Clinical aspects

Description

	• Some of the alternative therapies are complete systems of medicine, whereas others are only methods.
	• The most common use of alternative methods for neurologic disorders is for painful conditions.
	• Patients with neurologic disorders that do not have an effective treatment are more likely to resort to alternative methods.
	• Herbs and unconventional pharmaceuticals should not be used for neurologic disorders unless the constituents are known and safety data are available.

A practical classification of the major alternative therapies is shown in Table 1. Some of these therapies are complete systems of medicine, whereas others are only methods; however, some overlap does exist. Although numerous books are available on alternative medicine, none of these critically evaluate the various alternative therapies.

Table 1. Classification of Common Alternative or Complementary Methods of Treatment

Alternative systems of medicine
	• Ayurveda • Chinese medicine • Homeopathy • Chiropractic
		- spine manipulations
Complementary methods of treatment
	• Bioelectromagnetic therapies
		-magnetotherapy -electroacupuncture
	• Therapies based on mind-body relationships
		- biofeedback - meditation - spiritual healing - yoga
	• Manual therapies
		- touch therapy - spinal manipulation - massage
	• Herbs and unconventional pharmaceuticals • Aroma therapy • Nutritional therapies
		- ketogenic diet - megavitamins - nutraceuticals - herbal teas

Ayurveda. The word "Ayurveda" comes from two Sanskrit roots: ayus meaning "life" and veda meaning "science" or "knowledge," and is translated as "the science of life." It is the oldest existing system of medicine, having its heritage in ancient India (5000 BC to 3000 BC). Ayurveda's major textbook of medicine, the Charaka Samhita, was written in approximately 500 BC and translated into English in 1977 (43). Ayurveda is recognized by the World Health Organization and is still widely practiced in India. Practitioners of this system are also found in the United States and Europe. Considerable research has been done on Ayurvedic medicine in modern India (42). Ayurveda aims to maintain the equilibrium Dosha, dynamic forces of the nature. The major components of Ayurveda are transcendental meditation and herbs. Neurology, as such, cannot be identified in ancient Indian medical texts, but the concept of disorders of muscles can be found in the Charaka Samhita (12). Herbal treatments were available for neurologic disorders resembling Parkinson disease and epilepsy.

Ayurgenomics. Despite a holistic approach aimed to cure disease, therapy is customized to the individual's constitution (Prakruti) – an ancient counterpart of genotype. The Institute of Genomics and Integrative Biology (Delhi) and Indian Genome Variation Consortium are investigating Ayurgenomics by combining genomics with phenotyping principles of Ayurveda as well as objective parameters of modern medicine for identifying molecular endophenotypes (40). According to Ayurveda, every individual is born with his or her own basic constitution, which to a great extent regulates inter-individual variability in susceptibility to diseases and response to external environment, diet, and drugs. Researchers in India have demonstrated that integration of a stratified approach of Ayurveda into genomics, ie, Ayurgenomics, could complement personalized medicine (13).

Prakriti has also been shown to have molecular and genomic correlates as exome sequencing revealed significant differences between Prakriti types in 28 SNPs of 11 FDA approved genes of pharmacogenomics relevance, ie, CYP2C19, CYP2B6, ESR1, F2, PGR, HLA-B, HLA-DQA1, HLA-DRB1, LDLR, CFTR, CPS1. Thus, integration of Prakriti concepts can augment the efficiency of drug discovery and development programs through a unique initiative of Ayurgenomics TRISUTRA consortium across ethnically and geographically diverse Indian populations (34).

Transcendental meditation. This is defined as "turning the attention inwards toward the subtler levels of thought until the mind transcends the experiences of the subtlest state of thought and arrives at the source of thought."

Yoga. This term is from the Sanskrit word yuga meaning "to join." Yoga aims at the perfect union of body, mind, and spirit through a system of postures, breath control, and meditation. The effect of yoga has been studied neurophysiologically, and changes in autonomic function and states of consciousness have been demonstrated. Yoga has been used for the treatment of neurologic and psychiatric disorders, but only a few controlled clinical trials have been conducted.

