Ventricular size following head injury: a clinico-radiological study

Volumetric MRI Findings in Mild Traumatic Brain Injury (mTBI) and Neuropsychological Outcome

Region of interest (ROI) volumetric assessment has become a standard technique in quantitative neuroimaging. ROI volume is thought to represent a coarse proxy for making inferences about the structural integrity of a brain region when compared to normative values representative of a healthy sample, adjusted for age and various demographic factors. This review focuses on structural volumetric analyses that have been performed in the study of neuropathological effects from mild traumatic brain injury (mTBI) in relation to neuropsychological outcome. From a ROI perspective, the probable candidate structures that are most likely affected in mTBI represent the target regions covered in this review. These include the corpus callosum, cingulate, thalamus, pituitary-hypothalamic area, basal ganglia, amygdala, and hippocampus and associated structures including the fornix and mammillary bodies, as well as whole brain and cerebral cortex along with the cerebellum. Ventricular volumetrics are also reviewed as an indirect assessment of parenchymal change in response to injury. This review demonstrates the potential role and limitations of examining structural changes in the ROIs mentioned above in relation to neuropsychological outcome. There is also discussion and review of the role that post-traumatic stress disorder (PTSD) may play in structural outcome in mTBI. As emphasized in the conclusions, structural volumetric findings in mTBI are likely just a single facet of what should be a multimodality approach to image analysis in mTBI, with an emphasis on how the injury damages or disrupts neural network integrity. The review provides an historical context to quantitative neuroimaging in neuropsychology along with commentary about future directions for volumetric neuroimaging research in mTBI.

Impact of timing of ventriculoperitoneal shunt placement on outcome in posttraumatic hydrocephalus

OBJECTIVE

Posttraumatic hydrocephalus (PTH) is a frequent sequela of traumatic brain injury (TBI) and complication of related cranial surgery. The roles of PTH and the timing of cerebrospinal fluid (CSF) shunt placement in TBI outcome have not been well described. The goal of this study was to assess the impact of hydrocephalus and timing of ventriculoperitoneal (VP) shunt placement on outcome during inpatient rehabilitation after TBI.

METHODS

In this cohort study, all TBI patients admitted to Craig Hospital between 2009 and 2013 were evaluated for PTH, defined as ventriculomegaly, and hydrocephalus symptoms, delayed or deteriorating recovery, or elevated opening pressure on lumbar puncture. Extent of ventriculomegaly was quantified by the Evans index from CT scans. Outcome measures were emergence from and duration of posttraumatic amnesia (PTA) and functional status as assessed by means of the Functional Independence Measure (FIM). Findings in this group were compared to findings in a group of TBI patients without PTH (controls) who were admitted for inpatient rehabilitation during the same study period and met specific criteria for inclusion.

RESULTS

A total of 701 patients were admitted with TBI during the study period. Of these patients, 59 (8%) were diagnosed with PTH and were included in this study as the PTH group, and 204 who were admitted for rehabilitation and met the criteria for inclusion as controls constituted the comparison group (no-PTH group). PTH was associated with initial postinjury failure to follow commands, midline shift or cistern compression, subcortical contusion, and craniotomy or craniectomy. In multivariable analyses, independent predictors of longer PTA duration and lower FIM score at rehabilitation discharge were PTH, emergency department Glasgow Coma Scale motor score < 6, and longer time from injury to rehabilitation admission. PTH accounted for a 51-day increase in PTA duration and a 29-point reduction in discharge FIM score. In 40% of PTH patients with preshunt CT brain imaging analyzed, ventriculomegaly (Evans index > 0.3) was observed 3 or more days before VP shunt placement (median 10 days, range 3-102 days). Among PTH patients who received a VP shunt, earlier placement was associated with better outcome by all measures assessed and independently predicted better FIM total score and shorter PTA duration.

CONCLUSIONS

Posttraumatic hydrocephalus predicts worse outcome during inpatient rehabilitation, with poorer functional outcomes and longer duration of PTA. In shunt-treated PTH patients, earlier CSF shunting predicted improved recovery. These results suggest that clinical vigilance for PTH onset and additional studies on timing of CSF diversion are warranted.

Decompressive craniectomy and CSF disorders in children

INTRODUCTION

Decompressive craniectomy (DC) is a lifesaving procedure but is associated to several post-operative complications, namely cerebrospinal fluid (CSF) dynamics impairment. The aim of this multicentric study was to evaluate the incidence of such CSF alterations after DC and review their impact on the overall outcome.

