This is the most common location of the lesion, and therefore most individuals will have weakness of the lower limbs.A lesion of the lumbar segment, the lower part of the spinal cord (L1–S5) often produces a combination of upper and lower motor neuron signs in the lower limbs. Lumbar lesions account for about 10% of cases. Causes
TM is a heterogeneous condition, that is, there are several identified causes. Sometimes the term Transverse myelitis spectrum disorders is used. In 60% of patients the cause is idiopathic. In rare cases, it may be associated with meningococcal meningitisWhen it appears as a comorbid condition with neuromyelitis optica (NMO), it is considered to be caused by NMO-IgG autoimmunity, and when it appears in multiple sclerosis (MS) cases, it is considered to be produced by the same underlying condition that produces the MS plaques.Other causes of TM include infections, immune system disorders, and demyelinating diseases. Viral infections known to be associated with TM include HIV, herpes simplex, herpes zoster, cytomegalovirus, and Epstein-Barr. Flavivirus infections such as Zika virus and West Nile virus have also been associated. Viral association of  transverse myelitis could result from the infection itself or from the response to it. Bacterial causes associated with TM include Mycoplasma pneumoniae,  Bartonella henselae, and the types of Borrelia that cause Lyme disease. Lyme disease gives rise to neuroborreliosis  which is seen in a small percentage (4 to 5  per cent) of acute transverse myelitis cases.
Pterygium inversum unguis or ventral pterygium is characterized by the adherence of the distal portion of the nailbed to the ventral surface of the nail plate. : 788   The condition may be present at birth or acquired, and may cause pain with manipulation of small objects, typing, and close manicuring of the nail. : 788  secondary due to connective tissue disorders

See also
Pterygium unguis
Nail
List of cutaneous conditions


== References ==