María-José Almagro

Shunt-related craniocerebral disproportion: treatment with cranial vault expanding procedures.

Two patients with intracranial arachnoid cysts, one with myelomeningocele–hydrocephalus and the other with a subdural fluid collection, were given a cerebrospinal (CSF) extracranial shunt. All four patients developed features of CSF overdrainage following shunting and were treated by cranial vault expanding procedures. Before undergoing decompressive craniotomy, the patients were treated by a variety of procedures, including changing of obstructed ventricular catheters (n=4), insertion or upgrading of programmable valves (n=3), and foramen magnum decompression (n=1). Clinical manifestations of these four patients were attributed to craniocerebral disproportion caused by chronic and progressive skull changes due to dampening of the CSF pulse pressure, which is necessary for maintaining normal cranial growth. On the basis of our previous experience with expanding craniotomies in cases of minimal forms of craniosynostosis, we treated these patients with bilateral parietal craniotomies, with satisfactory results. In conclusion, biparietal decompressive craniotomy constitutes a useful and safe procedure for relieving the clinical manifestations of some CSF overdrainage syndromes, especially in cases with slit-ventricle syndrome and craniocerebral disproportion that prove to be refractory to simpler management procedures.

Hydrocephalus and arachnoid cysts

AimThe management of arachnoid cysts (AC) remains controversial. An additional problem derives from the management of hydrocephalus associated with an AC. In this work, we discuss existing procedures proposed in the current literature for their treatment.MethodsWe reviewed selected reports on intracranial ACs placing special interest in those about the association of hydrocephalus and ACs. We also briefly surveyed data of our patients with this association.Results and discussionHydrocephalus is often found in midline and posterior fossa ACs. Interhemispheric lesions may also evolve with ventriculomegaly, while middle fossa lesions rarely produce hydrocephalus. Patients’ age, cyst location and size, and macrocephaly have all been related to the development of hydrocephalus. Some authors remark on the role played by hydrocephalus and hypothesize that some ACs would result from disturbed cerebrospinal fluid (CSF) dynamics. They also propose that ACs might represent a localized form of hydrocephalus. We also comment on hydrocephalus in relation to the diverse locations of ACs. Neuroendoscopic techniques have transformed previous ways of management as cystoperitoneal shunting and open fenestration.ConclusionsACs may be pathogenetically related with hydrocephalus, and conversely, ACs may cause hydrocephalus. In some patients, aberrant CSF dynamics seems to play a major role in the development of both cyst and hydrocephalus. Hydrocephalus and ACs may be treated exclusively with neuroendoscopic procedures, although some patients will still require CSF shunting. The ideal option seems to consist of choosing the method that offers the highest success with a single procedure for treating the hydrocephalus and the AC simultaneously.

Regression of syringomyelia and tonsillar herniation after posterior fossa arachnoid cyst excision: case report and literature review

BACKGROUND Some reports have documented posterior fossa cysts resulting in syringomyelic obstruction of cerebrospinal fluid (CSF) flow caused by cyst displacement within the foramen magnum. Rarely the syringomyelia is caused by acquired Chiari malformation due to a retrocerebellar arachnoid cyst. OBJECTIVE To report the case of a 38-year-old man with hydrocephalus and syringomyelia, who was found to have a Chiari malformation secondary to a posterior fossa arachnoid cyst. After endoscopic third ventriculostomy, the patient was submitted to foramen magnum decompression and arachnoid cyst removal that were followed by resolution of both the Chiari malformation and the syringomyelia. DISCUSSION In most published cases the syringomyelia has been attributed to obstruction of CSF flow at the foramen magnum by the arachnoid cyst itself. There is only one previous report of a posterior fossa arachnoid cyst producing tonsillar descent and syringomyelia. CONCLUSIONS Posterior fossa arachnoid cysts can result in acquired Chiari malformation and syringomyelia. In our view, the management of these patients should be directed at decompressing the foramen magnum and include the removal of the walls of the coexistent arachnoid cyst as it seems to be the crucial factor that accounts for the development of the syringomyelia that these patients present.

