Age-dependent changes of cerebral ventricular size. Part I: Review of intracranial fluid collections

Slit ventricle syndrome: Historical considerations, diagnosis, pathophysiology, and treatment review

After the introduction of shunt treatment for the management of childhood hydrocephalus, a wide variety of complications related to this treatment modality have been recognized. The entity of slit ventricle syndrome (alternatively, symptomatic ventricular coaptation) is one of them, is frequently encountered in the pediatric population and its symptom complex resembles that of shunt failure. We conducted research on PubMed^®, MEDLINE^®, and Web of Science^®, using the keywords: “slit ventricles,” “slit ventricle syndrome,” “SVS” and “ventricular coaptation.” The aim of our review was to trace the advances made through the past decades, concerning our knowledge about the clinical characteristics, pathophysiology, and treatment options of this entity. The discrepancy among researchers about the offending etiology and the optimum treatment algorithm of this entity, as well as the necessity of an updated concept regarding shunt over drainage is analyzed. The multiple treatment modalities proposed and pathophysiologic mechanisms implicated for the treatment of slit ventricle syndrome illustrate the complexity of this entity. Consequently, the issue requires more detailed evaluation. In this review, we comment on all the main facets related to shunt over drainage and the resultant slit ventricle syndrome.

Long-Standing Overt Ventriculomegaly in Adults (LOVA): Diagnostic Aspects, CSF Dynamics with Lumbar Infusion Test and Treatment Options in a Consecutive Series with Long-Term Follow-Up

BACKGROUND

Long-standing overt ventriculomegaly in adults is a chronic form of hydrocephalus without a clear pathophysiological description and a consensus about the treatment. We present the results of endoscopic third ventriculostomy (ETV) in a consecutive series with a mean follow-up of 79 ± 23 months, highlighting how the preoperative lumbar infusion test could facilitate understanding the pathophysiology of the disease.

METHODS

We retrospectively collected data regarding clinical assessment, neuroradiological findings, and preoperative lumbar infusion tests in 22 symptomatic patients.

RESULTS

In the majority of cases, patients reported imbalance and gait disorders, and 8 subjects had headaches. The preoperative lumbar infusion test demonstrated a mean opening pressure of 13.95 ± 2.88 mm Hg, with plateau values ranging from 22 to 39 mm Hg. The resistance to outflow was 11.21 ± 2.00 mm Hg/mL/min. After the procedure, all patients reported improvement or halted progression in their presenting symptoms, whereas no significant reduction was demonstrated in Evans' index. One subject underwent a second ETV procedure after more than 2 years because of the failure of the endoscopic approach.

CONCLUSIONS

A progressive exhaustion of brain compliance plays an important role in explaining the dichotomy between severe ventriculomegaly and mild clinical symptoms in patients with long-standing overt ventriculomegaly in adults. The role of the aqueductal stenosis as a diagnostic criterion might be reconsidered. The preoperative infusion test data support this observation. Preoperative assessment should include not only clinical and neuroradiological evaluation but also the study of cerebrospinal fluid dynamics. ETV should be considered the treatment of choice because of its safety and efficacy. Long-term follow-up is mandatory.

Mortality and One-Year Functional Outcome in Elderly and Very Old Patients with Severe Traumatic Brain Injuries: Observed and Predicted

The aim of the present study was to evaluate mortality and functional outcome in old and very old patients with severe traumatic brain injury (TBI) and compare to the predicted outcome according to the internet based CRASH (Corticosteroid Randomization After Significant Head injury) model based prediction, from the Medical Research Council (MRC). Methods. Prospective, national multicenter study including patients with severe TBI ≥65 years. Predicted mortality and outcome were calculated based on clinical information (CRASH basic) (age, GCS score, and pupil reactivity to light), as well as with additional CT findings (CRASH CT). Observed 14-day mortality and favorable/unfavorable outcome according to the Glasgow Outcome Scale at one year was compared to the predicted outcome according to the CRASH models. Results. 97 patients, mean age 75 (SD 7) years, 64% men, were included. Two patients were lost to follow-up; 48 died within 14 days. The predicted versus the observed odds ratio (OR) for mortality was 2.65. Unfavorable outcome (GOSE < 5) was observed at one year follow-up in 72% of patients. The CRASH models predicted unfavorable outcome in all patients. Conclusion. The CRASH model overestimated mortality and unfavorable outcome in old and very old Norwegian patients with severe TBI.

Slitlike ventricle syndrome: a life-threatening presentation

Severely increased intracranial pressure can be life-threatening in shunted children who do not experience ventricular enlargement. This condition is termed normal ventricular hydrocephalus and represents the most severe form of slit ventricle syndrome.

