Hi, my wife who works in this area says of the old Glenfrith hospital that it was next to the current Glenfield Hospital, which is a 'normal' hospital she also tells me that the building is now called the Mansion House and is now the administrative building for learning disabilities for the whole of Leicestershire, it was an institution but has been closed for 50 odd years.
Wouldn't have a clue about the records im afraid.
Kev.