Early decompressive craniectomy may be effective in the treatment of refractory intracranial hypertension after traumatic brain injury

INTRODUCTION

We compared the effect of early decompressive craniectomy (<24 h) vs non-operative treatment on the outcome of children with refractory intracranial hypertension after severe traumatic brain injury.

MATERIAL AND METHODS

We retrospectively reviewed 12 consecutive patients treated between 1999 and 2001 for refractory intracranial hypertension after isolated severe head injury without any intracranial haematomas. In all patients, treatment included sedation, paralysis and i.v. mannitol under intracranial pressure monitoring. Early decompressive craniectomy was carried out in six patients (mean age: 13 years) at mean time from injury of 7 h (range: 2-18 h), whereas six patients (mean age: 11.5 years) were managed with non-operative treatment. The Marshall Grading system was used to score the severity of radiological abnormalities in CT scans. The Glasgow Outcome Scale (GOS) at 1-year follow-up was used as outcome measure.

RESULTS

The mean Marshall grade was 3 in the craniectomy group and 2 in the non-operative group. All patients in the craniectomy group survived: four patients scored 5 and two patients scored 4 on the GOS. In the non-operative group, two patients (33%) died, one of whom received late decompressive craniectomy at 9 days, while three patients scored 5 and one patient scored 3 on the GOS.

CONCLUSION

In children who suffered severe head injury with refractory intracranial hypertension without intracranial haematoma, early decompressive craniectomy employed in the first few hours after injury before the onset of irreversible ischaemic changes may be an effective method to treat the secondary deterioration that commonly leads to death or severe neurological deficit.

Diffusion tensor imaging of benign intracranial hypertension: absence of cerebral oedema

Cerebral oedema, it has been suggested, may have a role in the pathophysiology of benign intracranial hypertension (BIH). We applied diffusion tensor MR imaging (DTI), a technique able to detect cerebral oedema, to the study of patients with BIH. A quantitative regional analysis of diffusion parameters (trace and relative anisotropy) was conducted by comparing five BIH patients and six healthy controls. A small but significant increase in anisotropy accompanied by a small but significant decrease in trace was found in the putamen and head of the caudate nucleus. No significant changes were demonstrated in the thalamus, cerebral white matter or cortical regions. Our findings support other recent work that suggests cerebral oedema is not a factor in the pathogenesis of BIH.

Retinal nerve fiber layer analysis in idiopathic intracranial hypertension

BACKGROUND

The chronic nature of idiopathic intracranial hypertension (IIH) represents a risk factor for progressive optic nerve damage and structural abnormalities of the retina.

AIM

We measured the retinal nerve fiber layer (RNFL) thickness in patients followed with the diagnosis of IIH who had no or mild visual impairment to search for possible structural alterations in the retina for diagnostic and prognostic purposes.

SETTINGS AND DESIGN

Case-control prospective study.

MATERIALS AND METHODS

The study group consisted of 12 women followed and treated with the diagnosis of IIH in our clinic. The selection criteria were the, normal optic nerve, normal visual fields or mild visual field defects (Grade 1-3) by Humphrey perimeter. Randomly assigned, age-matched 12 healthy women were taken as the control group. Retinal nerve fiber layer thickness was evaluated with scanning laser polarimetry and both eyes were studied for each case in both groups.

STATISTICAL ANALYSIS USED

Mann-Whitney U test.

RESULTS

The mean ages of the patient and the control groups were 34.58+/-4.2 and 34.42+/-5.7 years respectively (P=0.87). The mean duration of disease was 5.5+/-3 years. Some parameters related to RNFL thickness were found to differ significantly between patients with IIH and control subjects. Namely superior ratio (P=0.007), inferior ratio (P=0.039), superior-nasal ratio (P=0.025), maximum modulation (P=0.01) and symmetry (P=0.006) were lower in the patient group than controls.

CONCLUSION

Scanning laser polarimetry might be a good adjunct for determining possible structural affects of IIH on the retina in patients with no or mild visual impairment.

