COVID-19 and Surgical Practice in Slovenia: Managing the Crisis in Neurosurgery during the COVID-19 Pandemic.

Worldwide, the novel coronavirus disease 2019 (COVID-19) has become a significant threat to global health. Worldwide, COVID-19 has affected the health service also in Slovenia. During this time, neurosurgery is facing difficulties in its service, both in emergency and elective surgeries. In the article, we describe the anti-COVID-19 measures taken at our neurosurgical department in a medical centre in Ljubljana, Slovenia, and analysed and compared the number of emergency and elective neurosurgical procedures during the time of the pandemic.

Twenty years of intrathecal baclofen therapy in Slovenia: a retrospective single-center analysis of complications.

Since the first implantation in July 2001, the intrathecal baclofen (ITB) therapy for patients with generalized spasticity has been used in Slovenia for 20 years. The aim of this retrospective study was to evaluate the rates of different complications, especially if catheter-related complications were less frequent after the introduction of the coated catheter type in February 2013, and the potential correlation between higher baclofen doses and the incidence of complications. We retrospectively collected data from all patients in the registry during the period from 3 July 2001 to 31 December 2021. Among 138 patients (48 females), 120 patients had the first ITB system implanted at the University Medical Centre Ljubljana. Forty-three complications were reported in 38 patients (27%), with a total complication rate of 0.203/1000 days or 0.074/pump year. The most frequent was catheter-related (0.083/1000 days or 0.030/pump year), followed by skin-related (0.063/1000 days or 0.023/pump year) and pump-related complication (0.026/1000 days or 0.009/pump year). The incidence of catheter-related complications decreased significantly since the use of Ascenda type catheter: 14/7 complications per 88/147 implantations ( P  = 0.008). Patients with complications had a statistically significantly higher dose of baclofen: median 400 µg/24h vs. median 300 µg/24h ( P  = 0.016). Our retrospective analysis confirmed a significant decrease of catheter-related complications after the implementation of Ascenda type catheter in February 2013. Patients with a higher ITB dose had a statistically significantly higher incidence of complications. The total complication rate was a bit higher as previously reported in other studies, which is consistent with a long follow-up time.

Long-term effect of bilateral STN-DBS on non-motor symptoms in Parkinson's disease: A four-year observational, prospective study.

BACKGROUND: Several studies have shown beneficial effects of bilateral stimulation of the subthalamic nucleus (STN-DBS) on motor as well as on non-motor symptoms (NMS) up to 36 months post-surgery in advanced Parkinson's disease (PD) patients. We set to explore the long-term effect of STN-DBS on NMS in a four-year follow-up, prospective, observational study. METHODS: Forty patients were enrolled and assessed at baseline. Twenty-eight were followed-up at 6, 12, 24, 36 and 48 months after the operation. The effect of post-operative time on NMS was analyzed by six-level repeated measures ANOVA. In a post-hoc analysis the follow-up scores were compared to baseline using a paired t-test. RESULTS: The following scores stayed improved up to 24 months after surgery, presented as baseline/24 months, p-value (t-test): total Non-Motor Symptoms Scale score (54.0 ± 5.6/44.9 ± 5.0, p = 0.029), Hamilton Anxiety Scale (14.3 ± 1.3/11.3 ± 1.2, p = 0.019) and PDQ39 (53.4 ± 4.5/40.2 ± 2.9, p = 0.012). PD Sleep Scale 2 remained improved throughout the study (17.4 ± 2.0/12.8 ± 1.3 at 48 months, p = 0.032), while Beck Depression Inventory only at six months post-surgery (9.5 ± 1.2/6.7 ± 0.7 at 6 months, p = 0.006). Montreal Cognitive Assessment remained stable up to 24 months and then declined at 36 months (26.3 ± 0.5/25.4 ± 0.5 at 36 months, p = 0.003), Starkstein Apathy Scale deteriorated throughout the study (7.6 ± 0.7/12.7 ± 0.9 at 48 months, p = 0.006). CONCLUSIONS: We observed beneficial effect of STN-DBS in several but not all domains of NMS at least up to 24 months post-op in advanced PD. Further long-term studies on larger cohorts of PD patients and longer follow-up need to be conducted to better understand the long-term effect of STN-DBS on NMS.

Early medical rehabilitation after neurosurgical treatment of malignant brain tumours in Slovenia.

BACKGROUND: The number of patients with malignant brain tumours is on the rise, but due to the novel treatment methods the survival rates are higher. Despite increased survival the consequences of tumour properties and treatment can have a significant negative effect on the patients' quality of life. Providing timely and appropriate rehabilitation interventions is an important aspect of patient treatment and should be started immediately after surgery. The most important goal of rehabilitation is to prevent complications that could have a negative effect on the patients' ability to function. CONCLUSIONS: By using individually tailored early rehabilitation it is often possible to achieve the patients' independence in mobility as well as in performing daily tasks before leaving the hospital. A more precise evaluation of the patients' functional state after completing additional oncologic therapy should be performed to stratify the patients who should be directed to complex rehabilitation treatment. The chances of a good functional outcome in patients with malignant brain tumours could be increased with good early medical rehabilitation treatment.

