Post-traumatic meningioma: three case reports of this rare condition and a review of the literature.

We present three cases of meningiomas developing at the site of an old head trauma. We then review the literature regarding the controversies on the development of post-traumatic brain tumors and, finally, we emphasize the medico-legal characteristics of post-traumatic meningiomas, particularly with respect to their cell type which is frequently atypical or anaplastic and which have a poor outcome.

Cervicothoracic postarachnoiditic hydrosyringomyelia secondary to pedicular hook dislocation: case report.

BACKGROUND: Pedicular hook dislocation is a rare complication of spinal instrumentation. We report on the first case of hydrosyringomyelia secondary to intracanalar hook displacement after scoliosis surgery. CASE DESCRIPTION: A 15-year-old girl presented to our institution with a 7-month history of persistent neck and occipital pain as well as numbness of the lower extremities and previous dorsolumbar instrumentation with dorsal pedicular hooks and lumbar screws. Magnetic resonance imaging showed intramedullary cystic cavity from C5 to T7, isointense to cerebrospinal fluid (CSF) on T1- and T2-weighted images. Computed tomographic scan showed intracanalar displacement of the left hook. On admission, the patient presented with mild weakness of the lower extremities, hypalgesia below the level of T4, and urinary disturbance. The patient underwent surgical hook removal, T4 laminectomy, and midline dural opening: the arachnoid membrane was found to be thick and adhered to the dura and dorsolateral spinal cord. The arachnoid scarring was dissected, and the cord was untethered. A small posterior-median myelotomy was performed, and a syringosubarachnoid catheter was placed into the subarachnoid space to restore CSF flow. CONCLUSIONS: Late intracanalar displacement of spinal devices is an event that may complicate spinal instrumentation for scoliosis. This case highlights the importance of correct spinal device positioning and that of careful follow-up after instrumentation to detect complications early. We also discuss the pathogenetic pathway of the postarachnoiditic syringomyelia in this case.

Traumatic spinal-cord herniation associated with pseudomeningocele after lower-thoracic nerve-root avulsion.

BACKGROUND: Traumatic spinal-cord herniation after nerve root avulsion is rare. We report on the first patient with spinal-cord herniation associated with pseudomeningocele in the lower conus medullaris region after nerve avulsion. CASE: This 72-year-old man presented with progressive pain in the left leg and motor weakness after two traumatic accidents. Constructive interference in steady-state (CISS) imaging showed the attachment of the spinal cord to the wall of a herniated pseudomeningocele and associated syringomyelia at the level of T12. At the time of surgery, a herniated pseudomeningocele was observed. The lateral portion of the spinal cord that had herniated into the pseudomeningocele was detached from its wall; this was followed by repair of the dural defect. A redundant nerve root was observed inside the pseudomeningocele, suggesting nerve root avulsion as the primary lesion. To facilitate cerebrospinal fluid drainage from the syringomyelia, we next performed dorsal root entry zone (DREZ)tomy to the pseudomeningocele. Postoperatively, he manifested significant clinical improvement. CONCLUSIONS: This is the first report of spinal cord herniation after nerve root avulsion in the conus medullaris region. CISS imaging is highly useful for the demonstration of spinal cord herniation, syringomyelia and pseudomeningocele. To restore neurological function in patients with progressive symptoms, we recommend surgical treatment.

Safe intrathecal fluorescein use for identification of cerebrospinal fluid leaks: Case-report and perioperative algorithm description. / Uso seguro de fluoresceína intratecal en la localización de las fístulas de líquido cefalorraquídeo: descripción de un caso e implementación de un algoritmo perioperatorio.