Chinese medicine. The concept of ancient Chinese medicine is based on the interaction between two primal forces: Yang (positive) and Yin (negative). The most ancient medical text from China is the Yellow Emperor's Classic of Internal Medicine, believed to have been written about 2697 BC and now available as an English translation (50). Important components of Chinese medicine are pulse diagnosis, herbs, and acupuncture. There was no system of neurology within Chinese medicine. Integration of Chinese medicine and Western medicine started in China in the 1960s. Herbs and acupuncture are used in the treatment of neurologic disorders.

Homeopathy. This was founded by Samuel Hahnemann in Germany in 1789. The basic principle is that "like cures like." The materia medica of this system is based on the description of symptoms induced by several substances, including metals and plant derivatives. Extreme dilutions of the same substance are thought to be effective for the treatment of the symptoms. Homeopathy flourished in the United States in the 19th century but was suppressed in the earlier part of 20th century with the rise of modern medicine. Currently, a resurgence of interest in homeopathy both in Europe and the United States has taken place. More than six million persons use homeopathic medicines in the USA. Although generally considered to be safe, there is no scientific proof of effectiveness of homeopathic medicines. In 2015, the FDA started to consider greater regulation of both homeopathic drugs and the advertising of such products (32). Homeopathic treatments are based on symptoms; therefore, no systematic treatment of neurologic disorders is used.

Chiropractic. See the article titled Neurologic complications of chiropractic manipulation.

Herbs. Herbs are a part of all ancient medical systems and are still in use. Even before medicine was developed, herbs were used by primitive humans for the treatment of illness. Several old cultures still have traditional herbal treatments for common ailments.

It is estimated that 500,000 flowering plant species inhabit the world; therefore, this is an inexhaustible source of medicines. Eighty percent of the world population uses plants exclusively to treat illness. Some of the pharmaceuticals in current use have herbal origins, and 35% of the conventional drugs contain active principles of natural origin. Herbal derivatives with antioxidant and anti-inflammatory properties play a role in neuroprotection. Of these, the most promising are trigonelline, shogaol, curcumin, resveratrol, baicalein, wogonin, ginsenosides, tanshinones, withanolides, picrosides, parthenolide, cannabinoids, Devil's claw, and white willow bark, including Chinese formulations Ren Shen Shou Wu and Shengmai San (30). The neuroprotective effects of medicinal plants for stroke in Korean traditional medicine were demonstrated using both in vitro and in vivo cerebral ischemia models (06).

Several pharmaceutical companies are developing herbal remedies. The United States Food and Drug Administration is now developing guidelines for herbal mixtures, and several products have a new investigational drug status that allow them to enter clinical trials.

Herbal teas. Several teas are available for as sleep-promoting agents. Green tea and its extracts are claimed to have beneficial effects in neurologic disorders, eg, antidepressant, antineurodegenerative, and neuroprotective effects (01). There is a need for pharmacokinetic studies and controlled clinical trials to introduce these for therapeutic purposes.

Magnetotherapy. The treatment of illnesses with magnetized, iron-containing stones was used in ancient Egyptian and Greek medicine. In 18th-century Europe, Franz Mesmer claimed to heal the sick with magnetism. In the 19th century, further investigations were made possible by the availability of devices for measuring electromagnetic fields. The role of electromagnetic fields on the biological system is well known, and neurologists are familiar with magnetoencephalography magnetic brain stimulation. The therapeutic potentials of electromagnetic fields have been investigated as there have been claims made that pulsating electromagnetic energy can restore the rhythm of inadequate energy fields in various diseases as well as restore cell metabolism and energy. This method has been applied to the treatment of various neurologic disorders.

Dietary therapies. These form a prominent part of complementary medicine. Those most relevant to neurologic disorders are the ketogenic diet and megavitamins.