MATERIAL AND METHODS

We performed a retrospective multicentric study to analyze the CSF disorders occurring in children aged from 0 to 17 years who had undergone a DC for traumatic brain injury (TBI) in the major Departments of Pediatric Neurosurgery of France between January 2006 and August 2016.

RESULTS

Out of 150 children, ranging in age between 7 months and 17 years, mean 10.75 years, who underwent a DC for TBI in 10 French pediatric neurosurgical centers. Sixteen (6 males, 10 females) (10.67%) developed CSF disorders following the surgical procedure and required an extrathecal CSF shunting. External ventricular drainage increased the risk of further complications, especially cranioplasty infection (p = 0.008).

CONCLUSION

CSF disorders affect a minority of children after DC for TBI. They may develop early after the DC but they may develop several months after the cranioplasty (8 months), consequently indicating the necessity of clinical and radiological close follow-up after discharge from the neurosurgical unit. External ventricular drainage and permanent CSF shunt placement increase significantly the risk of cranioplasty infection.

Surgical management and outcomes of non-missile open head injury: Report of 44 cases from a single trauma centre

OBJECTIVE

To retrospectively analyse the surgical management and outcomes of non-missile open head injuries (NMOHI).

METHODS

Forty-four patients who suffered from NMOHI were included. The Glasgow outcome score (GOS), computed tomography (CT), aetiology and outcomes and complications at discharge and during a 6-month follow-up were analysed. All patients underwent debridement. Intracranial haematoma evacuation, decompressive craniectomy (DC) or replacement were performed.

RESULTS

Motor vehicle accident and struck by/against were the most common causes (43.2% each). At admission, 33 patients had Glasgow coma scores (GCS) > 8 and 27 of them had a GCS score of > 13. Mean follow-up was 8.7 ± 4.3 months. All patients underwent debridement, 20 underwent bone fracture replacement and 27 underwent haematoma evacuation; 11 patients underwent haematoma evacuation and DC and one had bilateral DC. Twenty-seven patients showed good recovery; 11 patients had moderate disability; three patients had severe disability; and three patients died. After 6 months, 32 patients had good recovery and the morbidity of severe disability had decreased to 13.6%. Thirteen patients developed intracranial infection. Post-traumatic epilepsy and hydrocephalus was detected in three patients. Cerebrospinal fluid fistula was found in five patients. Only one patient developed a brain abscess after 6 months.

CONCLUSIONS

NMOHI yielded satisfactory recovery and achieved good outcomes.

Clinical Analysis of Results of Shunt Operation for Hydrocephalus Following Traumatic Brain Injury

Objective

Ventricular enlargement following head injury is a frequent finding but cases requiring shunt operation are rare. The incidence and developing factors of post-traumatic hydrocephalus (PTH) have been variously reported, but studies for factors influencing outcomes of shunt operation for PTH are rare. The incidence of PTH requiring shunt operation, causing injuries, and factors influencing outcome of shunt operation need to be identified.

Methods

In total, 1,142 patients suffering from traumatic brain injury (TBI) between January 2007 and December 2012 were admitted to our department. Of them, 23 patients underwent shunt operation for diagnosed PTH. In this clinical study, we reviewed retrospectively our TBI database and in the 23 patients, we evaluated outcomes with Glasgow Outcome Score just before the operation, at 14 days, 3 months, and 6 months according to initial Glasgow Coma Scale (GCS) score, interval time between shunt operation and trauma, and lumbar cerebrospinal fluid (CSF) pressure.

Results

The incidence of PTH treated with shunt operation was 2.01%. Subdural hematoma (SDH) was the most common preceding head injury. The outcomes of shunt operation were not related with lumbar CSF pressure or interval time from trauma, but initial GCS score correlated with the outcome.

Conclusion

In present study, 2.01% of TBI patients underwent shunt operation. SDH was the most common preceding injury. Admission GCS score was related to the outcome of shunt operation. However, there were no correlation between the outcome of shunt operation and initial lumbar CSF pressure or interval time of shunt operation after the trauma.

