Cerebrolysin is a nootropic drug, which means that it has the capacity to enhance a number of cognitive functions such as memory, concentration, and thinking skills. The brain-boosting effects of cerebrolysin may be attributed to the neuropeptides it contains. These neuropeptides are active brain peptides (chains of amino acids) that are used by nerve cells (neurons) to enhance their communication with each other. Cerebrolysin is a natural compound derived from the brains of pigs using a safe and standardized enzymatic process. In order to achieve its therapeutic effect, cerebrolysin needs to be administered in the form of injections.
Overall Health Benefits of Cerebrolysin
- Boosts Cognitive Function [1-18]
- Improves Mood [19-22]
- Improves Symptoms of Autism [23-25]
- Improves Symptoms of Attention Deficit Hyperactivity Disorder (ADHD) [26-27]
- Improves Symptoms of Cerebral Palsy (CP) [28-21]
- Repairs Nerve Damage [32-37]
- Treats Hyperthermia-Induced Neurotoxicity [38-39]
- Treats Morphine Withdrawal Symptoms [40-41]
- Boosts Immune Function [42-50]
- Improves Eye Health [51-52]
Boosts Cognitive Function
There is increasing evidence that cerebrolysin may help improve cognitive function and counter the effects of certain medical condition that lead to cognitive impairment:
- In patients with schizophrenia dominated by negative symptoms, administration of cerebrolysin in addition to antipsychotic medication appears to improve cognitive function and memory. 
- In healthy older adults with memory loss, administration of a derivative of cerebrolysin, N-PEP-12, improves memory. 
- In healthy elderly adults, a single dose of cerebrolysin improves memory performance. 
- In patients with Alzheimer’s disease and dementia, high doses of cerebrolysin reduce psychological symptoms and slow disease progression. 
- In animals with Alzheimer’s disease, cerebrolysin administration reduces the build-up of brain beta-amyloid plaques, which are sticky proteins known to cause the disease. [5-7]
- In patients with stroke and traumatic brain injury (TBI), cerebrolysin administration appears to improve cognitive recovery without any adverse side effects. [8-14]
- In infants with communication defects due to severe brain damage during pregnancy, cerebrolysin treatment for 3 months improves communication and social interaction. 
- In mouse and rat models of Parkinson’s disease, cerebrolysin promotes survival of brain cells, improves motor symptoms, and slows disease progression. [16-18]
- The brain-boosting effect of cerebrolysin also has a beneficial effect on mood, especially in depressive symptoms. Studies show that administration of cerebrolysin produces antidepressant effect:
In elderly patients with depression, intravenous infusions of cerebrolysin reduce symptoms of depression, anxiety and apathy (lack of interest, enthusiasm, or concern). 
- In patients with Alzheimer’s disease, cerebrolysin treatment improves scores in the Cornell Depression Scale. 
- In patients with treatment-resistant depression, cerebrolysin therapy improves depressive symptoms without any adverse side effects. 
- In rats, cerebrolysin administration produces anti-anxiety effect. 
Improves Symptoms of Autism
Autism, or autism spectrum disorder (ASD), refers to a wide range of medical conditions that affects social interaction, behavior, speech and nonverbal communication. Since cerebrolysin has the capacity to enhance a number of cognitive functions, this nootropic drug has also been studied for its beneficial effect on autism:
- In patients with childhood autism and Asperger’s syndrome (one of the autism spectrum disorders), cerebrolysin therapy improves various areas of cognitive function (expressive and receptive speech, fine motoring, and playing). 
- In children with autism, cerebrolysin therapy improves symptoms and scores in the Childhood Autism Rating Scale (CARS). 
In a rat model of autism, cerebrolysin therapy improves behavior and brain cell communication. 
Improves Symptoms of Attention Deficit Hyperactivity Disorder (ADHD)
ADHD is a mental disorder characterized by hyperactivity, impulsivity, and short attention span. This mental disorder affects children and teens and can transition into adulthood. Studies show that administration of cerebrolysin may help reduce symptoms of ADHD:
- In children with ADHD, cerebrolysin administration at a dose of 1 ml per 10 kg of weight intramuscularly for 1 month improves core symptoms of ADHD. 
- In patients with ADHD of unknown cause, cerebrolysin treatment reduces impulsivity and hyperactivity. 
Improves Symptoms of Cerebral Palsy (CP)
CP is a developmental disability that affects muscle tone, movement, and motor skills. It is believed that CP is caused by brain damage during pregnancy or birth. Studies show that cerebrolysin administration in patients with CP improves functional outcome:
- In patients with CP, intramuscular administration of cerebrolysin as a single daily dose of 0.1 cc/kg for 10 days and then continued weekly for 4 months appears to improve gross motor function. 
