'White Cord Syndrome': A Rare Catastrophic Complication Following Anterior Cervical Discectomy and Fusion.

Background: 'White-cord syndrome' is an extremely rare entity following decompression of cervical cord in which post-operative reperfusion injury results in worsening of patient's neurology and MRI reveals signal changes in spinal cord in absence of cord compression. We wish to report a case of 'white-cord syndrome' following a 'routine' ACDF. Case Description: A 39-year-old woman with paresthesias and spastic quadriparesis was found to have C5-C6 PIVD on MRI. ACDF was performed at C5-C6, after which worsening of quadriparesis was noted, for which intravenous high-dose steroids were started. An urgent MRI was done, which revealed findings of white-cord syndrome, without compression on underlying cord. With conservative management, her ASIA grade improved from C to D and the features of white-cord syndrome disappeared on follow-up imaging. Conclusion: It is important for surgeons and patients to be aware of this rare but potentially catastrophic entity as this needs to be discussed while taking consent for surgery.

Atypical Clinical and Neuroradiological Findings in a Child With Bifacial Weakness With Paresthesias.

BACKGROUND: Guillain-Barré syndrome (GBS) is the broad term used to describe a number of related acute autoimmune neuropathies, which together form a continuous spectrum of variable and overlapping syndromes. Bifacial weakness with paresthesias (BFP) is a rare variant of GBS, characterized by isolated facial diplegia in the absence of ophthalmoplegia, ataxia, or limb weakness, and it is usually associated with distal limb paresthesias. CASE DESCRIPTION: An 8-year-old boy was brought to our attention; because 5 days before coming to the hospital, he noticed he could no longer smile. Bilateral facial droop and inability to close both eyes were evident along with slight paresthesias at the hands and feet and gait disturbances. He progressively developed hypophonia, dysarthria, dysphagia associated with dysmetria, and limb ataxia. Nerve conduction studies showed a demyelinating polyneuropathy. Brain and spine magnetic resonance imaging (MRI) revealed contrast enhancement of both facial nerves and cauda equina nerve roots along with a hyperintense signal of the periaqueductal gray matter, superior cerebellar peduncles, and pontine tegmentum. Because BFP is not typically associated with other cranial neuropathies or ataxia, these clinical features along with peculiar MRI findings supported the diagnosis of "BFP plus." Finally, it can be speculated that this case configures a rare overlap between BFP and the other GBS variants, such as Bickerstaff encephalitis. CONCLUSIONS: This atypical case underlines the potential role of MRI in contributing to refining the nosological classification of GBS spectrum and optimizing individual treatment, especially in children where unusual manifestations are not infrequent and neurological examination is more challenging.

Variant Median Nerve Anatomy: Ultrasound Evidence of a Pseudoconduction Block.

INTRODUCTION: A conduction block at a noncompressible site warrants further investigation. METHODS AND MATERIALS: A 36-year-old woman with a history of Hodgkin lymphoma and chemotherapy-induced polyneuropathy developed bilateral hand numbness and paresthesias. Workup revealed bilateral carpal tunnel syndrome and an apparent superimposed conduction block of the median nerve in the forearm. Given the history of cancer, there was concern for an infiltrative or an immune-mediated process. RESULTS: Neuromuscular ultrasound demonstrated that the median nerve descended the upper extremity along an atypical path, deep along the posteromedial aspect of the upper arm, and relatively medially in the forearm. Ultrasound-directed nerve stimulation revealed there was no conduction block. This anatomical variant has been rarely described and has not been reported previously to mimic conduction block or been documented via ultrasound. CONCLUSIONS: This case demonstrates that neuromuscular ultrasound may supplement the electrodiagnostic study and limit confounding technical factors because of rare anatomic variation.

Evidence for a novel subcortical mechanism for posterior cingulate cortex atrophy in HIV peripheral neuropathy.

