraindications [13]. Given the progress made in diagnosis of stroke; therefore, the improvement and development of effective treatments, which include post-event recovery stage are vitally important in medical, social and economic terms [14]. 
To prevent the incidence of delirium or minimize the complications resulting from treatment in the acute phase, lavender is added to the main treatment of patients with stroke (anticoagulant and antiplatelet medications), and its effects are assessed on rehabilitation of motor function, speech and delirium in these patients. Hence, the present study was conducted to investigate the effect of aromatherapy with lavender 10% essential oil on motor function, speech, and delirium in a group of patients with thrombotic ischemic stroke receiving treatment with lavender compared to the control group.
Materials and Methods
The present randomized clinical trial was enrolled patients attending emergency department of Kashani Hospital in the city of in Iran from 2016 to 2018. Convenience non-randomized sampling was used to select the participants. The study inclusion criteria were age over 50 years, sudden onset of symptoms, diagnosis of thrombotic stroke, evidence of stroke in the patients’ CT scan, sufficient consciousness for cooperation in examinations, attending hospital immediately after the onset of symptoms (12 hours at the latest), no history of cognitive 
 or use of psychiatric medications, no alcohol dependence, no history of lengthy surgeries, and willingness to take part. 
The study exclusion criteria were blood glucose <50mg/dl, unwillingness to take part, not completing questionnaires, and failure to follow-up. A total of 70 patients with ischemic stroke were enrolled based on the study inclusion and exclusion criteria, and were randomly and equally divided into two groups of 35 after obtaining written consents. Randomization was carried out by random allocation software. 
The control and intervention groups were matched in terms of age (50-90 year-old), gender, severity of symptoms, and the ischemia site in CT scan. Data relating to the patients’ neurological disorders were collected using the National Institutes of Health Stroke Scale (NIHSS), which was completed by the relevant intern and a physician after assessment of the patients in two stages: 1.On the first day; and 2. After the first post-stroke week. Delirium was assessed using Delirium Rating Scale-Revised-98 (DRS-R-98) in two stages: 1. On the first day; and 2. A week after stroke to diagnose the symptoms of delirium. Data relating to each questionnaire were completed by the intern.  NIHSS is a quantitative questionnaire used for measuring neurological abnormalities of stroke. This questionnaire is used in nearly all studies on acute strokes in America as the initial and final criterion for the measurement of neurological abnormalities. Validity and reliability of this scale have been confirmed for prospective studies [15]. 
In the present study, only motor and parts of NIHSS were used, with two questions about the limb muscle strength, with maximum score of 4 (the lowest strength) and minimum of 0 (the highest strength), and two questions about speech, with maximum score of 3 (the lowest strength and minimum of 0 (the highest strength), and finally, the scores were summed up and analyzed. In DRS-R-98 scale, each variable is scored from 0, 1, 2, to 3 points, and the patient’s score for each variable is separately calculated and then summed up. Patients’ scoring higher than 15 points in total suffer from delirium. 
The highest score in this questionnaire is 39, which indicates the severity of this disorder. Validity of DRS-R-98 has been demonstrated in previous studies [16]. The control group received the routine treatment such as aspirin, enoxaparin, atorvastatin and antihypertension medications and placebo instead of lavender essential oil. The intervention group received aromatherapy with lavender essential oil 10% (produced by Barij Pharmaceuticals) in addition to the routine medications. Therapy began 12 hours after the onset of symptoms and continued for a week.
Identical capped bottles were used for placebo and lavender essential oil. A researcher who had PhD in pharmacognosy, prepared the identical capped bottles and filled half of them with cotton balls smeared with sunflower oil and marked them with 1. The other half of the bottles were filled with cotton balls smeared with 0.1 ml of lavender essential oil and marked with 2 [17]. 
Other members of the research team were blinded to the content of the bottles. Each time the patients received routine therapy, they inhaled the content of the bottles 5 minutes. When two patients with stroke were in one room, only one of them was selected. Blood samples were taken from the patients and sent to the laboratory to determine total serum antioxidant capacity and serum level of malondialdehyde. The two groups were compared before therapy and one week after.
Analysis of data
Data collected were analyzed in SPSS V. 18 using descriptive statistics (mean and standard deviation for quantitative data and frequency or percentage for qualitative ones) and analytical statistics (Chi-square test to compare the qualitative data in two groups, paired t-test to compare the quantitative data before and after therapy, and independent t-test to compare the quantitative data in two groups) at a significance level of P<0.05. 
Results
A total of 70 patients (33 men and 37 women) participated in the present study, and were randomly divided into two equal groups (35 patients each). The gender distribution was as follows: 19(54.3%) men in the intervention group and 21(60%) women in the control, and Chi-square test showed no significant difference between the two groups in terms of gender distribution (P=0.23). The patients’ mean age was 71.87±9.82 years in total, 71.45±9.44 years in the intervention group, and 72.28±10.31 years in the control. Independent t-test showed no significant difference between the two groups in terms of mean age (P=0.77). The muscle strength and speech parts of NIHSS were completed on the first day, with no significant difference between the two groups in mean muscle strength (P=0.34).