Guidelines for use of alternative therapies. On behalf of the Federation of State Medical Boards and its continued commitment to assist state medical boards in protecting the public and improving the quality of health care in the United States, the Special Committee for the Study of Unconventional Health Care Practices, ie, complementary and alternative medicine (CAM), undertook an initiative in 2000 to develop model guidelines for state medical boards for use in educating and regulating (1) physicians who use CAM in their practices, and/or (2) those who co-manage patients with licensed or otherwise state-regulated CAM providers (07). Model guidelines for the use of CAM in medical practice were published.

The goal should be to evaluate various therapies and to use those that are safe and effective as an adjunct to the management of neurologic disorders that do not have a satisfactory mainstream treatment at present.

Alternative treatments should be given by qualified physicians trained in these methods or by health professionals working closely with physicians. The unsupervised treatment of neurologic disorders by nonmedical practitioners of alternative healing arts should be discouraged.

Indications

The most common use of these methods for neurologic disorders is in painful conditions such as headache and backache. Patients with multiple sclerosis frequently use complementary and alternative methods of treatment for several reasons, which include lack of efficacy of conventional treatment, anecdotal reports of benefits of alternative methods, and physician referral (26). Complementary and alternative medical treatments are commonly used for children with autism spectrum disorders, but most of these have not been adequately studied and do not have evidence to support their use.

Acupuncture and neurologic complications of chiropractic manipulation are dealt with in separate articles. The uses of herbs in neurologic disorders are shown in Table 2, and further details are given in the section of results and effects.

Table 2. Examples of the Use of Herbal Preparations for Neurologic Disorders

Disorder	Herbal preparation	Applications/mechanism of action
Migraine	• Feverfew (Tanacetum parthenium): active ingredient is Parthenolide	• Efficacy for the prevention of migraine has not been established.
Alzheimer disease	• Huperzine-A, a Chinese medicine • Transina, an Ayurvedic medicine with Medhyarasayanas as active ingredient • Curcumin, the yellow pigment in curry spice, is used in Ayurvedic medicine	•Increases brain acetylcholine levels by 40%, with improvement in memory, cognitive, and behavioral functions. • Reported to be effective in animal models of Alzheimer disease. Inhibits the accumulation of amyloid beta40 in the brains of patients with Alzheimer disease.
Stroke	• Rhizoma Ligustici (Ligusticum chuanxiong), a Chinese medicine with Cnidium lactone as active ingredient	• Antithrombolytic effect; improves microcirculation
Vascular dementia	• Ginkgo biloba, a Chinese medicine: eg, EGb 761 contains Ginkgolides (specific antagonists of platelet-activating factor) and flavonoids (free radical scavengers)	• Ginkgo preparations increase blood supply to the brain by decreasing blood viscosity. A Sian Clinical Expert group on Neurocognitive Disorders recommends EGb 761 for neuroprotection in cognitive disorders with/without cerebrovascular disease (20).
Parkinson disease	• Cowhage (Mucuna), an Ayurvedic herbal medicine contains L-dopa and other constituents •Kampo kami-shoyo-san, a Japanese herbal preparation, which consists of 10 medicinal herbs, including Radix Bulpleuri, Radix Paeoniae, Radix Angelicae Sinensis, and Radix Glycyrrhizae	• Still in use in India • Effective in reducing the tremor associated with antipsychotic-induced parkinsonism
Epilepsy	• Kava (Piper methysticum), a South Pacific folk remedy with active ingredient: Kavain Kampo (extract of nine herbs), is a Japanese medicine with active ingredient: 5, 6, 7-trihydroxy-2-pheyl-4H-1-benzopyran-4-1-(baicalein) • Pimpinella anisum L Apiaceae (anise oil) is a Persian medicine	•Antiepileptic effect demonstrated by EEG brain mapping. Also shown to improve intellectual performance. • Baicalein is a potent scavenger of radicals and has a neuroprotective effect in epilepsy • Reduced the amplitude and duration of epileptiform burst discharges induced by injection of intraperitoneal pentylenetetrazol in animal models (21)
Multiple sclerosis	•Cannabinoids with active ingredients: tetrahydrocannabinol and cannabidiol	• Used for the management of pain and spasticity
Neuroprotection in multiple neurologic disorders	• Glycyrrhiza glabra has the active ingredient, glycyrrhizic acid, a bioactive triterpenoid saponin	Attenuation of neuronal damage by inhibiting high mobility group box 1 (HMGB1) protein expression and translocation as well as by downregulating the expression of inflammatory cytokines (31).

