[MIM 275 900]

(recessive autosomal spastic paraplegia type 20, SPG20 acronym for Spastic Paraplegia 20)

Very rare. Slowly progressive neurodegenerative disease originally described in the Holmes County (Ohio) in the Amish population. Autosomal recessive transmission of a mutation of the SPG20 gene that codes for spartin, a protein involved in the transport at the level of the endosomes. The symptoms of the disease seem to be due to axonal degeneration at the level of the distal corticospinal fibers, the fasciculus gracilis and the spinocerebellar fibers, which form the longest nerve fibers of the CNS.

Association of:

-        spastic paraparesis: delay in acquisition of walking

-        pseudobulbar palsy: early dysarthria, emotional lability, dysphagia, choreoathetosis

-        pyramidal signs that are more pronounced at the level of the lower limbs: sharp reflexes, Babinsky sign

-        a distal amyotrophy marked at the level of the hands and feet;

-        skeletal abnormalities: short stature, hollow feet; hypermobile joints at the level of hands and wrists; kyphoscoliosis

-        mild mental retardation

-        abnormalities in the white matter at MRI

Anesthetic implications:

avoid succinylcholine given the status of chronic denervation of muscles of the lower limbs; swallowing disorders

References : 

-        Proukakis C, Cross H, Patel H, Patton MA, Valentine A, Crosby AH. 
Troyer syndrome revisited : a clinical and radiological study of a complicated hereditary spastic paraplegia. 
J Neurol 2004; 251: 1105-10.

Updated: September 2018