Onychophosis is a localized or diffuse hyperkeratotic tissue that develops on the lateral or proximal nailfolds, within the space between the nailfolds and the nail plate, and is a common finding in the elderly. Onychophosis may involve the subungual area, as a direct result of repeated minor trauma, and most frequently affects the first and fifth toe. == References ==
Radiographic appearance
In a recent analysis (Susac et al., 2003), MRI images from 27 patients fulfilling the diagnostic criteria of Susacs syndrome were reviewed. Multifocal supratentorial lesions were present in all patients. Most lesions were small (3 to 7 mm), though some were larger than 7 mm. All 27 patients had corpus callosum lesions. These all had a punched-out appearance on follow up MRI. Though most commonly involving white matter, many patients also had lesions in deep grey matter structures, as well as leptomeningeal enhancement. Multiple sclerosis (MS) and acute disseminated encephalomyelitis (ADEM) can mimic the MRI changes seen in patients with Susacs syndrome. However, the callosal lesions in Susacs syndrome are centrally located. In comparison, patients with MS and ADEM typically have lesions involving the undersurface of the corpus callosum. Deep gray matter involvement commonly occurs in ADEM but is very rare in MS. Leptomeningeal involvement is not typical of either MS or ADEM. What this means is that if 10 lesions are found in the brain of an MS patient, a lesion may be found in the corpus callosum. If you have 10 lesions in a Susac patient, more than half will be in the corpus callosum. A concern about this illness is that it mimics multiple sclerosis when looking at the vision loss and brain lesions. If close attention is not paid to the retina of a patient with vision loss and brain lesions, their symptoms may be mistaken for MS instead of Susacs syndrome.