- In patients with infantile cerebral paralysis, administration of cerebrolysin improves symptoms without any adverse side effects. 
- In pediatric patients living with CP, the combination of standard rehabilitation therapy with cerebrolysin improves gross motor skills. 
- In children with traumatic brain injury and cerebral palsy, cerebrolysin therapy induces repair of nerve cells of the brain. 
Repairs Nerve Damage
With nerve damage, there can be a broad range of symptoms depending on the location and types of nerves affected. In addition, chronic nerve damage may impair the sensation or function of the affected body part. Interestingly, numerous studies support the therapeutic benefits of cerebrolysin in different medical conditions associated with nerve damage:
- In patients with diabetic neuropathy (nerve damage caused by diabetes), daily cerebrolysin infusion over a period of 10 days alleviates pain and tingling sensations. 
- In a mouse model of diabetic neuropathy, administration of cerebrolysin improves dysfunction of the sciatic nerve (the largest single nerve located on each side of the lower spine going all the way down to the foot). 
- In patients with different nerve injuries, cerebrolysin treatment is associated with rapid neurological recovery after various peripheral nerve lesions than conventional therapies. 
- In aged rats, cerebrolysin treatment ameliorates performance deficits and nerve damage. 
- In mice, low-dose cerebrolysin administration promotes regeneration of injured spinal motor neurons. 
- In animals with nerve injury related to microsurgical suturing, cerebrolysin administration promotes regeneration of the injured peripheral nerve. 
Treats Hyperthermia-Induced Neurotoxicity
Adverse environmental circumstances such as heat stress related to hot climates can lead to disturbed mental function. This condition is known as hyperthermia-induced neurotoxicity. Researchers suggest that one of the suitable therapeutic strategies to treat heat-induced mental anomalies related to this condition is cerebrolysin administration. Studies show that cerebrolysin exerts its therapeutic effect through the following important mechanisms:
- In rats exposed to whole body hyperthermia (increased temperature), cerebrolysin administration induces marked reduction in brain toxicity, thus preventing mental dysfunction related to heat stress. 
- In rats suffering from heat stroke, cerebrolysin exerts superior neuroprotective effects as compared to other neuroprotective agents. 
Treats Morphine Withdrawal Symptoms
- Prolonged use of morphine changes the way nerve receptors in the brain work. As a result, sudden withdrawal from this drug can lead to debilitating symptoms such as sleep problems, restlessness, anxiety, digestive problems, high blood pressure, rapid heartbeat, and vision problems. Studies show that morphine withdrawal activates heat shock protein which is believed to trigger these unpleasant symptoms. 
- Interestingly, rat studies show that cerebrolysin counteracts the activation of heat shock protein, suggesting that it may help fight the negative effects of morphine withdrawal. 
Boosts Immune Function
There is mounting evidence that cerebrolysin may help heighten the immune response and prevent a wide array of diseases. Studies show that cerebrolysin positively affects the production of different cells of the immune system:
- In mice, cerebrolysin treatment boosts the production of Thy-1 cells. 
- In patients with mental developmental delay, cerebrolysin therapy at a dose of 0.1 mg/1kg of body mass for 42 days improves immune status. 
- In patients with minimal cerebral dysfunction, intrasmuscular cerebrolysin administration at a dose of 1 ml per 10 kg of body weight for 1 month increases blood levels of CD19(+) and CD16(+) cells with a simultaneous normalization of blood IgG, IgA, and natural killer cell levels. 
- Laboratory studies show that cerebrolysin exerts its immune-boosting properties by increasing the production of T- and B-lymphocytes, and promoting the survival of immunocompetent cells. 
- Cerebrolysin decreases the levels of free radicals, which are unstable molecules that damage cells and impair the function of immune system cells. [46-50]
Improves Eye Health
Cerebrolysin has the capacity to stimulate regeneration of various nerves and cells in the body. Studies show that this regenerative ability may help maintain visual health:
- In a rat model of optic nerve crush, injection of cerebrolysin promotes survival of retinal cells. 
- In a patient with vision loss in both eyes, intense photophobia (light sensitivity), and eye pain, cerebrolysin administration appears to reduce eye pressure and improve visual acuity. 
- Xiao S, Xue H, Li G. Therapeutic effects of cerebrolysin added to risperidone in patients with schizophrenia dominated by negative symptoms. The Australian and New Zealand journal of psychiatry. 2012; 46(2):153-60. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/22311531.
