A method for maintaining a therapeutically effective concentration of 4-aminopyridine in order to improve walking in a human with multiple sclerosis in need thereof, said method comprising: orally administering to the human a sustained release composition of 10 milligrams of 4-aminopyridine twice daily for a day; and thereafter, maintaining administration of 4-aminopyridine by orally administering to said human a sustained release composition of 10 milligrams of 4-aminopyridine twice daily for a time period of at least two weeks, whereby an in vivo 4-aminopyridine C_maxSS:C_minSS ratio of 1.0 to 3.5 and a C_avSS of 15 ng/ml to 35 ng/ml are obtained in the human. view more

The method of claim 6, whereby an increase in walking speed is obtained in said human.

The method of claim 37 wherein the sustained release composition elicits a C<sub>maxSS</sub>:C<sub>minSS </sub>ratio of 1.0 to 3.5 when administered b.i.d. or administered at 12-hour intervals to a human.

The method of claim 37 wherein said time period is twelve weeks.

A method according to claim 1 or 2, wherein the neurological disease is multiple sclerosis.

A method according to claim 1, wherein the active agent is 4-aminopyridine.

A method of increasing walking speed in a human multiple sclerosis patient in need thereof comprising orally administering to said patient a sustained release composition of 10 milligrams of 4-aminopyridine twice daily for a time period of at least two weeks, wherein said 10 milligrams of 4-aminopyridine twice daily are the only doses of 4-aminopyridine administered to said patient during said time period. view more

A method of improving walking in a human multiple sclerosis patient in need thereof comprising orally administering to said patient a sustained release composition of 10 milligrams of 4-aminopyridine twice daily for a time period of at least two weeks, wherein said 10 milligrams of 4-aminopyridine twice daily are the only doses of 4-aminopyridine administered to said patient during said time period. view more

The method of claim 1 wherein said time period comprises twelve weeks.

The method of claim 18 wherein said tablet exhibits a release profile to obtain a C<sub>avSS </sub>of about 15 ng/ml to about 35 ng/ml.

A method of increasing walking speed in a human multiple sclerosis patient in need thereof comprising orally administering to said patient a sustained release tablet of 10 milligrams of 4-aminopyridine at about every 12 hours for a time period of at least two weeks, wherein said 10 milligrams of 4-aminopyridine at about every 12 hours are the only doses of 4-aminopyridine administered to said patient during said time period. view more

The method of claim 32 wherein said time period comprises twelve weeks.

The method of claim 33 wherein said time period comprises twelve weeks.

The method of claim 2, wherein the lower extremity function is walking, and wherein said sustained release composition provides a release profile to obtain a C<sub>avSS </sub>of about 15 ng/ml to about 35 ng/ml.

The method of claim 2, wherein the lower extremity function is walking, and wherein said sustained release composition provides a mean T<sub>max </sub>in a range of about 2 to about 6 hours after administration of the sustained release composition to . view more

The method of claim 2, wherein the lower extremity function is walking, and wherein said time period is more than two weeks.

The method of claim 2 wherein the sustained release composition is capable of providing, upon administration to the patient, a release profile of the 4-aminopyridine extending over at least 6 hours.

The method of claim 1 wherein the sustained release composition provides an average plasma concentration at steady state in humans in the range of about 15 ng/ml to about 35 ng/ml.