Cervical spinal cord infarction after posterior fossa surgery: a case-based update

BackgroundSeveral positions are currently utilized for operating patients with posterior fossa lesions. Each individual position has its own risks and benefits, and none has demonstrated its superiority. A dreaded, and probably underreported, complication of these procedures is cervical cord infarction with quadriplegia.DiscussionWe reviewed eight previous reported instances of this devastating complication aimed at ascertaining its pathogenesis to suggest preventive strategies. Several hypotheses have been put forward to explain the occurrence of this complication. Some factors involved in the production of cervical cord infarction include patients position (seated or prone), hyperflexion of the neck, excessive spinal cord traction, canal stenosis, and systemic arterial hypotension. We hypothesize that spinal cord infarction in our patient might have resulted from compromised blood supply to the midcervical cord caused by tumor infiltration of the cervical leptomeninges in addition to a brief episode of arterial hypotension during venous air embolism.Case reportWe treated an 8-year-old girl who developed quadriplegia after surgery for a fourth ventricular ependymoma. Postoperative magnetic resonance imaging demonstrated cervical cord infarction. Evoked potentials confirmed the diagnosis.ConclusionsWith this report, we want to draw the attention of neurosurgeons to the possibility of the occurrence of this dreadful complication during posterior fossa procedures. Retrospectively, the only measures that might have helped to avoid this complication in our patient would have been using the prone position and intraoperative monitoring of evoked potentials.

Depressed skull fracture by a three-pin head holder: a case illustration

Background and case reportMany surgical procedures require a rigid immobilization of the patients’ head, which is usually achieved by using a pin-type head holder. We briefly illustrate the case of a 4-year-old girl who sustained a depressed skull fracture by penetration of a pin of the head holder. The fracture was noted at the end of the surgery performed for treatment of a cerebellar astrocytoma and was managed conservatively.DiscussionSeveral factors seem to be involved in the production of this complication as are faulty application of the pins, excessive pin pressure, skull thinning, young patient’s age, and pathological conditions that evolve with long-standing raised intracranial pressure. Prevention and management measures are briefly discussed.

Reanclaje medular en pacientes con mielomeningocele y lipomeningocele: la segunda operación

Antecedentes. La medula espinal puede fijarse tras la reparacion inicial en pacientes operados de mielomeningocele (MMC) y lipomeningocele (LMC), produciendo graves lesiones fisicas y psicologicas. Asimismo, la introduccion accidental de restos cutaneos durante la reparacion de estas lesiones puede dar lugar al desarrollo de tumores intraespinales de estirpe cutanea. Objetivos. Averiguar la incidencia del anclaje medular tras la cirugia de MMC y LMC y analizar los factores que puedan explicar su aparicion. Tambien, investigamos las maniobras tecnicas durante la operacion primaria susceptibles de evitar la aparicion del sindrome de medula fijada. Pacientes y metodos. Revision retrospectiva de las historias de los pacientes operados de MMC (n=162) y de espina bifida oculta (n=54) en el periodo 1975-2005 que desarrollaron cuadros de anclaje medular sintomatico. Resultados. Once pacientes con MMC (6,79%) y dos con LMC (3,7%) presentaron manifestaciones de anclaje medular tras intervalos de 2 a 37 anos despues de la reparacion primaria. Las indicaciones de reintervencion se basaron fundamentalmente en criterios clinicos. Un hallazgo constante fue la fibrosis cicatricial que estuvo presente en todos los casos. Otros hallazgos operatorios causantes de la fijacion medular consistieron en tumores cutaneos de inclusion (n=3), reacciones de cuerpo extrano (n=2), estenosis del canal lumbar (n=2), restos de lipoma (n=1), y filum hialinizado (n=1). En 3 casos de MMC se encontro ademas un quiste epidermoide intradural (1,85% de los MMC), lo que supone una tasa de epidermoides en la reintervencion de MMC de 27%. El periodo medio de seguimiento fue de 5,5 anos y los resultados fueron: mejoria en 8, dos no experimentaron cambios, y uno sufrio empeoramiento. Conclusiones. El deterioro neurologico de los pacientes operados de MMC o LMC no constituye una consecuencia obligada o parte de la historia natural de estos procesos. El deterioro, precoz o tardio, puede estar motivado por el anclaje posquirurgico de la medula espinal. Ello hace necesario realizar un seguimiento periodico de estos pacientes, acompanado de los oportunos estudios de neuroimagen y, en su caso, de exploracion quirurgica. Los resultados fueron satisfactorios, ya que el 92% de los pacientes reoperados experimentaron mejoria o estabilizacion de su enfermedad. Se describen ademas dos causas infrecuentemente descritas de deterioro tardio: la estenosis del canal y las reacciones fibrosas de cuerpo extrano a materiales implantados.

