Causes of meningocele include teratoma and other tumors of the sacrococcyx and of the presacral space, and Currarino syndrome.A meningocele may also form through dehiscences in the base of the skull. These may be classified by their localisation as occipital, frontoethmoidal or nasal. Endonasal meningoceles lie at the roof of the nasal cavity and may be mistaken for a nasal polyp. They are treated surgically. Encephalomeningoceles are classified in the same way and also contain brain tissue. Myelomeningocele
Myelomeningocele (MMC), also known as meningomyelocele, is the type of spina bifida that often results in the most severe complications and affects the meninges and nerves. In individuals with myelomeningocele, the unfused portion of the spinal column allows the spinal cord to protrude through an opening. Myelomeningocele occurs in the third week of embryonic development, during neural tube pore closure. MMC is a failure of this to occur completely. The meningeal membranes that cover the spinal cord also protrude through the opening, forming a sac enclosing the spinal elements, such as meninges, cerebrospinal fluid, and parts of the spinal cord and nerve roots. Myelomeningocele is also associated with Arnold–Chiari malformation, necessitating a VP shunt placement.Toxins and conditions associated with MMC formation include: calcium-channel blockers, carbamazepine, cytochalasins, hyperthermia, and valproic acid. Myelocele
Spina bifida with myelocele is the most severe form of myelomeningocele. In this type, the involved area is represented by a flattened, plate-like mass of nervous tissue with no overlying membrane.
It is used to prevent or treat dry mouth, particularly in Sjögren syndrome, but also as a side effect of radiation therapy for head and neck cancer.It may be used to help differentiate Adie syndrome from other causes of unequal pupil size.It may be used to treat a form of dry eye called aqueous deficient dry eye (ADDE)

Surgery
Pilocarpine is sometimes used immediately before certain types of corneal grafts and cataract surgery. It is also used prior to YAG laser iridotomy. In ophthalmology, pilocarpine is also used to reduce symptomatic glare at night from lights when the patient has undergone implantation of phakic intraocular lenses; the use of pilocarpine would reduce the size of the pupils, partially relieving these symptoms. The most common concentration for this use is pilocarpine 1%. Pilocarpine is shown to be just as effective as apraclonidine in preventing intraocular pressure spikes after laser trabeculoplasty. Presbyopia
In 2021, the US Food and Drug Administration approved pilocarpine hydrochloride as an eyedrop treatment for presbyopia, age-related difficulty with near-in vision. It works by causing the pupils to constrict, increasing depth of field, similar to the effect of pinhole glasses. Marketed as Vuity, the effect lasts for more than 6 hours. Other
Pilocarpine is used to stimulate sweat glands in a sweat test to measure the concentration of chloride and sodium that is excreted in sweat. It is used to diagnose cystic fibrosis. Adverse effects
Use of pilocarpine may result in a range of adverse effects, most of them related to its non-selective action as a muscarinic receptor agonist.