Rafael Martinez-Perez

Cranioplasty after decompressive craniectomy. A prospective series analyzing complications and clinical improvement.

BACKGROUND Cranioplasty is carried out for cosmetic reasons and for protection, but it may also lead to some neurological improvement after the bone flap placement. Complications of cranioplasty are more frequent than expected for a scheduled neurosurgical procedure. We tried to identify factors associated with both complications and improvement after cranioplasty. METHODS We prospectively studied the cranioplasties performed in our hospital from November 2009 to November 2013. Patients whose initial reason for bone removal was tumor infiltration were excluded. Demographic, clinical and radiological data were collected. The NIH Stroke Scale and Barthel Self-Care Index scores were obtained both before and within 72 h after cranioplasty. The outcome measures were the occurrences of complications and clinical improvement. RESULTS Fifty-five cranioplasties were performed. The material used for the cranioplasty was autologous bone in 42 cases, polyetheretherketone (PEEK) in 7 and methacrylate in 6. The average size of the bone defect was 69.5 (19.5-149.5) cm2. The time elapsed between decompressive craniectomy and cranioplasty was 309 (25-1217) days. There were 10 complications (7 severe and 3 mild), an 18.2% complication rate. Statistically significant risk factors of complications were identified as a Barthel≤70 (Odds ratio [OR] 22; 2.5-192; P=0.005), age over 45 years (OR 13.5; 1.5-115; P=0.01) and early surgery (≤85 days; OR 8; 1.69-37.03, P=0.004). After multivariate analysis, Barthel≤70 and age over 45 years remained independent predictors of complications. Twenty-two (40%) of the 55 patients showed objective improvement. Early surgery (<85 days) increased the likelihood of improvement (OR 4.67; 1.05-20.83; P=0.035). Larger bone defects seemed to be related with improvement, but differences in defect size were not statistically significant (75.3 vs 65.6 cm2; P=0.1). CONCLUSIONS The complication rate of cranioplasty is higher than for other elective neurosurgical procedures. Older age, poorer functional situation (worse Barthel index score) and early surgery (≤85 days) are independent risk factors for complications. However, cranioplasty produces clinical benefits beyond protection and esthetic improvement. Earlier surgery and larger bone defects seem to increase the likelihood of clinical improvement.

Acute neurological deterioration as a result of two synchronous hemorrhagic spinal ependymomas

Background: Ependymomas are the most common intramedullary tumors in adults and are the most common in mid-adult years. The presence of synchronous ependymomas in different sites of the spine is not common and it is even more infrequent to find hemorrhage from a spinal ependymoma as a cause of neurological deterioration. Case Description: A 32-year-old man presented with back pain and progressive paraparesia. Magnetic resonance (MR) showed two intradural extramedullary lesions on spinal canal with signs of acute hemorrhage. The patient underwent emergent surgical decompression and resection. Pathology revealed myxopapillary ependymomas. Conclusion: To our knowledge, we report the first case of a patient with acute neurological deterioration as a consequence of synchronous bleeding of two spinal ependymomas located at different levels in the spinal cord. This study illustrates the importance of recognizing the rare, but known occurrence of acute neurological deterioration after spontaneous hemorrhage in spinal ependymomas.

Cervical Spinal Cord Injury without Computed Tomography Evidence of Trauma in Adults: Magnetic Resonance Imaging Prognostic Factors

BACKGROUND Spinal cord injury (SCI) without computed tomography evidence of trauma is underreported in adults and is considered a subtype of SCI with relatively good outcome. Despite this, few studies have been performed to determine specific imaging-related prognostic factors. Our objective is to describe the imaging characteristics of patients experiencing blunt cervical spine trauma with neurologic deficits, but without radiologic abnormalities and associated prognostic factors. METHODS A retrospective review of all adult patients with cervical SCI admitted to the emergency room of 2 university hospitals from January 2004 to December 2013 was performed. Only patients with a magnetic resonance imaging (MRI) performed within 72 hours after trauma were included for further analysis. All patients with bony injury or traumatic malalignment were excluded. Data gathered on the remaining patients included demographics, mechanism of injury, severity of SCI, long-term patient outcome, improvement in neurologic condition, and MRI results. RESULTS There were 48 patients who met the inclusion and exclusion criteria, and 40 who demonstrated improvement in the neurologic examination at follow-up. Disruption of either the anterior longitudinal ligament or ligamentum flavum and larger lesions in the MRI were predictors of lack of neurologic improvement. CONCLUSIONS Early MRI has prognostic value in patients suffering SCI without computed tomography evidence of trauma. Lesion length is a powerful predictor of outcome in this subgroup of patients. Soft tissue injury plays a role in the severity of injury and the ability to recover in this subgroups of patients.