CASE REPORT

A 7-year-old girl with a repaired lumbosacral myelomeningocele and shunted at birth who presented with headache, vomiting, seizure, and deterioration of level of consciousness was admitted to the pediatric intensive care unit. Because her ventricles were small to slitlike on cranial computed tomographic (CT) scan, the shunt was presumed to be working. Although the cerebrospinal fluid analysis was normal, she received initial empirical treatment of viral encephalitis. Twenty-four hours after admission, she evolved with apnea and bradycardia, requiring ventilatory support. Repeated CT scans were unchanged from one study to the next. After 48 hours, her condition worsened, and cerebrospinal pressure during lumbar puncture reached more than 30 mm Hg despite the serial CT scan disclosing no ventricular enlargement. She underwent a shunt revision that showed that the catheter was occluded and had adhered to the ventricular wall. The shunt was replaced, resulting in dramatic neurological improvement. This report highlights a life-threatening condition involving chronically shunted children who present severe intracranial hypertension without ventriculomegaly and may often be neglected or unrecognized by emergency physicians or general neurosurgeons.

EVALUATION AND TREATMENT OF PATIENTS WITH SUSPECTED NORMAL PRESSURE HYDROCEPHALUS ON LONG-TERM WARFARIN ANTICOAGULATION THERAPY

OBJECTIVE

Long-term anticoagulation is often considered a contraindication to shunt surgery for elderly patients with normal pressure hydrocephalus (NPH). However, no studies have investigated this question.

METHODS

We evaluated 25 patients who were taking warfarin for NPH between 2001 and 2004 with a protocol of cerebrospinal fluid (CSF) pressure monitoring and controlled CSF drainage via spinal catheter. Warfarin was stopped 5 to 7 days before lumbar puncture or shunt surgery and restarted 3 to 5 days after operation or at the time of discharge from the hospital. Programmable shunts with antisiphon devices set at the high-pressure range were preferentially used and adjusted in small increments.

RESULTS

After CSF drainage, 16 patients showed improvement and 15 underwent shunt surgery. Thirteen (87%) out of these 15 patients showed significant improvement in at least one symptom during a mean follow-up period of 8.2 months (range, 1–70 mo) after shunt surgery. There were two bleeding complications. One patient (6.7%) with cirrhosis who developed a subdural hematoma 13 days after operation had the shunt removed; another patient who developed an abdominal subcutaneous hematoma 5 days after operation required surgical evacuation and shunt revision surgery. Otherwise, 14 (93.3%) out of the 15 patients had no subdural hematoma during the follow-up period and there were no thromboembolic complications while the patients were not taking warfarin.

CONCLUSION

Elderly patients on long-term warfarin anticoagulation can be safely evaluated and treated for NPH using a protocol of continuous CSF drainage via spinal catheter for diagnosis, cautious periprocedural management of anticoagulation, and use of programmable shunts with antisiphon devices. The risk of subdural hematoma is not higher than reported series. Long-term anticoagulation with warfarin is not a contraindication per se for shunt surgery in NPH.

Vertical displacement of stereotaxic target in the cat brain after burr hole production of the skull

In order to observe the postoperative vertical displacement caused by various open functional stereotaxic procedures in the coordinate of brain target, we produced a similar surgical procedure in 14 cats. On preoperative computed tomography (CT) scans, certain well defined brain structures (the cortical surface of the brain and the floor of the third ventricle) were chosen as anatomical landmarks and their relationship to the skull were determined with the cat in a prone position. Thereafter, a burr hole was opened on the right side of the skull of each animal and a small dural incision was made. All animals were re-examined with CT scanning using the same technique and the distances to the skull were determined. There was a cortical descent in postoperative coronal CT images (range 1.2-3.6, mean 2.1 mm). On the other hand, the vertical coordinate of the floor of the third ventricle was found to be lower than it had been preoperatively, with an average of 0.6 mm lower (range -1.2(-)+0.3 mm). These results indicate that there was a good correlation between the degree of cortical descent and displacement of the vertical coordinate of the floor of the third ventricle (r = 0.70 and r = 0.69, respectively; P < 0.01). Our results also suggest that thalamic targets can be calculated by compensatory adjustment of the vertical coordinate by an additional distance of about half of the vertical descent. However, further experimental and clinical studies will be needed to determine the validity of this result in human beings.

