Researchers are digging deep into the cellular and molecular causes of neurological diseases to develop game-changing new medicines. For many patients these potential new medicines are a source of great hope. Consider Alzheimer's: existing medicines treat the symptoms of the disease, but they cannot slow, prevent, or reverse the progressive deterioration and dementia the disease causes.

Neurological disorders - which include Alzheimer's, Parkinson's and epilepsy - afflict as many as 50 million Americans – nearly a sixth of the country. They are among the most difficult conditions to treat – and to live with.

Many of these disorders still do not have an approved treatment or are in need of new treatments – but biopharmaceutical research companies are responding with the development more than 400 new medicines to help.

In the case of Alzheimer's, recent research on the plaques and tangles that form in the brains of patients with the disease could lead to treatment that delays its onset, sparing millions of patients and families the indignity of dementia, and saving more than $350 billion per year in health care costs by 2050.

By homing in on the individual elements of the nervous system at the heart of the most destructive disorders, pharmaceutical researchers are raising new hopes of treating these conditions. Their modern method formed its roots more than a century ago.

At the turn of the 20th Century, the German scientist Paul Ehrlich – a pioneer of drug research and winner of a 1908 Nobel Prize – proposed the idea of what he called a “magic bullet,” a compound that could specifically target the substances playing a role in the disease. By the end of the century, researchers were regularly producing these agents, known as monoclonal antibodies, and using them to target disease-causing cells.

One monoclonal antibody now in development may find success in treating amyotrophic lateral sclerosis – ALS, also known as Lou Gehrig's Disease. Researchers suspect that a protein called Nogo-A plays a role in ALS, which prevents the motor neurons that control muscles from transmitting nerve impulses, leaving patients effectively paralyzed. By inhibiting Nogo-A, a drug called ozanezumab could slow or even stop the progression of the disease. The process could keep motor neurons connected to muscle fibers – and keep patients on their feet.

Another drug now in development may succeed in treating relapsing multiple sclerosis (MS). In MS patients, the immune system attacks the protective sheath around nerve fibers, impairing a patient's ability to move, see, and think. By blocking the production of a protein called LINGO which is believed to inhibit growth of nerve protection, this potential new drug called BIIB033 could help return patients to more normal lives.

Creating and administering treatments like these requires not only an understanding of the disorders themselves, but of the underlying neurological processes – which can, in turn, unlock additional creative strategies for treatment.

For instance, tens of millions of Americans suffer from back pain. Some smaller number has sciatica, a condition in which spinal nerves become pinched. It leads to loss of sensation or shooting pains in the legs. Researchers have found a new way to help. By selectively inhibiting nerve impulses, anti-seizure medication can eliminate pain in the extremities without robbing sciatica patients of the ability to walk.

In another promising new avenue of treatment for chronic pain, pharmaceutical researchers are developing a medication to combat migraines, intense headaches that affect nearly 30 million Americans. To treat these debilitating headaches, researchers are going after molecules that play a role in widening blood vessels and transmitting pain signals. Scientists hope that by targeting these peptides, they can limit the transmission of pain signals, making it possible for migraine patients to go about their lives.

From headaches to Alzheimer's, multiple sclerosis to Parkinson's disease, these neurological disorders and diseases are challenging researchers in their complexity. The more than 400 medicines currently being developed in an effort to unlock these complex mysteries promise to help patients live better lives.