It has been proposed that a positive biofeedback loop may exist, where raised ICP (intracranial pressure) causes venous narrowing in the transverse sinuses, resulting in venous hypertension (raised venous pressure), decreased CSF resorption via arachnoid granulation and further rise in ICP. Diagnosis
The diagnosis may be suspected on the basis of the history and examination. To confirm the diagnosis, as well as excluding alternative causes, several investigations are required; more investigations may be performed if the history is not typical or the person is more likely to have an alternative problem: children, men, the elderly, or women who are not overweight. Investigations
Neuroimaging, usually with computed tomography (CT/CAT) or magnetic resonance imaging (MRI), is used to exclude any mass lesions. In IIH these scans typically appear to be normal, although small or slit-like ventricles, dilatation and buckling of the optic nerve sheaths and "empty sella sign" (flattening of the pituitary gland due to increased pressure) and enlargement of Meckels caves may be seen. An MR venogram is also performed in most cases to exclude the possibility of venous sinus stenosis/obstruction or cerebral venous sinus thrombosis. A contrast-enhanced MRV (ATECO) scan has a high detection rate for abnormal transverse sinus stenoses. These stenoses can be more adequately identified and assessed with catheter cerebral venography and manometry. Buckling of the bilateral optic nerves with increased perineural fluid is also often noted on MRI imaging. Lumbar puncture is performed to measure the opening pressure, as well as to obtain cerebrospinal fluid (CSF) to exclude alternative diagnoses.
Primary cutaneous amyloidosis is a form of amyloidosis associated with oncostatin M receptor. This type of amyloidosis has been divided into the following types:: 520 
Macular amyloidosis is a cutaneous condition characterized by itchy, brown, rippled macules usually located on the interscapular region of the back. : 521  Combined cases of lichen and macular amyloidosis are termed biphasic amyloidosis, and provide support to the theory that these two variants of amyloidosis exist on the same disease spectrum. Lichen amyloidosis is a cutaneous condition characterized by the appearance of occasionally itchy lichenoid papules, typically appearing bilaterally on the shins. : 521 
		
		
Nodular amyloidosis is a rare cutaneous condition characterized by nodules that involve the acral areas. : 521

See also
Amyloidosis
List of cutaneous conditions

References


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