Cerebellum: The cerebellum is responsible for coordinating movements, including those of the arms and hands. A problem in the cerebellum, such as a cerebellar stroke or a tumor, could lead to ataxia, which is characterized by lack of coordination and balance, potentially causing difficulty in performing precise movements like bringing a fork to the mouth.

Cerebral: Cerebral disorders, including those affecting the motor cortex, could lead to weakness or paralysis of the arm, making it difficult to perform tasks that require fine motor skills, such as eating with utensils.
Temporal: Temporal lobe issues might not directly cause motor dysfunction in the traditional sense but could lead to seizures or other neurological disturbances that indirectly affect motor control.

Stroke: Although rare in a 16-year-old, a stroke could occur due to various reasons (e.g., congenital heart defects, blood clotting disorders) and would be catastrophic if not promptly diagnosed and treated.
Brain Tumor: Tumors in the brain, depending on their location, could cause a variety of symptoms, including motor dysfunction. Early diagnosis is crucial for treatment and prognosis.
Multiple Sclerosis: This autoimmune disease can cause a wide range of neurological symptoms, including motor weakness and coordination problems. It's less common in teenagers but should be considered, especially if other symptoms are present.

Peripheral Neuropathy: Conditions affecting the nerves outside the brain and spinal cord could lead to weakness or numbness in the hands, making it hard to perform fine motor tasks.
Muscular Dystrophy: Certain types of muscular dystrophy could present with weakness in specific muscle groups, potentially affecting the ability to use utensils.
Infectious or Inflammatory Conditions: Such as meningitis or encephalitis, which could cause a range of neurological symptoms, including motor dysfunction, though these would typically be accompanied by other systemic signs of illness.