* Paolo Bortoluzzi, 55, an Italian dancer and choreographer, died of a stroke following viral pneumonia Oct. 16 in a hospital in Brussels.
* John Ashworth, 83, an author of short stories, died of complications from cancer Oct. 15 at Northern Westchester Hospital Center in Mount Kisco, N.Y.
* Dror Sadeh, 60, a renowned astrophysicist who helped prove Albert Einstein's relativity theory, died Oct. 15 of cancer in Jerusalem.
* Eda Helen Brooks, 94, an actress and voice teacher, died Oct. 15 at her home in Manhattan.
* Alexis George Pincus, 82, a retired ceramics engineer who had written 18 books on glass manufacturing, died suddenly Oct. 15 while visiting his son in Princeton, N.J.
* John J. Reynolds, 70, developer of the MasterCard charge card, died Oct. 14 in New York.
* Joan Sibley, 52, a fashion designer whose work is included in the Costume Institute of the Metropolitan Museum of Art, died of Burkitt's lymphoma Oct. 12 in Manhasset, N.Y.
* Dr. W. Wallace Lozier, 87, a physicist who helped United Carbide Corp. win an Oscar in the 1950s with his work on lighting techniques, died Oct. 9 after a series of strokes in Bay Village, Ohio.