Basilar megadolicho trunk causing obstructive hydrocephalus at the foramina of Monro

We report on a 54-year-old man with megadolicho basilar artery presenting with acute signs of raised intracranial pressure due to a compromise of cerebrospinal fluid (CSF) flow at the level of the foramina of Monro by the basilar apex extending more than 3 cm cranially to the dorsum sellae. The diagnosis was confirmed on computed tomographic angiography and emergent CSF drainage relieved symptoms immediately.

Photodynamic therapy increases brain edema and intracranial pressure in a rabbit brain tumor model

The objective of this study was to evaluate the effect of a single photodynamic therapy (PDT) on brain edema and intracranial pressure (ICP) in a rabbit model of brain tumor. A total of 57 adult New Zealand rabbits were assigned to 3 groups: the PDT group, the tumor group, and the tumor plus PDT group. Rabbits in the PDT group (n = 9) received PDT but no tumor implantation; rabbits in the tumor group (n = 18) received VX2 carcinoma implantation but no PDT; rabbits in the tumor plus PDT group (n = 30) received tumor implantation with subsequent PDT 16 days later. Brain edema and ICP levels were then evaluated. We found that ICP in the PDT group was 7.43 +/- 0.50 mmHg. After tumor implantation, ICP increased rapidly (18.43 +/- 1.10 mmHg, 21 days later). PDT alone did not increase ICP, but compared with that in the tumor group, ICP increased significantly in the tumor plus PDT group (9.55 +/- 1.32 vs. 13.31 +/- 1.13 mmHg, p < 0.01) 24 hours after treatment. Brain water content in the tumor group increased rapidly after tumor implantation. PDT again increased perineoplastic brain edema 24 hours after treatment (81.09 +/- 0.97% vs. 78.32 +/- 0.49%, p < 0.01). It should be noted that PDT alone did not induce brain edema. In conclusion, PDT causes transient brain edema and increases ICP in a rabbit brain tumor model.

Primary empty sella syndrome in a series of 142 patients

OBJECT

The primary empty sella syndrome (ESS) represents a heterogeneous clinical picture characterized by endocrine disturbances and signs of intracranial hypertension. An increase in intracranial pressure (ICP) is proposed to be one of the involved pathogenetic factors.

METHODS

The series included 142 patients who were observed during a period of 20 years. All patients underwent an ICP and cerebrospinal fluid (CSF) dynamics evaluation through the use of a lumbar constant-rate infusion test. Impairment of ICP and CSF dynamics was observed in 109 patients (76.8%). In 35 of the 36 patients affected by severe intracranial hypertension without rhinorrhea, improvement in adverse neurological symptoms was achieved after implanting a CSF shunt. Visual function, already seriously compromised before surgery, remained severely altered in one patient. In the group of 34 patients affected by rhinorrhea, CSF leakage was controlled using different surgical treatments: CSF shunt placement in 16 cases, surgical repair of the sellar floor in three, and both procedures in the remaining 13. Two patients refused any surgical treatment.

CONCLUSIONS

The role of increased ICP in the pathogenesis and perpetuation of primary ESS has been confirmed. Adverse neurological signs and a CSF leak are correlated with an actual increase in ICP and are relieved after CSF shunt insertion. Cerebrospinal fluid rhinorrhea is more common than generally thought. Its resolution can be achieved using a careful diagnostic protocol and sometimes may require different surgical procedures.

