A snapshot of European neurosurgery December 2019 vs. March 2020: just before and during the Covid-19 pandemic.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 or Covid-19), which began as an epidemic in China and spread globally as a pandemic, has necessitated resource management to meet emergency needs of Covid-19 patients and other emergent cases. We have conducted a survey to analyze caseload and measures to adapt indications for a perception of crisis. METHODS: We constructed a questionnaire to survey a snapshot of neurosurgical activity, resources, and indications during 1 week with usual activity in December 2019 and 1 week during SARS-CoV-2 pandemic in March 2020. The questionnaire was sent to 34 neurosurgical departments in Europe; 25 departments returned responses within 5 days. RESULTS: We found unexpectedly large differences in resources and indications already before the pandemic. Differences were also large in how much practice and resources changed during the pandemic. Neurosurgical beds and neuro-intensive care beds were significantly decreased from December 2019 to March 2020. The utilization of resources decreased via less demand for care of brain injuries and subarachnoid hemorrhage, postponing surgery and changed surgical indications as a method of rationing resources. Twenty departments (80%) reduced activity extensively, and the same proportion stated that they were no longer able to provide care according to legitimate medical needs. CONCLUSION: Neurosurgical centers responded swiftly and effectively to a sudden decrease of neurosurgical capacity due to relocation of resources to pandemic care. The pandemic led to rationing of neurosurgical care in 80% of responding centers. We saw a relation between resources before the pandemic and ability to uphold neurosurgical services. The observation of extensive differences of available beds provided an opportunity to show how resources that had been restricted already under normal conditions translated to rationing of care that may not be acceptable to the public of seemingly affluent European countries.

Postprocedural discitis of the vertebral spine: challenges in diagnosis, treatment and prevention.

BACKGROUND: Although post-procedural discitis is relatively uncommon, the consequences can be very clinically significant. AIM: We reviewed aspects on the diagnosis, management and prevention of post-procedural discitis. METHODS: We reviewed the literature published in English over the last twenty years using a variety of appropriate search terms. RESULTS: Clinical features, microbiology results, imaging and inflammatory makers should be used in diagnosis. Every effort should be made to confirm infection to avoid unnecessary antibiotics and to facilitate targeted therapy. Surgical debridement or source control is a crucial aspect of treatment and can provide diagnosis specimens to guide antibiotic treatment. When culture results are positive, antibiotic treatment should be based on the results of antibiotic susceptibilities. There are no definitive guidelines on antibiotic therapy. A combination of agents, such as a quinolone or clindamycin, with fusidic acid or rifampicin, is indicated for empirical therapy. Early intravenous to oral switch and a minimum of six weeks of antibiotic treatment is recommended. Prevention involves antimicrobial prophylaxis perioperatively, good surgical technique and minimally invasive surgery where possible. CONCLUSION: Much of the information currently available is sub-optimal with the absence of good clinical trials. Further research is required on alternative approaches to routine culture and on the potential role of local antibiotics as prevention measures.

Operative techniques for cervical radiculopathy and myelopathy.

The surgical treatment of cervical spondylosis and resulting cervical radiculopathy or myelopathy has evolved over the past century. Surgical options for dorsal decompression of the cervical spine includes the traditional laminectomy and laminoplasty, first described in Asia in the 1970's. More recently the dorsal approch has been explored in terms of minimally invasive options including foraminotomies for nerve root descompression. Ventral decompression and fusion techniques are also described in the article, including traditional anterior cervical discectomy and fusion, strut grafting and cervical disc arthroplasty. Overall, the outcome from surgery is determined by choosing the correct surgery for the correct patient and pathology and this is what we hope to explain in this brief review.

Effect of inspired air conditions on exercise-induced bronchoconstriction and urinary CC16 levels in athletes.

