BACKGROUND: Primary spinal melanoma is extremely rare, accounting for ∼1% of all primary melanomas. Typically presenting insidiously in the thoracic spinal cord, primary spinal melanomas can have an acute presentation due to their propensity to hemorrhage.
METHODS: Despite its rarity, primary spinal melanoma should be included in the differential diagnosis when a hemorrhagic pattern of T1 and T2 intensities is seen on magnetic resonance imaging. Furthermore, the complete diagnosis is crucial because the prognosis of a primary spinal melanoma is considerably more favorable than that of a primary cutaneous melanoma with metastatic spread.
CONCLUSIONS: Resection is the treatment of choice, with some authors advocating for postoperative chemotherapy, immunotherapy, and/or radiation. We describe a case of acute quadriplegia from hemorrhagic primary spinal melanoma requiring resection.

BACKGROUND: Primary intramedullary spinal tumors cause significant morbidity and death. Intraoperative ultrasound as an adjunct for localization and monitoring the extent of resection has not been systematically evaluated in these patients; the effectiveness of intraoperative contrast-enhanced ultrasound (CEUS) remains almost completely unexplored.
METHODS: A retrospective case series of patients at a single institution who had consented to the off-label use of intraoperative CEUS was identified. Seven patients with a mean age of 52.8 ± 15.8 years underwent resection of intramedullary tumors assisted by CEUS performed by a single attending neurosurgeon. Histopathological evaluation revealed 3 cases of hemangioblastoma, 1 case of pilocytic astrocytoma, 2 cases of ependymoma, and 1 case of subependymoma. Contrast enhancement correlated with gadolinium enhancement on preoperative magnetic resonance imaging. Intraoperative CEUS facilitated precise lesion localization and myelotomy planning. Dynamic CEUS studies were useful in demonstrating the blood supply to lesions with a dominant vascular pedicle. Regardless of contrast uptake, the differential enhancement between spinal cord tissue and neoplasm assisted in determining interface boundaries.
CONCLUSIONS: Intraoperative CEUS constitutes a useful adjunct for the intraoperative delineation of contrast-enhancing intramedullary tumors and in vivo confirmation of gross-total resection. Systematic investigation is needed to establish the role of CEUS for resection of intramedullary spinal tumors of various pathologies.

BACKGROUND: Acute disseminated encephalomyelitis (ADEM) is a rare, acquired demyelination syndrome that causes cognitive impairment and focal neurological deficits and may be fatal. The potentially reversible disease mainly affects children, often after vaccination or viral infection, but may be seen rarely in adults.
METHODS: A 50-year-old woman presented with loss of visual acuity of the left eye. Magnetic resonance imaging (MRI) revealed an intra- and suprasellar mass, which was removed successfully. On postoperative day 1, MRI showed gross total resection of the lesion and no surgery-related complications. On postoperative day 2, the patient presented with a progressive left-sided hemiparesis, hemineglect, and decline of cognitive performance. MRI showed white matter edema in both hemispheres. Cerebrospinal fluid analysis revealed mixed pleocytosis (355/µL) without further evidence of infection. In synopsis of the findings, ADEM was diagnosed and treated with intravenous immunoglobulins. Shortly thereafter, the patient recovered, and no sensorimotor deficits were detected in the follow-up examination.
CONCLUSIONS: Pituitary gland pathologies are commonly treated by transsphenoidal surgery, with only minor risks for complications. A case of ADEM after craniopharyngioma resection has not been published before and should be considered in case of progressive neurological deterioration with multiple white matter lesions.