 

Mean score of muscle strength after the first week was significantly less in the intervention group than that in the control group (P<0.001). Moreover, mean score of muscle strength in each group before therapy was significantly higher compared to after therapy (P<0.001) (Table 1-3).
 

 

Mean changes before and after therapy were significantly greater in the intervention group compared to the control (P<0.001) (Table 4). No significant difference was found between the two groups in mean score of speech on the first day of admission (P=0.39). A week after therapy, mean score of speech was significantly lower in the intervention group than that in the control group (P<0.001). Mean score of speech in each group was significantly higher before therapy compared to after (P<0.001) (Table 3), and mean changes before and after therapy was significantly higher in the intervention group compared to the control (P<0.001) (Table 2). DRS-R-98 was used to assess the patients’ delirium. No significant difference was observed between the two groups in the delirium score on the first day of admission (P=0.38). A week after therapy, mean score of delirium was significantly lower in the intervention group compared to the placebo group (P=0.001). Furthermore, mean score of delirium in each group was significantly greater before therapy compared to after (P<0.001) (Table 4), and mean changes before and after therapy were significantly higher in the intervention group compared to the control (P<0.001) (Table 3).

 

A week after therapy, the patients' serum antioxidants and plasma malondialdehyde levels were measured. The level of antioxidants was significantly lower in the intervention group compared to the control (P=0.04), and plasma malondialdehyde was also significantly lower in the intervention group compared to the control (P=0.04) (Table 4).
Discussion
According to the results, mean scores of muscle strength and speech were higher in the lavender group compared to the placebo group, which means that muscle strength and speech were better in the intervention group compared to the placebo group. Furthermore, the score of delirium was significantly lower after therapy in the lavender group compared to the placebo group, which means that lavender group had less delirium compared to the placebo group. 
Other results obtained related to the measurement of serum antioxidants and plasma malondialdehyde a week after therapy. The serum antioxidant level was significantly higher in the lavender group compared to the placebo group. The level of plasma malondialdehyde (a marker that increases in ischemia) was significantly lower in lavender group compared to the placebo group. According to the results, lavender improved the patients’ muscle strength, speech, and alertness, and increased antioxidants and reduced malondialdehyde. Some studies have mentioned the effect of lavender in preventing ischemia, which will be discussed in the present study. 
A study by Wang et al. to assess the effect of lavender oil on cerebral ischemia in rats showed that lavender oil therapy significantly reduced the score of neurological disturbance, the size of infarction area, malondialdehyde level and catalase level in these rats, and it was concluded that lavender oil has nneuro-protecting  properties against cerebral ischemia, which may be due to its antioxidant property [12]. 
Rabiei et al. investigated the protective effect of lavender on the size of stroke and its potential mechanisms in stroke model in 42 rats that had been divided into six groups. They reported using 200 mg/kg of lavender for 20 days significantly reduced the size of tissue damage caused by stroke in the cortical and focal regions of the brain compared to the control. This dose of medication significantly increases nitric oxide in the blood. Finally, it was stated that lavender extract has protective effects on the brain against cerebral ischemia, and reduces the size of stroke in rats exposed to ischemia. Its mechanism may be explained by lavender effect on increasing the level of antioxidants. It was also argued that lavender reduces the size of stroke by increasing the endothelial nitric oxide level by inhibition of reduced cerebral blood flow [18]. 