Spinal Cord Injury after Blunt Cervical Spine Trauma: Correlation of Soft-Tissue Damage and Extension of Lesion

This study retrospectively evaluates whether ligamentous injury or disk disruption after spinal cord injury correlates with lesion length. Length of lesion, disk disruption, ligamentous injury association, and extent of spinal cord injury were statistically assessed. The number of ligaments affected had a positive correlation with the extension of the lesion. Thus, in cervical spine trauma, a specific pattern of ligamentous injury correlates with the length of the spinal cord lesion. BACKGROUND AND PURPOSE: In patients with spinal cord injury after blunt trauma, several studies have observed a correlation between neurologic impairment and radiologic findings. Few studies have been performed to correlate spinal cord injury with ligamentous injury. The purpose of this study was to retrospectively evaluate whether ligamentous injury or disk disruption after spinal cord injury correlates with lesion length. MATERIALS AND METHODS: We retrospectively reviewed 108 patients diagnosed with traumatic spinal cord injury after cervical trauma between 1990–2011. Plain films, CT, and MR imaging were performed on patients and then reviewed for this study. MR imaging was performed within 96 hours after cervical trauma for all patients. Data regarding ligamentous injury, disk injury, and the extent of the spinal cord injury were collected from an adequate number of MR images. We evaluated anterior longitudinal ligaments, posterior longitudinal ligaments, and the ligamentum flavum. Length of lesion, disk disruption, and ligamentous injury association, as well as the extent of the spinal cord injury were statistically assessed by means of univariate analysis, with the use of nonparametric tests and multivariate analysis along with linear regression. RESULTS: There were significant differences in lesion length on T2-weighted images for anterior longitudinal ligaments, posterior longitudinal ligaments, and ligamentum flavum in the univariate analysis; however, when this was adjusted by age, level of injury, sex, and disruption of the soft tissue evaluated (disk, anterior longitudinal ligaments, posterior longitudinal ligaments, and ligamentum flavum) in a multivariable analysis, only ligamentum flavum showed a statistically significant association with lesion length. Furthermore, the number of ligaments affected had a positive correlation with the extension of the lesion. CONCLUSIONS: In cervical spine trauma, a specific pattern of ligamentous injury correlates with the length of the spinal cord lesion in MR imaging studies. Ligamentous injury detected by MR imaging is not a dynamic finding; thus it proved to be useful in predicting neurologic outcome in patients for whom the MR imaging examination was delayed.

Normal pressure subdural hygroma with mass effect as a complication of decompressive craniectomy

Background: Subdural posttraumatic collections are called usually Traumatic Subdural Hygroma (TSH). TSH is an accumulation of cerebrospinal fluid (CSF) in the subdural space after head injury. These collections have also been called Traumatic Subdural Effusion (TSE) or External Hydrocephalous (EHP) according to liquid composition, or image features. There is no agreement about the pathogenesis of these entities, how to define them or if they are even different phenomena at all. Case Description: We present a case of a complex posttraumatic subdural collection, the role of cranioplasty as definite solution and review the literature related to this complication. Conclusion: Patients who undergo decompressive craniectomy (DC) have a risk of suffering a subdural collection of 21-50%. Few of these collections will become symptomatic and will need evacuation. When this happens, cranioplasty might be the definitive solution.

