Subarachnoid blood acutely induces spreading depolarizations and early cortical infarction.

See Ghoshal and Claassen (doi:10.1093/brain/awx226) for a scientific commentary on this article. Early cortical infarcts are common in poor-grade patients after aneurysmal subarachnoid haemorrhage. There are no animal models of these lesions and mechanisms are unknown, although mass cortical spreading depolarizations are hypothesized as a requisite mechanism and clinical marker of infarct development. Here we studied acute sequelae of subarachnoid haemorrhage in the gyrencephalic brain of propofol-anaesthetized juvenile swine using subdural electrode strips (electrocorticography) and intraparenchymal neuromonitoring probes. Subarachnoid infusion of 1­2 ml of fresh blood at 200 µl/min over cortical sulci caused clusters of spreading depolarizations (count range: 12­34) in 7/17 animals in the ipsilateral but not contralateral hemisphere in 6 h of monitoring, without meaningful changes in other variables. Spreading depolarization clusters were associated with formation of sulcal clots (P < 0.01), a high likelihood of adjacent cortical infarcts (5/7 versus 2/10, P < 0.06), and upregulation of cyclooxygenase-2 in ipsilateral cortex remote from clots/infarcts. In a second cohort, infusion of 1 ml of clotted blood into a sulcus caused spreading depolarizations in 5/6 animals (count range: 4­20 in 6 h) and persistent thick clots with patchy or extensive infarction of circumscribed cortex in all animals. Infarcts were significantly larger after blood clot infusion compared to mass effect controls using fibrin clots of equal volume. Haematoxylin and eosin staining of infarcts showed well demarcated zones of oedema and hypoxic-ischaemic neuronal injury, consistent with acute infarction. The association of spreading depolarizations with early brain injury was then investigated in 23 patients [14 female; age (median, quartiles): 57 years (47, 63)] after repair of ruptured anterior communicating artery aneurysms by clip ligation (n = 14) or coiling (n = 9). Frontal electrocorticography [duration: 54 h (34, 66)] from subdural electrode strips was analysed over Days 0­3 after initial haemorrhage and magnetic resonance imaging studies were performed at ∼ 24­48 h after aneurysm treatment. Patients with frontal infarcts only and those with frontal infarcts and/or intracerebral haemorrhage were both significantly more likely to have spreading depolarizations (6/7 and 10/12, respectively) than those without frontal brain lesions (1/11, P's < 0.05). These results suggest that subarachnoid clots in sulci/fissures are sufficient to induce spreading depolarizations and acute infarction in adjacent cortex. We hypothesize that the cellular toxicity and vasoconstrictive effects of depolarizations act in synergy with direct ischaemic effects of haemorrhage as mechanisms of infarct development. Results further validate spreading depolarizations as a clinical marker of early brain injury and establish a clinically relevant model to investigate causal pathologic sequences and potential therapeutic interventions.

Degenerative Cervical Myelopathy: A Clinical Review.

Degenerative Cervical Myelopathy (DCM) is the most common form of spinal cord impairment in adults and results in disability and reduced quality of life. DCM can present with a wide set of clinical and imaging findings, including: 1) pain and reduced range of motion of the neck, and motor and sensory deficits on clinical exam, and 2) cord compression due to static and dynamic injury mechanisms resulting from degenerative changes of the bone, ligaments, and intervertebral discs on MRI. The incidence and prevalence of DCM has been estimated at a minimum of 4.1 and 60.5 per 100,000, respectively, but surgical trends and an aging population suggest these numbers will rise in the future. The diagnosis of DCM is based on clinical examination, with a positive Hoffmann's sign and hand numbness typically appearing in the upper limbs, and gait abnormalities such as difficulty with tandem gait serving as sensitive diagnostic findings. Loss of bladder function may also occur in patients with severe DCM. The degree of neurological impairment can be measured using the modified Japanese Association Scale (mJOA) or Nurick grade. Non-operative management has a limited role in the treatment, while surgical management has been shown to both be safe and effective for halting disease progression and improving neurological function. Predictors of surgical outcome include age and baseline severity, indicating that early recognition of DCM is important for ensuring an optimal surgical outcome.