The authors present the cases of 3 patients with severe injuries affecting the peroneal nerve combined with loss of tibialis posterior function (inversion) despite preservation of other tibial nerve function. Loss of tibialis posterior function is problematic, since transfer of the tibialis posterior tendon is arguably the best reconstructive option for foot drop, when available. Analysis of preoperative imaging studies correlated with operative findings and showed that the injuries, while predominantly to the common peroneal nerve, also affected the lateral portion of the tibial nerve/division near the sciatic nerve bifurcation. Sunderland\'s fascicular topographic maps demonstrate the localization of the fascicular bundle subserving the tibialis posterior to the area that corresponds to the injury. This has clinical significance in predicting injury patterns and potentially for treatment of these injuries. The lateral fibers of the tibial division/nerve may be vulnerable with long stretch injuries. Due to the importance of tibialis posterior function, it may be important to perform internal neurolysis of the tibial division/nerve in order to facilitate nerve action potential testing of these fascicles, ultimately performing split nerve graft repair when nerve action potentials are absent in this important portion of the tibial nerve.

Greater extent of resection (EOR) improves overall survival and progression-free survival for patients with low- and high-grade glioma. While resection for newly diagnosed insular gliomas can be performed with minimal morbidity, perioperative morbidity is not clearly defined for patients undergoing a repeat resection for recurrent insular gliomas. In this study the authors report on tumor characteristics, tumor EOR, and functional outcomes in patients undergoing reoperation for recurrent insular glioma.
Adult patients with insular gliomas (WHO grades II-IV) who underwent index resection followed by reoperation were identified through the University of California San Francisco Brain Tumor Center. Treatment history and functional outcomes were collected retrospectively from the electronic medical record. Pre- and postoperative tumor volumes were quantified using software with region-of-interest analysis based on FLAIR and T1-weighted postgadolinium sequences from pre- and postoperative MRI.
Forty-four patients (63.6% male, 36.4% female) undergoing 49 reoperations for recurrent insular tumors were identified with a median follow-up of 741 days. Left- and right-sided tumors comprised 52.3% and 47.7% of the cohort, respectively. WHO grade II, III, and IV gliomas comprised 46.9%, 28.6%, and 24.5% of the cohort, respectively. Ninety-five percent (95.9%) of cases involved language and/or motor mapping. Median EOR of the insular component of grade II, III, and IV tumors were 82.1%, 75.0%, and 94.6%, respectively. EOR during reoperation was not impacted by Berger-Sanai insular zone or tumor side. At the time of reoperation, 44.9% of tumors demonstrated malignant transformation to a higher WHO grade. Ninety-day postoperative assessment confirmed that 91.5% of patients had no new postoperative deficit attributable to surgery. Of those with new deficits, 3 (6.4%) had a visual field cut and 1 (2.1%) had hemiparesis (strength grade 1-2/5). The presence of a new postoperative deficit did not vary with EOR.
Recurrent insular gliomas, regardless of insular zone and pathology, may be reoperated on with an overall acceptable degree of resection and safety despite their anatomical and functional complexities. The use of intraoperative mapping utilizing asleep or awake methods may reduce morbidity to acceptable rates despite prior surgery.

Traumatic spondylolisthesis is a known occurrence in trauma, but complete cord transection is relatively rare. Moreover, complete cord transection at a site distant from the traumatic spondylolisthesis without spondyloptosis is exceedingly rare. In this report, authors describe the first case of thoracic cord avulsion following a traumatic grade II lumbar spondylolisthesis. The unusual presentation of this case highlights the importance of further evaluating patients with neurological symptoms out of proportion with the injuries seen on initial imaging. Magnetic resonance imaging performed after initial imaging studies demonstrated T11 cord transection with the distal cord herniating into the lumbar paraspinal soft tissues, thus allowing for preoperative planning to prepare for a more significant intervention including complex dural repair and lumbar drain placement, in addition to instrumented fusion to stabilize the traumatic spondylolisthesis.