More than one alternative method may be employed in the treatment of neurologic disorders, as shown by examples of headache, stroke, and Alzheimer and Parkinson diseases. Brief comments will be given on psychiatric disorders as well.

Headache. Most traditional medical systems have remedies for headaches, including migraine. One of the largest selections was available in the Persian system of medicine. Emodin and Rhein, two main anthraquinone derivatives of rhubarb (a Persian folk remedy for headache), have been shown to inhibit the production of compounds such as nitric oxide, cyclooxygenase 2, and prostaglandin E2, which play an important role in triggering different types of headaches. A randomized, controlled trial demonstrated a significant reduction in migraine headache frequency and associated clinical features in patients treated with yoga over a period of three months (19). A survey in the United States showed that those with migraines or severe headaches used complementary or alternative medicine more often than those without because of provider recommendation and because conventional treatments were perceived as ineffective or too costly (51). Mind-body therapies such as deep breathing exercises, meditation, and yoga were used most commonly. Although complementary and alternative medicine is widely used by both physicians and patients with primary headache syndromes, the overall evidence for efficacy is still poor as revealed in a review of publications written on this topic throughout the past two decades (39).

Low back pain. In a German survey of primary headache and low back patients, 84.75% of all patients reported use of alternative and complementary medicine with significantly more low back patients (11). Thermotherapy was used by 77.4%, massage by 62.7%, and acupuncture by 51.4%.

Alzheimer disease. In traditional practices of medicine, numerous plants have been used to treat cognitive disorders, including neurodegenerative diseases such as Alzheimer disease and other memory-related disorders. Some alkaloids from plant sources have been investigated for their potential in Alzheimer disease therapy and are now in clinical use (eg, galantamine is derived from Galanthus nivalis). Plants and their constituents with pharmacological activities may be relevant to the treatment of cognitive disorders, including enhancement of cholinergic function in the CNS and anticholinesterase effects. Polyphenolic phytochemicals such as curcumin, resveratrol, and green tea catechins are considered to have the potential to slow the progression of Alzheimer disease because of their anti-amyloidogenic, anti-oxidative, and anti-inflammatory properties (22).

A systematic review and meta-analysis of controlled clinical trials showed that compared with placebo, Huperzine significantly increased the scores of memory quotient and mini-mental state examination in patients with early Alzheimer disease (15). Efficacy of ginkgo biloba extract was investigated in a randomized, double-blind, placebo-controlled, parallel-group, multicenter trial in elderly patients with dementia (Alzheimer disease or vascular dementia) or age-associated memory impairment (49). There was no dose-effect relationship and no effect of prolonged Ginkgo treatment. The trial results do not support the view that Ginkgo is beneficial for patients with dementia or age-associated memory impairment.

Withania somnifera (ashwagandha) is a medicinal plant used in India to treat a wide range of age-related disorders and to preserve the health of the aging brain. Withania somnifera root extract inhibits AChE in much the same way as donepezil. Withania somnifera extract and metabolite sominone are capable of halting and even repairing damage to brain cells in a mouse model of Alzheimer disease produced by exposure to amyloid beta.

Several nutritional therapies have been used for Alzheimer disease. Axona (AC-1202), a proprietary formulation of caprylic triglyceride, increases plasma concentrations of ketone bodies to provide an alternative energy source for the brains of Alzheimer disease patients. A placebo-controlled double-blind study found that AC-1202 was safe and produced cognitive benefits in a predefined analysis of patients who did not carry the epsilon4 variant of the APOE4 gene (14).