Retrograde ejaculation following anterior lumbar surgery: a systematic review and pooled analysis.

OBJECTIVE: The present systematic review and pooled analysis aims to assess the incidence and risk factors for the development of retrograde ejaculation (RE) following first-time open anterior lumbar surgery. METHODS: A systematic MEDLINE review via PubMed was performed, identifying 130 clinical papers relating to the topic. Eighteen publications were selected according to predetermined inclusion and exclusion criteria and were used to determine the incidence of RE. Only the publications that provided data on surgical risk factors present specifically in the men in the study were included in the analysis of risk factors. RESULTS: Of the 2503 men included, there were 57 reported events of RE (2.3%). Of the cases for which long-term data were provided, 45.8% had resolved by final follow-up. There was a statistically significant increased risk associated with a transperitoneal as opposed to a retroperitoneal approach (8.6% vs 3.2%), as well as with the use of recombinant human bone morphogenetic protein-2 (rhBMP-2) in anterior lumbar interbody fusion (ALIF) as opposed to ALIF with bone graft or arthroplasty in controls (5.0% vs 1.8%). However, when excluding from analysis the patients operated on prior to the FDA's 2008 warning that commented on the drug's neuroinflammatory properties, there was no significant difference in rates of RE in patients receiving rhBMP-2 versus the control group (2.4% vs 2.5%). There was no significant difference in risk based on single- versus multilevel procedure or on ALIF versus arthroplasty. CONCLUSIONS: In a pooled analysis of currently published data on men undergoing first-time open anterior lumbar surgery, this study found an overall incidence of RE of 2.3%. Nearly half of these patients recovered, reporting resolution of symptoms anywhere between 3 months and 48 months. Analysis of risk factors was limited by a paucity of published literature segregating data by sex. However, there was an increased risk associated with rhBMP-2 only when including data collected prior to the FDA warning on its detrimental properties. The authors therefore posit that the risk of RE is probably overestimated in the literature, given that the vast majority of the data available were collected prior to this warning and given the subsequent implementation of precautions when handling rhBMP-2.

Case Report of Transgender Patient with Gonadotropic Dysfunction Secondary to Craniopharyngioma: Toward Improving Understanding of Biopsychosocial Dynamics of Gender Identity in Neurosurgical Care.

BACKGROUND: There is a paucity of information in the literature linking possible neuroendocrinologic repercussions of anterior pituitary insufficiency from tumor-associated mass effect with gender identity in transindividuals. The authors present the case of a 26-year-old transgender woman who was found to have a sellar/suprasellar neoplasm after reporting loss of vision in a bitemporal distribution. CASE DESCRIPTION: Magnetic resonance imaging demonstrated a 2.6-cm complex cystic and solid sellar/suprasellar mass, suggestive of craniopharyngioma, intimately associated with the pituitary stalk. Importantly, this radiographic diagnosis was made 2 years following the initiation of gender-affirming hormone therapy (HT). Laboratory testing following radiographic diagnosis demonstrated evidence of diffuse anterior pituitary insufficiency with decreased morning cortisol, free thyroxine, insulin-like growth factor-1, and testosterone. Following optimization with the endocrinology team, the patient was taken to the operating room for expanded endonasal resection of tumor with lumbar drain insertion and nasoseptal flap coverage. Gross total resection was achieved with marked improvement in vision noted following surgery. The patient continued her HT following surgery. CONCLUSIONS: In hindsight, the neuroendocrinologic manifestations of the craniopharyngioma may have influenced distressing pubertal experiences that distanced her from her assigned male sex, as well as the desired effects of feminization HT in this patient, ultimately delaying her presentation to the neurosurgery service and diagnosis of craniopharyngioma. As the first report of the neurosurgical evaluation and treatment of a transgender patient with anterior pituitary insufficiency secondary to craniopharyngioma, this case examines the biopsychosocial interplay between the development of gender identity and the neuroendocrinologic manifestations of craniopharyngioma.