Rapid spontaneous resolution of acute subdural hematoma and HIV related cerebral atrophy: case report

BACKGROUND

The natural history of a traumatic acute subdural hematoma is usually interrupted by its prompt surgical removal. Rapid spontaneous resolution within 48 hours, although infrequently reported, may be, underestimated and demonstrates a benign course of this condition. To our knowledge, this is the first case of rapid spontaneous resolution of an acute subdural hematoma in a patient with HIV encephalopathy and cerebral atrophy.

METHODS AND RESULTS

This 27-year-old man, an intravenous drug user with AIDS-related complex and HIV encephalopathy, suffered an acute subdural hematoma due to head injury in a car accident. The hematoma spontaneously resolved within 12 hours, resulting in a favorable outcome with nonoperative treatment.

CONCLUSIONS

AIDS related cerebral atrophy may not only have predisposed the patient to the development of an extracerebral collection, but may have also favorably influenced the spontaneous resolution of the hematoma. The mechanism of the hematoma resolution and the influence of HIV related cerebral atrophy is discussed.

Benign intracranial hypertension or communicating hydrocephalus: factors in pathogenesis

Benign intracranial hypertension and communicating hydrocephalus are uncommon but important disorders that affect cerebrospinal fluid dynamics. They have clinical similarities but their management is usually different. The factors determining which of the two disorders will develop include brain compliance, the state of the cranial sutures, the nature of the insult and its magnitude. I propose that the time course of the pathological events leading to presentation may be a further factor to consider in the pathogenesis and management of these disorders.

Idiopathic intracranial hypertension in female homozygous twins

The authors report on female homozygous twins with idiopathic intracranial hypertension. At the age of 12 years, both twins simultaneously developed visual disturbances with photophobia. At the age of 19 years, an ophthalmological examination disclosed papilloedema in both their eyes. At the age of 22 years, a lumbar puncture showed raised CSF pressure over (200 mm H2O) in both twins. Their neurological and radiological examinations were extremely similar; both of them had severely impaired visual acuity and impaired visual field, bilateral optic nerve atrophy, intracranial hypertension, an enlarged and partial empty sella turcica, digital markings of the calvalium, and an enlarged frontal subarachnoid space. This is the first case report describing idiopathic intracranial hypertension occurring in homozygous twins.

Postpartum bilateral subdural hematomas following spinal anesthesia: case report

BACKGROUND

Intracranial subdural hematoma is an exceptionally rare complication of spinal anesthesia. We report a case of this infrequent event and consider the influence of cerebral atrophy as a predisposing factor.

METHODS AND RESULTS

This 18-year-old woman with severe headaches was admitted to the hospital 42 days after delivery. She had a history of normal pregnancy and uneventful labor and delivery. The epidural anesthesia was satisfactory. Computed tomography showed bilateral chronic subdural hematomas that were surgically removed. An early follow-up scan showed marked resolution of the hematomas and a small sized brain with large subarachnoid space. A late follow-up scan confirmed the diagnosis of brain atrophy.

CONCLUSIONS

Persistence of headache and gradual progression despite treatment must be regarded as a sign of intracranial complication following spinal anesthesia. In this case, cerebral atrophy is considered to be a contributory factor for the development of subdural hematoma following dural puncture.

External hydrocephalus in adults. Report of three cases

The authors report three adult patients who developed a symptomatic extraaxial collection of cerebrospinal fluid (CSF) after an intracranial hemorrhage. The fluid shifted from the extraaxial into the ventricular space as the patients' symptoms progressed. The symptoms resolved after placement of a ventriculoperitoneal shunt. External hydrocephalus, which is frequently observed in children, had not yet been described in adults. It is important to differentiate chronic subdural collections from external hydrocephalus, because ventricular CSF shunting increases the former while it is the treatment for the latter. The authors believe that symptomatic extraaxial fluid collections developed in these three adults during the early phase of posthemorrhagic hydrocephalus because the ventricles presented great resistance to distention at the onset of hydrocephalus. Animal experiments have led to the same result.

Computer tomographic assessment of the pre- and postoperative ventricle width in patients with traumatic intracranial haematomas

The cellular integrity of the brain tissue is not only disturbed by space occupying traumatic intracranial haematomas but also by traumatic brain tissue damage and the accompanying oedema. Due to the insufficiency of visual inspection, methods for an objective quantification of the ventride width are required. A number of techniques have been used for evaluation of the CSF-space after cerebral trauma. In the present study changes of the ventricle size have been evaluated by using planimetric measurements of CT scans. In 222 patients with traumatic intracranial haematomas significant changes in the ventricle width could be demonstrated when the data were analysed by Wilcoxon signed rank test for pair differences. Comparison of the initial cranial computed tomography (CT) with a CT 14 days later revealed a significant dilatation of the ventricle width in all age groups in the second measurement. When patients were divided into groups with or without signs and symptoms of brainstem alteration after trauma, patients with symptoms of brainstem alteration exhibited a significantly greater ventricle width as compared to patients without such symptoms and signs.

