Hypokalemic sensory overstimulation
Encyclopedia
Hypokalemic sensory overstimulation is a form of attention deficit hyperactivity disorder that has several similarities to disorders of ion channels, in particular to the muscle disorder hypokalemic periodic paralysis
.
The sensory overstimulation is triggered by large carbohydrate meals, sodium chloride
intake, and the period following exercise, the same factors known to trigger hypokalemic periodic paralysis. People with hypokalemic sensory overstimulation also have a reduced effectiveness of the local anesthetic lidocaine
. This was first noted during minor surgery, in which one person was given lidocaine "in repeated injections totaling 15 mL because the patient reported continued sensation" but nevertheless he "could document the inadequacy of anesthesia by reporting accurately the location of forceps touches to the toe under conditions in which he could not see his toe". Similar reduced effectiveness of lidocaine in dental work was noted in his mother and in another family.
results from mutations in subunits of sodium or calcium channels. Since hypokalemic sensory overstimulation and hypokalemic periodic paralysis have similar triggers and treatments, and since there is a relative ineffectiveness of the sodium-channel blocker lidocaine
in hypokalemic sensory overstimulation, hypokalemic sensory overstimulation may be another disorder in the "channelopathy
" group. Since the lidocaine effect occurs outside the brain, this suggests that in some patients with attention deficit disorder the underlying abnormality may be overstimulation from sensory pathways rather than a defect in the brain itself.
The triggering effect of carbohydrates is believed to be due to digested carbohydrates causing release of insulin
, which results in uptake of potassium into cells and the resulting hypokalemia
.
potassium supplements have been used to treat hypokalemic sensory overstimulation, however potassium supplements can cause hyperkalemia
if used in high doses or in very susceptible people without physician supervision. These issues and other treatment approaches are discussed in a detailed review of treatment of hypokalemic periodic paralysis by Dr. Jacob O Levitt, a dermatologist who has hypokalemic periodic paralysis.
Prevention by avoiding high carbohydrate meals and excessive sodium chloride
carries no risks, and there is other evidence for a subset of people with attention deficit disorder who benefit from reduction of sugar intake.
To deal with the relative ineffectiveness of local anesthetics used in dental care, the more diffusible local anesthetic articaine has been used instead of lidocaine, together with potassium supplementation.
Occupational therapists describe a "sensory integration disorder" with findings overlapping with those of attention deficit disorder. People with hypokalemic sensory overstimulation fit criteria for both disorders, and since the genetic basis for these disorders has not been discovered, the precise relationships among these descriptions is not yet clear.
Hypokalemic periodic paralysis
Hypokalemic periodic paralysis is a rare channelopathy characterized by muscle weakness or paralysis with a matching fall in potassium levels in the blood...
.
Characterization of the disorder
The most prominent feature of hypokalemic sensory overstimulation is the feeling of sensory overstimulation that is characteristic of attention deficit disorder. In hypokalemic sensory overstimulation, the sensory overstimulation goes away abruptly after taking potassium supplements; one person described the disappearance of the sensory overstimulation as being “as if a shade had been pulled down” 20 minutes after she took a dose of oral potassium.The sensory overstimulation is triggered by large carbohydrate meals, sodium chloride
Sodium chloride
Sodium chloride, also known as salt, common salt, table salt or halite, is an inorganic compound with the formula NaCl. Sodium chloride is the salt most responsible for the salinity of the ocean and of the extracellular fluid of many multicellular organisms...
intake, and the period following exercise, the same factors known to trigger hypokalemic periodic paralysis. People with hypokalemic sensory overstimulation also have a reduced effectiveness of the local anesthetic lidocaine
Lidocaine
Lidocaine , Xylocaine, or lignocaine is a common local anesthetic and antiarrhythmic drug. Lidocaine is used topically to relieve itching, burning and pain from skin inflammations, injected as a dental anesthetic or as a local anesthetic for minor surgery.- History :Lidocaine, the first amino...
