WordNet

a unit of geological time during which a system of rocks formed; "ganoid fishes swarmed during the earlier geological periods" (同)geological period
(ice hockey) one of three divisions into which play is divided in hockey games
the end or completion of something; "death put a period to his endeavors"; "a change soon put a period to my tranquility"
the interval taken to complete one cycle of a regularly repeating phenomenon
a punctuation mark (.) placed at the end of a declarative sentence to indicate a full stop or after abbreviations; "in England they call a period a stop" (同)point, full_stop, stop, full point
happening or recurring at regular intervals; "the periodic appearance of the seventeen-year locust" (同)periodical
recurring or reappearing from time to time; "periodic feelings of anxiety" (同)occasional
relating to or having the characteristics of a family; "children of the same familial background"; "familial aggregation"
occurring among members of a family usually by heredity; "an inherited disease"; "familial traits"; "genetically transmitted features" (同)genetic, hereditary, inherited, transmitted, transmissible
loss of the ability to move a body part (同)palsy

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(あることが続く)『期間』 / (歴史的な)『時代』 / (試合の)『一区切り』,ピリオド / 授業時間,時限: / (循環して起こる現象などの)周期 / (回転運動などの)周期 / 紀(地質時代の区分の一つ;era(代)の下,epoch(世)の上) / 《おもに米》『ピリオド』,終止符(《英》full stop;Mr.,U.S.など略語の符号(.)も含む) / 《複数形で》《文》掉尾(とうび)文(多くの節から成り,論理的に緊密な構成をもっている文) / 《名詞の前にのみ用いて》ある時代[特有]の,時代物の / (文の終わりに感嘆詞的に)以上,終わり・月経（期間）
定期的な,周期的な / ときぎき起こる: / 掉尾(とうび)的の:
家族の,家族特有の / 違伝的な,血統にあらわれる
(体の)麻痺(まひ),中風 / (…の)停滞《+『of』+『名』》

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2016/03/15 13:54:09」(JST)

wiki en

Periodic paralysis (also known as Myoplegia paroxysmalis familiaris) is a group of rare genetic diseases that lead to weakness or paralysis (rarely death) from common triggers such as cold, heat, high carbohydrate meals, not eating, stress or excitement and physical activity of any kind. The underlying mechanism of these diseases are malfunctions in the ion channels in skeletal muscle cell membranes that allow electrically charged ions to leak in or out of the muscle cell, causing the cell to depolarize and become unable to move (a channelopathy).

The symptoms of periodic paralysis can also be caused by hyperthyroidism, and are then labeled thyrotoxic periodic paralysis; however, if this is the underlying condition there are likely to be other characteristic manifestations, enabling a correct diagnosis.

Types

Periodic paralysis is an autosomal dominant myopathy with considerable variation in penetrance, leading to a spectrum of familial phenotypes (only one parent needs to carry the gene mutation to affect the children, but not all family members who share the gene are affected to the same degree). Specific diseases include:

Hypokalemic periodic paralysis (Online 'Mendelian Inheritance in Man' (OMIM) 170400), where potassium leaks into the muscle cells from the bloodstream.

Hyperkalemic periodic paralysis (Online 'Mendelian Inheritance in Man' (OMIM) 170500), where potassium leaks out of the cells into the bloodstream.

Paramyotonia congenita (Online 'Mendelian Inheritance in Man' (OMIM) 168300), a form which often accompanies hyperkalemic periodic paralysis, but may present alone. The primary symptom of paramyotonia congenita is muscle contracture which develops during exercise or activity. Paramyotonia congenita attacks may also be triggered by a low level of potassium in the bloodstream. This means people with both hyperkalemic periodic paralysis and paramyotonia congenita can have attacks with fluctuations of potassium up or down.

Andersen-Tawil syndrome (Online 'Mendelian Inheritance in Man' (OMIM) 170390), a form of periodic paralysis that includes significant heart rhythm problems, fainting and risk of sudden death. Potassium levels may be low, high, or normal during attacks of ATS. Patients with ATS may also have skeletal abnormalities like scoliosis (curvature of the spine), webbing between the second and third toes or fingers (syndactyly), crooked fingers (clinodactyly), a small jaw (micrognathia) and low-set ears. Patients need to have another form of periodic paralysis to have the Andersen-Tawil. If a patient has hypo or hyper periodic paralysis they have a 50% chance of getting Andersen-Tawil. They just have to have the gene that causes it. This is a rare occurrence of having this. Only around 100 people in the world are recorded to have it.

Diagnosis

This disease is unusually difficult to diagnose. Patients often report years of wrong diagnosis and treatments that made them worse instead of better. Part of this may be that migraines are present in up to 50% of patients and can cause a confusing array of symptoms including headaches, speech difficulties and visual, auditory or sensory auras. DNA testing is available for only a half dozen common gene mutations, while dozens of known mutations are possible but are not routinely tested. Electromyography (EMG) findings are not specific. The old glucose/insulin provocative testing can cause life-threatening symptoms and should not be used.

