Risk analysis of thrombo-embolic and recurrent bleeding events in the management of intracranial haemorrhage due to oral anticoagulation.

PURPOSES: Intracranial haemorrhage (ICH) is a rare but potentially devastating complication of oral anticoagulants (OAC). This raises the difficult clinical choice between either permanent cessation of OAC, or continuing OAC and if so, when to restart. To make this choice, one needs to balance the thrombo-embolic risk after cessation of OAC against the risk of recurrent intracranial haemorrhage when OAC are restarted. There are few published data to base this difficult clinical decision on. METHODS: We present an observational study of a consecutive series of 108 patients, collected prospectively and admitted to our department, with an OAC-related intracranial haemorrhage, in whom we assessed the thrombotic event rate and the recurrent intracranial bleeding rate during follow-up. RESULTS: In the 25 patients in whom OAC were reinstituted no new thrombo-embolic events occurred (0/506 unprotected patient-days). In the group of patients in whom OAC were not restarted (n = 81), the thrombo-embolic event rate was 8/11590 unprotected patient-days, of which only 2 were cerebrovascular thrombo-embolisms. The overall risk of a thrombo-embolic complication can be estimated to be 0.66 events/1000 patient-days at risk (95% exact confidence limits of 0.3 to 1.3 events/1000 patient-days at risk). In three patients the thrombo-embolic event was fatal. We saw recurrent intracranial bleeding in eight patients, 2 of which were fatal. Seven of these occurred before the restarting of the OAC. CONCLUSIONS: In OAC-related intracranial haemorrhages, OAC can be stopped safely for a considerable period, with a very low overall thrombotic event rate. The recurrent bleeding risk after restarting OAC is low. Recurrent bleeding mostly occurred before restarting OAC and is probably caused by insufficient or unsustained correction of the initial coagulation deficit. Immediate reversal of anticoagulation provides the patient with the best possible treatment options including surgery. OAC-related intracranial haemorrhages can therefore be actively treated.

Tethered cord syndrome in occult spinal dysraphism: timing and outcome of surgical release.

OBJECTIVE: To investigate the influence of neurosurgical intervention on the appearance of upper motor neuron (UMN) signs in newborns diagnosed with occult spinal dysraphism and tethered cord (TC) during the first month of life. METHODS: A prospective study (1990 to 1996) of 22 consecutive newborns with occult spinal dysraphism monitored for the appearance of UMN signs. Untethering was performed when neurologic or urodynamic investigation indicated the presence of UMN dysfunction. RESULTS: Of 22 patients, 10 remained free of UMN symptoms during follow-up (mean, 67+/-22 months). Untethering was performed in 12 of 22 patients because of the presence of UMN symptoms. In 7 of these 12 patients, there was a documented asymptomatic period of 13+/-11 months before the onset of UMN symptoms. Untethering at a mean age of 18+/-17 months restored normal neurologic and urinary function in all patients (mean postoperative follow-up, 25+/-16 months). Of the 12 children, 5 presented with UMN signs at birth. In these children, untethering was performed at a mean age of 9+/-5 months. In two of these five patients, UMN symptoms did not resolve after surgery, and ongoing conservative bladder treatment was required (mean follow-up, 37+/-14 months). In none of the 12 operated children did signs of retethering occur. CONCLUSIONS: A significant number (10/22) of children born with occult spinal dysraphism and TC did not develop UMN symptoms during follow-up; neurosurgical correction after the appearance of an UMN sign restored normal neurologic and urinary function in all children; and untethering in children presenting at birth with UMN symptoms resulted in poorer outcome.

Arterial hypertension in neurosurgical emergencies.

The Cushing, or ischemic response, is a useful mechanism in intracranial hypertension because it restores normal cerebral perfusion pressure and cerebral circulation. In patients with acute intracranial hypertension due to mass-expanding lesions such as brain edema, hydrocephalus or brain tumor, cerebral perfusion pressure decreases and plateau waves occur. In experimental animals, spontaneous or induced arterial hypertension can compensate for the reduction of cerebral perfusion pressure. The interrelation between arterial pressure, intracranial pressure and cerebral perfusion pressure in an experimental model of hydrocephalus in dogs was investigated. Plateau waves were preceded by a decrease in cerebral perfusion pressure and a Cushing response was seen 5 to 15 seconds before abolition of the wave. Arterial hypertension, induced by intravenous infusion of Aramin, restored cerebral perfusion pressure and intracranial pressure became normal. Arterial hypertension appears to be an efficient stimulus to abort plateau waves. Hypertensive patients in whom subarachnoid bleeding develops from ruptured aneurysm are at high risk of bleeding again and need antihypertensive treatment together with drainage of cerebrospinal fluid. Induced arterial hypertension is the most effective treatment of vasospasm but increases the danger of aneurysmal rebleeding and can only be safe after clipping of the aneurysm. This is one of the strongest arguments for early operation on cerebral aneurysms.