Intrathecal injection of fluorescein is a method for repairing cerebrospinal fluid fistulas. The most frequent surgical procedure is endonasal endoscopy and the purpose of injecting this dye is to locate the fistula. The anaesthesiologists usually perform the puncture, therefore it is necessary to review this method and to specify some anaesthetic considerations such as correct dosing, safe management protocols and medical-legal aspects. In this case-report we describe the pre, intra and postoperative protocol of action implemented in our department that basically consists of: obtaining a specific consent, prior neurological/ophthalmologic assessment to rule out hypertension and brain damage, use of corticosteroids and previous antihistamines, choosing the correct dose and concentration of intrathecal sodium fluorescein (maximum 1ml at a concentration of 5% diluted in 9ml of cerebrospinal fluid) and close intra and postoperative monitoring.

Symptomatic contralateral subdural hygromas after decompressive craniectomy: plausible causes and management protocols.

OBJECT: Contralateral subdural hygromas are occasionally observed after decompressive craniectomies (DCs). Some of these hygromas are symptomatic, and the etiology and management of these symptomatic contralateral subdural collections (CLDCs) present surgical challenges. The authors share their experience with managing symptomatic CLSDCs after a DC. METHODS: During a 10-month period, 306 patients underwent a DC. Of these patients, 266 had a head injury, 25 a middle cerebral artery infarction (that is, a thrombotic stroke), and 15 an infarction due to a vasospasm (resulting from an aneurysmal subarachnoid hemorrhage [SAH]). Seventeen patients (15 with a head injury and 2 with an SAH) developed a CLSDC, and 7 of these patients showed overt symptoms of the fluid collection. These patients were treated with a trial intervention consisting of bur hole drainage followed by cranioplasty. If required, a ventriculo- or thecoperitoneal shunt was inserted at a later time. RESULTS: Seven patients developed a symptomatic CLSDC after a DC, 6 of whom had a head injury and 1 had an SAH. The average length of time between the DC and CLSDC formation was 24 days. Fluid drainage via a bur hole was attempted in the first 5 patients. However, symptoms in these patients improved only temporarily. All 7 patients (including the 5 in whom the bur hole drainage had failed and 2 directly after the DC) underwent a cranioplasty, and the CLSDC resolved in all of these patients. The average time it took for the CLSDC to resolve after the cranioplasty was 34 days. Three patients developed hydrocephalus after the cranioplasty, requiring a diversion procedure, and 1 patient contracted meningitis and died. CONCLUSIONS: Arachnoid tears and blockage of arachnoid villi appear to be the underlying causes of a CLSDC. The absence of sufficient fluid pressure required for CSF absorption after a DC further aggravates such fluid collections. Underlying hydrocephalus may appear as subdural collections in some patients after the DC. Bur hole drainage appears to be only a temporary measure and leads to recurrence of a CLSDC. Therefore, cranioplasty is the definitive treatment for such collections and, if performed early, may even avert CLSDC formation. A temporary ventriculostomy or an external lumbar drainage may be added to aid the cranioplasty and may be removed postoperatively. Ventriculoperitoneal or thecoperitoneal shunting may be required for patients in whom a hydrocephalus manifests after cranioplasty and underlies the CLSDC.

Vicryl (polyglactin 910) mesh as a dural substitute in the presence of pia arachnoid injury.

Previously presented data showed that Vicryl mesh was a potentially effective dural grafting material. It is easily handled, relatively inexpensive, absorbed over time, and elicits a minimal inflammatory response. The present experimental project was conducted to investigate the effectiveness of a tightly woven version of the material as a watertight seal and to evaluate its performance in the presence of pia arachnoid injury. The mesh formed a seal promptly and adhesion formation was slight. Tightly woven Vicryl mesh appears to have a significant potential as an absorbable dural substitute.

External hydrocephalus after aneurysm surgery: paradoxical response to ventricular shunting.