Parkinson disease. Herbal preparation, massage, biofeedback, and acupuncture have been combined in the treatment of Parkinson disease by traditional approaches. A significant percentage of patients with Parkinson disease, which varies according to the country, have used at least one alternative therapy, with vitamins, herbs, massage, and acupuncture as the most common treatments. Clinical studies in China and Korea have shown a positive benefit of acupuncture in treating Parkinson disease, particularly in reducing the doses of dopaminergic medications and their side effects (52). Experimental studies show that this effect is mediated through the same mechanisms as other neuroprotective agents, including antioxidative, anti-inflammatory, and antiapoptotic pathways at molecular and cellular levels.

Stroke. Approximately half the stroke survivors in the United States use some form of alternative therapy (41). In India, more than one-third of the patients in a stroke study opted for alternative medicine (28). Predictors for this choice were presence of limb weakness, dysphagia, dyslipidemia, hypertension, hemorrhagic stroke, severe stroke, and poor outcome.

A case study of a woman who used yogic breathing as Ayurvedic therapy in her recovery from poststroke aphasia after no significant improvement following conventional speech therapy has been published (24). In view of improvement in language and visual attention, the authors suggest further studies of Ayurvedic therapy in poststroke aphasia. In a randomized controlled trial in 22 patients with poststroke hemiparesis, yoga intervention did not result in any significant improvements in objective motor function measures; however, there was a significant improvement in quality of life associated with perceived motor function (16). These yoga benefits need to be rigorously evaluated in larger clinical trials.

Using herbs together with acupuncture is the most common combination in the traditional Chinese management of stroke. Even among the herbs, various preparations are combined that have antithrombotic, anti-inflammatory, and neuroprotective effects. The rationale for the use of complex herbal formulations is that therapeutic efficacy is enhanced by synergistic effect of multiple ingredients, each of which covers a different manifestation of stroke.

NaoXinQing, a traditional Chinese medicine, has been used for years for the treatment of stroke but the underlying mechanism is not clear. One study has shown that it improves the activity of endogenous antioxidants and reduces apoptosis in cells exposed to hydrogen peroxide (04).

Multiple sclerosis. Use of alternative methods of treatment is very common among multiple sclerosis patients, and healthcare professionals should provide guidance and monitoring in the use of these therapies to improve outcomes (46). A program sponsored by the Danish Multiple Sclerosis Society at a special hospital for multiple sclerosis has integrated traditional with alternative management of this condition, including therapies such as homeopathy (44). This has improved the management by strengthening of the patients’ resources and competences on a physical, an emotional, and a cognitive level.

Evidence-based recommendations for complementary and alternative medicine in multiple sclerosis were summarized by the American Academy of Neurology in 2014 (53). Oral cannabis extract for spasticity symptoms (subjective only) and pain (excluding central neuropathic pain) was rated as Level A and tetrahydrocannabinol for spasticity symptoms and pain (excluding central neuropathic pain) as Level B. There is strong evidence to indicate benefits of cannabinoids in treatment of spasticity and neuropathic pain in multiple sclerosis (36). Interaction of several other alternative therapies with multiple sclerosis is unknown.

Psychiatric disorders. More than 40% of adults with neuropsychiatric symptoms commonly observed in many diagnoses use complementary and alternative medicine (35). An increasing number of symptoms was associated with an increased likelihood of this approach. According to a review of randomized controlled trials by a Task Force of the American Psychiatric Association, commonly used complementary and alternative medicine treatments such as omega-3 fatty acids, St John's wort, acupuncture, light therapy, exercise, and mindfulness psychotherapies showed promising results (10). More rigorous and larger studies were recommended.