- Crook TH, Ferris SH, Alvarez XA, Laredo M, Moessler H. Effects of N-PEP-12 on memory among older adults. International clinical psychopharmacology. 2005; 20(2):97-100. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/15729085.
- Alvarez XA, Lombardi VR, Corzo L. Oral Cerebrolysin enhances brain alpha activity and improves cognitive performance in elderly control subjects. Journal of neural transmission. Supplementum. 2000; 59:315-28. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/10961443.
- Allegri RF, Guekht A. Cerebrolysin improves symptoms and delays progression in patients with Alzheimer’s disease and vascular dementia. Drugs of today (Barcelona, Spain: 1998). 2012; 48 Suppl A:25-41. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/22514793.
- Rockenstein E, Torrance M, Mante M. Cerebrolysin decreases amyloid-beta production by regulating amyloid protein precursor maturation in a transgenic model of Alzheimer’s disease. Journal of neuroscience research. 2006; 83(7):1252-61. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/16511867.
- Rockenstein E, Mallory M, Mante M. Effects of Cerebrolysin on amyloid-beta deposition in a transgenic model of Alzheimer’s disease. Journal of neural transmission. Supplementum. 2002. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/12456076.
- Rockenstein E, Adame A, Mante M, Moessler H, Windisch M, Masliah E. The neuroprotective effects of Cerebrolysin in a transgenic model of Alzheimer’s disease are associated with improved behavioral performance. Journal of neural transmission (Vienna, Austria : 1996). 2003; 110(11):1313-27. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/14628195.
- Ladurner G, Kalvach P, Moessler H, . Neuroprotective treatment with cerebrolysin in patients with acute stroke: a randomised controlled trial. Journal of neural transmission (Vienna, Austria : 1996). 2005; 112(3):415-28. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/15583955.
- Muresanu DF, Heiss W-D, Hoemberg V, et al. Cerebrolysin and Recovery After Stroke (CARS): A Randomized, Placebo-Controlled, Double-Blind, Multicenter Trial. Stroke; a Journal of Cerebral Circulation. 2016;47(1):151-159. doi:10.1161/STROKEAHA.115.009416. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4689177/.
- Guekht A, Vester J, Heiss WD. Safety and efficacy of Cerebrolysin in motor function recovery after stroke: a meta-analysis of the CARS trials. Neurological sciences : official journal of the Italian Neurological Society and of the Italian Society of Clinical Neurophysiology. 2017; 38(10):1761-1769. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/28707130.
- Chen CC, Wei ST, Tsaia SC, Chen XX, Cho DY. Cerebrolysin enhances cognitive recovery of mild traumatic brain injury patients: double-blind, placebo-controlled, randomized study. British journal of neurosurgery. 2013; 27(6):803-7. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/23656173.
- Bornstein N, Poon WS. Accelerated recovery from acute brain injuries: clinical efficacy of neurotrophic treatment in stroke and traumatic brain injuries. Drugs of today (Barcelona, Spain : 1998). 2012; 48 Suppl A:43-61. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/22514794.
- Wong GK, Zhu XL, Poon WS. Beneficial effect of cerebrolysin on moderate and severe head injury patients: result of a cohort study. Acta neurochirurgica. Supplement. 2005; 95:59-60. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/16463821.
- Zhang D, Dong Y, Li Y, Chen J, Wang J, Hou L. Efficacy and Safety of Cerebrolysin for Acute Ischemic Stroke: A Meta-Analysis of Randomized Controlled Trials. BioMed Research International. 2017;2017:4191670. doi:10.1155/2017/4191670. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5474547/.
- Hassanein SM, Deifalla SM, El-Houssinie M, Mokbel SA. Safety and Efficacy of Cerebrolysin in Infants with Communication Defects due to Severe Perinatal Brain Insult: A Randomized Controlled Clinical Trial. Journal of clinical neurology (Seoul, Korea). 2016; 12(1):79-84. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/26365023.
- Ozkizilcik A, Sharma A, Muresanu DF. Timed Release of Cerebrolysin Using Drug-Loaded Titanate Nanospheres Reduces Brain Pathology and Improves Behavioral Functions in Parkinson’s Disease. Molecular neurobiology. 2017. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/28875428.
- Requejo C, Ruiz-Ortega JA, Cepeda H. Nanodelivery of Cerebrolysin and Rearing in Enriched Environment Induce Neuroprotective Effects in a Preclinical Rat Model of Parkinson’s Disease. Molecular neurobiology. 2017. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/28840482.
