G
Gadolinium - A chemical compound which can be administered to a person undergoing a MRI procedure, to enhance the distinction between new vs old lesions. It also increases the scan's sensitivity, which enables the imaging of lesions that would be missed on unenhanced T1 and T2 scans. #28
Gait Ataxia - Broad-based, staggering patterns of walking usually a sign of Cerebellar damage, causing poor coordination of the Limbs and balance difficulties. #25
Gamma Globulin (ImmunoGlobulin) - A protein fraction of Blood Serum that contains many different AntiBodies. Increased percentages of ImmunoGlobulin and/or the presence of Ig Clonal Bands are characteristic of MSers' CerebroSpinal Fluid; but they are not conclusive proof you have MS.
- Because identical Bands are also produced by many other CNS diseaseses, which renders this an important but nonspecific finding. #01, #25, #09
Ganglia - Are collections of Nerve Fibers and Neuron Cell Bodies. Neurons are large cells with appropriately large nuclei. Patches of Basophilic material and pigment are often seen in Ganglion Cell CytoPlasm.
Gene - The biological unit of Heredity. Genes determine the structure and function of all proteins in the body. In turn, these proteins govern body shape and function. #01
Genetic Determinant - The unique Genetic Antigens that identify all Cells as Self, due to Heredity, ie, HLA, to the Immune System. #09
Girdle Sensation (MS Hug) - A sensation of feeling a tight band (like wearing an overly tight girdle or corset) around your trunk that is experienced by some MSers, who have a lesion (old or new) on the Spinal Cord. If it prevents you from taking in a full breath, it is best to treat with a course of IV MethylPrednisolone.
- This Hug is usually the first indication of a new exacerbation, when the inflammation is primarilly centered around the Spinal Cord. Alternately, the MS Hug can also be brought on by an increase in temperature (body core or ambient); if you have a pre-existing Spinal lesion. #25
(Also See: Transverse Myelitis)
Glands
- A collection of Cells specialized to secrete materials unrelated to their ordinary needs. For instance, the Salivary Gland is a collection of Cells that secrete Saliva. Those Cells have no use for the product, which aids digestion in the Mouth and Stomach. #01
Glia Cells - outnumber Neurons by about five to one in the Nervous System, they have processes but do not form or conduct Action Potentials, and retain the capacity to divide throughout life. The following are Glia Cell types and their known functions:
Astrocyte Cells - are of two types, depending on number and degree of branching of their Processes:
- Fibrous Astrocytes
- - have fewer and Less branched Processes
- ProtoPlasmic (Mossy) Astrocytes
- - have more and Highly branched Processes
- Both Astrocyte types constitute the cohesive force (Neurilemma), which maintains the structural and nutritional relationship of Neurons with their Vascular supply.
- They aid BBB regulation, and can display MHC Antigens. However, Astrocytes produce the Scars (Plaques) on DeMyelinated Axons, which either prevent Oligodendrocytes from repairing damaged Myelin or protect newly bared Axons.
- Astrocytes also maintain a specific relationship with Sodium channel-rich regions on Axonal membranes (Nodes of Ranvier) and may play a role in the deployment and/or maintenance of Sodium Channels within DeMyelinated Axons; thereby restoring Nerve Impulse conduction. #27
Oligodendrocyte Cells - are Myelin forming cells of the CNS that produce, maintain, and repair Myelin Sheaths surrounding Axons. Each section of CNS Myelin (InterNode) is the CytoPlasmic Process of a single Oligo-Dendro-Cyte cell.
- Each Oligodendrocyte simultaneously maintains numerous InterNodes on many different Axons. The loss or injury to one of these cells, produces multiple DeMyelinated areas on many different Axons. (View Image) #20, #27
Satellite Cells - are formed in Peripheral Ganglia and serve to support the cell bodies of Neurons in those Ganglia.
Gliosis (Glial)
- Scars that are produced by enlargement of Astrocyte processes. When a portion of the CNS is damaged (Neuron or Axon), Astrocyte processes enlarge and replace the damaged tissue. This process is referred to as Gliosis, while the resulting permanent scar tissue is called Plaque (Sclerosis). #17
GlucoCorticoid Hormones (Steroids) - Hormones that are produced by the Adrenal Glands in response to stimulation by AdrenoCorticoTropic Hormone (ACTH) from the Pituitary Gland.
- These Steroids (Prednisone, Prednisolone, MethylPrednisolone, Betamethasone, Dexamethasone), which can also be manufactured synthetically, are artifically increased to serve both an ImmunoSuppressive and an Anti-Inflammation role in the treatment of acute MS exacerbations. #28 (Also See: Hormones)
- Five major Steroid Hormone Classes:
- Progestagens (Progestational Hormones)
- GlucoCorticoids (Stress-related Hormones)
- MineralCorticoids (Na+ Uptake Regulators)
- Androgens (Male Hormones)
- Estrogens (Female Hormones)
Granulocytes - A subset of Leukocytes (PolyMorphoNuclear Leukocytes) that are part of the Adaptive Immune System and includes Neutrophils, Eosinophils, and Basophils.
Gray Matter - Portions of the CNS where Nerve Cell Bodies are concentrated. Cortex is Gray Matter. So are the Anterior (Front) and Posterior (Back) Horns of the Spinal Cord and more. #01
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