Deferoxamine attenuates acute hydrocephalus after traumatic brain injury in rats

Acute post-traumatic ventricular dilation and hydrocephalus are relatively frequent consequences of traumatic brain injury (TBI). Several recent studies have indicated that high iron levels in brain may relate to hydrocephalus development after intracranial hemorrhage. However, the role of iron in the development of post-traumatic hydrocephalus is still unclear. This study was to determine whether or not iron has a role in hydrocephalus development after TBI. TBI was induced by lateral fluid-percussion in male Sprague-Dawley rats. Some rats had intraventricular injection of iron. Acute hydrocephalus was measured by magnetic resonance T2-weighted imaging and brain hemorrhage was determined by T2* gradient-echo sequence imaging and brain hemoglobin levels. The effect of deferoxamine on TBI-induced hydrocephalus was examined. TBI resulted in acute hydrocephalus at 24 h (lateral ventricle volume: 24.1 ± 3.0 vs. 9.9 ± 0.2 mm(3) in sham group). Intraventricular injection of iron also caused hydrocephalus (25.7 ± 3.4 vs. 9.0 ± 0.6 mm(3) in saline group). Deferoxamine treatment attenuated TBI-induced hydrocephalus and heme oxygenase-1 upregulation. In conclusion, iron may contribute to acute hydrocephalus after TBI.

Hydrocephalus after decompressive craniotomy: a case series

BACKGROUND

Post-craniectomy hydrocephalus in patients with intracranial hypertension is becoming a major concern for neurosurgeons because of the increasing number of hospital admissions for head trauma, stroke and other lesions which may lead to severe brain oedema requiring decompressive craniectomy.

METHODS

We collected records of all the paediatric patients who developed hydrocephalus following decompressive craniotomy from October 2011 to October 2013 and analysed their clinical profiles.

RESULTS

We had 3 patients in this group, ranging in age from 6 to 18 years; 1 patient died and the other 2 patients continue to remain in follow-up.

CONCLUSION

Post-traumatic hydrocephalus is one of the rare complications of decompressive craniotomy; CSF diversion remains the only option for improvement in neurological status.

Papilloedema as a non-invasive marker for raised intra-cranial pressure following decompressive craniectomy for severe head injury

BACKGROUND

Decompressive craniectomy is an extremely useful surgical procedure for decreasing intra cranial pressure following severe head injury. However, there is anecdotal evidence to suggest that some of these patients may continue to have raised intracranial pressure in spite of an apparently adequate Decompressive craniectomy.

AIMS AND OBJECTIVES

(1) To assess whether fundoscopic findings accurately reflect changes in ICP in severe head injury. (2) To study the temporal course of fundoscopic findings in patients with severe head injury following decompressive craniectomy and to correlate fundoscopy findings with ventriculomegaly (if any) on serial Computerized tomography in these patients.

MATERIALS AND METHODS

In this prospective study from November 2008 to March 2009, 32 patients severe head injury (GCS ≤8) admitted at the Department of Neurosurgery, JPN Apex Trauma Center, All India Institute of Medical Sciences, New Delhi who underwent a wide (>80 cubic cm) decompressive craniectomy with a lax duraplasty for severe head injury were subjected to fundoscopic examinations on the 1st, 3rd, 5th, 7th and 14th post operative days along with serial C.T. imaging studies to check for ventriculomegaly. Ventriculomegaly was defined as dilatation of temporal horn >2mm along with ballooning of III ventricle and/or presence of peri-ventricular lucency. Seven severe head injury patients who were conservatively managed with continuous ICP monitoring were also subjected to serial fundoscopic examinations.

RESULTS

32 patients who underwent decompressive craniectomy for severe head injury were evaluated during the study period. The age group of the patients ranged from 12 to 75 years. The mean GCS on admission was 6/15 (range 3/15-8/15). There were 12 cases of acute traumatic subdural hemorrhage and 20 cases of intracerebral contusion (frontal/temporal regions). Fundoscopic examination showed papilloedema in 81% (n=26) on the first post operative day, 66% (n=21) on the third post operative day, 28% (n=9) on the fifth post operative day, 13% (n=4) on the seventh post operative day and 6% (n=2) at 14 days post-operatively. In 4 (13%) patients papilloedema reappeared on fundoscopy after one week of surgery. Of these, only 1 (3%) patient had ventriculomegaly on CT scans. Lumbar drain was placed in 2 of these patients and resulted in prompt resolution of papilloedema. In the 7 patients who were managed conservatively and had ICP monitoring, serial fundoscopic examination were found to accurately reflect the ICP readings in all cases. No papilloedema was seen in any of the patients when ICP was below 20mm of Hg and papilloedema appeared in all cases where the ICP was ≥20mm of Hg.

