DISINHIBITION Several local inhibitory circuits and descending inhibitory pathways serve to modulate the perception of pain. However, after peripheral nerve injury, primary afferents, dorsal horn neurons, and gamma-aminobutyric acid (GABA)ergic…
PAIN CHARACTERISTICS The patient typically reports a burning, stinging, stabbing, or shooting pain; hyperalgesia to temperature and touch are often noted. Pain may travel unilaterally from the extremities to sometimes…
Neural injury triggers a range of processes affecting primary afferent receptors, their axons and cell bodies, as well as unleashing a complex immune response in central neurons and glial cells….
The locus ceruleus and the A5 and A7 noradrenergic cell groups of the posterolateral pons are the main source of noradrenergic input to the dorsal horn. These regions send bilateral…
The current model of descending pain modulation involves both inhibitory and facilitatory influences on spinal nociceptive transmission. The balance between inhibition and facilitation is dependent on different behavioral, emotional, and…
The thalamus is the main relay structure for sensory information destined for the cortex; it is involved in reception, integration, and transfer of nociceptive potentials. WDR neurons project to the…
Autonomic disorders may be classified as peripheral or central and acute or chronic disorders. ACUTE PERIPHERAL AUTONOMIC DISORDERS Acute/subacute autonomic neuropathies are usually due to toxic, metabolic, autoimmune, or paraneoplastic…
C-type fibers (unmyelinated) slowly propagate dull, burning (secondary) pain sensation information. Some C fibers are modality-specific and respond only to thermal, mechanical, or chemical noxious stimuli. However, the majority of…
Although initially the affected pupil is larger than the contralateral pupil, with time it can become smaller. The pupil is very sensitive to acetylcholine (probably due to denervation supersensitivity), with…
SWEAT TESTING The thermoregulatory sweat test consists of the visual detection of skin humidity in response to warm external temperature. A dye that changes color when moist is painted or…
