Spinal cord concepts

Neuropathic pain is defined as spontaneous pain and hypersensitivity to pain associated with damage to or pathologic changes in the peripheral nervous system as in painful diabetic peripheral neuropathy (DPN), acquired immunodeficiency syndrome (AIDS), polyneuropathy, post-herpetic neuralgia (PHN) or pain originating in the central nervous system (CNS), that which occurs with spinal cord injury, multiple sclerosis, and stroke. Functional pain, a relatively newer concept, is pain sensitivity due to an abnormal processing or function of the central nervous system in response to normal stimuli. Several conditions considered to have this abnormal sensitivity or hyperresponsiveness include fibromyalgia and irritable bowel syndrome. 

Moreover, analysis of data coming from greater MR series and our own observations reveal no predominance of infarcts in the upper and mid-thoracic region (Mawad et al. 1990 Weidauer et al. 2002). Thus, the concept of a vulnerable watershed zone at T4 is no longer valid in acute spinal cord ischemia. 

Functional disturbances within the spinal cord are caused by the venous congestion due to arteriali-zation and elevated pressure of the medullary veins (Aminoff et al. 1974). In addition, venous outlets are insufficient and thus reinforcing impairment of the venous circulation and chronic spinal hypoxia. In particular, Merland and coworkers (1980) introduced the concept of blocked venous drainage into the epidural space. 

The concept of localization is central to the practice of neurology. A disorder can affect the cerebral hemispheres, the brainstem, the spinal cord, the peripheral nerves, and the muscles. Malfunctions... 

Victor, M., and Lear, A. A., 1956, Subacute combined degeneration of the spinal cord— Current concepts of the disease process. Value of serum vitamin Bjj determinations in clarifying some of the common clinical problems. Am. J. Med. 20 896. 

For extracellular signal recordings from electrically active cells in culture, two main concepts have been developed in the past microelectrode arrays (MEAs) (see Fig. 2a) with metalized contacts on silicon or glass substrates have been used to monitor cardiac impulse propagation from dissociated embryonic myocytes [1-3], dissociated invertebrate neurons [4, 5] and mammalian neurons [6] spinal cord [7], and mouse dorsal root... 

The spinal cord is the organizer of information, which is processed from the brain to other regions. Feedback from these areas to the brain helps maintain normal function. A difficult concept to grasp is that parts of the body may communicate directly with one another without the brain s intervention. In these communications, the nervous system is less like a two-way intercom system in a large apartment house than like a fully interactive telephone system with the brain acting as the operator. A common example... 

---