Stent Placement for Carotid Web

BACKGROUND The carotid web is an intraluminal shelf-like projection arising from the posterior wall of the carotid bifurcation and an uncommon etiology of ischemic strokes. We describe the feasibility of endovascular stent placement to treat this condition. CASE REPORT A 47-year-old woman presented with a sudden occlusion of the right middle cerebral artery. Computed tomography angiography and digital subtraction angiography showed a carotid web in the ipsilateral carotid bifurcation. Treatment included mechanical thrombectomy for the middle cerebral artery occlusion and carotid stent placement to prevent further ischemic episodes from the carotid web. At the 6-month follow-up, good apposition of the stent against the artery wall was noted, and the patient was free of neurologic symptoms. CONCLUSIONS Carotid artery stent placement is a feasible option in the management of carotid webs.

Ligaments disruption: a new perspective in the prognosis of spinal cord injury.

The worldwide prevalence of spinal cord injury (SCI) ranges from 233 to 755 per million inhabitants, whereas the reported incidence lies between 10.4 and 83 per million inhabitants annually (Wyndaele and Wyndaele, 2006). Thus, the socioeconomic impact of SCI associated with cervical trauma is high enough that it could become an important concern in the vast majority of developed countries. The ability to predict recovery following SCI is an important part of the physicians role in providing the best care and guidance to patients and families during recovery. The diagnosis of cervical spine injury is an essential aspect of the trauma evaluation. This task is especially difficult in patients whose clinical examinations are not reliable in the midst of distracting painful injuries, intoxication, or concomitant head injury (Levi et al., 2006; Hasler et al., 2011). For this population, the use of radiology is essential. In particular, magnetic resonance imaging (MRI) has become the tool of choice for the diagnosis and management of cervical spine injury after trauma (Levi et al., 2006; Boese and Lechler, 2013). Several studies have been designed to find an association between neurological outcome and a specific radiological finding (Kulkarni et al., 1988; Silberstein and Hennessy, 1993; Flanders et al., 1996; Tewari et al., 2005; Miyanji et al., 2007). Larger lesions and hemorrhage within the spinal cord have been classically described as predictors of bad clinical outcomes in most of these (Kulkarni et al., 1988; Silberstein and Hennessy, 1993; Flanders et al., 1996). Because of its accuracy in detecting soft tissue injuries, MRI is a useful and well-known tool in the management of cervical trauma, particularly in cases of doubtful structural stability (Pizones et al., 2012a). However, there is a lack of knowledge about the prognostic role of ligament injuries (Song et al., 2008). In previous work, disruptions of the ligamentum flavum, anterior longitudinal ligament, and posterior longitudinal ligament were found to be statistically associated with bilateral facet dislocation (Vaccaro et al., 2001). A systematic review that included 1,132 cases of spinal cord injury without radiological abnormalities (SCIWORA) showed that patients with extraneural abnormalities had worse prognoses than patients without abnormalities in their MRIs, but better prognoses than patients with intraneural abnormalities such as edema or hemorrhage (Boese and Lechler, 2013). We recently added substantial information to this topic. In a group of 108 patients with SCI after a cervical trauma (Martinez-Perez et al., 2013), we demonstrated that a specific pattern of ligamentous injury is correlated with the length of spinal cord lesions seen in MRIs. Our results showed that ligamentum flavum injury is independently associated with larger lesions measured at high signal intensity within the spinal cord on T2 sequences. At this point, interpretation of our results should be viewed with caution, because lesion length represents the degree of SCI but is not a measure of neurologic outcome at follow-up. Subjectivity associated with neurological examinations and difficulties with statistical interpretation dictate the use a continuous scale of quantitative variables to analyze the role of soft tissues in SCI. In our opinion, there are two mechanisms that synchronically act to produce greater spinal cord lesions when the ligamentum flavum is damaged. First, the elastic nature of the ligamentum flavum implies that more pressure is required to disrupt it, and these forces are also transmitted to the spinal cord (Figure 1). Secondly, posterior elements are associated with increased instability and therefore with greater SCI. This theory may explain why there are patients without evidence of trauma on radiological imaging, but who manifest neurological deficits secondary to SCIWORA, and why there are patients with different grades of SCI in this subgroup of patients. In fact, we are trying to elucidate a specific pattern of soft tissue injuries in those patients diagnosed with SCIWORA and more severe neurological deficits. Figure 1 Colour scheme showing cervical spine after blunt trauma. Ligamentum flavum is disrupted and associated with intramedullary abnormalities and spinal cord injury. The different mechanisms of injury play unclear roles in the development of SCI (Allen et al., 1982; Alday, 1996; Vaccaro et al., 2007). We may be able to provide a basis of understanding of the association between a specific mechanism of injury and the degree of SCI, which should be corroborated in future studies. Allen and associates (Allen et al., 1982) established a classification based on the mechanism of trauma. In the distractive flexion injuries, failure of the posterior ligamentous complex, including the ligamentum flavum, resulted from a major injury vector directed away from the trunk. The degree of these ligamentous failures was sequentially greater with the grade of Allen classification, and was associated with the progressive severity of SCI (Allen et al., 1982). However, this association is not seen only in flexion injuries. Song and associates (Song et al., 2008) used a group of patients with distractive extension injuries to classify, in grades of progressive severity, the patterns of soft tissue injuries. They found that injuries Grade IV and above, which included damage to the ligamentum flavum, showed increased signal cord changes. Most of the relevant predictors of SCI (edema or intramedullary hemorrhage) are well identified in sagittal T2-weighted images (Silberstein and Hennessy, 1993; Flanders et al., 1996). This sequence should be included in all protocols of cervical trauma for assessing the integrity of soft tissues (Bozzo et al., 2011). However, some authors believe that this may not be enough, and that the standard MRIs have low to moderate specificity in discriminating ligament disruption (Goradia et al., 2007). Fat-suppressed T2 images (Short T1 Inversion Recovery (STIR) sequences) have been used to more accurately rule out ligament disruption (Pizones et al., 2012a, 2012b). Regretfully, STIR is not available in all protocols, and T2 sagittal images are the minimum needed in cervical trauma MRIs. The timing of the MRI is a potential source of critical bias. A literature review by Bozzo and associates (Bozzo et al., 2011) concluded that, for prognostication, MRI should be done in the acute period following SCI. It has been recommended that the first MRI be performed 24–72 hours post injury (Bondurant et al., 1990). There is a lack of evidence supporting a more precise guideline (Goradia et al., 2007; Bozzo et al., 2011). According to previous reports, the extent of lesion is related to the clinical prognosis of SCI when the MRI is performed in the acute phase (Tewari et al., 2005; Miyanji et al., 2007). However, we should take into consideration the findings of other investigators who have found that lesion length changes over time and depends on the length of time between trauma and MRI (Leypold et al., 2008). Most of patients with SCI after cervical trauma are managed in intensive care units under unstable conditions, so performing an MRI, especially within the first days after trauma, can sometimes be challenging, and can worsen the clinical condition of the patient. Ligament disruption is a more stable finding and its detection can be useful in predicting neurological prognosis when the MRI must be delayed. In conclusion, in the past, the role of the ligamentum flavum in the development of SCI has been underestimated. In the future, more effort should be put forth in detecting this injury pattern, particularly in patients whose clinical conditions impede an MRI in the acute phase, and when the classical predictors are not as useful. The MRI is the gold standard to detect and to identify ligament disruption, but most useful sequences, such as STIR, are not included in all cervical trauma protocols.