CONCLUSION

Fundoscopy is an extremely useful non-invasive tool to assess changes in intracranial pressure in severe head injury. Reappearance of papilloedema in the postoperative period even in the absence of ventriculomegaly indicates raised ICP and should be treated aggressively.

Rehabilitation of traumatic brain injury

Rehabilitation following traumatic brain injury (TBI) is best provided by an interdisciplinary team of health care providers that takes advantage of the unique skills of multiple specialists, as well as their combined strengths that address problems that cut across disciplines. The setting where rehabilitation is provided is determined by the medical stability of patients, their ability to tolerate intensive therapies, and their likelihood of community reintegration within a reasonable period of time. Successful rehabilitation requires prompt recognition and treatment of TBI-related medical, cognitive, and behavioral problems to promote recovery and enhance community reintegration, using a combination of rehabilitation modalities and medications.

Interhemispheric hygroma after decompressive craniectomy: does it predict posttraumatic hydrocephalus?

OBJECT

The aim of this study was to determine the incidence of posttraumatic hydrocephalus in severely head-injured patients who required decompressive craniectomy (DC). Additional objectives were to determine the relationship between hydrocephalus and several clinical and radiological features, with special attention to subdural hygromas as a sign of distortion of the CSF circulation.

METHODS

The authors conducted a retrospective study of 73 patients with severe head injury who required DC. The patients were admitted to the authors' department between January 2000 and January 2006. Posttraumatic hydrocephalus was defined as: 1) modified frontal horn index greater than 33%, and 2) the presence of Gudeman CT criteria. Hygromas were diagnosed based on subdural fluid collection and classified according to location of the craniectomy.

RESULTS

Hydrocephalus was diagnosed in 20 patients (27.4%). After uni- and multivariate analysis, the presence of interhemispheric hygromas (IHHs) was the only independent prognostic factor for development of posttraumatic hydrocephalus (p<0.0001). More than 80% of patients with IHHs developed hydrocephalus within the first 50 days of undergoing DC. In all cases the presence of hygromas preceded the diagnosis of hydrocephalus. The IHH predicts the development of hydrocephalus after DC with 94% sensitivity and 96% specificity. The presence of an IHH showed an area under the receiver-operator characteristic of 0.951 (95% CI 0.87-1.00; p<0.0001).

CONCLUSIONS

Hydrocephalus was observed in 27.4% of the patients with severe traumatic brain injury who required DC. The presence of IHHs was a predictive radiological sign of hydrocephalus development within the first 6 months of DC in patients with severe head injury.

Clinical factors for the development of posttraumatic hydrocephalus after decompressive craniectomy

OBJECTIVE

Earlier reports have revealed that the incidence of posttraumatic hydrocephalus (PTH) is higher among patients who underwent decompressive craniectomy (DC). The aim of this study was to determine the influencing factors for the development of PTH after DC.

METHODS

A total of 693 head trauma patients admitted in our hospital between March 2004 and May 2007 were reviewed. Among thee, we analyzed 55 patients with severe traumatic brain injury who underwent DC. We excluded patients who had confounding variables. The 33 patients were finally enrolled in the study and data were collected retrospectively for these patients. The patients were divided into two groups: non-hydrocephalus group (Group I) and hydrocephalus group (Group II). Related factors assessed were individual Glasgow Coma Score (GCS), age, sex, radiological findings, type of operation, re-operation and outcome.

RESULTS

Of the 693 patients with head trauma, 28 (4.0%) developed PTH. Fifty-five patients underwent DC and 13 (23.6%) developed PTH. Eleven of the 33 study patients (30.3%) who had no confounding factors were diagnosed with PTH. Significant differences in the type of craniectomy and re-operation were found between Group I and II.

CONCLUSION

It is suggested that the size of DC and repeated operation may promote posttraumatic hydrocephalus in severe head trauma patients who underwent DC.

