A very rare syndrome combining mental retardation and early spastic diplegia. Same term also used for permanent damage to upper motor neuron secondary to cerebral anoxia and periventricular leukomalacia (prematurity).
The incidence and prevalence remain unknown.
Autosomal recessive inheritance.
Affected patient presents with spastic diplegia in early infancy. Motor development is slow and there is generalized muscular hypotonia and hyperreflexia. Ataxia is usually absent but gait is often waddling with inward-turning feet. There is mild to moderate mental retardation with slow speech development. Longterm follow-up has not been reported.
Assess gait and motor function. Obtain history of previous anesthetics and muscle biopsy result if available. Biochemistry including potassium and creatine phosphokinase level. Careful intraoperative positioning is needed. Prophylactic treatment of muscle spasms. Bispectral index (BIS) values may be low before induction of anesthesia.
Relative resistance to nondepolarizing muscle relaxants. Succinylcholine safe to use despite increase of extra junctional muscarinic receptors.
A: Hereditary spastic diplegia with mental retardation in two young siblings. Clin Genet
AJ, de Leeuw
et al: Lower bispectral index values in children who are intellectually disabled. Anesth Analg