Novel Distributed Loading Technique Using Multimaterial, Long-Segment Spinal Constructs to Prevent Proximal Junctional Pathology in Adult Spinal Deformity Correction-Operative Technique and Radiographic Findings.

BACKGROUND: Proximal junctional kyphosis (PJK) and proximal junction failure are common and costly complications after long-segment adult spinal deformity (ASD) correction. Although much research has focused on the concept of "softening the landing" to prevent proximal junction pathologies, long-segment constructs largely deviate from the force-deformation curve of the physiologic spine. Our novel distributed loading technique for ASD correction is described using multimaterial, long-segment constructs to create a biomechanically sound, yet physiologic, decremental stiffness toward the rostral end. METHODS: Operative steps detail the custom-designed constructs of dual-headed pedicle screws and varied rod diameters and materials (cobalt chromium or titanium) for an initial 20 patients (mean 66.6 ± 4.8 years). Standing scoliosis films were obtained preoperatively and at regular intervals postoperatively to assess for PJK. RESULTS: No patient had evidence of PJK or proximal junction failure at latest radiographic follow-up (mean 17.9 months, range 13-25 months). Radiographic findings for sagittal vertical axis averaged 11.2 ± 5.6 cm preoperatively and 3.6 ± 2.3 cm postoperatively. Compared with preoperative parameters, postoperative reductions in pelvic incidence-lumbar lordosis mismatch averaged 28.7 ± 12.9 degrees, and sagittal vertical axis averaged 7.6 ± 5.2 cm while PJA was essentially unchanged. CONCLUSIONS: Preliminary results suggest that the distributed loading technique is promising for prevention of PJK with stiffness gradients that mimic the force-deformation curve of the physiologic posterior tension band. Our technique may optimize the degree of stress at the proximal junction without overwhelming the anterior column bony while remodeling and mature arthrodesis takes place.

Bilateral Sequential Spontaneous Otogenic Pneumocephalus, Lessons in Pathophysiology, and Management of a Rare Case.

OBJECTIVE: Report the details of an unusual case of initially unilateral intradural spontaneous otogenic pneumocephalus in which the patient developed contralateral pneumocephalus after surgical repair of temporal bone and dural defects on the initial side. Discuss the lessons learned concerning management and pathophysiology of this rare case. PATIENT: A 73-year-old male presenting with bilateral retro-orbital pain and headache was found to have unilateral intradural pneumocephalus in the temporal lobe with an adjacent defect in the temporal bone. INTERVENTION: Surgical repair of the initial defect in the temporal bone and dura via a middle cranial fossa approach with obliteration of the mastoid cavity. RESULTS: The patient's symptoms and degree of pneumocephalus on first affected side decreased initially after surgery. Two weeks after surgery he developed worsening pneumocephalus on the contralateral side in the temporal and frontal lobes with weakness and mild somnolence. This side was repaired via a similar technique without mastoid obliteration. Two weeks after surgery the patient recovered to normal level of consciousness with mild residual weakness. CONCLUSIONS: Spontaneous otogenic intradural pneumocephalus is an extremely rare but serious condition related to defects in the temporal bone and dura. The precise mechanism by which this occurs is poorly understood. This unusual case where there were bilateral defects presenting with spontaneous otogenic pneumocephalus in sequence illustrates that it represents a rare sequelae of processes which thin the skull base. These processes should be addressed in addition to acute management of the defect and intracranial air.

Transient Dorsal Column Dysfunction After Extreme Cervical Deformity Correction: Report of 3 Cases.