Comparison of simultaneous continuous intracranial pressure (ICP) signals from a Codman and a Camino ICP sensor

Simultaneous continuous intracranial pressure (ICP) signals from two different sensors were compared. Continuous ICP monitoring from two ICP sensors (i.e. Codman ICP MicroSensor; Johnson & Johnson, Raynham, MA and Camino OLM ICP; Camino Laboratories, San Diego, CA) placed within the brain parenchyma was performed in three patients within the intensive care unit (ICU) as part of routine management of severe subarachnoid hemorrhage. For each 6s time window mean ICP was computed, showing large differences in mean ICP values between the signals. Differences above 5 mmHg were observed in 13% of the 128,425 time windows derived from 214 h ICP recordings in these three patients. In one patient, mean ICP differed more than 10 mmHg in 23% of the time windows. Comparisons of 675,503 individual single pressure wave pairs of these 128,425 time windows revealed marginal differences in single wave amplitude (dP, i.e. pulse pressure) and latency (dT, i.e. rise time) values, suggesting that differences in mean ICP were caused by differences in baseline pressure. For the individual time windows were computed the mean wave amplitude and mean wave latency values according to a new algorithm. There were as well marginal differences between signals of mean wave amplitude and latency values. Thus, changes in baseline pressure affect mean ICP but not single pressure wave characteristics such as amplitude (dP) and (dT) latency values.

Intracranial hypertension as an initial manifestation of spinal neuroectodermal tumor

A 19-year-old girl had headaches, blurred vision and vomiting for 2 weeks. Neurological examination revealed only bilateral papilloedema and left abducens palsy. Neuroimaging of the brain was normal. Cerebrospinal fluid study showed intracranial hypertension (IH), hypoglycorrhachia, hyperproteinorrhachia, and a negative cytology study. Eight months after the onset, paraparesis occurred. Spinal magnetic resonance imaging showed intramedullary masses at the cervical and thoracic cords with extensive seeding. Biopsy of the mass showed primitive neuroectodermal tumor (PNET). IH rarely occurs in patients with spinal cord neoplasms. Its incidence is low and the condition is always associated with signs of myelopathy. We report a patient whose initial manifestation of spinal PNET was IH only. Spinal tumor should be considered in IH patients whose intracranial examinations are negative.

IPSAPIRONE AND KETANSERIN PROTECTS AGAINST CIRCULATORY SHOCK, INTRACRANIAL HYPERTENSION, AND CEREBRAL ISCHEMIA DURING HEATSTROKE

We assess the effects of ipsapirone (a 5-HT1A receptor agonist), ketanserin (a 5-HT2A receptor antagonist), (-)-pindolol (a 5-HT1A receptor antagonist), and DOI (a 5-HT2A receptor agonist) on heatstroke in a rat model. Animals, under urethane anesthesia, were exposed to high ambient temperature of 42 degrees C until mean arterial pressure and local cerebral blood flow in the striatum began to decrease, which was arbitrarily defined as the onset of heatstroke. Normothermic controls were exposed to room temperature of 24 degrees C. In rats treated with normal saline immediately before the initiation of heat stress, the values for survival time were found to be 21 to 25 min. Systemic administration of ipsapirone (10 mg/kg) or ketanserin (2 mg/kg) immediately before the initiation of heat stress significantly increased the survival time to new values of 92 to 104 min. Combined treatment with ipsapirone and ketanserin had additive effects (survival time of 156-194 min). In contrast, systemic administration of (-)-pindolol (2 mg/kg) or DOI (2 mg/kg) significantly decreased the survival time to new values of 2 to 3 min. In vehicle-treated heatstroke rats, the values for core temperature, intracranial pressure, and the extracellular levels of cellular ischemia (e.g., glutamate and lactate/pyruvate ratio) or damage (e.g., glycerol) markers and neuronal damage scores in striatum were significantly higher than those of normothermic controls. On the other hand, the values for mean arterial pressure, cerebral perfusion pressure, cerebral blood flow, and brain partial pressure of O2 were significantly lower than those of normothermic controls. The heatstroke-induced hyperthermia, arterial hypotension, intracranial hypertension, cerebral hypoperfusion and hypoxia, and increased levels of cellular ischemia and damage markers in striatum were all significantly attenuated by prior administration of ipsapirone or ketanserin. The present results strongly suggest that previous activation of 5-HT1A receptors or antagonism of 5-HT2A receptors protects against heatstroke by reducing circulatory shock and cerebral ischemia, whereas prior antagonism of 5-HT1A receptors or activation of 5-HT2A receptors exacerbates heatstroke.

