[MIM 253 400]

(Spinal muscular atrophy type III, Wohlfart-Kugelberg-Welander disease)

Very Rare. Autosomal recessive transmission of mutations or deletions in the SMN1 gene (5q11.2-q13.3) responsible for the synthesis of a protein essential to the survival of motor neurons. Involvement of the neurons of the anterior horns of the spinal cord.

his form is called "pseudomyopathic" because it looks like a limb girdle myopathy.  Clinical onset between 2 years and 17 years of age; acquisition of walking; muscle atrophy and weakness begin in the lower limbs and predominate in the limb girdles; loss of osteotendinous reflexes, tremulations of the hands and sudden movements of the fingers; slow evolution; frequent scoliosis at the onset of axial hypotonia; loss of ambulation usually around puberty; survival until adulthood; a few cases of cardiomyopathy have been described.

A distinction between 2 forms has been made:

-        form IIIa: onset before 3 years of age and loss of ambulation before 20 years of age

-        form IIIb: onset after 3 years of age and ambulation often maintained until around 40 years of age

Anesthetic implications: 

restrictive syndrome. Scoliosis. Monitoring of curarization. Respiratory physiotherapy during the pre- and postoperative periods. Chronic muscle denervation causes a change in the composition of the muscle fibres i.e. a decrease in glycogen, an alteration of the ß-oxidation of fatty acids and a secondary carnitine deficiency. The more severe the phenotype, the more important these changes are. These patients are therefore similar to those who suffer from a congenital pathology of the ß-oxidation of fatty acids with a risk of acute hepatic failure (Reye-like syndrome) in a situation of catabolism. It is therefore important to ensure an adequate supply of glucose to prevent lipid catabolism, provide carnitine supplements and avoid using a continuous infusion of propofol. Risk of difficult intubation: progressive ankylosis of the temporomandibular joint and decrease in cervical mobility ( muscular contracture or secondary to the correction of the scoliosis)

References: 

 -        Veen A, Molenbuur B, Richardson FJ. 
Epidural anaesthesia in a child with possible spinal muscular atrophy. 
Paediatr Anaesth 2002; 12: 556-8.

-        Wilton NCT. Spinal muscular atrophy : the challenges of "doing the right thing". 
Pediatr Anesth 2009; 19: 1041-7.

-         Vilela H, Santos J, Colaço J, Oliveira E, Canas-da-Silva P. 
Reversal of neuromuscular blockade with sugammadex in a patient with spinal muscular atrophy type III (Kugelberg-Welander syndrome). 
J Anesth 2012 ; 26 : 306-7.

-         Zolkipli Z, Sherlock M, Biggar WD, Taylor G et al. 
Abnormal fatty acid metabolism in spinal muscular atrophy may predispose to perioperative risks. 
Eur J Pediatr Neurol 2012; 16: 549-53.

-         El Harchaoui AK, Dwars BJ, Soesan M, Pijl AJ. 
Anaesthesia and orphan disease: a patient with spinal muscular atrophy type III (Wohlfart-Kugelberg-Welander syndrome) undergoing laparoscopic cholecystectomy. 
Eur J Anaesthesiol 2015 ; 32 : 211-3. 

-        Salort-Campana E,
Quijano-Roy S. Clinical features of spinal muscular atrophy (SMA) type 3 (Kugelberg-Welander disease).
Arch Pédiatr 2020 ; 27 :S23-8

Updated: June 2022