Pathophysiologic and anesthetic considerations for patients with myotonia congenita or periodic paralyses

Abstract

Myotonia congenita and periodic paralyses are hereditary skeletal muscle channelopathies. In these disorders, various channel defects in the sarcolemma lead to a severely disturbed membrane excitability of the affected skeletal muscles. The clinical picture can range from severe myotonic reactions (e.g., masseter spasm, opisthotonus) to attacks of weakness and paralysis. Provided here is a short overview of the pathomechanisms behind such wide-ranging phenotypic presentations in these patients, followed by recommendations concerning the management of anesthesia in such populations.

Fatigue effects on the electromechanical delay components during the relaxation phase after isometric contraction

“…This alteration would lead, in turn, to a delay in muscle inactivation that could be quantified by both R‐EMD components. Moreover, fatigue might elongated R‐EMD components to a greater extent given the higher muscle fatigability typical of some channelopathies, such as myotonia congenita (Bandschapp & Iaizzo ). This approach may represent a valid means also to detect possible physiological adaptations induced by physical exercise and to follow the effects of therapeutic and/or rehabilitative treatments focused on restoring normal muscle relaxation.…”

“…The functional insights into these processes can provide useful information both in clinical and exercise fields. Several neuromuscular disorders, such as those presenting the myotonic phenomenon, affect not only muscle contraction but also the relaxation phase (Lewis & Haller , Bandschapp & Iaizzo ). Moreover, the ability to quickly contract and relax the muscle, especially during cyclic movements, is a pivotal characteristic in some working and sport activities (McDaniel et al .…”

A Case of Thomsen Disease in Pregnancy: Case Report

“…The highest risk is with general anaesthesia in case of emergency caesarean section. Depolarizing muscle relaxant such as succinylcholine are contraindicated, as they carry a risk of triggering a hyperthermic reaction similar to what is seen in malignant hyperthermia [9]. Moreover, a case report published in 2003, described a serious respiratory complication following administration of suxamethonium to a patient with undiagnosed mytonia congenital [8].…”

“…Moreover, a case report published in 2003, described a serious respiratory complication following administration of suxamethonium to a patient with undiagnosed mytonia congenital [8]. In addition, Propofol was described to cause myotonic crisis [9] [10] and therefore, it should be avoided. Thus, regional anaesthesia is preferred in case of caesarean delivery.…”

Effects of Fatigue on Voluntary Electromechanical and Relaxation Electromechanical Delay

“…For example, it has been suggested [23,28] that individuals with EMD values greater than 300-ms are at an elevated risk for ACL injuries compared to those with shorter EMD values. Similar to EMD, R-EMD measures have been used in clinical settings to evaluate myotonia disorders [3,21], periodic paralysis [3,21], muscle atrophy [21], and denervation [21]. Bandschapp and Iaizzo [3] and Lewis and Haller [21] reported that myotonia disorders and periodic paralysis have impaired relaxation of the muscle due to an intrinsic dysfunction of the sarcolemma and sarcoplasmic reticulum, which may affect excitation-contraction coupling.…”