Contraindications

Contraindications for the use of acupuncture and chiropractic manipulation are described in articles on these topics. Herbs and unconventional pharmaceuticals should not be used for neurologic disorders unless the constituents are known and safety data (including adverse reaction information) are available.

Results

The results and effects of acupuncture and chiropractic manipulation are described in separate articles. Those of various herbal treatments and magnetotherapy will be discussed here.

Clinical trials of alternative therapies. ClinicalTrials.gov lists 3238 trials as of July 2021. Of these trials of alternative therapies, approximately 388 are for neurologic disorders.

Herbs. An Ayurvedic remedy, Cowhage (Mucuna pruriens), is administered as powdered seeds orally and was shown in a study to result in significant improvement in 23 patients with Parkinson disease (48). Qishe Pill, a mixture of Chinese herbs, was developed to treat various symptoms of cervical radiculopathy, particularly neck pain (08). A double-blind, prospective, randomized-controlled trial evaluated this therapy, and a postmarketing study is ongoing in China (ClinicalTrials.gov Identifier: NCT01875562).

Ginkgo biloba is used extensively for the treatment of memory impairment associated with aging and dementia but properly controlled trials have not established its efficacy.

Aromatherapy. A systematic review of clinical trials concluded that benefits of aromatherapy for dementia are equivocal (09). There were several methodologies in the included studies, and properly designed, large-scale, randomized controlled trials are required before any conclusions can be drawn about the effectiveness of aromatherapy for dementia.

Magnetotherapy. This approach has been used for the treatment of migraine headaches, neuralgias, sciatica, and stroke. Improvement has been claimed in patients with epilepsy. Controlled studies have not been performed so far.

Yoga. In a randomized controlled trial on patients with low back pain, the yoga group showed significant reduction in pain and anxiety at 12 weeks, but no changes in the intervertebral discs and in the vertebrae as shown by MRI (47). A Cochrane Database review of 50 patients from two controlled clinical trials of yoga in epilepsy shows a possible beneficial effect in control of seizures (29). Overall efficacy analysis shows that yoga treatment is better when compared with no intervention or interventions other than yoga (postural exercises mimicking yoga). Yoga reverses memory loss and reduces anxiety, depression, and stress in neurodegenerative diseases, but most studies have several limitations, and further research is required to validate these findings benefits (02).

Adverse effects

Neurologic adverse effects of acupuncture and chiropractic manipulation have been dealt with in separate articles on these topics. Most of the other adverse effects relate to herbal and unconventional pharmaceutical preparations. A more detailed description is given elsewhere (18). Although herbal remedies are generally better tolerated than synthetic medications, potentially serious adverse events, including herb-drug interactions, have been reported (17). Many adverse reactions to herbal medicines are not reported because of the lack of a pharmacovigilance system such as that for modern pharmaceuticals. There is need for caution when using herbal remedies, particularly in special populations, such pregnant women, children, and the elderly. Lead poisoning has been reported with the use of alternative remedies for multiple sclerosis. Several reasons for concern about the safety of unconventional pharmaceuticals are:

	• Inadequate quality control of phytotherapeutic products, as this can lead to inferior or contaminated products.
	• Ineffective herbal healing that can produce serious sequelae because the patient is deprived of the proper treatment.
	• Overconsumption of the substances due to the lack of information about the exact amount of active ingredients in most of these preparations.
	• As nearly all herbal remedies contain multiple, biologically active constituents, interaction with conventional drugs is a concern.
	• Little pharmacovigilance and knowledge of side-effect profiles of these substances.

Most of the reported adverse effects of herbal remedies are related to hepatotoxicity; however, neurologic adverse effects have also been reported. Chinese herbs containing aristolochic acids may cause Fanconi syndrome and should be considered as a cause of hypokalemic paralysis. Some of the neurologic adverse effects of herbal preparations are listed in Table 3.