Simultaneous occurrence of developmental venous anomalies and cavernous angiomas.

PURPOSE: To study the clinical and radiologic findings in 15 patients presenting with both developmental venous anomalies and cavernous angiomas and to determine which lesions caused the acute clinical symptoms. METHODS: Lesions were infratentorial in 7 patients and supratentorial in 7 other patients. In one patient the developmental venous anomaly was infratentorial and the cavernous angioma supratentorial. In all 15 patients clinical examination and CT were performed. In 10 patients MR was performed at the time of the initial CT scan. In 5 patients only late MR is available. RESULTS: Acute clinical signs were present in 9 patients (epilepsy, hemiplegia, meningeal signs, cranial nerve deficit). On CT the cavernous angioma was missed in 9 patients, in 6 patients because of acute hemorrhage. On MR the cavernous angioma was missed in 1 of 2 cases with acute hemorrhage but seen in all other patients. On repeat MR all cavernous angiomas were correctly identified. On CT, 11 developmental venous anomalies were seen. On MR all developmental venous anomalies were seen. CONCLUSIONS: The frequent association of developmental venous anomalies and cavernous angiomas is confirmed. MR is superior to CT in the detection of both cavernous angiomas and developmental venous anomalies. Furthermore our data support the hypothesis that cavernous angiomas and not the developmental venous anomalies cause the acute clinical symptoms because of hemorrhage.

Gyriform calcifications in tuberous sclerosis simulating the appearance of Sturge-Weber disease.

Two cases of tuberous sclerosis are presented. Extensive superficial occipital calcifications were found as classically described in Sturge-Weber syndrome. Other radiologic signs of tuberous sclerosis, such as subependymal calcifications in both patients and surgically proved giant cell astrocytoma in one patient, were present. At pathologic examination, the calcifications appeared to be located in extensive cortical tubers.

Prominent dural enhancement adjacent to nonmeningiomatous malignant lesions on contrast-enhanced MR images.

Prominent dural enhancement was noted in 10 (16%) of 61 superficial malignant intracranial tumors studied with contrast-enhanced MR imaging during a 2-year period. Included were six glioblastomas, three parenchymal metastases, and one case of dural metastasis. Seven patients had surgery. In four, there was extensive leptomeningeal invasion in the center of the lesion. In two of these lesions there was firm attachment of the center of the tumor to the dura, but without dural invasion despite extensive external carotid artery supply to the tumor in one case. In two cases the overlying dura was normal, and there was no leptomeningeal tumoral invasion. In the case of dural metastasis, huge nodular lesions were present along the inner aspect of the dura. In none of the cases did prominent dural enhancement adjacent to the tumor correspond with tumoral invasion or extension to the dura. Prominent dural enhancement on contrast-enhanced MR images appears to be much less frequent in malignant tumor than in meningioma, where it is seen in up to 60% of the cases. We believe this finding is more likely to represent reactive changes of the dura than tumoral invasion.

CT and MR in infants with pericerebral collections and macrocephaly: benign enlargement of the subarachnoid spaces versus subdural collections.

PURPOSE: To compare CT and MR in the differentiation of benign enlargement of the subarachnoid spaces and subdural collections in infants with macrocephaly. METHODS: MR was performed in 19 infants with macrocephaly, showing bifrontal enlargement of the subarachnoid spaces on CT. RESULTS: In 11 patients, a single fluid layer could be distinguished on MR of the pericerebral collections, suggesting benign enlargement of the subarachnoid spaces. In eight patients, two separate layers were clearly differentiated, an outer layer that was hyperintense on all sequences and an inner layer with the same intensity as the cerebrospinal fluid. This indicated the presence of subdural collections. These collections were mainly frontal in six and extended over the entire hemisphere in two patients. On CT, these separate lesions were seen only in three patients and missed in three others. In two final patients, CT findings were equivocal with evidence of membrane formation within the hypodense collections. In seven patients with a subdural collection, subdural-external drainage was performed. In three patients, the collection was hemorrhagic. The protein content of the fluid showed a mean of 1381.7 +/- 785.6 mg/dL. The MR and surgical findings of a subdural collection correlated with the absence of a family history of macrocrania, an age under 5 months, and acute clinical signs of vomiting, somnolence, and hypotonia. CONCLUSION: MR appears essential in the differential diagnosis between benign enlargement of the subarachnoid spaces and subdural collections in infants.