Spontaneous Tension Pneumocephalus: A Rare Complication of Shunting

BACKGROUND Spontaneous tension pneumocephalus (STP) is a rare but serious complication derived from shunting procedures. Few cases have been published with purely intraventricular location. Treatment options and physiopathology considerations are discussed in this case report. CASE DESCRIPTION A 75-year-old woman with a 15-year-old lumboperitoneal (LP) shunt insertion was treated with a ventriculoperitoneal shunt for her normotensive hydrocephalus. Two months later she was brought to the emergency room showing symptoms of lethargy and confusion. A helicoidal computed tomography (CT) scan revealed a bone defect in the floor of the right temporal fossa. The patient underwent a temporal craniotomy for closing the bone and dural defect, and the LP shunt was removed, at which point her condition improved. CONCLUSIONS A high-resolution CT scan of the skull base is useful to localize the point where the air enters into the intracranial cavity in STP cases. Coexistent or preceding otologic symptoms might direct the suspicion toward an otogenic origin. Shunt removal, or adjusting the opening pressure, if feasible, is recommended. Otherwise, dural repair and covering of the bone defect have acceptable rates of success and should be performed before any other more aggressive techniques to avoid the risk of hearing loss.

Subaxial cervical spine injury classification system: is it most appropriate for classifying cervical injury?

The cervical spine injury represents a potential devastating disease with 6% associated in-hospital mortality (Jain et al., 2015). Neurological deterioration ranging from complete spinal cord injury (SCI) to incomplete SCI or single radiculopathy are potential consequences of the blunt trauma over this region. The subaxial cervical spine accounts the vast majority of cervical injuries, making up two thirds of all cervical fractures (Alday, 1996). Few classifications (Holdsworth, 1970; White et al., 1975; Allen et al., 1982; Denis, 1984; Vaccaro et al., 2007) have been proposed to describe injuries of the cervical spine for several reasons. First, to delineate the best treatment in each case; second, to determinate an accurate neurological prognosis, and third, to establish a standard way to communicate and describe specific characteristics of cervical injuries patterns. Classical systems are primarily descriptive and no single system has gained widespread use, largely because of restrictions in clinical relevance and its complexity. Classical systems: Allen classification has been commonly used over the past two decades. This system is based on a clinical review of 165 patients with blunt cervical trauma (Allen et al., 1982). Each lower cervical injury is divided into 6 categories of injury, which truly describe the attitude of the cervical spine at the time of injury and the dominant force vectors – compressive flexion, vertical compression, distractive flexion, compressive extension, distractive extension and lateral flexion. Distractive flexion injuries were the most common in these 165 patients. Within each category, a series of injury are described, ranging from mild to severe, which are related at the same time with neurological impairment. However, this classification does not allow to make a comparison, in terms of neurological outcome, between different categories of injury mechanisms. Allen system also fails to explain clearly some important force vectors, such as rotation and their implication in spine stability. Neurological status is not included as a criteria of this structural and mechanistic classification. Those individuals with SCI without radiological abnormalities (SCIWORA) are underrepresented and may lead to mistakes in terms of management and predicting clinical outcome, despite the potential disability in this subgroup of patients. White and Panjabi (1975) elucidated that similar injury mechanisms can produce different injury patterns due to the complexity of the specific forces, moments and positions. They described a complex point-based system to asses cervical spine stability. Not only clinical data, but also in vitro biomechanics testing are the basis of this classification. A street test is also required, which runs against the simplicity and applicability in critical patients. This system also fails in terms of validity and inter observer reliability. Two-column and three-column (Holdsworth, 1970; Denis, 1984) systems may provide more simplicity and a better understanding of the common injury patterns seen in the lower cervical spine. Holds worth in his two column model, postulated that the integrity of the posterior bony elements and the posterior ligamentous complex is the major determinant of stability. However, this scheme was insufficient to predict the presence of an unstable subset of compression fractures. Dennis modified the two column theory