. This was first noted during minor surgery, in which one person was given lidocaine "in repeated injections totaling 15 mL because the patient reported continued sensation" but nevertheless he "could document the inadequacy of anesthesia by reporting accurately the location of forceps touches to the toe under conditions in which he could not see his toe". Similar reduced effectiveness of lidocaine in dental work was noted in his mother and in another family.
Molecular mechanism
Hypokalemic periodic paralysisHypokalemic periodic paralysis
Hypokalemic periodic paralysis is a rare channelopathy characterized by muscle weakness or paralysis with a matching fall in potassium levels in the blood...
results from mutations in subunits of sodium or calcium channels. Since hypokalemic sensory overstimulation and hypokalemic periodic paralysis have similar triggers and treatments, and since there is a relative ineffectiveness of the sodium-channel blocker lidocaine
Lidocaine
Lidocaine , Xylocaine, or lignocaine is a common local anesthetic and antiarrhythmic drug. Lidocaine is used topically to relieve itching, burning and pain from skin inflammations, injected as a dental anesthetic or as a local anesthetic for minor surgery.- History :Lidocaine, the first amino...
in hypokalemic sensory overstimulation, hypokalemic sensory overstimulation may be another disorder in the "channelopathy
Channelopathy
Channelopathies are diseases caused by disturbed function of ion channel subunits or the proteins that regulate them. These diseases may be either congenital or acquired .There are a large number of distinct dysfunctions known to be caused by ion channel...
" group. Since the lidocaine effect occurs outside the brain, this suggests that in some patients with attention deficit disorder the underlying abnormality may be overstimulation from sensory pathways rather than a defect in the brain itself.
The triggering effect of carbohydrates is believed to be due to digested carbohydrates causing release of insulin
Insulin
Insulin is a hormone central to regulating carbohydrate and fat metabolism in the body. Insulin causes cells in the liver, muscle, and fat tissue to take up glucose from the blood, storing it as glycogen in the liver and muscle....
, which results in uptake of potassium into cells and the resulting hypokalemia
Hypokalemia
Hypokalemia or hypokalaemia , also hypopotassemia or hypopotassaemia , refers to the condition in which the concentration of potassium in the blood is low...
.
Treatment
Over the counterOver-the-counter drug
Over-the-counter drugs are medicines that may be sold directly to a consumer without a prescription from a healthcare professional, as compared to prescription drugs, which may be sold only to consumers possessing a valid prescription...
potassium supplements have been used to treat hypokalemic sensory overstimulation, however potassium supplements can cause hyperkalemia
Hyperkalemia
Hyperkalemia refers to the condition in which the concentration of the electrolyte potassium in the blood is elevated...
if used in high doses or in very susceptible people without physician supervision. These issues and other treatment approaches are discussed in a detailed review of treatment of hypokalemic periodic paralysis by Dr. Jacob O Levitt, a dermatologist who has hypokalemic periodic paralysis.
Prevention by avoiding high carbohydrate meals and excessive sodium chloride
Sodium chloride
Sodium chloride, also known as salt, common salt, table salt or halite, is an inorganic compound with the formula NaCl. Sodium chloride is the salt most responsible for the salinity of the ocean and of the extracellular fluid of many multicellular organisms...
carries no risks, and there is other evidence for a subset of people with attention deficit disorder who benefit from reduction of sugar intake.
To deal with the relative ineffectiveness of local anesthetics used in dental care, the more diffusible local anesthetic articaine has been used instead of lidocaine, together with potassium supplementation.
Relation to other disorders
One of the original patients had symptoms of premenstrual syndrome and found that "oral potassium supplementation blunted the menstrual pain to a dramatic degree", suggesting that the sensory overstimulation may be expressed more widely than just as attention deficit disorder.Occupational therapists describe a "sensory integration disorder" with findings overlapping with those of attention deficit disorder. People with hypokalemic sensory overstimulation fit criteria for both disorders, and since the genetic basis for these disorders has not been discovered, the precise relationships among these descriptions is not yet clear.