Injury to the airway epithelium has been proposed as a key susceptibility factor for exercise-induced bronchoconstriction (EIB). Our goals were to establish whether airway epithelial cell injury occurs during EIB in athletes and whether inhalation of warm humid air inhibits this injury. Twenty-one young male athletes (10 with a history of EIB) performed two 8-min exercise tests near maximal aerobic capacity in cold dry (4°C, 37% relative humidity) and warm humid (25°C, 94% relative humidity) air on separate days. Postexercise changes in urinary CC16 were used as a biomarker of airway epithelial cell perturbation and injury. Bronchoconstriction occurred in eight athletes in the cold dry environment and was completely blocked by inhalation of warm humid air [maximal fall in forced expiratory volume in 1 s = 18.1 ± 2.1% (SD) in cold dry air and 1.7 ± 0.8% in warm humid air, P < 0.01]. Exercise caused an increase in urinary excretion of CC16 in all subjects (P < 0.001), but this rise in CC16 was blunted following inhalation of warm humid air [median CC16 increase pre- to postchallenge = 1.91 and 0.35 ng/µmol in cold dry and warm humid air, respectively, in athletes with EIB (P = 0.017) and 1.68 and 0.48 ng/µmol in cold dry and warm humid air, respectively, in athletes without EIB (P = 0.002)]. The results indicate that exercise hyperpnea transiently disrupts the airway epithelium of all athletes (not only in those with EIB) and that inhalation of warm moist air limits airway epithelial cell perturbation and injury.

Episodic cauda equina compression from an intradural lumbar herniated disc: a case of 'floppy disc'.

Intradural disc herniation (IDDH) is a rare complication of intervertebral disc disease and comprises 0.26-0.30% of all herniated discs, with 92% of them located in the lumbar region (1). We present a case of IDDH that presented with intermittent symptoms and signs of cauda equina compression. We were unable to find in the literature, any previously described cases of intermittent cauda equina compression from a herniated intradural disc fragment leading to a "floppy disc syndrome".

The burden of motorcycle-related neuro-trauma in Ireland and associated helmet usage.

Motorcycles represent less than 2% of the licensed vehicles but motorcyclists account for 12% of road deaths in Ireland. The British Road Safety Authority has introduced the Sharp programme, which hopes to save 50 lives in the U.K. each year alone by helping riders to choose the best-fitting and safest helmets. We evaluated the pattern of head injuries sustained by motorcyclists referred to the two neurosurgical centres Beaumont Hospital and Cork University Hospital in Ireland and ascertained if the new SHARP guidelines could be of benefit in reducing the burden of motorcycle related neurotrauma and disability in Ireland. Despite Ireland having mandatory helmet laws almost a quarter of our motorcyclists with traumatic brain injury were unhelmeted. A significant reduction in mortality and morbidity is predicted if all motorcyclists in Ireland were to wear helmets that satisfied the SHARP criteria.

Lateral mass screw fixation of complex spine cases: a prospective clinical study.

The purpose of this paper was to report our experience with lateral mass screw fixation when used in a variety of complex cervical pathologies. A prospective observational study was undertaken of all patients who underwent lateral mass screw fixation for complex spinal pathology. There were 59 patients. Pathology included cervical spondylosis with deformity 58%, rheumatoid arthritis 19%, tumours 15%, multiple level trauma 8%. The median follow-up time was 23 months. The patient's myelopathy scores improved in 64% of patients. 79% reported an improvement in their neck disability scores. 73% had improvement in their visual analogue pain score. Sixty-one per cent had preoperative high signal change on T2WI MRI. Sixty per cent had loss of normal cervical lordosis on presentation or were kyphotic. Sixty-four per cent of patients had grade 3 compression on MRI (Singh). Postoperative alignment was maintained in all cases. No late kyphotic deformity occurred. Lateral mass screw fixation can be used effectively and safely for different cervical spine pathologies with good functional and radiological outcome.

Molecular characterisation of SMARCB1 and NF2 in familial and sporadic schwannomatosis.