Also of note is that potassium levels do not have to range outside of normal limits to cause serious, even life-threatening paralysis. These diseases are not the same as having a very low level of potassium (hypokalemia) or high potassium (hyperkalemia) and must not be treated as such. The total body store of potassium is usually normal; it is just in the wrong place.

Treatment

Treatment of the periodic paralyses may include carbonic anhydrase inhibitors (such as acetazolamide, methazolamide or dichlorphenamide), taking supplemental oral potassium chloride and a potassium-sparing diuretic (for hypos) or avoiding potassium (for hypers), thiazide diuretics to increase the amount of potassium excreted by the kidneys (for hypers), and significant lifestyle changes including tightly controlled levels of exercise or activity. However, treatment should be tailored to the particular type of periodic paralysis. ^[1]^[2]^[3]

Treatment of periodic paralysis in Andersen-Tawil syndrome is similar to that for other types. However, Pacemaker insertion or an implantable cardioverter-defibrillator may be required to control cardiac symptoms.^[4]

Prognosis

While the disability can range from minor, occasional weakness to permanent muscle damage, inability to hold a normal job and use of a powerchair, most people function fairly well with drugs and lifestyle changes.

References

^ Kim, SJ; Lee, YJ; Kim, JB (Jan 2010). "Reduced expression and abnormal localization of the KATP channel subunit SUR2A in patients with familial hypokalemic periodic paralysis". Biochemical and Biophysical Research Communications 391: 974–8. doi:10.1016/j.bbrc.2009.11.177. PMID 19962959.
^ Kim, JB; Kim, MH (Dec 2007). "The Genotype and Clinical Phenotype of Korean Patients with Familial Hypokalemic Periodic Paralysis". J Korean Med Sci 22: 946–51. doi:10.3346/jkms.2007.22.6.946.
^ Lee, GM; Kim JB (June 2011). "Hyperkalemic periodic paralysis and paramyotonia congenita caused by a de novo mutation in the SCN4A gene". Neurology Asia 16 (2): 163–6.
^ Kim, JB; Chung, KW (Dec 2009). "Novel de novo Mutation in the KCNJ2 gene in a Patient with Andersen-Tawil Syndrome". Pediatric Neurology 41 (6): 464–466. doi:10.1016/j.pediatrneurol.2009.07.010. PMID 19931173.

Song, YW; Kim, SJ; Heo, TH; Kim, MH; Kim, JB (Dec 2012). "Normokalemic periodic paralysis is not a distinct disease". Muscle & Nerve 46 (6): 908–913. doi:10.1002/mus.23441. PMID 22926674.

External Links

http://www.periodicparalysisnetwork.com/
Periodic Paralysis Association
Periodic Paralysis News Desk
NIH information page on periodic paralysis
Cleveland Clinic
eMedicine

UpToDate Contents

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1. 低カリウム性周期性四肢麻痺 hypokalemic periodic paralysis
2. 甲状腺中毒性周期性四肢麻痺 thyrotoxic periodic paralysis
3. 高カリウム性周期性四肢麻痺 hyperkalemic periodic paralysis
4. 甲状腺機能亢進症およびバセドウ病の神経学的症状 neurologic manifestations of hyperthyroidism and graves disease
5. Etiology and evaluation of the child with weakness

English Journal

[Familial hypokalemic periodic paralysis associated with autoimmune thyroiditis].

Cano Megías M1, Fernández Rodríguez L2, Mancha Ramos J2, Espinosa Figueroa JL2.
Medicina clínica.Med Clin (Barc).2016 Apr 15;146(8):375-6. doi: 10.1016/j.medcli.2015.10.022. Epub 2015 Dec 23.
PMID 26723938

Dichlorphenamide (Keveyis) for periodic paralysis.

[No authors listed]
The Medical letter on drugs and therapeutics.Med Lett Drugs Ther.2016 Apr 11;58(1492):50.
PMID 27049510

Novel susceptibility gene for nonfamilial hypokalemic periodic paralysis.

Song IW1, Sung CC1, Chen CH1, Cheng CJ1, Yang SS1, Chou YC1, Yang JH1, Chen YT1, Wu JY2, Lin SH2.
Neurology.Neurology.2016 Mar 29;86(13):1190-8. doi: 10.1212/WNL.0000000000002524. Epub 2016 Mar 2.
OBJECTIVE: To identify susceptibility genes to nonfamilial hypokalemic periodic paralysis (hypoKPP) consisting of thyrotoxic periodic paralysis (TPP) and sporadic periodic paralysis (SPP) and explore the potential pathogenic mechanisms.METHODS: We enrolled patients with nonfamilial hypoKPP not carry
PMID 26935888

Japanese Journal

A Family of Hypokalemic Periodic Paralysis with CACNA1S Gene Mutation Showing Incomplete Penetrance in Women

KAWAMURA Shuji,IKEDA Yoshio,TOMITA Koji,WATANABE Nobuaki,SEKI Kouichi
Internal medicine 43(3), 218-222, 2004-03-01
… Familial hypokalemic periodic paralysis is an autosomal dominant genetic muscle disease characterized by periodic attacks of muscle weakness associated with a decrease in serum potassium. …
NAID 130000084521