The aim of this study was to compare sensitivity and specificity between the novel threshold and amplitude criteria for motor evoked potentials (MEPs) monitoring after transcranial electrical stimulation (TES) during surgery for supratentorial lesions in the same patient cohort.
One hundred twenty-six patients were included. All procedures were performed under general anesthesia. Craniotomies did not expose motor cortex, so that direct mapping was less suitable. After TES, MEPs were recorded bilaterally from abductor pollicis brevis (APB), from orbicularis oris (OO), and/or from tibialis anterior (TA). The percentage increase in the threshold level was assessed and considered significant if it exceeded by more than 20% on the affected side the percentage increase on the unaffected side. Amplitude on the affected side was measured with a stimulus intensity of 150% of the threshold level set for each muscle.
Eighteen of 126 patients showed a significant change in the threshold level as well as an amplitude reduction of more than 50% in MEPs recorded from APB, and 15 of the patients had postoperative deterioration of motor function of the arm (temporary in 8 cases and permanent in 7 [true-positive and false-negative results]). Recording from TA was performed in 66 patients; 4 developed postoperative deterioration of motor function of the leg (temporary in 3 cases and permanent in 1), and showed a significant change in the threshold level, and an amplitude reduction of more than 50% occurred in 1 patient. An amplitude reduction of more than 50% occurred in another 10 patients, without a significant change in the threshold level or postoperative deterioration. Recording from OO was performed in 61 patients; 3 developed postoperative deterioration of motor function of facial muscles (temporary in 2 cases and permanent in 1) and had a significant change in the threshold level, and 2 of the patients had an amplitude reduction of more than 50%. Another 6 patients had an amplitude reduction of more than 50% but no significant change in the threshold level or postoperative deterioration.Sensitivity of the threshold criterion was 100% when MEPs were recorded from APB, OO, or TA, and its specificity was 97%, 100%, and 100%, respectively. Sensitivity of the amplitude criterion was 100%, 67%, and 25%, with a specificity of 97%, 90%, and 84%, respectively.
The threshold criterion was comparable to the amplitude criterion with a stimulus intensity set at 150% of the threshold level regarding sensitivity and specificity when recording MEPs from APB, and superior to it when recording from TA or OO.

OBJECTIVE Neonatal brachial plexus palsy (NBPP) continues to be a problematic occurrence impacting approximately 1.5 per 1000 live births in the United States, with 10%-40% of these infants experiencing permanent disability. These children lose elbow flexion, and one surgical option for recovering it is the Oberlin transfer. Published data support the use of the ulnar nerve fascicle that innervates the flexor carpi ulnaris as the donor nerve in adults, but no analogous published data exist for infants. This study investigated the association of ulnar nerve fascicle choice with functional elbow flexion outcome in NBPP. METHODS The authors conducted a retrospective study of 13 cases in which infants underwent ulnar to musculocutaneous nerve transfer for NBPP at a single institution. They collected data on patient demographics, clinical characteristics, active range of motion (AROM), and intraoperative neuromonitoring (IONM) (using 4 ulnar nerve index muscles). Standard statistical analysis compared pre- and postoperative motor function improvement between specific fascicle transfer (1-2 muscles for either wrist flexion or hand intrinsics) and nonspecific fascicle transfer (> 2 muscles for wrist flexion and hand intrinsics) groups. RESULTS The patients\' average age at initial clinic visit was 2.9 months, and their average age at surgical intervention was 7.4 months. All NBPPs were unilateral; the majority of patients were female (61%), were Caucasian (69%), had right-sided NBPP (61%), and had Narakas grade I or II injuries (54%). IONM recordings for the fascicular dissection revealed a donor fascicle with nonspecific innervation in 6 (46%) infants and specific innervation in the remaining 7 (54%) patients. At 6-month follow-up, the AROM improvement in elbow flexion in adduction was 38° in the specific fascicle transfer group versus 36° in the nonspecific fascicle transfer group, with no statistically significant difference (p = 0.93). CONCLUSIONS Both specific and nonspecific fascicle transfers led to functional recovery, but that the composition of the donor fascicle had no impact on early outcomes. In young infants, ulnar nerve fascicular dissection places the ulnar nerve at risk for iatrogenic damage. The data from this study suggest that the use of any motor fascicle, specific or nonspecific, produces similar results and that the Oberlin transfer can be performed with less intrafascicular dissection, less time of surgical exposure, and less potential for donor site morbidity.