We previously reported that neuropathic pain was associated with smaller posterior cingulate cortical (PCC) volumes, suggesting that a smaller/dysfunctional PCC may contribute to development of pain via impaired mind wandering. A gap in our previous report was lack of evidence for a mechanism for the genesis of PCC atrophy in HIV peripheral neuropathy. Here we investigate if volumetric differences in the subcortex for those with neuropathic paresthesia may contribute to smaller PCC volumes, potentially through deafferentation of ascending white matter tracts resulting from peripheral nerve damage in HIV neuropathy. Since neuropathic pain and paresthesia are highly correlated, statistical decomposition was used to separate pain and paresthesia symptoms to determine which regions of brain atrophy are associated with both pain and paresthesia and which are associated separately with pain or paresthesia. HIV+ individuals (N = 233) with and without paresthesia in a multisite study underwent structural brain magnetic resonance imaging. Voxel-based morphometry and a segmentation/registration tool were used to investigate regional brain volume changes associated with paresthesia. Analysis of decomposed variables found that smaller midbrain and thalamus volumes were associated with paresthesia rather than pain. However, atrophy in the PCC was related to both pain and paresthesia. Peak thalamic atrophy (p = 0.004; MNI x = - 14, y = - 24, z = - 2) for more severe paresthesia was in a region with reciprocal connections with the PCC. This provides initial evidence that smaller PCC volumes in HIV peripheral neuropathy are related to ascending white matter deafferentation caused by small fiber damage observed in HIV peripheral neuropathy.

Klippel-Feil Syndrome With Auxiliary Anterior Cervical Meningomyelocele and Thoracic Syringomyelia: A Case Report.

STUDY DESIGN: Case report. OBJECTIVE: Since this is the first ever case of a male patient with Klippel-Feil syndrome (KFS) with anterior cervical meningomyelocele and syringomyelia. All four previously reported cases were female patients. This makes this case unique. SUMMARY OF BACKGROUND DATA: KFS with auxiliary anterior cervical meningomyelocele is a rare entity. To the best of our knowledge so far only four cases are reported. METHODS: A 22-year-old male patient was presented to neurology outpatient department with 2-year history of left hand paresthesia and progressive weakness. The diagnostic evaluation showed KFS with auxiliary anterior cervical meningomyelocele and thoracic syringomyelia. RESULTS: Patient was sent to neurosurgery department for intervention. After discussing the possible risks and complications of intervention he opted for conservative therapy and declined the surgery. CONCLUSION: The paucity of data is the key reason for any recommended protocol for management of such patients but the available literature recommends neurosurgical intervention in symptomatic patients. LEVEL OF EVIDENCE: 5.

An unusual cause of paraesthesia in a neo-adjuvant gastro-oesophageal cancer.

There is ongoing debate about the best neo-adjuvant strategy for localised resectable oesophageal cancer, however chemotherapy is often employed. Both oesophageal cancer and cisplatin carry an increased risk of thrombosis. Here, we look at an unusual finding in a previously fit woman who presented following neo-adjuvant chemotherapy for resectable oesophageal cancer with increasing difficulty in walking and lower limb paraesthesia. This case looks particularly at the diagnostic challenge and concerns raised in a patient undergoing radical treatment as well as the challenge of complications secondary to treatment with chemotherapy. Willingness to reassess and revisit is a vital part of the diagnostic process. Vascular complications of a disease can be notorious to diagnose and, as in this case can mimic arguably more logical diagnoses. Cancer care provides the unique challenge of investigating unusual presentations related both to disease and treatment.

Dissociable Contributions of Precuneus and Cerebellum to Subjective and Objective Neuropathy in HIV.

