Venous hemodynamics in neurological disorders: an analytical review with hydrodynamic analysis.

Venous abnormalities contribute to the pathophysiology of several neurological conditions. This paper reviews the literature regarding venous abnormalities in multiple sclerosis (MS), leukoaraiosis, and normal-pressure hydrocephalus (NPH). The review is supplemented with hydrodynamic analysis to assess the effects on cerebrospinal fluid (CSF) dynamics and cerebral blood flow (CBF) of venous hypertension in general, and chronic cerebrospinal venous insufficiency (CCSVI) in particular.CCSVI-like venous anomalies seem unlikely to account for reduced CBF in patients with MS, thus other mechanisms must be at work, which increase the hydraulic resistance of the cerebral vascular bed in MS. Similarly, hydrodynamic changes appear to be responsible for reduced CBF in leukoaraiosis. The hydrodynamic properties of the periventricular veins make these vessels particularly vulnerable to ischemia and plaque formation.Venous hypertension in the dural sinuses can alter intracranial compliance. Consequently, venous hypertension may change the CSF dynamics, affecting the intracranial windkessel mechanism. MS and NPH appear to share some similar characteristics, with both conditions exhibiting increased CSF pulsatility in the aqueduct of Sylvius.CCSVI appears to be a real phenomenon associated with MS, which causes venous hypertension in the dural sinuses. However, the role of CCSVI in the pathophysiology of MS remains unclear

Neoplasms of the genitourinary system

Nephroblastoma or Wilms’ tumor (WT) is the most common renal neoplasm in children accounting for 90 % of pediatric renal tumors (Pastore et al. 2006). It is a tumor with a good prognosis and with well-established treatment strategies. Other rare malignant renal tumors, such as clear cell sarcoma and rhabdoid tumor of the kidney, have a poor prognosis despite aggressive treatment. Renal cell carcinoma occurs in older children, while mesoblastic nephroma is the most frequent renal tumor in the neonate. Hematological malignancies, the most frequent neoplasms in children, may also involve the kidney, most often as part of a multi-organ involvement. Renal infections and malformations are much more common in children than renal tumors and may show a pseudotumoral pattern mimicking a renal tumor. In all cases, close collaboration among radiologists, pediatricians, and pathologists is essential so as to avoid diagnostic pitfalls due to atypical presentations