BACKGROUND: Schwannomatosis is a rare condition characterised by multiple schwannomas and lack of involvement of the vestibular nerve. A recent report identified bi-allelic mutations in the SMARCB1/INI1 gene in a single family with schwannomatosis. We aimed to establish the contribution of the SMARCB1 and the NF2 genes to sporadic and familial schwannomatosis in our cohort. METHODS: We performed DNA sequence and dosage analysis of SMARCB1 and NF2 in 28 sporadic cases and 15 families with schwannomatosis. RESULTS: We identified germline mutations in SMARCB1 in 5 of 15 (33.3%) families with schwannomatosis and 2 of 28 (7.1%) individuals with sporadic schwannomatosis. In all individuals with a germline mutation in SMARCB1 in whom tumour tissue was available, we detected a second hit with loss of SMARCB1. In addition, in all affected individuals with SMARCB1 mutations and available tumour tissue, we detected bi-allelic somatic inactivation of the NF2 gene. SMARCB1 mutations were associated with a higher number of spinal tumours in patients with a positive family history (p = 0.004). CONCLUSION: In contrast to the recent report where no NF2 mutations were identified in a schwannomatosis family with SMARCB1 mutations, in our cohort, a four hit model with mutations in both SMARCB1 and NF2 define a subset of patients with schwannomatosis.

Image-guided transarticular atlanto-axial screw fixation.

BACKGROUND: The aim of this paper was to outline the use of frameless stereotaxy for the safe insertion of C1/C2 transarticular screws in the clinical setting of patients with atlanto-axial instability. METHODS: A retrospective review was conducted of cases involving the use of image guidance for the accurate placement of transarticular C1/C2 screws. The outcome measures considered were neural injury, vascular injury, death, and screw placement on postoperative imaging. RESULTS: We evaluated 60 patients for image-guided C1/2 transarticular screw fixation. There was a total of 109 screws inserted. There were no intraoperative complications. CONCLUSIONS: Frameless stereotaxy can be applied safely in a clinical setting for transarticular screw fixation. Image guidance can facilitate preoperative planning and help determine an optimal trajectory that avoids the vertebral artery.

Low rates of cutaneous adverse reactions to alcohol-based hand hygiene solution during prolonged use in a large teaching hospital.

We assessed cutaneous adverse reactions (CARs) to alcohol-based hand rub (ABHR) after the introduction of a hand hygiene culture change program at our institution. CARs were infrequent among exposed health care workers (HCWs) (13/2,750; 0.47%; 1 CAR per 72 years of HCW exposure) and were not influenced by the duration or intensity of ABHR use but were associated with the presence of irritant contact dermatitis.

Preoperative cervical traction in cases of cranial settling with halo ring and Mayfield skull clamp.

Rheumatoid cervical myelopathy presents one of the most daunting challenges in neurological surgery. Preoperative cervical traction can help to distract the dens from the brainstem prior to performing occipitocervical fusion in cases of cranial settling. Valuable millimetres gained in preoperative traction can be lost in placing the patient in the prone position after removing the halo to allow application of the Mayfield skull clamp. The authors have found that traction can be adequately maintained during surgery by applying the Mayfield skull clamp with skull pins to the halo ring itself.

Use of topically applied rt-PA in the evacuation of extensive acute spinal subdural haematoma.

Spontaneous spinal subdural haematoma is a rare cause of spinal cord compression, usually confined to a few vertebral levels. When the haematoma extends over several spinal segments, surgical decompression is a major undertaking. Recombinant tissue plasminogen activator (rt-PA) has previously been used in a number of surgical procedures, but not in the setting of acute spinal subdural haematoma. A minimally invasive technique of decompression, using topical rt-PA, is presented in two patients with extensive spinal intradural haematoma. Two patients receiving long-term anticoagulation therapy presented with acute-onset back pain progressing to paraparesis. Magnetic resonance imaging of the spine demonstrated spinal subdural haematomas extending over 15 vertebral levels in one patient and 12 in the other. An angiography catheter was introduced into the subdural space through a limited laminectomy. Thrombolysis and evacuation of haematoma was then achieved by intermittent irrigation of the subdural space with rt-PA, followed by saline lavage. Postoperative imaging demonstrated satisfactory decompression in both patients. There was significant improvement of neurological function in one patient. Topical application of rt-PA for spinal subdural haematoma allows evacuation of the haematoma through a limited surgical exposure. Decompression of the subdural space by this minimally invasive technique may be advantageous over extensive surgery by minimising surgical exposure, reducing postoperative pain and risk of neuronal injury. This technique may be useful in patients presenting with compression extending over several vertebral levels or poor surgical candidates.

