Trigeminal neuralgia (TN or TGN), also called Fothergill Disease, Tic Douloureux, or Trifacial Neuralgia is a long-term pain disorder that affects the trigeminal nerve, the nerve responsible for sensation in the face and motor functions such as biting and chewing. It is a form of neuropathic pain. There are two main types: typical and atypical trigeminal neuralgia. The typical form results in episodes of severe, sudden, shock-like pain in one side of the face that lasts for seconds to a few minutes. Groups of these episodes can occur over a few hours. The atypical form results in a constant burning pain that is less severe. Episodes may be triggered by any touch to the face. Both forms may occur in the same person. It is regarded as one of the most painful disorders known to medicine, and often results in depression.The exact cause is unknown, but believed to involve loss of the myelin of the trigeminal nerve. This might occur due to compression from a blood vessel as the nerve exits the brain stem, multiple sclerosis, stroke, or trauma. Less common causes include a tumor or arteriovenous malformation. It is a type of nerve pain. Diagnosis is typically based on the symptoms, after ruling out other possible causes such as postherpetic neuralgia.Treatment includes medication or surgery. The anticonvulsant carbamazepine or oxcarbazepine is usually the initial treatment, and is effective in about 90% of people. Side effects are frequently experienced that necessitate drug withdrawal in as many as 23% of patients.
Ocular melanosis (OM) is a blue-gray and/or brown lesion of the conjunctiva that can be separated into benign conjunctival epithelial melanosis (BCEM) and primary acquired melanosis (PAM), of which the latter is considered a risk factor for uveal melanoma. The disease is caused by an increase of melanocytes in the iris, choroid, and surrounding structures. Overproduction of pigment by these cells can block the trabecular meshwork through which fluid drains from the eye. The increased fluid in the eye leads to increased pressure, which can lead to glaucoma. In humans, this is sometimes known as pigment dispersion syndrome. Benign Conjunctival Epithelial Melanosis
BCEM, also referred to as conjunctival hypermelanosis, complexion-associated melanosis, or racial melanosis, is a non-cancerous lesion of the conjunctiva that is more commonly found in dark-skinned individuals (over 90% of lesions are found in black persons and around 5% in white persons). It is due to excess production of melanin in the setting of a normal number of melanocytes in the conjunctiva. It appears very early in life and the pattern does not seem to change upon reaching adulthood. There can be asymmetrical involvement of the eyes, and lesions are usually described as flat, brown, and patchy areas of pigmentation. Primary Acquired Melanosis
PAM is a potentially cancerous lesion of the conjunctiva, which has a higher risk of transforming into a malignant melanoma in white persons. Nearly 75% of all melanomas that arise from the conjunctiva have been found to have occurred in the setting of PAM.