Anterior cervical fusion and osteosynthetic stabilization according to Caspar: a prospective study of 41 patients with fractures and/or dislocations of the cervical spine.

Between June 1984 and April 1988, 41 patients with severe posttraumatic lesions of the cervical spine between the C2-C3 and the C7-T1 level seen consecutively were treated by an anterior cervical fusion and osteosynthetic stabilization according to Caspar. These patients were prospectively studied. Seven patients had a bilateral facet dislocation, 5 a unilateral facet dislocation, 9 an anterior subluxation, 9 an anterior compression fracture, 5 a hangman's fracture, and 6 a hyperextension injury at a lower cervical level. From a neurological point of view, there were 12 patients with an initial complete transverse lesion and 14 with an incomplete transverse lesion, and the remaining 15 patients did not have any deficit initially. Four patients died during the first 3 months after the operation. In 38 patients good anatomical position was obtained, generally by the intraoperative use of the vertebral distractor of Caspar. In all patients excellent immediate postoperative stability of the spine was obtained, although in 2 patients a second operation was necessary a few days after the first one. Postoperatively all patients were "immobilized" by a soft collar for 3 months. Four patients with an initial complete transverse lesion showed some neurological recovery in the postoperative period, and all patients with an incomplete transverse lesion improved. There were no postoperative neurological disturbances in the group of patients who were neurologically normal from the beginning. The mean postoperative hospitalization time was 13.6 days. These results were compared to the results from the literature, concerning other conservative and operative treatments for posttraumatic lesions of the cervical spine.

The radiological differentiation of acoustic neurinoma and meningioma occurring together in the cerebellopontine angle.

A patient with right hearing loss, in whom computed tomographic scanning demonstrated a mass in the right cerebellopontine angle with widening of and extension into the internal auditory canal, but with important posterior extension and broad implantation on the surface of the petrous bone, is reported. On both T2-weighted and gadolinium-enhanced T1-weighted magnetic resonance images, there were clearly two separate tumoral lesions: an acoustic neurinoma extending into the internal auditory canal and a meningioma with broad implantation on the petrous apex. These findings were confirmed at surgery.

Synovial cyst at the C1-C2 junction.

Intraspinal synovial or ganglion cysts of the cervical spine are rare. We present the third reported case of a degenerative articular cyst of the upper cervical spine, involving the quadrate ligament of the odontoid process. Magnetic resonance examination reveals typical images. A new, more general terminology is proposed.

Transient cerebellar mutism after posterior fossa surgery in children.

Cerebellar mutism has been reported after surgery for posterior fossa tumors in children and, rarely, in adults. The pathogenesis of this syndrome remains unclear, and controversy exists regarding whether it is a purely psychogenic disorder or an organic syndrome. The anatomical substrate for the mutism also remains unknown. We encountered five cases of postoperative transient cerebellar mutism in a consecutive series of 63 children with posterior fossa tumors. These cases were analyzed and compared with the patients without mutism to find predictive factors for the occurrence of mutism, with the hope of elucidating further the pathophysiological mechanism. The most significant finding was the presence in all cases of a period of cerebellar dysarthria after resolution of the muteness. We, therefore, believe that cerebellar mutism is an extreme form of dysarthria, rather than a real cognitive deficit or a psychological disturbance.

Catecholamine response to a gradual increase of intracranial pressure.

To determine the catecholamine response to progressive intracranial hypertension, intracranial pressure (ICP) was raised gradually by continuous expansion of an epidural balloon in seven dogs. Hemodynamic parameters, ICP, and cerebral perfusion pressure (CPP) were monitored continuously and serum catecholamine levels began to rise when CPP was in the low-positive range (20 to 30 mm Hg), reaching a peak just after brain death (CPP < or = o mm Hg). There was no correlation between ICP and the catecholamine peak. Compared to control values, the mean increase was 286-fold for epinephrine and 78-fold for norepinephrine. Temporally, the catecholamine peak corresponded well with the observed hemodynamic changes. These results suggest that ischemia in certain parts of the brain stem is responsible for the hemodynamic changes observed in intracranial hypertension (such as the Cushing response), and they show that catecholamines play an important role in these hemodynamic changes.

Secondary supratentorial anaplastic astrocytoma following treatment of medulloblastoma.

The development of secondary tumours is a rare but well known late effect of radiation therapy of lesions in the central nervous system. Most radiation-induced tumours are of mesenchymal origin, but on rare occasions gliomas can occur. We describe a patient in whom a supratentorial anaplastic astrocytoma developed 15 years after surgery and radiotherapy for a childhood posterior fossa medulloblastoma. A concise review of the pertinent literature is given.

Closed spinal dysraphism: a review on diagnosis and treatment in infancy.