The anatomical distribution of cerebral gliomas in mobile phone users.

We analysed the association between mobile phone use and the anatomical distribution of glial brain tumours in Irish neurosurgical patients. All patients with unilateral histologically proven glioma were enrolled over a 12 month period. We hypothesised that were a cellular phone to cause a glioma then it would do so on the dominant hand side. Fifty mobile phone users and twenty three non-users were identified. The vast majority of patients (69/73) were right handed and the right side of the brain was more common as the tumour site (48/73). Fisher's exact test revealed no statistical significance for glioma location based on the handedness of the patient in the mobile phone user group and location of the tumour in both user and non-user groups. We discuss our findings and the stable trend in the incidence of reported glioma cases.

Schwann cell invasion of the conus medullaris: case report.

As Schwann cells possess regenerative capabilities there is intense interest concerning their role in central nervous system (CNS) regeneration. We report on a case of an intramedullary schwannoma involving the conus medullaris and spinal cord above it. We discuss the possible origin of these cells and the mechanisms by which these cells may invade the CNS. We offer imaging and discuss experimental studies to support our hypothesis. This case concerns a 48-year-old man, who presented with a 6-month history of bilateral lower extremity weakness. Magnetic resonance imaging (MRI) revealed an intramedullary tumour extending from the conus to T11. At operation, following laminectomy and durotomy, a schwannoma was dissected free from the conus. Total gross resection of tumour was achieved. The patient made an uneventful and full recovery. This case shows that Schwann cells can invade the CNS. Manipulation of the transitional zone astrocytic barrier may offer a potential avenue for Schwann cells to enter the CNS in pathological states.

Comparison of ocular microtremor and bispectral index during sevoflurane anaesthesia.

BACKGROUND: A practical and reliable monitor of depth of anaesthesia would be a major advance on current clinical practice. None of the present monitors is both simple to use and accurate. Ocular microtremor (OMT) is a physiological tremor that is suppressed by propofol in a dose-dependent manner. We studied OMT during propofol induction and nitrous oxide-oxygen-sevoflurane maintenance of anaesthesia in 30 patients, and compared OMT with the bispectral index (BIS) as a predictor of response to verbal command. METHODS: OMT was measured using the closed-eye piezoelectric strain-gauge technique. OMT and BIS were measured at specific times during the anaesthetic, including at loss of consciousness, at end-tidal sevoflurane 1 and 2%, and at emergence. RESULTS: OMT decreased significantly after induction, did not decrease as end-tidal sevoflurane was increased from 1 to 2%, and increased at emergence in all patients. By logistic regression, OMT was more sensitive and specific than BIS in distinguishing the awake from the anaesthetized state (OMT, 84.9 and 93.1% respectively; BIS, 75.7 and 69.0%). CONCLUSIONS: OMT is suppressed by sevoflurane and accurately predicts response to verbal command. OMT may be a useful monitor of depth of hypnosis.

Ocular microtremor: a tool for measuring depth of anaesthesia?

Ocular microtremor (OMT) is a fine high frequency tremor of the eyes caused by extra-ocular muscle activity stimulated by impulses emanating in the brain stem. Several studies have shown that the frequency of this tremor is reduced in patients whose consciousness is reduced by anaesthesia or head injury. Therefore, OMT may possibly be used to determine depth of anaesthesia. Twenty-two unpre-medicated subjects undergoing surgery with general anaesthesia were studied. OMT activity was measured at admission using the open eye piezoelectric strain gauge technique. Anaesthesia was induced with propofol using a target controlled infusion delivery system (Diprifusor). OMT activity was then recorded at predicted plasma propofol concentrations of 1, 2, 3 and 5 microg ml(-1). The patient's level of consciousness (response to command or stimulation) was assessed after each OMT measurement. OMT activity was reduced progressively at predicted plasma concentrations of propofol of I and 2 microg ml(-1) and then plateaued between 3 and 5 microg ml(-1). There was a significant difference between the last awake OMT recording and the first recording at loss of consciousness (P < 0.001). OMT recording holds promise as a practical indicator of the depth of anaesthesia.

A technique for frameless stereotaxy and placement of transarticular screws for atlanto-axial instability in rheumatoid arthritis.