The results of a study by Vakili et al. to assess the effect of lavender oil in reducing cerebral edema in in-vitro stroke models showed that intravenous administration of 200 and 400 mg/kg doses at the onset of ischemia significantly reduced the size of infarction, cerebral edema, and corrected functional outcomes following cerebral ischemia. It was argued that using 200 mg/kg dose significantly reduced malondialdehyde and increased superoxidase dismutase activity, glutathione peroxide, and total antioxidants. 
The authors argued that lavender oil has neuro-protective activity against cerebral ischemia, because of anti-oxidant effect. However, their results showed that lavender oil cannot suppress the process of apoptosis in these models [19]. Other similar studies have shown that lavender has an effective role in the treatment of cognitive disorders, especially Alzheimer’s [20]. In addition, some evidence indicates that lavender essence significantly reduces tumor necrosis factor in mast cells isolated from rats [21]. 
To the best of our knowledge, no study has yet been conducted on the effect of lavender on stroke in humans. The effect of lavender in treating anxiety and postoperative pain was assessed in a study by Mesri et al. whose results showed that aromatherapy with lavender before surgery is effective in reducing anxiety and postoperative pain [22]. 
In another study by Wang et al. to assess the effect of lavender flower in treating ischemia and cardiac damage, it was concluded that lavender reduces the heart tissue damage following ischemia by reducing malondialdehyde and increasing antioxidants [23]. Also, some studies have mentioned that lavender has a role in certain diseases such as hyperactivity and attention deficit in children [24].
The present study limitations included small sample size, short follow-up period, the lack of control and consideration of other factors that can be effective in improving stroke symptoms and creating delirium, and the lack of similar studies. Therefore, given all the above and the effect of this plant in treating neurological and ischemic diseases, and also the fact that no similar study has been conducted on the effect of lavender in the treatment of stroke, it is recommended that further studies on the subject be conducted in the future.
Conclusion
Using lavender 10% essential oil improved the patients’ symptoms such as muscle strength, speech, and delirium following ischemic stroke, and this was accompanied by reduced malondialdehyde and increased antioxidants levels.
Ethical Considerations
Compliance with ethical guidelines
The study protocol was approved by the ethics committee of Shahrekord University of Medical Sciences (No. IR.SKUMS.REC.1396.210). All the study procedures were in compliance with the ethical guidelines of the Declaration of Helsinki 1957. 
Funding
The cost of this thesis (No. IR.SKUMS.REC.1396.210) was taken by graduate studies at the University of Isfahan in the Research Laboratories of the Department of Biology.
Authors contributions
Conception, Collection, Critical revision of the article for important intellectual content: Shiva Seyed Salehi; Final approval of the study; Interpretation of data, assembly, Critical revision of the article for important intellectual content, final approval of the study: Zahra lorigooini; Design of the study, collection, critical revision of the article for important intellectual content, final approval of the study: Nahid Jivad; Analysis, statistical expertise, critical revision of the article for important intellectual content, Final approval of the study: Keyvan Ghadimi. 
Conflict of interest
The authors declare no conflict of interest.


Acknowledgements
Thanks to the personnel of Kashani Hospital emergency department for their help in this project.