OBJECT: The authors sought to investigate the mechanisms and pathophysiological effects of subdural fluid collection after surgery for aneurysmal subarachnoid hemorrhage (SAH). METHODS: The authors retrospectively analyzed the medical records of 76 patients who had undergone craniotomy. The patients included 55 with aneurysmal SAH (SAH group) and 21 with unruptured aneurysms (non-SAH group) who were used as controls. Subdural fluid collection was more common in the SAH than in the non-SAH group (38% compared with 14%, p < 0.05). Although older patients appeared to be at greater risk for subdural fluid collection in both groups (p < 0.05), this condition developed even in relatively young patients with SAH. In the SAH group most subdural fluid collection was associated with ventricular dilation (81%), and a significant correlation was seen between fluid collection and the need for subsequent shunt placement (48% compared with 21%, p < 0.05). These results point to an association between hydrodynamic dysfunction and subdural fluid collection. The course of patients with subdural fluid collection varied from spontaneous resolution to normal-pressure hydrocephalus. Seven patients with persistent subdural collections underwent shunt placement (ventriculoperitoneal [VP] shunt in six and lumboperitoneal in one), which resulted in resolution of fluid collection in all seven. CONCLUSIONS: The results indicate that for most patients in the SAH group, subdural fluid collection represented "external hydrocephalus" rather than simple "subdural hygroma." Decreased absorption of cerebrospinal fluid because of SAH and surgically created tears in the arachnoid membrane communicating with the subdural space were factors in the development of external hydrocephalus. The authors believe that differentiating external hydrocephalus from subdural hygroma is extremely important, because VP shunt placement can be used to treat the former but could worsen the latter.

[Incidence and treatment of subdural hygroma in severe head injuries]. / Incidence et traitement des hygromes sous-duraux chez le traumatisé crânien grave.

In a population of 109 subjects with severe head injury (Liège score less than or equal to 12) we observed secondary development of subdural hygroma in sixteen patients. These liquefying processes were mostly secondary to the entry of CSF in the subdural space from tears in the arachnoid. Half the accumulations were accompanied by increased subdural pressure. Drainage of the subdural fluid brought clinical improvement in patients with elevated subdural pressure (greater than 15 torr).

Intraspinal extradural arachnoid cyst with spinal cord herniation.

A 17-year-old male presented with thoracic myelopathy 12 months after a stab injury to the thoracic spine. The patient reported that symptoms and signs had gradually worsened in the 3 months prior to his examination. Magnetic resonance imaging depicted not only an extradural arachnoid cyst but severe spinal cord compression. The cerebrospinal fluid pressure and dynamics associated with herniation of the spinal cord resulted in the formation and enlargement of an extradural arachnoid cyst. The pressure effect of the cyst accounted for the thoracic myelopathy.

Multi-level disruption of the spinal nerve root sleeves in spontaneous spinal cerebrospinal fluid leakage--two case reports.

A 37-year-old male and an 18-year-old male presented with spontaneous spinal cerebrospinal fluid (CSF) leakage from multiple nerve root sleeves. Both patients suffered abrupt onset of intense headache followed by nausea, dizziness, and one patient with and one without positional headache. Radioisotope spinal cisternography of both patients revealed that the CSF leaks were not localized in a special zone but distributed to multiple spinal nerve root sleeves. Magnetic resonance (MR) myelography suggested that the spinal CSF column was fully expanded to the root sleeves. The extraspinal nerve bundles demonstrated numerous high intensity spots. Both patients were treated conservatively, and their symptoms resolved within one month. Repeat radioisotope cisternography and MR myelography confirmed the spine was normal after recovery. We suggest that spreading disruption of the arachnoid membrane occurs at the nerve root sleeves due to CSF overflow into the spinal canal.

[Traumatic rupture of the medulla with subarachnoid-pleural fistula (author's transl)]. / Rupture médullaire traumatique avec fistule sous-arachnoïdo-pleurale.

A case of total dural and spinal cord disruption at level T2 in a 23 month-old female is presented. The authors emphasized the absence of spinal shock in this young child. Spine X-ray examination failed to reveal any abnormality. X-ray films of the chest demonstrated fluid in the right pleural space and mediastinum associated with a subarachnoid-pleural fistula. The possible mechanisms responsible for the spinal cord disruption and the absence of spinal shock are discussed.

[Studies on the operative factors affecting the reduction of chronic subdural hematoma, with special reference to the residual air in the hematoma cavity].