The aim of the present study was to outline a new surgical technique and describe how, in a clinical setting, computer-generated image-guidance can assist in the planning and accurate placement of transarticular C1/C2 screws inserted using a minimally invasive exposure. Forty-six patients with atlanto-axial instability due to rheumatoid arthritis underwent posterior stabilisation with transarticular screws. This was achieved with a minimal posterior exposure limited to C1 and C2 and percutaneous screw insertions via minor stab incisions. The Stealth Station (Medtronic Sofamor Danek, Memphis, Tenn., USA) was used for image guidance to navigate safely through C2. Reconstructed computed tomographic (CT) scans of the atlanto-axial complex were used for image guidance. It was possible to perform preoperative planning of the screw trajectory taking into account the position of the intraosseous portion of the vertebral arteries, the size of the pars interarticularis and the quality of bone in C2. Screws could be inserted percutaneously over K-wires using a drill guide linked to the image-guidance system. Preoperative planning was performed in all 46 patients and accurate registration allowed proposed screw trajectories to be identified. Thirty-eight patients had bilateral screws inserted and eight had a unilateral screw. A total of 84 screws were inserted using the Stealth Station. There were no neurovascular injuries. This technique for placing transarticular screws is accurate and safe. It allows a minimally invasive approach to be followed. Image guidance is a useful adjunct for the surgeon undertaking complex spinal procedures.

Effect of age on ocular microtremor activity.

BACKGROUND: Ocular microtremor (OMT) is a high-frequency tremor of the eyes. It is present in all individuals and is related to brainstem activity. The OMT signal appears as an irregular oscillatory movement with intermittent burst-like components. The clinical interest in OMT has centered on its use in the assessment of the comatose patient, with broad agreement among authors of its prognostic value. The purpose of this study was to examine the changes in OMT activity related to aging. METHODS: OMT was recorded from 72 normal healthy subjects using the piezoelectric strain gauge technique. The subjects ranged in age from 21 to 88 years (54.22 +/- 20.43 years, mean +/- SD). RESULTS: Our results show that the overall frequency and frequency content of the bursts falls with age (p < .002 and p < .001, respectively). There is a highly significant drop in all three frequency parameters of OMT (p < .0001) in subjects older than 60 years of age. CONCLUSIONS: These results suggest that different values of normality should operate for subjects over 60 years of age when considering the clinical application of OMT.

Design of an occipito-cervical fixation device.

Metal plates may be used to stabilize the cervical spine. The plates are attached to the posterior of the vertebra by placing screws into the lateral masses. The plating may be extended, in the form of rod or plate, to connect with and support the occiput. Several problems, such as screw loosening and the plate obscuring the surgeon's view as a screw is being inserted, have been identified with present plate systems. This paper describes the initial design for a cervical fixation device to overcome these problems, and the design and development that was undertaken to enable a prototype device to be manufactured.

Ocular microtremor (OMT): a new neurophysiological approach to multiple sclerosis.

Using a piezoelectric transducer, the frequency and pattern of ocular microtremor (OMT) between 50 normal subjects and 50 patients with multiple sclerosis were compared. Controls were age matched. All records were analysed blindly. The frequency of OMT in the normal group was 86 (SD 6) Hz, which was significantly different from that of the multiple sclerosis group (71 (SD) 10 Hz, p<0.001). Those in the multiple sclerosis group with clinical evidence of brain stem or cerebellar disease (n=36) had an average OMT frequency of 67 (SD 9) Hz (p<0.001) compared with normal (n=86), whereas those with no evidence of brain stem or cerebellar involvement (n=14) had a frequency of 81.2 (SD 6) Hz (p<0.05, n=64). The differences between the two multiple sclerosis groups were also significant (p<0. 001, n=50). At least one abnormality (frequency and pattern) of OMT activity was seen in 78% of patients with multiple sclerosis. In the presence of brain stem or cerebellar disease 89% had abnormal records whereas in the absence of such disease 50% had abnormal records. This is the first report of the application of this technique to patients with multiple sclerosis. The results suggest that OMT activity may be of value in the assessment of multiple sclerosis.