Ventricular enlargement after moderate or severe head injury: a frequent and neglected problem

The primary goal of this study was to determine the incidence of post-traumatic ventriculomegaly (Evans' index > or = 0.30) in 95 head-injured patients with a Glasgow Coma Scale (GCS) score of < or =13 at admission. Additional objectives were to determine the relationship between an increase in ventricular size and several clinical and radiological features and outcome. A planimetric study was carried out in the sequential control computed tomography (CT) scans of 34 moderately head-injured (GCS 9-13) and 61 severely head-injured (GCS 3-8) patients with a minimum follow-up of 2 months. Between two and six CT scans were evaluated in each patient. The presence of subarachnoid hemorrhage (SAH) was registered. Evans' index was determined in all CT scans. In the final CT scan of each patient, ventricular size was related to the admission GCS score, age, the presence of SAH in the initial CT scans, type of brain lesion (classified according to the final diagnosis in the Traumatic Coma Data Bank classification), and outcome. Ventriculomegaly was found in 39.3% of patients with severe head injury and in 27.3% of those with a moderate head injury. Increased ventricular size was evident 4 weeks after injury in 57.6% and 2 months after injury in 69.7%. No relationship was found between post-traumatic ventriculomegaly and age, initial GCS score, the presence of SAH, or type of lesion (focal or diffuse). Post-traumatic ventriculomegaly was significantly correlated with outcome. Post-traumatic ventriculomegaly is a frequent and early finding in patients with moderate or severe traumatic brain injury.

Hydrocephalus, ventriculomegaly and the vegetative state: a review

The revised guidelines from the Royal College of Physicians make it clear that structural problems such as hydrocephalus should be excluded before the diagnosis of vegetative state (VS) can be made. Ventriculomegaly is common after severe head injury but the distinction between atrophy and potentially treatable hydrocephalus cannot be made on the basis of conventional computerised tomographic (CT) or magnetic resonance (MR) scanning alone--physiological measurements of intracranial pressure (ICP) and cerebrospinal fluid (CSF) outflow resistance may be helpful. These techniques are reviewed together with the limited literature available that documents the effect of CSF diversion on outcome in "vegetative" patients.

Posttraumatic hydrocephalus: a clinical, neuroradiologic, and neuropsychologic assessment of long-term outcome 11No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit upon the author(s) or upon any organization with which the author(s) is/are associated

OBJECTIVES

To detect the clinical and radiologic characteristics of posttraumatic hydrocephalus (PTH), to define its prognostic value, and to assess the effects of shunt surgery.

DESIGN

Correlational study on a prospective cohort.

SETTING

Brain injury rehabilitation center.

PARTICIPANTS

One hundred forty patients with severe traumatic brain injury (TBI) referred to an inpatient intensive rehabilitation unit of primary care in a university-based system.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

The Glasgow Outcome Scale (GOS), Disability Rating Scale (DRS), FIM instrument, and Neurobehavioural Rating Scale (NRS), as well as single-photon emission computed tomography (SPECT) and magnetic resonance imaging.

RESULTS

PTH was found in 45% of patients. Risk factors for PTH were as follows: age (P<.04), duration of coma (P<.0001), and decompressive craniectomy (P<.0001). PTH correlated with the degree of hypoperfusion in the temporal lobes (P<.001). Patients who showed clinical deterioration improved after surgery. PTH correlated significantly with GOS, DRS, FIM, and NRS (P<.0001) 1 year after the trauma, and it influenced the appearance of posttraumatic epilepsy (P<.02).

CONCLUSIONS

PTH concerns about 50% of patients with severe TBI. It influences functional and behavioral outcome and the appearance of posttraumatic epilepsy. The selection of patients for surgery can be defined principally on a clinical basis. SPECT may be helpful for differentiating ventricular enlargement due to cortical atrophy and hydrocephalus.

Neurologic improvement following shunt placement for post-traumatic hydrocephalus in a child

Post-traumatic hydrocephalus (PTH) is a medical complication of traumatic brain injury (TBI). There have been numerous reports of functional gains after shunt placement for PTH in adults but only rare observations about children. In this report, we present a child with PTH who displayed dramatic neurologic improvement after shunting. A 7-year-old boy sustained a severe TBI in a motor vehicle accident. When admitted for rehabilitation, his eyes were spontaneously open and he withdrew all extremities to pain but failed to follow commands. In rehabilitation, he made slow, steady progress in his cognitive and physical abilities. A CT scan conducted two months post-injury revealed marked ventriculomegaly necessitating shunt placement. Post-surgery, he began to verbalize, and was oriented to personal information. This case suggests that in children as well as adults with severe TBI and limited cognitive recovery, the possibility of PTH should be considered.