Bilateral involvement of a single cranial nerve: Analysis of 578 cases

The author reviewed 34 years of personal experience with inpatients in a large municipal hospital to analyze the seats and causes of involvement of single pairs of cranial nerves. Among 578 cases, the sixth (n = 234) and second (211) nerves predominated, followed by the fourth (48), seventh (30), third (27), and eighth (18) cranial nerves. Trauma (99), infection (94), tumor (92), increased intracranial pressure (85), vascular disease (74), and demyelination (66) were common causes.

Resolution of neurogenic arterial hypertension after suboccipital decompression for Chiari malformation. Case report

A Chiari malformation Type I may remain asymptomatic until the patient has reached adulthood and acute presentation of symptoms occurs. In several clinical and experimental studies it has been shown that essential hypertension is associated with vascular compression of the brainstem, particularly of the rostral ventrolateral medulla oblongata. Nevertheless, two cases of Chiari malformation and neurogenic arterial hypertension have been reported. In this article the authors describe a patient with Chiari malformation Type I and neurogenic arterial hypertension. A simple suboccipital decompression not only provided neurological improvement, but also led to resolution of the hypertension. In cases of Chiari malformation and concomitant neurogenic arterial hypertension, careful preoperative clinical and neuroimaging assessments may reveal the cause of the arterial hypertension. Resolution of neurogenic arterial hypertension may be expected even in a case of simple suboccipital decompression.

Trigeminal neuralgia secondary to Chiari's malformation—treatment with ventriculoperitoneal shunt

BACKGROUND

Trigeminal neuralgia (TN) is most commonly related to vascular compression of the trigeminal nerve. Trigeminal neuralgia associated with Chiari's malformation and associated hydrocephalus are rare.

CASE DESCRIPTION

A 31-year-old male presented with classical TN affecting the mandibular division of the right trigeminal nerve. His symptoms were poorly controlled with increasing doses of carbamazepine. Magnetic resonance imaging scan of brain revealed Chiari's type I malformation and associated hydrocephalus. Approximately 1 month after insertion of a programmable ventriculoperitoneal shunt, his TN resolved.

CONCLUSIONS

Chiari's malformation and hydrocephalus are rare associates of TN. The pathophysiology of TN in these cases may be due to neurovascular conflict, related to raised intracranial pressure from the hydrocephalus and/or the small posterior fossa volume in these patients. Drainage of associated hydrocephalus may be an effective surgical treatment.

Postischemic reperfusion: ultrastructural blood-brain barrier and hemodynamic correlative changes in an awake model of transient forebrain ischemia

OBJECTIVE

In nonrecovery models of cerebral ischemia, blood-brain barrier (BBB) and cerebral blood flow (CBF) changes are known to occur during reperfusion. It is unknown, however, whether those CBF and BBB alterations occur after brief, transient ischemia with neurological recovery. The purpose of this study was to characterize the time course of CBF and BBB ultrastructural changes during reperfusion in an awake, recovery model of transient global forebrain ischemia (GFI).

METHODS

Forty-five adult Sprague-Dawley rats were subjected, while awake, to 10 minutes of GFI by the nine-vessel occlusion method. Thirty-five age-matched animals composed a sham-operated group. Normal control (n = 5), sham-operated (n = 5), and nine-vessel occlusion/reperfusion (n = 15) rats were selected for ultrastructural analysis. Electroencephalography was performed, and CBF, mean arterial blood pressure, and intracranial pressure were measured during ischemia and reperfusion up to 24 hours. Quantitative morphological analysis of cortical BBB capillaries was performed by transmission electron microscopy at the same time points at which specific CBF changes occurred during reperfusion.

