One or both pupils may be dilated and fail to constrict in response to light. Vomiting can also occur due to compression of the vomiting center in the medulla oblongata. Severe headaches and seizures as a result of increased intracranial pressure are not uncommon. Cardiovascular and pulmonary symptoms may also be present as the brain loses function, but might also be associated with bleeding. They can include: hypertension, respiratory depression, arrhythmia and in severe cases cardiac arrest. Causes
Causes of brain herniation include:
Brain edema
Hematoma
Stroke
Tumour
Infection

Classification
The tentorium is an extension of the dura mater that separates the cerebellum from the cerebrum. There are two major classes of herniation: supratentorial and infratentorial. Supratentorial refers to herniation of structures normally found above the tentorial notch, and infratentorial refers to structures normally found below it. Supratentorial herniation1) Uncal (transtentorial)
2) Central
3) Cingulate (subfalcine/transfalcine)
4) Transcalvarial
5) Tectal (posterior)

Infratentorial herniation6) Upward (upward cerebellar or upward transtentorial)
7) Tonsillar (downward cerebellar)

Uncal herniation
In uncal herniation, a common subtype of transtentorial herniation, the innermost part of the temporal lobe, the uncus, can be squeezed so much that it moves towards the tentorium and puts pressure on the brainstem, most notably the midbrain. The tentorium is a structure within the skull formed by the dura mater of the meninges. Tissue may be stripped from the cerebral cortex in a process called decortication.The uncus can squeeze the oculomotor nerve (a.k.a.
They are also seen in patients with end-stage kidney disease on hemodialysis, Hodgkins disease, pellagra, and sickle cell anaemia.The lines remain visible as long as protein intake is inadequate or synthesis is impaired, and they should disappear upon return to normal function.In extreme conditions, Muehrckes lines may also arise from physical changes in peripheral circulation: one case study reported appearance of the lines in a healthy subject following ascent to 8,848 meters (29,029 ft) on Mount Everest. History
Muehrckes lines were described by American physician Robert C. Muehrcke (1921–2003) in 1956. In a study published in BMJ, he examined patients with known chronic hypoalbuminemia and healthy volunteers, finding that the appearance of multiple transverse white lines was a highly specific marker for low serum albumin (no subject with the sign had SA over 2.2 g/dL), was associated with severity of the underlying condition, and disappeared upon successful treatment (corticosteroids in nephrotic syndrome) or direct infusion of HSA. See also
Mees lines – a similar appearance, except the lines are in the nail and move as the nail grows
Half and half nails
Terrys nails
List of cutaneous conditions

References
Bibliography
Fawcett, Robert S.; Sean Linford; Daniel L. Stulberg (March 15, 2004). "Nail Abnormalities: Clues to Systemic Disease". American Family Physician. 69 (6): 1417–24. PMID 15053406. James, William; Berger, Timothy; Elston, Dirk (2005). Andrews Diseases of the Skin: Clinical Dermatology. (10th ed.). Saunders. ISBN 0-7216-2921-0. Muehrcke Lines of the Fingernails at eMedicine
Muehrckes Lines of the Fingernails on WebMD