Neurotrophic Factor Infusion System for the Treatment of Pain
Publication Date: 2003-Apr-29
The IP.com Prior Art Database
Todd K. Whitehurst: INVENTOR [+3]
An implantable system infuses neurotrophic factors, such as glial-cell-derived neurotrophic factor (GDNF) or brain-derived neurotrophic factor (BDNF) and delivers electrical stimulation which may be applied together, concurrently or asynchronously, to provide immediate and long-term relief of chronic pain. In particular, the stimulation provides immediate paresthesia and the neurotrophic factor can stop the progression of long-term damage to neural tissue, as well as facilitate neural tissue repair.
Background & Summary
Debilitating chronic pain is a socio-economic burden that afflicts between 70-90 million Americans, in conjunction with headache (24 million), backache (23 million), arthritis (40 million), and millions more with other pathologies, diseases, and injuries. Debilitating chronic pain costs Americans over $50 billion annually, including $900 million for over-the-counter analgesics, and billions more in lost production costs.
Chronic pain has multiple causes and manifestations. Pain can usually be linked to causes such as injury or diseases but can also be idiopathic, i.e, having no diagnosable origin. Pain may be characterized simplistically in the following types: (1) nociceptive (2) neuropathic (3) psychogenic and (4) mixed.
Nociceptive pain is caused by tissue irritation, impending injury or actual injury to the tissue or cells. With nociceptive pain, the perception of pain is specific, e.g., hot or sharp. Nociceptors are pain receptors in the affected area, which activate and transmit signals via the peripheral nerves, through the spinal cord and to the brain.
Neuropathic pain results from a malfunction in the nervous system, for example, in the peripheral nerves or in the central nervous system. Neuropathic pain is often triggered by injury, although the injury may not necessarily involve the nervous system. The pain may persist for years, even when the damaged tissues have apparently healed.
Psychogenic pain occurs when there is no physiological explanation. It is universally agreed, however, that a psychogenic factor often plays a role in the perceived intensity of pain that also have other underlying causes. It is rare, however, that pain is exclusively psychogenic.
In many instances, the pain appears to be caused by a complex interaction of nociceptive and neuropathic factors. An initial nervous system dysfunction or injury may trigger the neural release of inflammatory mediators and subsequent neurogenic inflammation. For example, migraine headaches probably represent a mixture of neuropathic and nociceptive pain. Myofascial pain is probably secondary to nociceptive input from the muscles, but abnormal muscle activity may be the result of neuropathic conditions. Chronic pain, including chronic myofascial pain, may cause the development of ongoing perception of pain within the central nervous system that are independent of signals from the peripheral nerves. This phenomenon is called the centralization or encephalization of pain.
A multi-disciplinary approach for treating chronic pain is gaining increased favor. Such approach includes psychological rehabilita...