More helpful resources with many various solutions you may see on following topics
http://www.sqlservercentral.com/Forums/Topic1618894-2893-1.aspx
http://www.sqlteam.com/forums/topic.asp?TOPIC_ID=196415
But if you can't handle the issue, then your mysql database has hard corruption and you may refer to more powerful solution
https://www.repairtoolbox.com/mysqlrepair.html Repair Toolbox for MySQL
To fix this do the following please:
1. Open a command line by clicking start, type "cmd", hit return/enter.
2. Stop the TV Service: Type (or Copy/Paste)
net stop TVService
3. Type (or Copy/Paste)
cd C:\Program Files\MySQL\MySQL Server 5.1\bin (this should be the path to the bin subdirectory within your MySQL install folder) and hit return/enter.
4. Type (or Copy/Paste)
mysqlcheck mptvdb --auto-repair -e -u root -p ,and hit return/enter.
5. A password prompt should appear. The default password is
MediaPortal (case sensitive).
6. Start the TV Service: Type (or Copy/Paste)
net start TVService
Note: mysqlcheck must be used when the
mysqld server is running.
Caution: It is the best practice to make a backup of database before performing repair operation; under some circumstances the operation might cause data loss.
Note: When you have a different version of MySQL installed (for example when you updated to the 5.6 install), you'll have to adjust the Program Files path (step 3). For 5.6 that would become cd C:\Program Files\MySQL\MySQL Server 5.6\bin