RESULTS

CBF decreased to 6% of preocclusion values during GFI. This correlated with coma and decerebrate rigidity. During reperfusion, short-lived hyperemia (225 +/- 18%, P < 0.001) was characterized by increased intracranial pressure (28.3 +/- 2.6 mm Hg, P < 0.001) and isoelectric electroencephalogram. This was followed by hypoperfusion, which reached a nadir of 59.7% (59.7 +/- 8.8%, P < 0.01) from baseline by 90 minutes. At this time point, the electroencephalogram recovered, and intracranial pressure and mean arterial blood pressure showed no abnormalities. By 8.5 hours, CBF returned to normal, and this coincided with complete recovery of the animal. Ultrastructural BBB analysis revealed astrocyte end-foot process edema and patent capillaries during hyperemia. Severe interstitial BBB edema and capillary lumen collapse was observed during hypoperfusion. Detachment and migration of pericytes was observed during hypoperfusion and beyond.

CONCLUSION

A biphasic CBF response is elicited during reperfusion after brief nonlethal GFI under awake conditions.

[Sonography of the optical nerve -- experience in 483 children]

INTRODUCTION

In case of increased intracranial pressure (IICP), the inflow of cerebrospinal fluid widens the space between the optic nerve (ON) itself and the surrounding dura mater leading to the sonographic appearance of increased diameter of the ON. The purpose of the study was to gain clinical experience in children and to determine (a) the mean values for patients without proven IICP and (b) pathologic values of those with proven IICP.

MATERIALS AND METHODS

Ultrasound of the optic nerve was performed in 483 children with symptoms consistent with IICP, comprising 287 males and 196 females at an age ranging from 4 days to 24 years with a mean age of 7.5 + 5.1 years. The measured diameter of the ON of both eyes and the morphologic criteria concerning nerve sheath and papilla were evaluated retrospectively.

RESULTS

Most of the investigated patients (n = 466) had no IICP as confirmed by neurological examination, EEG, sometimes CCT and/or MRI and clinical follow-up. The typical morphological findings in patients with normal intracranial pressure (ICP) were a clear and longitudinally extended demarcation of the ON with a well-delimited nerve sheath and without prominent papilla. The mean diameter of the ON in patients with normal ICP was 3.4 mm + 0.7 mm. In 17 patients with proven IICP, the mean diameter of the ON increased to 5.6 mm + 0.9 mm. Typically, the nerve sheath was indistinguishable from the hypoechoic ON, often but not invariably associated with a prominent papilla. In patients with IICP, the diameter of the ON alone matches the diameter of the ON plus nerve sheath in patients with normal ICP.

CONCLUSION

IICP was detected with a high sensitivity by ultrasound using the diameter and the morphological criteria of an indistinguishable nerve sheath. A diameter of more than 4.5 mm is definitely pathologic and requires further investigation. Prominence of the papilla is an unreliable criterion for acute IICP.

Correlation of cell apoptosis with brain edema and elevated intracranial pressure in traumatic brain injury

OBJECTIVE

To study the correlation between brain edema, elevated intracranial pressure (ICP) and cell apoptosis in traumatic brain injury (TBI).

METHODS

In this study, totally 42 rabbits in 7 groups were studied. Six of the animals were identified as a control group, and the remaining 36 animals were equally divided into 6 TBI groups. TBI models were produced by the modified method of Feeney. After the impact, ICP of each subject was recorded continuously by an ICP monitor until the animal was sacrificed at scheduled time. The apoptotic brain cells were detected by an terminal deoxynucleotide-transferase-mediated dUTP-digoxigenin nick end labeling (TUNEL) assay. Cerebral water content (CWC) was measured with a drying method and calculated according to the Elliott formula. Then, an analysis was conducted to determine the correlation between the count of apoptotic cells and the clinical pathological changes of the brain.

RESULTS

Apoptotic cell count began to increase 2 h after the impact, and reached its maximum about 3 days after the impact. The peak value of CWC and ICP appeared 1 day and 3 days after the impact, respectively. Apoptotic cell count had a positive correlation with CWC and ICP.

CONCLUSIONS

In TBI, occurrence of brain edema and ICP increase might lead to apoptosis of brain cells. Any therapy which can relieve brain edema and/or decrease ICP would be able to reduce neuron apoptosis, thereby to attenuate the secondary brain damage.

