Subdural posttraumatic collections are called usually Traumatic Subdural Hygroma (TSH). TSH is an accumulation of cerebrospinal fluid (CSF) in the subdural space after head injury. These collections have also been called Traumatic Subdural Effusion (TSE) or External Hydrocephalous (EHP) according to liquid composition, or image features. There is no agreement about the pathogenesis of these entities, how to define them or if they are even different phenomena at all. We present a case of a complex posttraumatic subdural collection, the role of cranioplasty as definite solution and review the literature related to this complication. Patients who undergo decompressive craniectomy (DC) have a risk of suffering a subdural collection of 21-50%. Few of these collections will become symptomatic and will need evacuation. When this happens, cranioplasty might be the definitive solution.

Cranioplasties are performed to protect the brain and correct cosmetic defects, but there is growing evidence that this procedure may result in neurological improvement. We prospectively studied cranioplasties performed at our hospital over a 5-year period. The National Institute of Health Stroke Scale and Barthel index were recorded prior to and within 72 h after the cranioplasty. A perfusion computed tomography (PCT) and transcranial Doppler sonography (TCDS) were performed prior to and 72 h after the surgery. For the PCT, regions irrigated by the anterior cerebral artery, the middle cerebral artery (MCA), the posterior cerebral artery, and the basal ganglia were selected, as well as the mean values for the hemisphere. The sonography was performed in the sitting and the supine position for the MCA and internal carotid. The velocities, pulsatility index, resistance index, and Lindegaard ratio (LR) were obtained, as well as a variation value for the LR (ΔLR = LR sitting – LR supine). Fifty-four patients were included in the study. Of these, 23 (42.6%) patients presented with objective improvement. The mean cerebral blood flow of the defective side (m-CBF-d) increased from 101.86 to 117.17 mL/100 g/min ( p = 0.064), and the m-CBF of the healthy side (m-CBF-h) increased from 128.14 to 145.73 mL/100 g/min ( p = 0.028). With regard to the TCDS, the ΔLR was greater on the defective side prior the surgery in those patients who showed improvement (1.295 vs. −0.714; p = 0.002). Cranioplasty resulted in clinical improvement in 40% of the patients, with an increase in the post-surgical CBF. The larger variations in the LR when the patient is moved from the sitting to the supine position might predict the clinical improvement.

Entrapment of the temporal horn is a rare form of noncommunicating focal hydrocephalus. Standard treatment has not yet been established for this condition, and only a few cases have been reported in the literature. The authors reviewed their cases of temporal horn entrapment treated between May 2013 and December 2014 and report their experience with endoscopic temporal ventriculocisternostomy. Four patients were identified (3 adults and 1 child) who underwent this treatment. In 3 patients, the condition developed after tumor resection, and in 1 patient it developed after resection of an arteriovenous malformation. In 1 patient, a recurrent trapped temporal horn developed and a refenestration was successfully performed. No procedure-related complications were observed, and all of the patients remained shunt-free at last follow-up (range 4–24 months). Endoscopic temporal horn ventriculocisternostomy is a safe and effective procedure for the treatment of symptomatic temporal horn entrapment in selected cases. However, there is little experience with the procedure to recommend it as the treatment of choice.