Post-traumatic ventricular dilatation may have a wide range of aetiological factors: starting from neuronal loss due to head trauma and possible secondary ischaemic insults, to obstruction of CSF circulation resulting in hydrocephalus. It is important to differentiate between post-traumatic hydrocephalus and brain atrophy before considering placement of a shunt. Making this decision can be facilitated by measurement of the resistance to CSF outflow.1 However, the pattern of the CSF circulation may change dramatically after a cranioplasty resulting from a previous decompressive craniectomy for refractory intracranial hypertension after head injury. The effect of the skull and dura on CSF hydrodynamics has been explored experimentally: the resistance to CSF outflow after craniectomy decreases twofold and brain compliance (expressed using the pressure-volume index, PVI) increases.2 This problem is important clinically as the following case illustrates:
CT and infusion studies. (A) Scan performed on admission. (B) After right frontal lobectomy and bone flap removal. (C) Four months after injury, before cranioplasty. (F) Infusion test demonstrated low resistance to CSF outflow and increased brain compliance. ICP=mean intracranial pressure; AMP= pulse amplitude of ICP waveform. Constant infusion rate of 1.5 …
[1]
T. Yamamoto,et al.
Posttraumatic ventriculomegaly: hydrocephalus or atrophy? A new approach for diagnosis using CSF dynamics.
,
1996,
Journal of neurosurgery.
[2]
J D Pickard,et al.
Testing of cerebrospinal compensatory reserve in shunted and non-shunted patients: a guide to interpretation based on an observational study.
,
1996,
Journal of neurology, neurosurgery, and psychiatry.
[3]
K. Shapiro,et al.
Effect of the skull and dura on neural axis pressure-volume relationships and CSF hydrodynamics.
,
1985,
Journal of neurosurgery.
[4]
F. Epstein,et al.
The Rôle of the Skull and Dura in Experimental Feline Hydrocephalus
,
1972,
Developmental medicine and child neurology. Supplement.