An electron microscopic study.
Levitt JO. Pirone A, Schredelseker J, Tuluc P, Gravino E, Fortunato G, Flucher BE, Carsana A, Salvatore F, Grabner M. Identification and functional characterization of malignant hyperthermia mutation T1354S in the outer pore of the Cavalpha1S-subunit. Groome JR, Lehmann-Horn F, Fan C, Wolf M, Winston V, Merlini L, Jurkat-Rott K. NaV1.4 mutations cause hypokalaemic periodic paralysis by disrupting IIIS4 movement during recovery. (2) TPP is distinct from hypokalemic periodic paralysis (hypoPP); however, at least two instances of genetically diagnosed familial hypoPP for which hyperthyroidism was an additional trigger for hypokalemic paralytic episodes have been reported [To establish the extent of disease and needs in an individual diagnosed with hypokalemic periodic paralysis (hypoPP), the evaluations summarized in this section (if not performed as part of the evaluation that led to the diagnosis) are recommended:Between attacks or in a currently asymptomatic individual:Note: (1) Hyperthyroidism may be a trigger for a hypokalemic episode in individuals with hypoPP; (2) thyroid function tests may help to distinguish between hypoPP and TPP in those who have a pathogenic variant in For a comprehensive summary of the management of hypokalemic periodic paralysis, see Principles of Treatment for Individuals with HypoPP During a paralytic attack, there is usually no true potassium depletion in the body (unless there are associated digestive or renal losses from another cause), but there is a reversible transfer of potassium from the extracellular to the intracellular space. If performed for differential diagnosis, it may show tubular aggregates and/or vacuoles that originate from T-tubules and the endoplasmic reticulum (All types of periodic paralysis benefit from the avoidance of triggering factors and from acetazolamide, which prevents attacks. Hypokalemic and normokalemic are two kinds of this genetic problem. Randomized, placebo-controlled trials of dichlorphenamide in periodic paralysis. Sokolov S, Scheuer T, Catterall WA. Winczewska-Wiktor A, Steinborn B, Lehman-Horn F, Biczysko W, Wiktor M, Gurda B, Jurkat-Rott K. Myopathy as the first symptom of hypokalemic periodic paralysis – case report of a girl from a Polish family with CACNA1S (R1239G) mutation. Struyk AF, Markin VS, Francis D, Cannon SC. 28 April 2009 (me) Comprehensive updated posted live4 August 2006 (me) Comprehensive update posted livePrimary or secondary inappropriate (pseudo) hyperaldosteronismSecondary hyperaldosteronism (increased renin blood concentration): renin secreting tumor, renal artery stenosis, malignant hypertensionHyperglucocorticism (normal renin blood concentration)Bartter syndrome (tubulopathy w/normo- or hypercalcuria, normomagnesemia)Gitelman syndrome (tubulopathy w/hypocalciuria, hypomagnesemia)Distal tubular acidosis type 1, 2 (but not 4, in which there is hyperkalemia)Monitor episodes of weakness noting time of day & specific triggersShorten/prevent aggravation of the weakness episodeProvide potassium supplementation (oral, or IV if oral impossible or if potassium very low)Oral potassium: initially, 1 mEq/kg; add 0.3 mEq/kg after 30 minutes if no improvementUse alpha- or beta adrenergic drugs w/caution, even in local anesthesia or ophthalmologyKinesiotherapy in case of long-lasting pelvic deficitAdaptive measures: (1) at school & especially for sports; (2) in the work setting Struyk AF, Cannon SC. Carbonic anhydrase inhibitors are specific openers of skeletal muscle BK channel of K1-deficient rats. including both hypokalemic and hyperkalemic periodic
Kuzmenkin A, Muncan V, Jurkat-Rott K, Hang C, Lerche H, Lehmann-Horn F, Mitrovic N. Enhanced inactivation and pH sensitivity of Na(+) channel mutations causing hypokalaemic periodic paralysis type II.
Practical aspects in the management of hypokalemic periodic paralysis.
However, sibs of a proband with clinically unaffected parents are still presumed to be at increased risk for hypoPP because of the possibility of reduced penetrance in a parent or the theoretic possibility of parental germline mosaicism.The optimal time for determination of genetic risk and discussion of the availability of prenatal testing is before pregnancy.It is appropriate to offer genetic counseling (including discussion of potential risks to offspring and reproductive options) to young adults who are affected or at risk.Cav1.1: outermost gating charges R1 or R2 of domains II, III, and IVNav1.4: outer arginine residues of S4 (R1 or R2) in domains I, II, or IIICav1.1: one missense corresponds to a Nav1.4 missense deeper in S4 compared to hypoPP variantsBendahhou S, Cummins TR, Hahn AF, Langlois S, Waxman SG, Ptácek LJ. A double mutation in families with periodic paralysis defines new aspects of sodium channel slow inactivation. Neurologic examination with attention to muscle strength in the legs should be performed, in order to detect long-lasting interictal weakness associated with myopathy.For those individuals who take acetazolamide the following parameters should be evaluated every three months: complete blood count, electrolytes, glucose, uric acid, and liver enzyme levels. The rarest of the dyskalemic periodic paralyses, the incidence of the hyperkalemic variety has been estimated at 1:500,000.