References
Warner DS, Sheng H, Batinić-Haberle I. Oxidants, antioxidants and the ischemic brain. J Exp Biol. 2004; 207(18):3221-31.  [DOI:10.1242/jeb.01022] [PMID]
Rezaee F. Sroke. In: Rezaee F. Translation of Kaplan & Sudock Synopsis of Psyhiatry Behavioral Science. Tehran: Arjmand Publications; 2007.
Voyer P, Richard S, Doucet L, Danjou C, Carmichael P-H. Detection of delirium by nurses among long-term care residents with dementia. BMC Nurs 2008. 7(1):1-4. [DOI:10.1186/1472-6955-7-4] [PMID] [PMCID]
Siscovick DS, Barringer TA, Fretts AM, Wu JH, Lichtenstein AH, Costello RB, et al. Omega-3 polyunsaturated fatty acid (fish oil) supplementation and the prevention of clinical cardiovascular disease: A science advisory from the American Heart Association. Circulation. 2017; 135(15): 867-84. [DOI:10.1161/CIR.0000000000000482] [PMID]
Jüttler E, Schellinger PD, Aschoff A, Zweckberger K, Unterberg A, Hacke W. Clinical review: Therapy for refractory intracranial hypertension in ischaemic stroke. Crit Care 2007;11(5):231. [DOI:10.1186/cc6087] [PMID] [PMCID]
Etemadifar M, Ghadimi M, Ghadimi K, Alsahebfosoul F. The Serum Amyloid β Level in Multiple Sclerosis: A Case- Control Study. Caspian J Neurol Sci 2017; 3 (11) :214-21. [DOI:10.29252/nirp.cjns.3.11.214]
Warlow C, Van Gijn J, Dennis M, Wardlaw J, Bamford J, Hankey G, et al. Stroke: Practical Management. 3th ed. Oxford: Blackwell Science; 2001.
Julien Bogousslavsky. Acute Stroke Treatment. London: Mosby, 1997.
Keegan L, Rosen S, Messervy L. Holistic nursing in New Zealand. J Holist Nurs 1994;12(3):343-9. [DOI:10.1177/089801019401200310] [PMID]
Wilkinson JM, Simpson MD. Personal and professional use of complementary therapies by nurses in NSW, Australia. Complement Ther Nurs Midwifery 2002;8(3):142-7.  [DOI:10.1054/ctnm.2002.0632] [PMID]
Omidbaigi R. Production and processing of medicinal plants. Astan Godesa Razavei Pub 2005;6(1):346-7.
Wang D, Yuan X, Liu T, Liu L, Hu Y, Wang Z, et al. Neuroprotective activity of lavender oil on transient focal cerebral ischemia in mice. Molecules 2012;17(8):9803-17. [DOI:10.3390/molecules17089803] [PMID] [PMCID]
Muzzarelli L, Force M, Sebold M. Aromatherapy and reducing preprocedural anxiety: A controlled prospective study. Gastroenterol Nurs 2006;29(6):466-71. [DOI:10.1097/00001610-200611000-00005] [PMID]
Hossieni M, Khankeh HR, Alaee S, Dibaei M. Determine the Effect of Home Care on Complication Resulting from Musculoskeletal System Immobility of Stroked Patients. Iranian Rehabilitation Journal 2004;5 (19):35-42
Goldstein LB, Samsa GP. Reliability of the National Institutes of Health Stroke Scale: extension to non-neurologists in the context of a clinical trial. Stroke 1997;28(2):307-10. [DOI:10.1161/01.STR.28.2.307] [PMID]
Trzepacz PT, Mittal D, Torres R, Kanary K, Norton J, Jimerson N. Validation of the Delirium Rating Scale-revised-98: comparison with the delirium rating scale and the cognitive test for delirium. J Neuropsychiatry Clin Neurosci 2001;13(2):229-42. [DOI:10.1176/jnp.13.2.229] [PMID]
Rabiei Z, Rafieian-Kopaei M, Mokhtari S, Alibabaei Z, Shahrani M. The effect of pretreatment with different doses of Lavandula officinalis ethanolic extract on memory, learning and nociception. Biomed Aging Path 2014;4(1):71-6.  [DOI:10.1016/j.biomag.2013.10.006]
Rabiei Z, Fathi F, Asgharzade S, Rafieian-Kopaei M. [Effect of Lavender Ethanolic Extract on Infarct Volume in Rats Subjected to Ischemia-Reperfusion]. JMP 2017;16(62):74-84.
Vakili A, Sharifat S, Akhavan MM, Bandegi AR. Effect of lavender oil (Lavandula angustifolia) on cerebral edema and its possible mechanisms in an experimental model of stroke. Brain Res 2014;1548 (1):56-62. [DOI:10.1016/j.brainres.2013.12.019] [PMID]
Xu P, Wang K, Lu C, Dong L, Gao L, Yan M, et al. The protective effect of lavender essential oil and its main component linalool against the cognitive deficits induced by D-Galactose and aluminum trichloride in mice. Evid Based Complement Alternat Med 2017:7426538. [DOI:10.1155/2017/7426538] [PMID] [PMCID]
Gamez MJ, Jimenez J, Navarro C, Zarzuelo A. Study of the essential oil of Lavandula dentata L. Pharmazie. 1990;45(1):69-70. 
Mesri M, Hosseini SM, Heydarifar R, Mirizadeh M, Forozanmeher MJ. Effect of lacvender aromatherapy on anxiety and hemodynamic changes: A Randomized Clinical Trial. Qom Univ Med Sci J 2017;10 (12):69-76. [DOI:10.29252/qums.12.8.10]
Wang D, Guo X, Zhou M, Han J, Han B, Sun X. Cardioprotective effect of the aqueous extract of lavender flower against myocardial ischemia/reperfusion injury. J Chem 2014;2014(1):1-6. [DOI:10.1155/2014/368376]
Shakibaei F, Borhani M, Kahkeshani M, Ghadimi K. [The Effect of Triphala Lavender Tablets on the Treatment of Children with Attention Deficit/Hyperactivity Disorder]. J Isfahan Med Sch. 2018;36 (466): 42-8.