Investigation of morphological change of lateral and midline fluid percussion injury in rats, using magnetic resonance imaging

OBJECTIVE

Investigating the time course of morphological changes in experimental traumatic brain injury (TBI) in vivo helps to clarify the mechanism of TBI and develop new therapeutic modalities. We examined the morphological changes in experimental TBI, using magnetic resonance imaging (MRI) in a rat model.

METHODS

We produced lateral fluid percussion injury (LFP) and midline fluid percussion injury (MFP) in rats, using the Yamaki fluid percussion device. The rats were divided into four groups: LFP, MFP, sham LFP, and sham MFP. MRI was performed with a 4.7-T magnetic resonance apparatus 2 days and 90 days after the induction of injury. T1-, T2-, and T2- weighted images were obtained using a surface coil.

RESULTS

Hemorrhage, contusion, and brain edema in LFP models were detected on the 2nd day after injury, and the necrotic tissue was absorbed and replaced by cerebrospinal fluid on the 90th day. In MFP animals, we detected a small hemorrhage in the corpus callosum with minimal brain edema around the hemorrhage on the 2nd day after injury, and on the 90th day, enlarged ventricles and cisterns were observed, indicating brain atrophy.

CONCLUSION

MRI, therefore, is useful for plotting morphological changes in experimental TBI in vivo. We report the novel and clinically important finding of brain atrophy after experimental TBI.

Posttraumatic ventriculomegaly: hydrocephalus or atrophy? A new approach for diagnosis using CSF dynamics

Cerebrospinal fluid (CSF) dynamics were correlated to the changes in ventricular size during the first 3 months posttrauma in patients with severe head injury (Glasgow Coma Scale score < or = 8, 75 patients) to distinguish between atrophy and hydrocephalus as the two possible causes of posttraumatic ventriculomegaly. Using the bolus injection technique, the baseline intracranial pressure (ICP), pressure volume index, and resistance for CSF absorption (R0) provided a three-dimensional profile of CSF dynamics that was correlated with ventricular size and Glasgow Outcome Scale (GOS) score at 3, 6, and 12 months posttrauma. Patients were separated into five different groups based on changes in ventricular size, presence of atrophy, and CSF dynamics. Group 1 (normal group, 41.3%) demonstrated normal ventricular size and normal ICP. Group 2 (benign intracranial hypertension group, 14.7%) showed normal ventricular size and elevated ICP. Group 3 (atrophy group, 24%) displayed ventriculomegaly, normal ICP, and normal R0. Group 4 (normal-pressure hydrocephalus group, 9.3%) had ventriculomegaly, normal ICP, and high R0. Group 5 (high-pressure hydrocephalus group, 10.7%) showed ventriculomegaly and elevated ICP with or without high R0. The GOS score in the nonhydrocephalic groups (Groups 1, 2, and 3) was better than in the hydrocephalic groups (Groups 4 and 5). It is concluded from these results that 44% of head injury survivors may develop posttraumatic ventriculomegaly. Posttraumatic hydrocephalus, as identified by abnormal CSF dynamics, was diagnosed in 20% of survivors and their outcome was significantly worse. This study demonstrates the importance of using CSF dynamics as an aid in diagnosis of posttraumatic hydrocephalus and identifying those patients who may benefit from shunt placement.

Shunting in chronic post-traumatic hydrocephalus: demonstration of neurophysiologic improvement

The neuronal metabolic state that forms the cellular basis for cognitive functioning and motor behavior is dependent on cerebral perfusion. As intracerebral pressure increases, cerebral perfusion is compromised. The management of acute hydrocephalus after head trauma has been extensively described. In this article, we present evidence of clinical, cerebral perfusion, and neurophysiologic improvement in a 19-year-old patient with chronic post-traumatic hydrocephalus. Lethargy, gaze palsy, torticollis, and triplegia were noted 2 years postinjury in a neurologically stable patient. Computed axial tomography (CAT) scan confirmed marked enlargement of the third and fourth ventricles with a prominent subgaleal fluid collection. Intraoperative cerebral spinal fluid pressure was 26cm H2O despite hyperventilation. A ventriculo-peritoneal shunt was placed. Postoperatively, marked improvement in clinical exam, cerebral perfusion (SPECT scan), and evoked potentials correlated with the reemergence of the cerebral mantle on CAT scan and magnetic resonance imaging (MRI). Chronic obstructive hydrocephalus should be suspected and aggressively pursued in chronic head injury.

