A 58-year-old man presents with complaints of numbness and i…

A 58-year-old man presents with complaints of numbness and inability to feel pain or temperature on the right side of his body below the waist. He reports that light touch and vibration sensation are intact. MRI reveals a lesion in the left lateral spinal cord at the T10 level.

A 9-year-old child struggles in school, frequently interrupt…

A 9-year-old child struggles in school, frequently interrupts others, talks excessively, blurts out answers, and forgets items despite reminders. The child denies sadness or anxiety and expresses embarrassment, saying, “I can’t help it.” Neuropsychological testing shows normal IQ. Which pathophysiologic mechanism most likely explains these symptoms?  

A 9-year-old boy reports feeling “stupid” because he cannot…

A 9-year-old boy reports feeling “stupid” because he cannot read like his classmates. He enjoys playing soccer and interacts well with peers. His mother and teachers report normal behavior at home and school. Neuropsychological testing shows normal IQ but deficits in phonologic and visual-spatial processing. Which diagnosis is most likely?