BACKGROUND: Chin-on-chest kyphotic cervical deformity can be debilitating. Surgical deformity correction serves to decompress neural elements and restore lordosis. This can be achieved through multiple osteotomies with instrumentation and fusion, sometimes requiring a staged approach. Such procedures carry a high risk of neurologic injury. Here we present examples of transient neurologic dysfunction not previously reported in the common literature. CASE DESCRIPTION: The authors present 3 patients who underwent extreme cervical deformity correction for chin-on-chest deformity. Deformity correction in all cases was obtained through multiple osteotomies with multilevel cervicothoracic posterior instrumentation and arthrodesis. On postoperative examination, all 3 patients developed transient ataxia, dysmetria, and decreased proprioception in all 4 extremities-examination findings consistent with dorsal column dysfunction. All symptoms resolved within 2-3 weeks postoperatively. CONCLUSIONS: Incomplete spinal cord syndromes such as posterior cord syndrome can be caused by compression or stretching of the ascending dorsal spinal tracts. Considering the large degree of correction obtained, we hypothesize the resulting shortening of the dorsal columns as the pathomechanism. Providers should be aware, and patients should be counseled preoperatively that these symptoms may occur. If these symptoms are present postoperatively, appropriate diligence is warranted with the understanding that these deficits may be transient.

Sacral Rheumatoid Nodule: An Unusual Indication for Coccygectomy.

Here, we present a case report of a woman who presented with a large sacral rheumatoid nodule. This patient failed conservative treatment and presented in search of a surgical solution. We successfully removed her rheumatoid nodule using a surgical approach typically reserved for traumatic coccydynia. We show how coccygectomy, although a rare surgical procedure, was effective in treatment of a large rheumatoid nodule.

Routine surveillance imaging following mild traumatic brain injury with intracranial hemorrhage may not be necessary.

BACKGROUND: Mild traumatic brain injury (mTBI) comprises the majority of pediatric traumatic brain injury. Children with mTBI even with traumatic intracranial hemorrhage (tICH) rarely experience a clinically significant neurologic decline (CSND). The utility of routine surveillance imaging in the pediatric population also remains controversial, especially owing to concerns about the risks of radiation exposure at a young age. This study aims to identify demographic or injury-related characteristics that may facilitate recognition of children at risk of progression with mTBI. METHODS: We performed a retrospective review of patients <16 years old with mTBI (GCS 13-15) and tICH admitted to a Level I pediatric trauma center between 2009 and 2014. Management of these patients was directed by the Cincinnati Children's Hospital Medical Center Minor Head Injury Algorithm. We reviewed each chart with emphasis on patient demographics, injury specific data, and radiographic or clinical progression. RESULTS: 154 patients met inclusion criteria with mean age of 4 [0-16]; 116 sustained an tICH and 38 patients had isolated skull fractures. Repeat neuroimaging was obtained in 68 patients (59%). Only 9 patients (13%) with tICH had radiographic progression, none of which resulted in CSND. In addition, 9 patients experienced CSND, leading to neurosurgical intervention in 6 patients. Notably, none of these patients had repeat imaging prior to their neurologic changes. Both CSND and need for intervention were significantly higher in patients with epidural hematomas than other types of tICH (19.2% vs. 1.1%, p = 0.002). Of 154 patients, 19 did not have documented follow-up, 135 were seen as outpatients and 65 (48%) had follow up neuroimaging. All patients who had surveillance imaging in the outpatient setting had stable or resolved tICH. CONCLUSION: Few children with mTBI and tICH experience clinical decline. Importantly, all patients that required neurosurgical intervention were identified by clinical changes rather than via repeat imaging. Our study suggests that in the vast majority of cases, clinical monitoring alone is safe and sufficient in patients in order to avoid exposure to repeat radiographic imaging. LEVEL OF EVIDENCE: Level III, prognostic and epidemiological.

Point-of-care testing in the acute management of traumatic brain injury: Identifying the coagulopathic patient.