A new model of diffuse brain injury in rats. Part I: Pathophysiology and biomechanics

This report describes the development of an experimental head injury model capable of producing diffuse brain injury in the rodent. A total of 161 anesthetized adult rats were injured utilizing a simple weight-drop device consisting of a segmented brass weight free-falling through a Plexiglas guide tube. Skull fracture was prevented by cementing a small stainless-steel disc on the calvaria. Two groups of rats were tested: Group 1, consisting of 54 rats, to establish fracture threshold; and Group 2, consisting of 107 animals, to determine the primary cause of death at severe injury levels. Data from Group 1 animals showed that a 450-gm weight falling from a 2-m height (0.9 kg-m) resulted in a mortality rate of 44% with a low incidence (12.5%) of skull fracture. Impact was followed by apnea, convulsions, and moderate hypertension. The surviving rats developed decortication flexion deformity of the forelimbs, with behavioral depression and loss of muscle tone. Data from Group 2 animals suggested that the cause of death was due to central respiratory depression; the mortality rate decreased markedly in animals mechanically ventilated during the impact. Analysis of mathematical models showed that this mass-height combination resulted in a brain acceleration of 900 G and a brain compression gradient of 0.28 mm. It is concluded that this simple model is capable of producing a graded brain injury in the rodent without a massive hypertensive surge or excessive brain-stem damage.

Ventricle size, cortical atrophy and the relationship with neuropsychological status in closed head injury: a quantitative analysis

Forty-eight patients with a history of moderate to severe closed-head injury (CHI) were examined with neuropsychological measures and computerized tomography (CT). CT scans were assessed with computerized techniques to determine estimated ventricular volumes (VV) and the degree of cortical atrophy (ATVOL) in each patient. VV's then were used to determine volumetric ventricle-brain ratios (VBR) to correct for head size. The WAIS, Wechsler Memory Scale (WMS) and Halstead-Reitan Neuropsychological Test Battery (HRNTB) were administered to all patients. Correlational analyses were undertaken between VBR and ATVOL measures. PIQ but not VIQ was negatively correlated with VBR and ATVOL, particularly in terms of right-hemisphere measures. WMS Memory Quotient (MQ) also was negatively correlated with VBR and ATVOL with no lateralization. Several HRNTB measures similarly were correlated with ventricular and atrophy estimates. Correlational results also were analyzed in terms of the influence of higher and lower VBR and ATVOL, and the prior presence of hematoma. Results are discussed in terms of the latent effects of cerebral damage secondary to CHI on neuropsychological functioning.

Late effects of hematoma on brain morphology and memory in closed head injury

In order to examine the late effects of prior hematoma on brain morphology and memory in closed head injury (CHI), 16 patients with a history of hematoma and craniotomy following injury were matched with CHI patients without prior hematoma. Volumetric estimates of cortical atrophy and ventricle size computed from CT scans were obtained in addition to Wechsler Memory scale (WMS) scores. Patients with a history of hematoma demonstrated significantly greater cortical atrophy than nonhematoma CHI patients irrespective of hematoma location. The hematoma group also was found to have greater ventricular dilation, although this difference only approached significance. In terms of memory abilities, the hematoma group was more impaired on WMS Memory Quotient (MQ) and the Associate Learning subtest in particular. Results suggest that hematoma following head injury may promote additional detrimental effects on brain morphology and memory status.

Posttraumatic hydrocephalus--a retrospective review

The authors retrospectively reviewed all cases of acquired hydrocephalus admitted to the Institute of Neurological Sciences, Glasgow, Scotland, within a 5-year period and encountered 17 cases of posttraumatic hydrocephalus. These represented 0.7% of 2374 cases of severe head injury. Hydrocephalus became symptomatic within 1 year from the time of injury in 16 of 17 cases. Meningitis, traumatic subarachnoid hemorrhage, posterior fossa mass, supratentorial clot with contralateral ventricular dilatation, and craniotomy contributed to the development of posttraumatic hydrocephalus. After shunting, eight patients (50%) improved markedly and four (25%) slightly.

Delayed sequelae of head injury

The evaluation of delayed sequelae of head injury is greatly facilitated by CT. This non-invasive technique provides us with the opportunity to evaluate the head trauma patients sequentially to detect the development and clinical significance of post-traumatic sequelae like delayed intracerebral hemorrhage, hydrocephalus, and post-traumatic atrophy.