This article reviews the clinical presentation, pathophysiology, diagnostic strategies, and therapeutic management of closed spinal dysraphism in infancy. Four groups of symptoms are distinguished: (1) cutaneous abnormalities, (2) lower motor neuron dysfunction due to congenital spinal and nerve root abnormalities, (3) upper motor neuron dysfunction due to tethering of the spinal cord, and (4) symptoms caused by associated malformations. Guidelines are proposed concerning timing and type of diagnostic investigations in infancy. This essentially encompasses a neurological assessment, including spinal ultrasonography and nuclear magnetic resonance imaging of the spine and the brain, and a urological assessment, including ultrasonography of kidneys and bladder, cystourethrography and a urodynamic study. As to the tethered cord syndrome it is concluded that first, already in infancy, a progressive neurological dysfunction can be detected; second, surgical untethering should be performed only upon appearance of upper motor neuron signs or upon progression of lower motor neuron signs. Despite its frequently asymptomatic course, the diagnosis of a congenital lumbosacral lipoma, and in the more general sense, of a closed spinal dysraphism, implies a periodic, multidisciplinary follow-up for life.

Effect of the serotonin agonist 8-OH-DPAT on the sensorimotor system of the rat.

8-Hydroxy-2-(di-n-propylamino)-tetralin hydrobromide (8-OH-DPAT, 2 mg/kg) is used to induce perseverative behavior in rats in a T-maze as a model for obsessive-compulsive disorder (OCD). Using the open-field test, radiant heat test, and the test with von Frey filaments, we examined whether alterations in sensorimotor functioning could contribute to the perseverative tendencies in this model by measuring differences in left versus right hind paw reactions after 8-OH-DPAT administration (2 mg/kg, sc). Also, the effect of repeated 8-OH-DPAT administration on sensorimotor functioning was tested every third day. 8-OH-DPAT administration induced a significantly decreased sensorimotor performance in the open-field test, an increased threshold for noxious thermal stimulation (increased withdrawal latency, WL, and decreased elevation time, ET) in the radiant heat test, and a decreased nociceptive threshold for mechanical stimulation in the test with von Frey filaments. All changes in sensorimotor functioning were similar for left and right hind paws suggesting that, these changes as measured with the tests in the present study, are not likely to contribute to the perseverative behavior of rats in a T-maze. Further, repeated administration of 8-OH-DPAT had no effect in the radiant heat test and the test with the Frey filaments, but produced a tolerance effect in the open-field test.

The value of immediate post-operative routine CT related to uncomplicated ventricle drainage in childhood hydrocephalus.

Retrospectively we assessed the value of routine postoperative CT scans in 113 children shunted for hydrocephalus. Of the 165 routine CT scans 13 showed fortuitous findings (= 8%) with a change in treatment accompanied by questionable benefits in only 2 (= 1.3%). Therefore we suggest that post-operative CT should not be performed as a routine examination but only on clinical grounds.

Intraparenchymal meningioma in a 14-month-old infant: case report.

The authors report a 14-month-old infant with an intraparenchymal meningioma. At this age, intracranial tumor is an unusual cause of hemiconvulsions, and an intraparenchymal tumor localisation is even more unusual.

Hypertrophic retromedullary venous drainage in spinal cord tumours: MR visualisation.

Pseudoangiomatous dilatation of retromedullary veins at myelography was noted in three cases of intramedullary spinal cord tumours. This concerned two haemangioblastomas at levels Th8 and L1, respectively, and an ependymoma of the conus terminalis. MRI accurately demonstrated the tumoural mass, together with the enlarged and tortuous draining perimedullary veins. In patients with dilated vascular shadows on myelography, MRI should be performed before medullary angiography to differentiate between spinal vascular malformations and intramedullary tumours with enlarged draining veins.

Association of conjoined and anastomosed nerve roots in the lumbar region. A case report.

Different types of anomalies of the lumbosacral nerve roots were documented in the literature. The present report is the first description of a combination of conjoined and anastomosed nerve roots, at the same level and unilaterally, in the lumbar region.

Intraspinal juxta-facet cysts: a case of bilateral ganglion cysts.

Juxta-facet cysts are relatively uncommon intraspinal lesions, causing radiculopathy, neurogenic claudication or myelopathy. To the best of our knowledge, only 4 cases of bilateral synovial or ganglioncysts were described. We report the 5th case of bilateral ganglioncysts of the lumbar spine. Generally, juxta-facet cysts should be differentiated from other intraspinal lesions, such as herniated discs, meningiomas and neurinomas. Correct preoperative diagnosis is necessary for adequate treatment, namely the (microscopic) resection of the cyst. After adequate treatment, complete recovery may be expected.