BACKGROUND: The use of anticoagulants or antiplatelet medications has become increasingly common and is a well-established risk factor for worsening of hemorrhages in trauma patients. The current study addresses the need to investigate the efficacy of point-of-care tests (POC) as an adjunct to conventional coagulation testing in traumatic brain injury (TBI) patients. METHODS: A retrospective review of 190 TBI patients >18 years of age who underwent both conventional and POC testing as part of their admission coagulopathy workup was conducted. Coagulation deficiency was defined as an international normalized ratio (INR) >1.4, a reaction time (r-value) on rapid thromboelastography >50 seconds, or a VerifyNow Aspirin (VN-ASA) level of < 550 Aspirin Reaction Units. RESULTS: Among 190 patients, 91 (48%) disclosed a history of either warfarin or antiplatelet use or had documented INR >1.4. Of the 18 (9%) patients who reported warfarin use, 83% had elevated INR and 61% had elevated r-value. However, 41% of the patients without reported anticoagulant usage revealed significantly elevated r-value consistent with a post-traumatic hypocoagulable state. Of 64 (34%) patients who reported taking ASA, 51 (80%) demonstrated therapeutic VN-ASA. Interestingly, 31 of 126 (25%) patients not reporting ASA use were also noted to have therapeutic VN-ASA suggestive of platelet dysfunction. CONCLUSIONS: The coagulopathy POC panel consisting of r-TEG and VN-ASA successfully identified a subset of TBI patients with an occult coagulopathy that would have otherwise been missed. Standardization of these POC assays on admission in TBI may help guide patient resuscitation in the acute setting.

Long-term resolution of delayed onset hypoglossal nerve palsy following occipital condyle fracture: Case report and review of the literature.

The authors present the case of a patient that demonstrates resolution of delayed onset hypoglossal nerve palsy (HNP) subsequent to occipital condyle fracture following a motor vehicle accident. Decompression of the hypoglossal nerve and craniocervical fixation led to satisfactory long-term (>5 years) outcome. There is a scarcity of literature in recognizing HNPs following trauma and a lack of pathophysiological understanding to both a delayed presentation and to resolution versus persistence. This is the first report demonstrating long-term resolution of hypoglossal nerve injury following trauma to the craniocervical junction.

Aneurysm growth and de novo aneurysms during aneurysm surveillance.

OBJECTIVE Many low-risk unruptured intracranial aneurysms (UIAs) are followed for growth with surveillance imaging. Growth of UIAs likely increases the risk of rupture. The incidence and risk factors of UIA growth or de novo aneurysm formation require further research. The authors retrospectively identify risk factors and annual risk for UIA growth or de novo aneurysm formation in an aneurysm surveillance protocol. METHODS Over an 11.5-year period, the authors recommended surveillance imaging to 192 patients with 234 UIAs. The incidence of UIA growth and de novo aneurysm formation was assessed. With logistic regression, risk factors for UIA growth or de novo aneurysm formation and patient compliance with the surveillance protocol was assessed. RESULTS During 621 patient-years of follow-up, the incidence of aneurysm growth or de novo aneurysm formation was 5.0%/patient-year. At the 6-month examination, 5.2% of patients had aneurysm growth and 4.3% of aneurysms had grown. Four de novo aneurysms formed (0.64%/patient-year). Over 793 aneurysm-years of follow-up, the annual risk of aneurysm growth was 3.7%. Only initial aneurysm size predicted aneurysm growth (UIA < 5 mm = 1.6% vs UIA ≥ 5 mm = 8.7%, p = 0.002). Patients with growing UIAs were more likely to also have de novo aneurysms (p = 0.01). Patient compliance with this protocol was 65%, with younger age predictive of better compliance (p = 0.01). CONCLUSIONS Observation of low-risk UIAs with surveillance imaging can be implemented safely with good adherence. Aneurysm size is the only predictor of future growth. More frequent (semiannual) surveillance imaging for newly diagnosed UIAs and UIAs ≥ 5 mm is warranted.