Crocodile tears is due to abnormal regeneration of
**Core Concept**
Crocodile tears syndrome is a rare neurological disorder characterized by involuntary lacrimation (tearing) during meals, often accompanied by abnormal salivation. This phenomenon occurs due to aberrant regeneration of the nerve fibers between the facial nerve (cranial nerve VII) and the glossopharyngeal nerve (cranial nerve IX), resulting in misdirected parasympathetic signals.
**Why the Correct Answer is Right**
During the process of nerve regeneration, the facial nerve's preganglionic parasympathetic fibers, which normally control salivation, aberrantly reconnect with the lacrimal gland's postganglionic parasympathetic fibers, leading to excessive tearing during meals. This condition is often seen in patients who have undergone facial nerve injury, such as those who have undergone surgery for Bell's palsy or other facial nerve disorders.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is not relevant to crocodile tears syndrome, as it does not involve the aberrant regeneration of nerve fibers.
* **Option B:** This option is incorrect, as it does not accurately describe the underlying cause of crocodile tears syndrome.
* **Option C:** This option is not relevant to crocodile tears syndrome, as it does not involve the aberrant regeneration of nerve fibers.
**Clinical Pearl / High-Yield Fact**
Crocodile tears syndrome is often seen in patients with a history of facial nerve injury or surgery, highlighting the importance of careful nerve repair and rehabilitation in these cases.
**Correct Answer: C. Aberrant regeneration of the nerve fibers between the facial nerve and the glossopharyngeal nerve.**