OBJECTIVE Spinal dural arteriovenous fistulas (dAVFs) are rare vascular abnormalities caused by arteriovenous shunting. They often form at the dural root sleeve between a radicular feeding artery and draining medullary vein causing venous congestion and edema, decreased perfusion, and ischemia of the spinal cord. Treatment consists of either surgical ligation of the draining vein or selective embolization via an endovascular approach. There is a paucity of data on which modality provides more durable and effective outcomes. METHODS The authors performed a retrospective review of a prospectively maintained database by the senior author to assess clinical outcomes in patients undergoing surgical treatment of spinal dAVFs. Preoperative and postoperative motor and Aminoff-Logue Scale (ALS) scores were collected. RESULTS A total of 41 patients with 44 spinal dAVFs were identified, with a mean patient age of 64 years. The mean symptom duration was 14 months, with weakness (82%), urinary symptoms (47%), and sensory symptoms (29%) at presentation. The fistula locations were as follows: 30 thoracic, 9 lumbar, 3 sacral, and 2 cervical. Five patients had normal motor and ALS scores at presentation. Among the remaining 36 patients with motor deficits or abnormal gait and micturition at presentation, 78% experienced an improvement while the remaining 22% continued to be stable. There was a trend toward improved outcomes in patients with shorter symptom duration; mean symptom duration among patients with clinical improvement was 13 months compared with 22 months among those without improvement. Additionally, rates of improvement were higher for lower thoracic and lumbosacral dAVFs (85% and 83%) compared with those in the upper thoracic spine (57%). No patient developed recurrent fistulas or worsening neurological deficits. CONCLUSIONS Surgery is associated with excellent outcomes in the treatment of spinal dAVFs. Early diagnosis and treatment are critical, with a trend toward improved outcomes. No patient in this study had fistula recurrence or worsening of symptoms. Among patients with abnormal motor or ALS scores, 78% improved after surgery. Therapeutic embolization is an option for some lesions, but for cases with unfavorable anatomy where embolization is not feasible, surgery is a safe option associated with high success.

OBJECTIVE Various neurological diseases are known to cause progressive painless paresis of the upper limbs. In this study the authors describe the previously unspecified syndrome of compression-induced painless cervical radiculopathy with predominant motor deficit and muscular atrophy, and highlight the clinical and radiological characteristics and outcomes after surgery for this rare syndrome, along with its neurological differential diagnoses. METHODS Medical records of 788 patients undergoing surgical decompression due to degenerative cervical spine diseases between 2005 and 2014 were assessed. Among those patients, 31 (3.9%, male to female ratio 4.8 to 1, mean age 60 years) presented with painless compressive cervical motor radiculopathy due to neuroforaminal stenosis without signs of myelopathy; long-term evaluation was available in 23 patients with 49 symptomatic foraminal stenoses. Clinical, imaging, and operative findings as well as the long-term course of paresis and quality of life were analyzed. RESULTS Presenting symptoms (mean duration 13.3 months) included a defining progressive flaccid radicular paresis (median grade 3/5) without any history of radiating pain (100%) and a concomitant muscular atrophy (78%); 83% of the patients were smokers and 17% patients had diabetes. Imaging revealed a predominantly anterior nerve root compression at the neuroforaminal entrance in 98% of stenoses. Thirty stenoses (11 patients) were initially decompressed via an anterior surgical approach and 19 stenoses (12 patients) via a posterior surgical approach. Overall reoperation rate due to new or recurrent stenoses was 22%, with time to reoperation shorter in smokers (p = 0.033). Independently of the surgical procedure chosen, long-term follow-up (mean 3.9 years) revealed a stable or improved paresis in 87% of the patients (median grade 4/5) and an excellent general performance and quality of life. CONCLUSIONS Painless cervical motor radiculopathy predominantly occurs due to focal compression of the anterior nerve root at the neuroforaminal entrance. Surgical decompression is effective in stabilizing or improving motor function with a resulting favorable long-term outcome.