Neuropathy, typically diagnosed by the presence of either symptoms or signs of peripheral nerve dysfunction, remains a frequently reported complication in the antiretroviral (ART)-treated HIV population. This study was conducted in 109 healthy controls and 57 HIV-infected individuals to investigate CNS regions associated with neuropathy. An index of objective neuropathy was computed based on 4 measures: deep tendon ankle reflex, vibration sense (great toes), position sense (great toes), and 2-point discrimination (feet). Subjective neuropathy (self-report of pain, aching, or burning; pins and needles; or numbness in legs or feet) was also evaluated. Structural MRI data were available for 126/166 cases. The HIV relative to the healthy control group was impaired on all 4 signs of neuropathy. Within the HIV group, an objective neuropathy index of 1 (bilateral impairment on 1 measure) or 2 (bilateral impairment on at least 2/4 measures) was associated with older age and a smaller volume of the cerebellar vermis. Moderate to severe symptoms of neuropathy were associated with more depressive symptoms, reduced quality of life, and a smaller volume of the parietal precuneus. This study is consistent with the recent contention that ART-treated HIV-related neuropathy has a CNS component. Distinguishing subjective symptoms from objective signs of neuropathy allowed for a dissociation between the precuneus, a brain region involved in conscious information processing and the vermis, involved in fine tuning of limb movements. Graphical Abstract In HIV patients, objective signs of neuropathy correlated with smaller cerebellar vermis (red) volumes whereas subjective symptoms of neuropathy were associated with smaller precuneus (blue) volumes.

Implanter's Integrated Information (I3) System: An Aid for Spinal Cord Stimulation Procedures.

OBJECTIVES: In spinal cord stimulation (SCS), the electrical stimulation of the spinal cord with an implanted lead evokes a tingling peripheral sensation known as paresthesias. Newer stimulation paradigms allow paresthesia-free treatment, but during the implantation of the lead, paresthesias must cover the painful area to achieve optimal treatment effect. The localization of the evoked paresthesias can be difficult to accurately describe for the patient, and furthermore depends on a complex and only partially predictable set of parameters that includes the anatomical localization and the programming of the electrical field. We aimed to optimize SCS implantation procedures by devising a way to aid the patient in making useful descriptions of the evoked paresthesias, then to visually convey the full set of information-anatomical position of the lead, programming parameters, and evoked paresthesias-directly to the implanting physician. MATERIALS AND METHODS: To aid the patient in making accurate descriptions of the evoked paresthesia, we use an app dedicated to creating pain drawings on a tablet. We used Chromecast and Apple TV to project the information from the pain drawing tablet and the programming device to two monitors placed in the implanter's field of vision, right next to the fluoroscopy monitor. RESULTS: The three monitors combined provide a direct visual representation of the dynamic dataset used during SCS implantation: Position, Programming, and Paresthesias, essentially creating the equivalent of the dashboard of a car. CONCLUSIONS: We present an Implanter's Integrated Information (I3) system; a simple, inexpensive solution for gathering, integrating, and conveying the complex set of information necessary for a successful SCS procedure.

Computational Study of the Effect of Electrode Polarity on Neural Activation Related to Paresthesia Coverage in Spinal Cord Stimulation Therapy.

OBJECTIVE: Using computer simulation, we investigated the effect of electrode polarity on neural activation in spinal cord stimulation and propose a new strategy to maximize the activating area in the dorsal column (DC) and, thus, paresthesia coverage in clinical practice. MATERIALS AND METHODS: A new three-dimensional spinal cord model at the T10 vertebral level was developed to simulate neural activation induced by the electric field distribution produced by different typical four-contact electrode polarities in single- and dual-lead stimulation. Our approach consisted of the combination of a finite element model of the spinal cord developed in COMSOL Multiphysics and a nerve fiber model implemented in MATLAB. Five evaluation parameters were evaluated, namely, the recruitment ratio, the perception and discomfort thresholds, and the activating area and depth. The results were compared quantitatively. RESULTS: The dual-guarded cathode presents the maximum activating area and depth in single- and dual-lead stimulation. However, the lowest value of the ratio between the perception threshold in DC and the perception threshold in the dorsal root (DR) is achieved when the guarded cathode is programmed. Although the two versions of bipolar polarity (namely bipolar 1 and bipolar 2) produce higher activating area and depth than the guarded cathode, they are suitable for producing DR stimulation. Similarly, dual-lead stimulation is likely to activate DR fibers because the electrodes are closer to these fibers. CONCLUSIONS: The results suggest that the activating area in the DC is maximized by using the dual-guarded cathode both in single- and dual-lead stimulation modes. However, DC nerve fibers are preferentially stimulated when the guarded cathode is used. According to these results, the new electrode programming strategy that we propose for clinical practice first uses the dual-guarded cathode, but, if the DR nerve fibers are activated, it then uses guarded cathode polarity.