- Noor NA, Mohammed HS, Mourad IM, Khadrawy YA, Aboul Ezz HS. A promising therapeutic potential of cerebrolysin in 6-OHDA rat model of Parkinson’s disease. Life sciences. 2016; 155:174-9. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/27210889.
- Kalyn IaB, Safarova TP, Sheshenin VC, Gavrilova SI. [Comparative efficacy and safety of antidepressant mono- and multimodal therapy in elderly patients with depression (a clinical experience in a psychogeriatric hospital)]. Zhurnal nevrologii i psikhiatrii imeni S.S. Korsakova. 2014; 114(6 Pt 2):20-9. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/25042499.
- Panisset M, Gauthier S, Moessler H, Windisch M, . Cerebrolysin in Alzheimer’s disease: a randomized, double-blind, placebo-controlled trial with a neurotrophic agent. Journal of neural transmission (Vienna, Austria : 1996). 2002; 109(7-8):1089-104. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/12111446.
- Retrieved from http://www.wfsbp.org/doi/wfsbp2011-abstractscd/en/abstracts/10025.html.
- Shabanov PD, Lebedev AA, Pavlenko VP, Ganapol’skiĭ VP. [Comparative study of behavioral effects of cortexin and cerebrolysine upon intraventricular and intraperitoneal administration in rats]. Eksperimental’naia i klinicheskaia farmakologiia. ; 70(3):13-9. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/17650626.
- Krasnoperova MG, Bashina VM, Skvortsov IA, Simashkova NV. [The effect of cerebrolysin on cognitive functions in childhood autism and in Asperger syndrome]. Zhurnal nevrologii i psikhiatrii imeni S.S. Korsakova. 2003; 103(6):15-8. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/12872620.
- Chutko LS, Yakovenko EA, Surushkina SY, Kryukova EM, Palaieva SV. [The efficacy of cerebrolysin in the treatment of autism spectrum disorders]. Zhurnal nevrologii i psikhiatrii imeni S.S. Korsakova. 2017; 117(9):71-75. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/29053124.
- Cuevas-Olguin R, Roychowdhury S, Banerjee A. Cerebrolysin prevents deficits in social behavior, repetitive conduct, and synaptic inhibition in a rat model of autism. Journal of neuroscience research. 2017; 95(12):2456-2468. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/28609577.
- Sotnikova NY, Gromova OA, Novicova EA. Dual effect of cerebrolysin in children with attention deficit syndrome with hyperactivity: neuroprotection and immunomodulation. Russian journal of immunology : RJI : official journal of Russian Society of Immunology. 2002; 7(4):357-64. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/12687248.
- Chutko LS, Yakovenko EA, Surushkina SY, Anisimova TI, Kropotov YD. [Clinical and neurophysiological heterogeneity of attention deficit hyperactivity disorder]. Zhurnal nevrologii i psikhiatrii imeni S.S. Korsakova. ; 116(10):117-121. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/27845323.
- Nasiri J, Safavifar F. Effect of cerebrolysin on gross motor function of children with cerebral palsy: a clinical trial. Acta neurologica Belgica. 2017; 117(2):501-505. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/28074392.
- Gershman RN, Vasilenko MA. [Use of cerebrolysin and ATP in treating infantile cerebral paralysis]. Pediatriia akusherstvo i ginekologiia.. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/1228606.
- Retrieved from https://cerebralpalsynewstoday.com/2017/06/07/cerebrolysin-can-help-improve-motor-skills-in-cerebral-palsy-patients/.
- Retrieved from https://clinicaltrials.gov/ct2/show/NCT02116348.
- Biesenbach G, Grafinger P, Eichbauer-Sturm G, Zazgornik J. [Cerebrolysin in treatment of painful diabetic neuropathy]. Wiener medizinische Wochenschrift (1946). 1997; 147(3):63-6. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/9173675.
- Dong H, Jiang X, Niu C, Du L, Feng J, Jia F. Cerebrolysin improves sciatic nerve dysfunction in a mouse model of diabetic peripheral neuropathy. Neural Regeneration Research. 2016;11(1):156-162. doi:10.4103/1673-5374.175063. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4774211/.
- Retrieved from https://www.researchgate.net/publication/286293430_Cerebrolysin_as_a_nerve_growth_factor_for_treatment_of_acquired_peripheral_nervous_system_diseases.
- Masliah E, Armasolo F, Veinbergs I, Mallory M, Samuel W. Cerebrolysin ameliorates performance deficits, and neuronal damage in apolipoprotein E-deficient mice. Pharmacology, biochemistry, and behavior. 1999; 62(2):239-45. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/9972690.
