BENIGN MONOMELIC AMYOTROPHY OF LOWER-LIMB - A RARE ENTITY WITH A CHARACTERISTIC MUSCULAR CT

Six patients presented with amyotrophy confined to a single lower limb and characterized by insidious onset, slow progression and later stab ilization. Wasting was out of proportion with disability and there wer e no sensory, pyramidal tract or bulbar signs. All cases were sporadic , and there was no history of poliomyelitis. CK, anti-ganglioside anti bodies, motor and sensory conductions were normal. Quantitative EMG an d muscle biopsy revealed neurogenic features also in clinically unaffe cted limbs. Muscular CT showed selective or predominant, asymmetrical involvement of posterior leg muscles and caput longus of biceps femori s. Monomelic amyotrophy of lower limb is a clinically localized varian t of spinal muscular atrophy with a particularly benign course. Althou gh in the early stage there are no clinical or laboratory findings whi ch allow differential diagnosis with other motor neuron diseases, the history of an amyotrophy clinically localized for more than 3 years to a lower single limb and the characteristic muscular CT pattern sugges t the diagnosis since the first observation and indicate a favorable p rognosis.