[MIM 168 300, 603 967]

(Eulenburg disease)

Rare. Autosomal dominant transmission of the SCN4A (17q23-25) causing a channelopathy with gain of function of the subunit α of  the Nav1.4 channel of the muscle fibre. Onset in the first decade of life. Episodes of myotonia, primarily affecting the face, neck and upper limb muscles. The episodes of muscle stiffness are often followed by a phase of muscular weakness. Symptoms are sometimes induced, or worsened by exposure to cold or prolonged exercise: this last characteristic is very specific and differentiates papmyotonia from the other myotonic syndromes. Episodes of myotonia are more frequent during pregnancy and menstruations.

Quite similar to the hyperkalemic familial periodic paralysis with myotonia because it is triggered by cold and induces hyperkalemia (5 to 7 mmol/L).

Treatment: mexiletine, sometimes acetazolamide. Good results with lamotrigine in adults.

Anesthetic implications:

avoid hypothermia and contact with cold objects; avoid stress; strict monitoring of the ECG for signs of hyperkalemia. Avoid succinylcholine, anticholinesterasic agents and hypokalemia. No risk of MH. Many reports of successful regional anesthesia have been reported.

References : 

-        Ay B, Gerçek A, Dogan VI, Gögus YF. 
Pyloromyotomy in a patient with paramyotonia congenita. 
Anesth Analg 2004; 98: 68-9.

-         Grace RF, Roach VJ. 
Caesarian section in a patient with paramyotonia congenita. 
Anaesth Intensive Care 1999; 27: 534_7

-         Parness J, Bandschapp O, Girard T. 
The myotonias and susceptibility to malignant hyperthermia. 
Anesth Analg 2009, 109: 1054-64.

-         Frossard B, Combret C, Benhamou D. 
Prise en charge anesthésique d’un accouchement chez une patiente atteinte d’une paramyotonie congénitale d’Eulenburg. 
Ann Fr Anesth Réanim 2013 ; 32 : 372-4. 

-        Bandschapp O, Iaizzo PA. 
Pathophysiologic and anesthetic considerations for patients with myotonia congenital or periodic paralyses. 
Pediatr Anesth 2013; 23: 824-33 

-        Stunnenberg BC, LoRusso S, Arnold WD, Barohn RJ, Cannon SC et al.
Guidelines on clinical presentation and management of nondystrophic myotonias.
Muscle Nerve 2020; 62:430-44.

-        Sender D, Doyal A.
Hyperkalemic periodic paralysis with paramyotonia and the anaesthetic implications.
BMJ Case Rep 2023;16:e251699. doi:10.1136/bcr-2022-251699

-        Henzi BC, Klein A.
Important considerations for children with non-dystrophic myotonia.
The Lancet Neurology 2024 ; 23 : 953-5

Updated: November 2024