- Keilhoff G, Lucas B, Pinkernelle J, Steiner M, Fansa H. Effects of cerebrolysin on motor-neuron-like NSC-34 cells. Experimental cell research. 2014; 327(2):234-55. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/24997385.
- Shchudlo NA, Shchudlo MM, Borisova IV. [The effect of cerebrolysin on the regeneration of the peripheral nerve depending on the scheme of paraneural administration]. Zhurnal nevrologii i psikhiatrii imeni S.S. Korsakova. 2013; 113(12):76-80. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/24430040.
- Sharma HS, Sharma A, Mössler H, Muresanu DF. Neuroprotective effects of cerebrolysin, a combination of different active fragments of neurotrophic factors and peptides on the whole body hyperthermia-induced neurotoxicity: modulatory roles of co-morbidity factors and nanoparticle intoxication. International review of neurobiology. 2012; 102:249-76. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/22748833.
- Sharma A, Muresanu DF, Mössler H, Sharma HS. Superior neuroprotective effects of cerebrolysin in nanoparticle-induced exacerbation of hyperthermia-induced brain pathology. CNS & neurological disorders drug targets. 2012; 11(1):7-25. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/22229316.
- Martínez-Laorden E, Hurle MA, Milanés MV, Laorden ML, Almela P. Morphine withdrawal activates hypothalamic-pituitary-adrenal axis and heat shock protein 27 in the left ventricle: the role of extracellular signal-regulated kinase. The Journal of pharmacology and experimental therapeutics. 2012; 342(3):665-75. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/22647273.
- Sharma HS, Ali SF, Patnaik R, Zimmermann-Meinzingen S, Sharma A, Muresanu DF. Cerebrolysin Attenuates Heat Shock Protein (HSP 72 KD) Expression in the Rat Spinal Cord Following Morphine Dependence and Withdrawal: Possible New Therapy for Pain Management. Current neuropharmacology. 2011; 9(1):223-35. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/21886595.
- Belokrylov GA, Malchanova IV. [Levamin and cerebrolysin as immunostimulants]. Biulleten’ eksperimental’noi biologii i meditsiny. 1992; 113(2):165-6. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/1611065.
- Govorin NV, Zlova TP, Akhmetova VV, Tarasova OA. [The pathophysiological analysis of cerebrolysin therapy of children with mental developmental delay caused by ecological factors]. Zhurnal nevrologii i psikhiatrii imeni S.S. Korsakova. 2008; 108(5):51-5. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/18577958.
- Sotnikova NY, Gromova OA, Novikova EA, Burtsev EM. Immunoactive Properties of Cerebrolysin. Russian journal of immunology : RJI : official journal of Russian Society of Immunology. 2000; 5(1):63-70. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/12687163.
- Garmanchuk LV, Perepelitsyna EM, Sidorenko Mv, Makarenko AN, Kul’chikov AE. [Cytoprotective effect of neuropeptides on immunocompetent cells (in vitro study)]. Eksperimental’naia i klinicheskaia farmakologiia. ; 72(4):28-32. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/19803367.
- González ME, Francis L, Castellano O. Antioxidant systemic effect of short-term Cerebrolysin administration. Journal of neural transmission. Supplementum. 1998; 53:333-41. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/9700669.
- Gromova OA, Avdeenko TV, Burtsev EM, Skal’nyĭ AV, Solov’ev OI. [Effects of cerebrolysin on the oxidant homeostasis, the content of microelements and electrolytes in children with minimal brain dysfunction]. Zhurnal nevrologii i psikhiatrii imeni S.S. Korsakova. 1998; 98(1):27-30. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/9505400.
- Retrieved from https://www.researchgate.net/publication/270571093_Antioxidant_properties_of_cerebrolysin_-_an_old_drug_with_a_newly_discovered_capabilities.
- González ME, Francis L, Castellano O. Antioxidant systemic effect of short-term Cerebrolysin administration. Journal of neural transmission. Supplementum. 1998; 53:333-41. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/9700669.
- Retrieved from http://europepmc.org/abstract/med/9505400.
- Huang TL, Huang SP, Chang CH, Lin KH, Sheu MM, Tsai RK. Protective effects of cerebrolysin in a rat model of optic nerve crush. The Kaohsiung journal of medical sciences. 2014; 30(7):331-6. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/24924838.
- Retrieved from http://www.roneurosurgery.eu/atdoc/16CostinDCombined.pdf.