Syringomyelia with quadriparesis in CSF shunt malfunction: a case illustration

BackgroundShunt malfunction typically presents with headaches, vomiting, and impaired consciousness. Paraparesis has been rarely reported as the initial manifestation of valve dysfunction.Case illustrationA 17-year-old boy was admitted with invalidating quadriparesis that after neuroimaging evaluation was found to be produced by communicating syringomyelia attributed to shunt malfunction.Discussion and conclusionPersistence of the central canal in association with communicating hydrocephalus may lead to the development of communicating syringomyelia. In this context, insufficient drainage of CSF produced by shunt dysfunction may evolve exclusively with symptoms and signs of spinal cord involvement in the absence of the usual cerebral manifestations related to shunt failure.

Keeping CSF valve function with urokinase in children with intra-ventricular haemorrhage and CSF shunts

BackgroundIntra-ventricular haemorrhage (IVH) can occur spontaneously or during the surgical revision of ventricular cerebrospinal fluid (CSF) shunts.AimThe aim of the study was to report the safety and efficacy of an original method for treatment of IVH that may occur at the time of valve revision aimed at maintaining the function of previously implanted CSF shunts.Patients and methodsWe reviewed the medical records of six patients who experienced an IVH in the presence of a previously placed ventriculoperitoneal (VP) shunt. Five of the haemorrhages occurred during ventricular catheter replacement and the remaining one in a child given a VP shunt who sustained a spontaneous intra-cerebral haemorrhage. We inserted an external ventricular drainage without removing the original shunt. Urokinase was administered via the ventricular drain during several days until blood clearance in the CSF. Disappearance of the ventricular clots was checked by a cranial computerised tomography scan, while CSF shunt function was verified by the children’s evolution and/or by a reservoir tap.ResultsFollow-up evaluation of the six patients demonstrated that the existing VP shunts were functioning appropriately and that the treatment was safe.ConclusionsPatients with IVH complicating ventricular catheter replacement and patients with spontaneous bleeding who harbour a VP shunt can be treated by intra-ventricular urokinase to avoid the removal of the initial shunt. The technique has proven to be safe and utilises the ventricular drain placed for the acute management of the IVH. Shunt replacement will always be possible in case of failure of the technique we are reporting.

Severe spinal cord injury in craniocervical dislocation. Case-based update

BackgroundCraniocervical distraction injuries, including atlanto-axial dislocation (AAD) and atlanto-ocipital dislocation (AOD), are often associated with severe spinal cord involvement with high morbidity and mortality rates. Many patients with these injuries die at the accident scene, but advances in emergency resuscitation and transport permit that many patients arrive alive to hospitals.DiscussionChildren with craniocervical distraction injuries usually present with a severe cranioencephalic traumatism that is the most relevant lesion at admission. After resuscitation and hemodynamic stabilization, the spinal cord damage appears as the main lesion. Apnea and quadriparesis, or quadriplegia, are usually present at the onset. Early diagnosis and management perhaps decrease life-threatening manifestations of the spinal lesion. But even so, the primary spinal cord insult is often irreversible and precludes obtaining a satisfactory functional outcome.Patients and methodsWe report the findings of four children with craniocervical distraction injuries (AOD and AAD) who presented with severe spinal cord damage. All patients were admitted with respiratory distress or apnea together with significant brain injuries. The medical records pertaining to these patients are summarized in regard to clinical features, management, and outcome.ConclusionsIn spite of timely and aggressive management, craniocervical injuries with spinal cord involvement continue to have a dismal prognosis. Outcome is closely related to the severity of the initial brain and spinal cord damage and is nearly always fatal in cases of complete spinal cord transection. Priority should be given to life-threatening complications. Ethic issues on indications for surgery deserve a detailed discussion with the children’s parents.

Staphylococcus warneri ventriculoperitoneal shunt infection: failure of diagnosis by ventricular CSF sampling

BackgroundThe definite diagnosis of hydrocephalus valve infection is generally made by cerebrospinal fluid (CSF) sampling via the valve reservoir, which is considered to be more dependable than that of the CSF obtained by lumbar puncture.Case reportWe treated a 17-year-old boy with an intra-abdominal pseudocyst due to ventriculoperitoneal shunt infection caused by Staphylococcus warneri whose ventricular CSF, obtained via the valve reservoir, was repeatedly sterile thus causing a considerable delay in the management of the complication.Discussion and conclusionsS. warneri constitutes an emergent contaminant of catheters and prostheses. We found only a detailed report of S. warneri infection of a ventriculoatrial shunt. If manifestations of peritoneal involvement in shunted patients would occur, the attention should be shifted to the distal component of the shunt hardware, even in the presence of a normal ventricular CSF as happened in our case to avoid unnecessary delay in diagnosis and management.