Final answer:
The specific details on how Beth Usher received the bump causing her first seizure isn't provided in 'Gifted Hands: The Ben Carson Story.' The book mentions medical histories of epilepsy related to brain injuries, like the famous case of temporal lobe removal, which may suggest a similar cause for Beth's condition.
Step-by-step explanation:
In Gifted Hands: The Ben Carson Story, there isn't a specific incident detailed regarding how Beth Usher received the bump that later caused her first seizure. The book, however, explains the medical history and progression of medical conditions such as epilepsy by illustrating various cases that Dr. Ben Carson encountered during his career. For example, it discusses how traumatic brain injuries can lead to seizures and later epilepsy, which might be inferred as a possible cause for Beth's condition. It is known that epilepsy can develop following head trauma or other brain-affecting events.
There are accounts like the famous case of a man whose medial temporal lobes were removed to treat intractable epilepsy, which offers insight into neurological structures and functions related to medical conditions such as seizures and memory. It is such cases that highlight the complexities of diagnosing and treating neurological disorders.