The authors previously reported the effect of preoperative factors affecting the reduction of chronic subdural hematoma. In this report, we evaluated some operative factors, including operative methods, duration of drainage, and residual air volume, with newly developed CT volumetry technique. As described before, the hematoma volume reduces exponentially. An exponential curve was fitted to the reduction curve using the least square method, and its half reduction days (HRD) was calculated. This HRD represents a mathematical indicator of the reduction rate of CSDH. Using this technique, the relationship between this HRD and operative method, the duration of drainage and the volume of the postoperative residual air were examined in 61 patients. Operative method (burr hole or small craniotomy) has no correlation with HRD. The duration of drainage also has no correlation. However, the volume of the residual air was highly correlated with the reduction rate of hematoma (r = 0.430; p less than 0.01). These results suggest that the residual air in the hematoma cavity may delay the reduction rate of the hematoma. Based on these results, the authors pay attention to the following points; 1) Less invasive burr hole method should be selected. 2) Patient's head position should be controlled to make the burr hole at the highest level in the operative field. 3) Hematoma cavity should be filled with saline as much as possible. 4) The inner membrane should never be injured, as it may cause tension pneumocephalus. Moreover, the drainage of cerebrospinal fluid may reduce the counter pressure and it leads to the delay of the hematoma reduction.

Pedunculated basilar terminus aneurysm with pseudo-septation due to anterior herniation through a perforated membrane of Liliequist.

Septations within cerebral arteries or aneurysms are exceedingly rare in the absence of associated fenestrations. We report an unusual unruptured pedunculated basilar apex aneurysm, with a "pseudoseptation" between the main aneurysmal sac and an anterior compartment, which was, in fact, represented by a perforation in the membrane of Liliequist, permitting anterior aneurysmal herniation into the carotid-chiasmatic cistern. The patient was successfully treated with detachable coils. This case is unusual on 2 accounts: 1) the aneurysm's appearance, and 2) the presence of a large fenestration in the membrane of Liliequist, of which anatomic features are herein reviewed.

Effect of arachnoid plasty using fibrin glue membrane after clipping of ruptured aneurysm on the occurrence of complications and outcome in the elderly patients.

BACKGROUND: In elderly patients with aneurysmal subarachnoid hemorrhage (SAH), complications including vasosopasm, subdural effusion, and late hydrocephalus, are liable to occur even after aneurysmal surgery. We examined prospectively the efficacy of arachnoid plasty using fibrin glue membrane during surgery of ruptured aneurysms in the elderly patients for preventing complications. The effects on the modified Rankin scale (mRS) and the Glasgow outcome scale (GOS) 3 months after SAH were noted. METHODS: Total of 31 patients aged more than 70 years selected from a consecutive series of patients with aneurysmal SAH, were divided into two groups alternately, a group with arachnoid plasty (n = 16) and a control group without arachnoid plasty (n = 15). Statistical analyses were performed to assess relationships among various clinical and neuroradiological variables, especially between arachnoid plasty and occurrence of symptomatic vasospasm, subdural effusion, late hydrocephalus, or outcome such as mRS and GOS 3 months after onset. FINDINGS: Statistical analyses revealed that arachnoid plasty were associated with late hydrocephalus and subdural effusion negatively, but with better mRS at 3 months after SAH. A tendency to be associated with less frequent symptomatic vasospasm was also noted. CONCLUSION: Arachnoid plasty using fibrin glue is suggested to be effective in preventing complications associated with SAH and aneurysmal surgery. A better outcome in the elderly patients can be achieved.

The subdural space: the third place to go astray.

Subdural placement of the tip of the Tuohy needle or epidural catheter may account for many unexpected complications of attempted epidural blockade, for example, 'unexplained' headache, false-negative aspiration test down needle or catheter, false-negative test dose, unilateral block, delayed total spinal and neurological sequelae, as well as profound block of delayed onset that is characteristic of subdural blockade. Cases are reported in support of this hypothesis.