Thrombectomy for late occlusion of high flow extracranial-intracranial saphenous vein bypass graft after 27 years of patency.

High flow extracranial-intracranial (EC-IC) bypass with a saphenous vein graft (SVG) has been used for more than 40 years in patients with giant aneurysms of the posterior circulation refractory to medical management, and has demonstrated high long term patency rates. We report the case of a patient treated with external carotid artery (ECA)-posterior cerebral artery SVG bypass in 1989 who presented 27 years later with paresthesias and confusion, and was found to have partial occlusion of her SVG bypass graft and a basilar occlusion. She was treated with mechanical thrombectomy of the basilar occlusion via the partially thrombosed graft, the first report of such a procedure through a high flow posterior circulation EC-IC SVG, resulting in improvement of the patient's neurologic examination. At 27 years, this is the longest reported delay in thrombosis of a high flow SVG bypass graft, highlighting the long term patency of these grafts and the feasibility of thrombectomy through occluded bypass grafts.

Neurological deficit following stereotactic radiosurgery for trigeminal neuralgia.

We report a unique case of neurological deficit from late onset multiple sclerosis (MS), in a 65-year-old woman, after stereotactic radiosurgery (SRS) for trigeminal neuralgia (TN). At 3.5months post-SRS for TN, the patient developed ataxia and left leg paraesthesiae and brain MRI showed altered signal and enhancement in the vicinity of the right trigeminal root entry zone (REZ). The symptoms remitted following treatment with intravenous methylprednisolone, however, 10months post-SRS, the patient developed gait ataxia and left lower limb weakness. MRI showed persistent T2 changes at the REZ and multiple new non-enhancing white matter lesions in the cerebrum and spinal cord; and oligoclonal bands were present in the cerebrospinal fluid but not serum. A diagnosis of multiple sclerosis (MS) was made. This report raises the issue of whether the risk of radiation-induced toxicity is increased in patients with MS treated with SRS. We hypothesise that breakdown in the blood brain barrier secondary to the radiosurgery may have triggered a vigorous local inflammatory response.

Method to Reduce the False-Positive Rate of Loss of Resistance in the Cervical Epidural Region.

Background. The cervical epidural space can be detected by the loss of resistance (LOR) technique which is commonly performed using air. However, this technique using air has been associated with a high false-positive LOR rate during cervical interlaminar epidural steroid injections (CIESIs). Objective. We investigated whether the detection of LOR with contrast medium might reduce the false-positive LOR rate on the first attempt. Methods. We obtained data retrospectively. A total of 79 patients were divided into two groups according to the LOR technique. Groups 1 and 2 patients underwent CIESI with the LOR technique using air or contrast medium. During the procedure, the injection technique (median or paramedian approach), final depth, LOR technique (air or contrast), total number of LOR attempts, and any side effects were recorded. Results. The mean values for the total number of LOR attempts were 1.38 ± 0.65 (Group 1) and 1.07 ± 0.25 (Group 2). The false-positive rate on the first attempt was 29.4% and 6.6% in Groups 1 and 2, respectively (P = 0.012). Conclusions. The use of contrast medium for LOR technique is associated with a lower rate of false-positivity compared with the use of air.