Gonadal steroids such as testosterone, estrogen and progesterone affect development and reproduction. Chemists can synthesize these natural substances, and patients may take them as supplements. Hormone replacement therapy is not an anti-aging panacea, yet steroids can improve life quality. Taking steroidal hormones protects brain cells from disease and facilitates neural recovery from damage. Steroid medical treatments can treat neurological disorders including Parkinson's disease, Alzheimer's disease and ischemic stroke.
Estrogen
Estrogen generates feminine characteristics such as breast growth, and it affects neurological disorders such as Parkinson's disease. Postmenopausal women are more likely than premenopausal women to be diagnosed with Parkinson's. Estrogen levels may affect this relationship, as estrogen decreases following menopause. Men, who typically have little estrogen, also have a greater incidence of Parkinson's disease. A 2001 report published in the journal Movement Disorders correlated Parkinson's disease with type of menopause, age at menopause and intake of estrogen. Surgically induced menopause, which reduces estrogen more than natural menopause, increased the risk of getting Parkinson's. Earlier menopause, which means longer periods with lower estrogen, also increased risk. Long-term estrogen use for greater than six months decreased risk.
No cure exists for Parkinson's disease. Estrogen intake, however, may improve Parkinsonian symptoms. A 1999 analysis offered in the periodical Neurology looked at estrogen use in patients with Parkinson's disease. Patients taking estrogen had less severe symptoms than those not taking it. Thus estrogen replacement therapy in women may reduce the incidence and aid the treatment of Parkinson's disease.
Testosterone
Testosterone fosters masculine qualities such as strength and aggression. This hormone starts decreasing in men during their 30s. This change produces a male correlate to the female menopause called androgen deficiency. The loss of androgens is associated with the development of neurological problems such as dementia. A causal relationship remains speculative, but low levels of testosterone correlate well with the risk of developing Alzheimer's disease.
Preventing the age-related decline in testosterone may reduce the risk of developing Alzheimer's disease. A 2001 study described in the Journal of Neurobiology used an animal model of dementia to test the protective effects of testosterone. In this model, giving mice a neurotoxin causes extensive cell loss in the hippocampus. This brain area, damaged in Alzheimer's, plays a role in learning and memory. Results of the study indicate that pretreatment with testosterone prevented brain damage.
Men with Alzheimer's disease have few treatment options. Yet testosterone intake may improve their quality of life. A 2003 experiment offered in the periodical "Aging Male" evaluated testosterone use in androgen-deficient men. The data show that testosterone treatment improved visual and spatial skills. Testosterone replacement therapy in men, therefore, can decrease the risk of developing Alzheimer's, and it can improve symptoms of the disease after diagnosis.
Progesterone
Progesterone facilitates pregnancy by increasing the immunity and improving the mood of a child-bearing woman. Chemically, estrogen and testosterone synthesis requires progesterone as a precursor. So progesterone indirectly affects the brain by mediating the effects of other gonadal steroids. Yet progesterone also has direct effects on the brain. For example, it reduces inflammation. So the steroid can affect neurological injury, such as in a stroke. Older adults experience greater risk for stroke due to the buildup of vascular plaque. Because they also have lower amounts of progesterone, stroke-induced damage can be fatal.
A 2008 study published in the journal Critical Care looked at progesterone administration in the treatment of head injuries. In this trial, patients received progesterone within eight hours of the trauma. Results indicate the steroidal treatment decreased mortality and increased healing. Progesterone administration produces similar effects in animal models of stroke. These findings suggest that progesterone replacement therapy may facilitate recovery from traumatic brain injury.
References
- "Movement Disorders"; Hysterectomy, Menopause, and Estrogen Use Preceding Parkinson's Disease: An Exploratory Case-Control Study; M. D. Benedetti et al; September 2001
- "Neurology"; Effect of Estrogen Replacement on Early Parkinson's Disease; R. Saunders-Pullman et al.; April 22, 1999
- "Journal of Neurobiology"; Brain Aromatase is Neuroprotective; I. Azcoitia et al.; June 15, 2001
- "Aging Male"; A Pilot Study on the Effects of Testosterone in Hypogonadal Aging Male Patients with Alzheimer's Disease; R. S. Tan et al.; March 2003
- "Critical Care"; Improved Outcomes from the Administration of Progesterone for Patients with Acute Severe Traumatic Brain Injury: A Randomized Controlled Trial