Early outcome in endoscopic extended endonasal approach for removal of supradiaphragmatic craniopharyngiomas: a case series and a comprehensive review.

BACKGROUND: The choice of endoscopic expanded endonasal approach introduces the possibility of improved gross total resection of craniopharyngioma while minimizing surgical morbidity in a significant subset of patients. METHODS: From our trans-sphenoidal surgical series of 331 cases, we retrospectively reviewed visual, endocrine and neuro-cognitive outcomes in the first consecutive eight patients (median age 63 years; range 47-73 years) with newly diagnosed supradiaphragmatic craniopharyngioma (median tumour height 23 mm; range 15-34 mm), removed by expanded endonasal approach (median follow-up 27 months; range 10-69 months). Gross total resection was attempted in all patients. RESULTS: Gross total resection was achieved in 6 of 8 patients. Visual improvement was present in 6 of 8 patients of patients or in 14 of 16 eyes. New endocrinopathy, including diabetes insipidus, appeared in 5 of 8 patients. Stalk was preserved in 4 patients. Cognitive decline was present in 2 cases. Five of 8 patients retained previous quality of life. CONCLUSIONS: Our early outcome results are comparable to the recent few expanded endonasal approach series, except for the incidence of new endocrinopathy and cerebrospinal fluid leak rate. This was influenced by higher number of transinfundibular tumours in our series, where stalk preservation is less likely, and not using nasoseptal flap or gasket closure in the first half of cases. Including data from the literature and ours, expanded endonasal approach shows a trend for improved gross total resection rate with less morbidity, more obviously for visual outcome and quality of life than for endocrine outcome. However, validity of expanded endonasal approach should be confirmed in a larger number of patients with a longer follow-up period.

Cortical potentials after electrical intraneural stimulation of the optic nerve during orbital enucleation.

BACKGROUND: The aim of this study was to present cortical potentials after electrical intraneural stimulation of the optic nerve during orbital enucleation due to malignant melanoma of the choroid or the ciliary body. These cortical potentials were related to cortical potentials after electrical epidural stimulation of the optic nerve, recorded during non-manipulative phases of neurosurgery for central skull base tumors. METHODS: Cortical potentials were recorded with surface occipital electrode (Oz) in six patients undergoing orbital enucleation under total intravenous anesthesia. Two thin needle stimulating electrodes were inserted inside the intraorbital part of the optic nerve. The electrical stimulus consisted of a rectangular current pulse of varying intensity (0.2-10.0 mA) and duration (0.1-0.3 ms); the stimulation rate was 2 Hz; the bandpass filter was 1-1,000 Hz; the analysis time was 50-300 ms. RESULTS: Cortical potentials could not be obtained or were inconsistently elicitable in three patients with longstanding history (>3 months) of severe visual deterioration, while they consisted of several positive and negative deflections in a patient with a short history of mild visual impairment. In two other patients, cortical potentials consisted of N20, P30 and N40 waves. DISCUSSION: Cortical potentials after electrical intraneural stimulation of the optic nerve could be recorded in patients with a short history of visual deterioration and without optic nerve atrophy and appear more heterogeneous than cortical potentials after electrical epidural stimulation of the optic nerve, recorded during non-manipulative phases of neurosurgery for central skull base tumors.

Intraoperative monitoring of the visual function using cortical potentials after electrical epidural stimulation of the optic nerve.

BACKGROUND: Central skull base meningiomas commonly present with visual deficit, and their removal often leads to improvement of visual function. However, the incidence of postoperative visual deterioration has been reported to be up to 10%. Intraoperative monitoring using flash visual evoked potential has only recently been used with success. Cortical potentials (CP) after electrical epidural stimulation of the optic nerve (ON) were correlated with ON manipulation due to central skull base tumor removal to contribute to improvement of the intraoperative monitoring of the visual function. METHODS: Blunt needle stimulating electrodes were attached epidurally alongside ON in an unroofed optic canal and used for delivering a rectangular current pulse (intensity 0.2-5.0 mA; duration 0.1-0.3 ms; rate 2 Hz). CPs after electrical epidural stimulation of ON were recorded with corkscrew electrodes at O(z) with the reference electrode at F(z). RESULTS: P20 and N30 amplitudes were significantly lower (p < 0.05) during tumor removal associated with ON manipulation than in other phases of surgery; the amplitude reductions were reversible in all cases. There were no significant changes in P20, N30 and P40 latencies during the surgery. Immediate postoperative visual function was unchanged in all patients. CONCLUSIONS: P20 and N30 amplitude changes seem to reliably correspond with the manipulation of ON during anterior skull base tumor removal. Reversible reduction of P20 and N30 amplitude was associated with unchanged immediate postoperative visual function. No correlation between intraoperative variation of CP and newly acquired postoperative visual deficit can presently be made.

