Hydrocephalus and Chiari type I malformation

Abstract

The radiological association of ventricular enlargement and hindbrain herniation would be the result of heterogeneous pathogenetic mechanisms which would then require specific therapeutic approaches. In this context, the endoscopic third ventricle-cisternostomy is gaining an increasing interest because of its more physiologic correction of the altered CSF dynamics and its minor interference on the developmental processes responsible for the association of hydrocephalus and CIM.

Reduction cranioplasty for macrocephaly with long-standing hydrocephalus and non-fused fontanelle in Chiari malformation type I

“…In addition, hydrocephalus affects only a minority of patients with Chiari type I malformation [9] but is closely related to the previously mentioned disorders. Therefore, it is important to manage hydrocephalus during the initial stages.…”

Upward Translation of Cerebellar Tonsils following Surgical Expansion of Supratentorial Cranial Vault: A Unified Biomechanical Explanation of Chiari Type I

“…Chiari type I deformity can also occur from sagging of the cerebellum as a consequence of a relatively low resistance spinal pathway for egress of CSF, as has been reported in patients having lumbar CSF shunts to deal with hydrocephalus or pseudotumor cerebri and patients with spinal leaks of CSF [4,24,36,52]. The sagging tonsils come into firm contact with the rim of the foramen magnum, become impacted, and then compromise or obstruct the flow of CSF from the supraforaminal cranial vault, where CSF is produced, to the infraforaminal thecal sac with its relatively low resistance pathway for egress of CSF, or possibly the patient's only such pathway, except for the central canal of the spinal cord [57].…”

“…In addition, there are reports of Chiari type I deformity occurring with space-occupying masses within the posterior fossa such as loculated fourth ventricle, arachnoid cyst, vein of Galen aneurysm [36,48,52,53,54,55,56], hematoma, and solid tissue such as neoplasm or Lhermitte-Duclos disease [5,49]. In each of these pathologies, the cerebellar tonsils are displaced across the foramen magnum by a downwardly directed force vector resulting from insufficient space within the posterior fossa.…”

Diffusion Tensor Imaging and Fiber Tractography in Children with Craniosynostosis Syndromes

“…However, they still might develop enlarged ventricles, mostly because of disturbed CSF absorption due to venous hypertension. 2 Enlarged ventricles can induce periventricular WM atrophy but also affect the shape of surrounding brain structures. Therefore, we included the frontal occipital horn ratio in our analyses to correct for ventricular size.…”

“…Not only are bony structures involved in craniosynostosis, but brain and CSF circulation appear to be directly affected by the genetic defect as well. [2][3][4][5] Because genes responsible for craniosynostosis syndromes are expressed during early embryonic development of the head, 6 it is likely that these intrinsic factors can also induce disturbances in microstructural WM organization. 4,7 Structural or mechanical cerebral abnormalities such as Chiari malformation type I are often reported in these patients.…”