Evolution of Brain Tissue Injury after Evacuation of Acute Traumatic Subdural Hematomas

OBJECTIVE:

Acute traumatic subdural hematoma complicated by brain parenchymal injury is associated with a 60 to 90% mortality rate. Early surgical evacuation of the mass lesion is essential for a favorable outcome, but the severity of the underlying brain injury determines the outcome, even when surgery has been prompt. The purpose of this study was to analyze tissue biochemical patterns in the brain underlying an evacuated acute subdural hematoma to identify a characteristic pattern of changes that might indicate evolving brain injury.

METHODS:

Prospectively collected data from 33 patients after surgical evacuation of acute subdural hematoma were analyzed. Both a brain tissue oxygen tension probe and an intracerebral microdialysis probe were placed in brain tissue exposed at surgery. On the basis of the postoperative clinical course, the patients were divided into three groups: patients with early intractable intracranial hypertension, patients with evolution of delayed traumatic injury (DTI), and patients with an uncomplicated course (the no-DTI group).

RESULTS:

The overall mortality rate was 46%, with 100% mortality in the intracranial hypertension group (five patients). Mortality in the DTI group was 53% compared with only 9% in the no-DTI group (P = 0.002). There were no significant differences in the initial computed tomographic scan characteristics, such as thickness of the subdural hematoma or amount of midline shift, among the three groups. Physiological variables, as well as the microdialysate measures of brain biochemistry, were markedly different in the intracranial hypertension group compared with the other groups. Differences between the other two groups were more subtle but were significant. Significantly lower values of brain tissue oxygen tension (14 ± 8 mm Hg versus 27 ± 14 mm Hg) and higher dialysate values of lactate and pyruvate were documented in patients who developed a delayed injury compared with patients with uncomplicated courses (4.1 ± 2.3 mmol/L versus 1.7 ± 0.7 mmol/L for lactate, and 104 ± 47 μmol/L versus 73 ± 54 μmol/L for pyruvate at 24 h after injury).

CONCLUSION:

Evolution of DTI in the area of brain underlying an evacuated subdural hematoma is associated with a significant increase in mortality. Postoperatively decreasing brain tissue oxygen tension and increasing dialysate concentrations of lactate and pyruvate in this area may warn of evolving brain injury and evoke further diagnostic and therapeutic activity.

Hypertonic Fluid Resuscitation from Subarachnoid Hemorrhage in Rats

OBJECTIVE

Increased intracranial pressure (ICP) and decreased cerebral blood flow leading to global cerebral ischemia are the primary causes of death after severe subarachnoid hemorrhage (SAH). Hypertonic saline has been demonstrated to exert neuroprotective properties after traumatic brain injury by osmotic mobilization of parenchymal water and improvement of microcirculation. We used a rat model to investigate the effects of hypertonic fluid resuscitation after SAH on ICP, cerebral blood flow, body weight, neurological recovery, and morphological damage.

METHODS

Sixty rats were subjected to SAH induced by an endovascular filament. ICP and local cerebral blood flow were recorded continuously. Animals were assigned to three groups: 1) NaCl 0.9%; 2) NaCl 7.5% (4 ml/kg); and 3) NaCl 7.5% plus 6% dextran 70 (4 ml/kg) given 30 minutes after SAH. Body weight and neurological deficits were assessed daily. Morphological damage was evaluated on Day 7.

RESULTS

SAH resulted in an immediate increase of ICP to approximately 60 mm Hg initially, and then to approximately 30 mm Hg for the next 90 minutes. Although NaCl 7.5% alone and in combination with dextran led to an immediate, significant, and lasting decrease of ICP to 15 to 20 mm Hg, only the combined therapy significantly increased body weight and improved neurological recovery. Furthermore, the group that received combined therapy exhibited significantly more surviving neurons in hippocampus, cortex, caudoputamen, and cerebellum. Mortality was reduced nonsignificantly, from approximately 65% in groups I and II to 35% in Group III.