into a three column system. He defined a middle column, consisting the posterior longitudinal ligament and the posterior third of the vertebral body. The term of “unstable fracture” was coined when the middle column and one of the remaining columns – anterior or posterior – were injured. In spite of being primarily described to elucidate different patterns of fracture in thoracic and lumbar spine, its use has commonly widespread over scientific community. Lower cervical biomechanics differ so much with lumbar and dorsal spine, as C-spine implies wider range of mobility, lesser fixation and a different distribution of articular facets. Denis model (two-column) widely used, is an oversimplification that fails to incorporate the biomechanics importance of the spinal ligaments, which are also linked to degree of SCI (Martinez-Perez et al., 2014b). Moreover, some specific patterns, such as “chance fracture”, is underreported in the cervical spine. So, in our opinion, resorting to these nomenclature to define some cervical fractures may result misleading (Alday, 1996). Changes in paradigma: from the structure to the function: All of these “classical” system mentioned above are based on the mechanism of injury extracted from plain radiographs or CT scans, ignoring the contribution of ligaments to stability and the role of MRI in the stratification (Martinez-Perez et al., 2014a). The role of neurological impairment to determine the prognosis has been clearly demonstrated in previous works and represents an important indicator of severity of cervical spine injury (Miyanji et al., 2007). Moreover, neurological status may be the single most influential factor to indicate conservative or surgical management. Its widely accepted that incomplete neurological injuries requires surgical decompressive procedure, even in the case of absence of frank structural instability. Then, some authors considere that neurological impairment should be include in new systems of classification in order to give them the possibility to help to the surgeon in decision making (Moore et al., 2006; Vaccaro et al., 2007). The need for a practical lower cervical spine classification system directly linked to a clinical decision-making algorithm prompted the Spine Trauma Study Group to develop the Subaxial Cervical Spine Injury Classification (SLIC) system (Vaccaro et al., 2007). This is a severity scale that attempts to provide a utilitarian classification framework to the clinician and surgeon involved in the treatment of sub-axial injuries. Instead of building the system on an inferred mechanism, it is based on 3 components of injury (mechanism/morphology, integrity of the posterior ligamentous complex and neurological status of the patients, Table 1) which, by consensus, represent major and largely independent determinants of prognosis and management. The total number of points is calculated for each cervical fracture or dislocation based on these three major categories, an the final score is linked to an algorithm to help guide management: injuries with a SLIC score of 4 or less are managed conservatively, fractures with a score of 6 or more are surgically operated, and injuries with a score of 5 may be managed either with surgery or non operatively at the surgeon΄s discretion (Dvorak et al., 2007). In this way, the SLIC severity scale is the first sub-axial trauma classification system to abandon mechanism and anatomy characterized by other systems in favor of injury morphology and clinical status. However, this system lacks the attention toward the level of injury, which also can determinate either the prognosis, as the surgical approach in each case. Other limitation of the mentioned system is the current use in neurosurgical community, lower than older classifications (Chhabra et al., 2015). Table 1 The Subaxial Injury Classification and Severity Score System (SLIC) Despite of being far from an ideal classification for cervical trauma, by building the system on injury patterns less severe to more severe, the SLIC severity scale helps to objectify the optimal management in each case. Further studies have shown that SLIC scale exhibits excellent validity and inter observer reliability, unlike other classifications (Vaccaro et al., 2007; Patel et al., 2010; Aarabi et al., 2013). Conclusion: “Classical” cervical injury classifications are characterized for its complexity, low applicability, and its uselessness in guiding therapeutic options. New schemes, as SLIC system, includes determinant factors in prognosis, such as neurological impairment. It will hopefully facilitate the development of evidence-based guidelines that may influence other aspects of the therapeutic decision-making process (e.g., which operative approach is most appropriate for a particular injury). We certainly believe its accuracy and reproducibility will increase over time as surgeons become more familiar with the protocol.

