Viruses that have been implicated include Epstein-Barr virus, herpes simplex virus and cytomegalovirus.Non-specific upper respiratory infections including rhinitis and pharyngitis are most often cited by patients. In one study, 46.5% patients recalled a specific trigger with a respiratory tract illness being the most common. In children, almost half report headache onset during an infection. A study by Rozen and Swindan in 2007 found elevated levels of tumor necrosis factor alpha, a proinflammatory cytokine, in the cerebrospinal fluid but not the blood of patients with NDPH, chronic migraine, and post-traumatic headaches suggesting inflammation as the cause of the headaches.NDPH as an inflammatory, post-infectious manifestation indicates a potential meningoencephalitis event in NDPH patients. Tissue specificity is a general feature of post-infectious, immune-mediated conditions, and the meninges are a type of connective tissue membrane. Inflammation of the meninges was first proposed as a possible pathophysiology for migraine in the 1960s and has recently been explored again. This hypothesis is based on meningeal mast cell activation. Reactive arthritis (ReA) is a post-infectious disease entity of synovium/joints with connective tissue membrane (synovial membrane of the joints) which provides a corollary. NDPH has been reported in Hashimotos encephalopathy, an immune-mediated type of encephalitis. A mean 5-year retrospective analysis of 53 patients with a history of viral meningitis and 17 patients with a history of bacterial meningitis showed an increased onset of subsequent new onset headache and increased severity of those with prior primary headaches. Treatment
There is no specific treatment for NDPH.
X-linked myopathy with excessive autophagy (XMEA) is a rare childhood onset disease characterized by slow progressive vacuolation and atrophy of skeletal muscle. There is no known cardiac or intellectual involvement. Presentation
The incidence of this disease is not precisely known but it is considered to be rare (< 1/106 population). It has been reported in 15 families to date mostly from Canada, Finland and France.This disease usually presents between the ages of 5 to 10 years old. The usual picture is with weakness involving the upper legs and affects activities such as running and climbing stairs. As the condition progresses, patients tend to experience weakness in their lower legs and arms. Some remain able to walk in advanced age, while others require assistance in adulthood. Genetics
This disorder is inherited in a recessive X linked fashion. As a result, males are much more commonly affected than females. It is due to a mutation in VMA21 gene - the human homolog of the yeast Vma21p protein. This gene is located on the long arm of chromosome X (Xq28). It is an essential assembly chaperone of the vacuolar ATPase - the principal mammalian proton pump complex. Mutations in this gene increase lysosomal pH. This in turn reduces lysosomal degradative ability and blocks autophagy. Pathology
The muscle fibers are rarely necrotic but have evidence of excessive autophagic activity and exocytosis of the phagocytosed material. They have increased variation in size and are predominantly composed of round small and hypertrophic fibers.