Is the slit ventricle syndrome always a slit ventricle syndrome?

The term 'slit ventricle syndrome' (SVS) refers to the occurrence of headache, vomiting, and possibly some degree of consciousness impairment in shunted hydrocephalic children in whom slit-like ventricles are seen on computerized tomography (CT) scan examination. The syndrome has been typically observed in older hydrocephalic children operated on in early infancy, even though it has also been observed occasionally in young children and adults. The clinical characteristics of the SVS, the results of the laboratory investigations and the therapeutic measures utilized in the various cases described in the literature differ so widely as to suggest that different clinical conditions are actually being described. In some cases, the diagnosis of SVS should be avoided and substituted by a correct diagnosis of CSF shunt malfunction or of disturbances unrelated to the CSF shunting therapy, e.g., childhood migraine.

The gravitational shunt: an alternative approach to cerebrospinal fluid shunting

Current cerebrospinal fluid shunts use complex differential pressure values to regulate drainage. Such systems are prone to overdrainage and obstruction, and thus have an unpredictable effect on intracranial pressure (ICP). The gravitational shunt (GS) introduces an alternative approach. It uses a single, simple valve to balance the pressures generated within a vertical shunt system. The ICP is then regulated by the position of the valve along the cranioabdominal shunt axis and not by the mechanical properties of the valve. Bench testing demonstrated that when using the GS (1) a linear correlation (r = 0.91, p < 0.001) exists between the ICP and the position of the valve along the vertical shunt axis, (2) positive and negative ICPs are maintained, and (3) the ICP can be predicted by an equation derived from theoretical principles. The GS uses a single, simple valve as a pressure regulator and an antisiphon device. It allows the maintenance of a normal negative ICP in the upright position without risk of over-drainage. The other benefits of this system are discussed.

Evaluation of intracranial pressure gradients by means of transcranial Doppler sonography

The authors investigated the effects of intracranial pressure gradients generated by a unilateral intracranial mass on transcranial Doppler (TCD) readings. Eleven patients harbouring a symptomatic chronic or subacute subdural haematoma underwent pre- and post-operative TCD examinations of the intracranial internal carotid and middle cerebral arteries. Mean values of velocity and pulsatility index (PI) were compared to the contra-lateral counterpart. The haematomas were evacuated by means of burr hole drainage under local anaesthesia. Symptomatic subdural haematomas lowered the ipsilateral blood velocity in the internal carotid and middle cerebral arteries by a mean side-to-side difference of 15.64 +/- 3.01 m.sec-1. The ipsilateral PI was higher than the contralateral values by an average of 0.23 +/- 0.04. Low mean velocity and high PI values were associated with high subdural pressure. Abnormal pre-operative ipsilateral TCD readings returned to normal following haematoma drainage. We postulate that intracranial pressure gradients generated by the subdural mass lesion are responsible for the asymmetry of TCD readings. These differences should be considered in the interpretation of post-subarachnoid haemorrhage vasospasm, as it is frequently associated with lateral clots. Our findings also provide a useful method for non-invasive monitoring of intracranial pressure gradients.

Duplex color ultrasound study of infantile progressive ventriculomegaly

Sequential measurements of ventricular sizes and Doppler variables of anterior cerebral artery (ACA) by duplex color ultrasound were performed on 14 ventriculomegalic infants (mean age: 3.4 months): 9 were postmeningitic, 3 posthemorrhagic, and 2 congenital. According to changes of the frontal horn radius (FHR) after shunts, the FHR was decreased greater than 30% (n = 9) in group I and less than or equal to 10% (n = 5) in group II. Before shunting, Pourcelot index (PI) in group I was greater than in group II (P less than 0.01), but FHR in group II was higher than in group I (P less than 0.01). The intracranial pressure did not vary between groups. Serial preshunt examinations showed a significant correlation between the degree of cerebrovascular resistance and the degree of ventricular dilation only in group I. After surgery, significant changes of end-diastolic velocity, the area under the velocity curve, and PI were found only in group I. The reservoir pumping test performed on 2 cases of recurrent ventriculomegaly in group I and 3 cases in group II showed a decreased PI only in group I, in which the outcome was better. PI is useful in differentiating between hydrocephalic and atrophic ventriculomegaly. These data suggest that a ventriculomegalic infant with an unelevated PI value hardly benefits from a ventricular shunt.