Hi,
Have you tried connecting an external USB mouse and did it work? Also have you tried disabling/enabling the mouse using the function keys? If these doesn't work start by doing a hard reset, remove the battery and AC adapter then press and hold the power button for 20 seconds then test it after the reboot. Next to try is to uninstall/reinstall the touchpad driver but you'll need to do it using an external mouse. Lastly a complete factory reset would be necessary if all the troubleshooting steps will not work and if again it will not work then it's a hardware problem a replacing it would be the solution.