Elevated levels of amino acids in the CSF of motor neuron disease patients.

Amino acid levels in the cerebrospinal fluid of patients with motor neuron disease were compared with an age-matched control group receiving diagnostic myelography. Five amino acids were significantly elevated in the cerebrospinal fluid of the motor neuron disease patients compared to the controls. These were isoleucine, glycine, alanine, phenylalanine, and threonine, which were increased by 60, 58, 38, 26, and 25% respectively. A significant increase was also obtained when the amino acids with nonpolar R groups were grouped together (34%). The significance of these findings is discussed in terms of amino acid changes that occur in both normal aging and other neurological conditions.