Complex sentence: Both retrograde amnesia and anterograde amnesia can occur together in the same patient, and commonly result from damage to the brain regions most closely associated with episodic/declarative memory: the medial temporal lobes and especially the hippocampus.
Split into simpler sentences: Both retrograde amnesia and anterograde amnesia can occur together in the same patient. Retrograde amnesia commonly results from damage to the brain regions most closely associated with episodic/declarative memory: the medial temporal lobes and especially the hippocampus.