When Beki Propst talks about the first 47 years of her life, it's as if she is describing the story of a stranger.
Her former status as an officer for the Colorado Association of Realtors. The printing company she owned. The hobbies she enjoyed. Her black belt in karate.
These are details of a life that her family and others have related to her. But Propst knows that photo albums and anecdotes can sketch only so much of the life she had before the fall of 1997 -- before a massive, grand mal seizure ripped away her connections with her past, stripping her memories bare.
"Now, I'm starting to kind of wonder what kind of person I was," said the 57-year-old from Sterling, Colo. "But it's not really relevant because I don't know that person."
"Everyone I knew before says my personality is the same. But I don't know if I'm the same person."
Details of the rare case continue to baffle doctors. What they do know is that a seizure -- what many neurological experts describe as a severe electrical storm within the brain -- caused Propst's declarative memory to be wiped clean. Facts, events, dates, acquaintances and even her identity were wiped away with it. As Propst describes it, "If I was a computer, it would be like my hard drive was erased."
What remained was her implicit memory -- qualities such as intelligence and work ethic -- as well as her vocabulary and her familiarity with a few dozen songs.
From this, she has rebuilt her life. Her persistence in rejoining the work force has led to stable employment as a custodian at a state facility. She enjoys strong relationships with her family. And she has written a book, titled "Absent Memories: Moving Forward When You Can't Look Back," which documents her experiences.
"Every single person I met said, 'You need to write a book about this,'" Propst said. "I thought, 'What the heck, what do I have to lose?'"
David Ewing of Centennial Neurology in Greeley, Colo., Propst's doctor, said that it is remarkable that Propst has adjusted so well to her new life, which, in a way, began slightly more than 10 years ago. The seizure, he says, effectively disconnected the area of her brain in which her memories were stored.
"The area is still there, still intact," he said. "But it was like someone threw a breaker switch. ... She had a single general event, after which she woke up and all of her memories were wiped out."
Even Propst said trying to appreciate the magnitude of losing one's memories is a mind-bending task. And having been through it, she said many people with whom she talks have little idea of the true impact of the event.
"Some people say to me, 'That must be really wonderful, it would be like being a kid again.' I think it would be wonderful if you could choose which memories to forget. But I don't remember my mother. I don't remember being part of a family. I don't remember being a kid."
Although cases like Propst's are rare, researchers have linked seizures with memory loss for some time.
"[Seizure-related] memory loss is a major concern for patients and has been well recognized since the mid-1850s," said Dr. Orrin Devinsky, director of the epilepsy program at New York University. "Recurrent seizures injure the brain, and the memory centers are particularly vulnerable."
Dr. James Grisolia, chair of neurology at Scripps Mercy Hospital in San Diego, said, "We don't know why, but the very parts of our brain that control memory ... are also the same parts that get the most stubborn, hard-to-control seizures, with huge implications for our memory."
In most cases, memory loss seems to be instigated by a series of smaller seizures over a long period of time. Propst had been diagnosed with epilepsy before the grand mal seizure that robbed her of her memory, and it's likely that the minor seizures she experienced were instrumental steps toward the major event.
Smaller seizures were what chipped away at the long-term memory of 42-year-old Mary Smith of Clinton, Mass. Smith was diagnosed with epilepsy when she was a senior in college, at the age of 21. But she says that as early as age 15, she started displaying the signs of psychomotor seizures.
"I would say all of my epileptic seizures have actually contributed to long-term memory loss," she said. Among the casualties are nearly every recollection of her college years.
"I don't remember being in college, but I have the pictures," she noted. There are other memories that she says she cannot recall -- things that she says she should remember but simply can't, like giving birth to her son.
"He's almost 20. I had him when I was 23," she said. "Twenty years old, but I remember hardly anything about his childhood."
"It is easy to feel really alone," said Smith, who, despite her memory loss, maintains good relationships with her friends and family and works as an adult education teacher.
Part of this isolation could be attributable to the fact that, for most people, memory is a significant part of identity.
"Memory remains one of the many unplumbed mysteries of the brain," Grisolia of Scripps Mercy Hospital said. "Our memories, accumulated over a lifetime, speak more to the heart of who we are than any external set of biologic, demographic or socioeconomic data about us."
Propst, too, said her memory loss has made it difficult in some cases to relate to others.
"It's hard to relate to other people if you don't have memories to share," Propst said.
Even with absent memories, however, the past has a way of catching up. Propst said that since the Denver Post covered her story last week, she has received a number of calls from old acquaintances who want to talk to her about her past life.
"As a custodian, I'm pretty invisible," Propst said. "I think people tend to think that I'm not very competent."
"I want to get together with someone who says, 'Yes, you were smart, you made a difference.'"
Once gone, are memories lost forever? Not all doctors think so. Ewing, her doctor, said he believes that somewhere, deep in Propst's brain, the memories she lost still exist.
"If you could find a way to reconstruct that connection, I think that they're there. I just don't think she has the ability to cross the bridge. ... Whatever switch it was that allowed her to access her memories, if we can throw it back, I have no doubt that these memories are still there. They should still be there; the brain area looks like it's intact."
But, if given the chance, Propst said, she would not want her old memories back.
"Actually, I haven't tried to reconnect with many of them," she said. "They really have nothing to do with my life now."
And she said that she hopes her book -- as well as the direction of her new life -- will inspire others to better understand the lives of those who have experienced memory loss.
"Memory is very important, but it's not all of you," she said. "All of us have something to offer, and it isn't always the things we can remember."
To find out more about Beki Propst, visit her Web site at www.absentmemories.com.
Gerard Middleton and Lara Salahi contributed to this report.