CONCLUSION

Treatment with NaCl 7.5% plus 6% dextran 70 is significantly effective for reducing the initial harmful sequelae of SAH. The regimen resulted in lowered ICP, improved neurological recovery, and less morphological damage after SAH in the rat.

Chronic Intracranial Hypertension with Unexplained Cerebrospinal Fluid Pleocytosis

In a retrospective review of all cases with a diagnosis of idiopathic intracranial hypertension in two academic departments of neurology over a nine-year period, the authors identified six patients with a clinical course typical of idiopathic intracranial hypertension (IIH) except for the finding of cerebrospinal fluid pleocytosis. There were five women and one man with a mean age at presentation of 25.7 years (range, 25-32 yr). All were obese but had no other associated medical conditions or identifiable risk factors for IIH. In five patients, all or most cerebrospinal fluid cells were lymphocytes. Cerebrospinal fluid pleocytosis persisted for several months in all patients. Patients underwent a thorough laboratory and neuroimaging evaluation that did not reveal a primary cause. Medical treatment directed solely at lowering intracranial pressure was effective in five patients; one patient required lumboperitoneal shunting. Ophthalmic manifestations of increased intracranial pressure stabilized or remitted after treatment was withdrawn with a mean follow-up period of 33 months (range, 14-55 mo). Some patients may present with idiopathic chronic meningitis and elevated intracranial pressure that responds to treatment used for IIH.

Giant Supratentorial Enterogenous Cyst: Report of a Case, Literature Review, and Discussion of Pathogenesis

OBJECTIVE AND IMPORTANCE

To describe a histologically well-documented adult case of a giant supratentorial enterogenous cyst (EC). Fewer than 15 cases of supratentorial ECs are on record: 8 associated with the brain hemispheres or the overlying meninges, 4 with the sellar region, and 2 with the optic nerve.

CLINICAL PRESENTATION

A 31-year-old woman complained of long-standing mild left brachial and crural motor deficit precipitated by headache and signs of intracranial hypertension. Magnetic resonance imaging revealed a huge cyst overlying the frontoparietal brain.

INTERVENTION

Symptoms were relieved by evacuation of the cyst content by means of a Rickam's reservoir, and the lesion was subsequently removed in toto. Histological and immunohistochemical examination of the cyst wall clearly established the enterogenous nature of its epithelium. Follow-up for up to 2 years after intervention showed no sign of recurrence, and symptoms, including treatment-resistant seizures in the postoperative period, have entirely subsided.

CONCLUSION

Supratentorial ECs, distinctly rare in adult patients, may in some cases present as giant lesions. Total removal seems to be curative once careful examination has eliminated the possibility of a metastasis from an unknown primary. A correct histological diagnosis is important because, in contrast to other benign cysts of similar location and size, ECs may be prone to intraoperative dissemination.

Functional genomics as an emerging strategy for the investigation of central mechanisms in experimental hypertension

Centrally mediated increases in sympathetic nerve activity and attenuated arterial baroreflexes contribute to the pathogenesis of hypertension. Despite the characterization of cellular and physiological mechanisms that regulate blood pressure and alterations that contribute to hypertension, the genetic and molecular basis of this pathophysiology remains poorly understood. Strategies to identify genes that contribute to central pathophysiologic mechanisms in hypertension include integrative biochemistry and physiology as well as functional genomics. This article summarizes recent progress in applying functional genomics to elucidate the genetic basis of altered central blood pressure regulatory mechanisms in hypertension. We describe approaches others and we have undertaken to investigate gene expression profiles in hypertensive models in order to identify genes that contribute to the pathogenesis of hypertension. Finally, we provide the readers a roadmap for negotiating the route from experimental findings of gene expression profiling to translating their therapeutic potential. The combination of gene expression profiling and the phenotypic characterization of in vitro and in vivo loss or gain of function experiments for candidate genes have the potential to identify genes involved in the pathogenesis of hypertension and may present novel targets for therapy.