Table 3. Neurologic Adverse Effects of Herbal and Unconventional Pharmaceutical Preparations

Preparation	Indication for use	Neurologic adverse effects
Germanium	Arthritis, cancer, antiviral, and as a general tonic	Renal damage associated with neuropathy and myopathy
Licorice (Glycyrrhiza glabra)	Found in Chinese medicines for a variety of indications	Hypokalemic myopathy
Laetrile or amygdalin (cyanogenetic glycoside in seeds of apricots)	Cancer (found to be ineffective)	Chronic toxicity (cyanide poisoning). Lesions of the spinal cord, as well as optic, auditory, and peripheral nerves.
Herbal preparations containing arsenic	Several Chinese and Indian herbal medicines for various indications such as eczema and hemorrhoids	Encephalopathy, peripheral neuropathy, convulsions
Aconite alkaloid (in various species of Aconitum)	Chinese medicine for neuralgia, headaches, and fever	Ataxia and cardiovascular disturbances
Herbal preparations containing lead	Various Chinese and other Asian medicines for a variety of indications	Anemia, gastrointestinal disturbances, peripheral neuropathy, encephalopathy
Yohimbine alkaloids (in various plant species)	It is in alpha2-adrenoreceptor agonist used in patients with autonomic insufficiency	Produces a variety of psychic reactions, such as manic state, in patients. Induces convulsions in experimental animals.

Neurologic complications are associated with several other unconventional medical practices. Few of these complications come to the attention of neurologists. "Coin rubbing" is a Vietnamese practice used to relieve fever, headache, and chills. The procedure involves applying hot, mentholated oil to the back and chest before the edge of a coin is rubbed over the spine to produce linear ecchymoses. A case of intracerebellar hemorrhage with brainstem compression has been reported following coin rubbing (33). The hemorrhage was attributed to a reflexive rise in blood pressure as a reaction to the painful coining procedure.

Although several eHealth technologies are available for detection of drug-drug interactions and adverse effects of drugs, considerably less attention is focused on that of complementary and alternative medicines as well as their interactions with conventional drugs. A review of the literature and eHealth technologies found that some resources are available to healthcare providers, researchers, and patients, but caution that the quality of many of these varies widely and has not been formally assessed (25).

Special considerations

A survey of pregnant women in the eastern United States reported that 45% of respondents had used herbal medicines, and a survey in Australia revealed that 36% of women had used at least one herbal product during pregnancy (23). Alternative therapies should be avoided or used with caution during pregnancy because insufficient information is available about their safety.

Scientific basis

• The wide range of alternative methods of treatment are not based on any scientific principles, and limited evidence for efficacy has been shown so far by modern investigations.

The whole of alternative methods taken together is a hodgepodge of practices that is not based on any common or consistent ideology, theory of illness, or treatment. Yet within each practice, a consistency exists that is derived from a wide variety of sources: folk traditions, religions, philosophies, and even mainstream medicine. Some of these methods have been investigated by modern scientific methods, and limited evidence for effectiveness has been discovered thus far.

Physiological effects of transcendental meditation have been studied by EEG, which shows predominant alpha activity with eyes half open. The alpha waves progressively increase in amplitude and decrease in frequency. The physiologic state attained in transcendental meditation is different from states induced by hypnosis or autosuggestion. Transcendental meditation has been shown to relieve mental and physical tension and has potential applications in some neurologic disorders.

Some claims are difficult to verify. For example, repeated dilutions of homeopathic substances are claimed to increase the potency of these medicines, but active substances could not be identified until recently. However, a study has used transmission electron microscopy, electron diffraction, and chemical analysis by Inductively Coupled Plasma-Atomic Emission Spectroscopy to examine market samples of metal-derived medicines from reputable homeopathic manufacturers, and demonstrated for the first time the presence of physical entities in these extreme dilutions in the form of nanoparticles of the starting metals and their aggregates (05).

Several randomized, placebo-controlled trials of alternative and complementary therapies have been carried out in recent years. The methods and statistical aspects of these trials, as well as the results, vary considerably. Some earlier-claimed successes are being refuted by rigorous clinical trials.