MRI Prognostication Factors in the Setting of Cervical Spinal Cord Injury Secondary to Trauma

OBJECTIVE Several studies have looked for an association between radiologic findings and neurologic outcome after cervical trauma. In the current literature, there is a paucity of evidence proving the prognostic role of soft tissue damage or bony integrity. Our objective is to determine radiologic findings related to neurologic prognosis in patients after incomplete acute traumatic cervical spinal cord injury, regardless of initial neurologic examination results. METHODS We retrospectively reviewed patients with acute traumatic cervical spinal cord injury who had a magnetic resonance imaging (MRI) performed within the first 96 hours. Clinical and epidemiologic data were recorded from the medical records along with several radiologic findings from the initial computed tomographic scan and MRI. Data were analyzed using a non-parametric test. Significant prognostic factors were analyzed through a stepwise multivariable logistic regression, adjusted by neurologic status at baseline. The receiver-operating characteristic curve was used to test the discriminative capacity of the model. RESULTS Eighty-six patients (68 males and 18 females) were included for the analysis. Mean age was 49 years. Ligamentum flavum injury, intramedullary edema larger than 36 mm, and facet dislocation were demonstrated to be associated with a lack of neurologic improvement at follow-up. Multivariable analysis showed that edema larger than 36 mm and facet dislocation were strong predictors of clinical outcome, regardless of the initial neurologic examination result. CONCLUSION Early MRI has an intrinsic prognostic value. Ligamentous injury and larger edema are strong predicting factors of a bad neurologic outcome at long-term follow-up.