Optic nerve potentials and cortical potentials after stimulation of the anterior visual pathway during neurosurgery.

The aim was to present cortical potentials after intraoperative electrical epidural stimulation of the optic nerve (ON) in individuals with normal preoperative vision. Optic nerve potentials after flash and electrical stimulation were additionally recorded. Contact electrodes on ON and occiput were used for monopolar recording of optic nerve potentials and cortical potentials, respectively. Epidural stimulating electrodes on ON were used to deliver a rectangular current pulse (intensity 0.2-5.0 mA; duration 0.1-0.3 ms; rate 2 Hz), and LED flash goggles were used for flash stimulation. Optic nerve potentials after flash stimulation predominantly consisted of a positive deflection with a latency around 40 ms, followed by a longer-lasting negativity with the peak at around 50 ms. Optic nerve potentials after electrical epidural stimulation of ON were comprised of a negative deflection at around 3 ms. A positive and a negative deflection at 20 and 30 ms, respectively, and a smaller positive deflection at 40 ms constituted cortical potentials after electrical epidural stimulation of ON. Stable and repeatable cortical potentials after electrical epidural stimulation of ON could safely be recorded in humans during neurosurgery. The origin of these presumably far-field potentials and their potential role in intraoperative monitoring remains to be established.

Direct epidural electrical stimulation of the optic nerve: a new method for intraoperative assessment of function.

Intraoperative visual system monitoring of lesions with a close relationship to the optic apparatus by using light flashes reportedly is difficult to perform, and the results are too unreliable to interpret. The authors used direct epidural electrical stimulation of the optic nerve (ON) during surgery instead of light flashes. Four patients were included in this feasibility study. In 3 patients-1 each harboring a planum sphenoidale meningioma, a tuberculum sellae meningioma, and an intraorbital ON sheath meningioma-2 stimulating needle electrodes were placed on each side of the ON just anterior to the optic canal, before unroofing the optic canal and an extradural anterior clinoidectomy. In the fourth patient, who harbored a frontotemporal astrocytoma, stimulation was applied at the exit of the ON from the canal. The electrically induced visual evoked potentials (eVEPs) were recorded from the scalp before, during, and after tumor removal. A typical eVEP consisted of N20 and N40 waves. The amplitude of the N40 wave varied up to 25% prior to tumor removal. In the patient with a symptomatic tuberculum sellae meningioma, the decompressive effect of opening the optic canal and the impact of manipulation during piecemeal tumor removal were detected by the eVEPs. In the patient with an ON sheath meningioma and light sensation, only the N20 wave was observed. Epidural electrical stimulation of the ON is a safe means of providing a stable signal and real-time information on nerve conduction during surgery. It may be a useful adjunct in improving visual outcomes postoperatively. Further clinical studies are necessary.

Electrophysiologic and clinical data support the use of dorsal root entry zone myelotomy in syringosubarachnoid shunting for syringomyelia.

BACKGROUND: The objectives of this study were to correlate preoperative changes in SEPs with clinical sensory dysfunction and to establish their importance in planning the microsurgical approach, either by DM myelotomy or by DREZ myelotomy, for patients with syringomyelia. METHODS: In addition to conducting clinical sensory examination, we evaluated the N13 potential after median nerve stimulation and CPs after tibial nerve stimulation intraoperatively before performing myelotomy on patients with syringomyelia (N = 14). RESULTS: Eleven patients with intact DS presented with unilateral PTD, and 9 had distressing unilateral dermatomal pain. Deep sensibility was affected in 3 patients (bilaterally in 1 patient) without PTD. Patients with PTD were likely to have spontaneous pain (P = .005). A significant correlation between preoperative PTD and the absence of the N13 potential was demonstrated on the right (P = .015) and left (P = .004) sides. In patients with PTD, DREZ myelotomy on the symptomatic side is suggested as the treatment of choice, whereas DM myelotomy might be superior in patients without PTD. CONCLUSIONS: Absence of pain or temperature sensation in patients with syringomyelia is usually accompanied by same-sided loss of the N13 potential, suggesting damage to the DH gray matter. Deep sensibility is typically normal, and DREZ myelotomy with preservation of DCs is proposed as the treatment of choice. Conducted potentials are usually distorted in patients with normal pain or temperature sensation and affected vibration and posture sensation, suggesting damage to DCs and making DM myelotomy the treatment of choice. Electrophysiologic and clinical data support the use of DREZ myelotomy in syringosubarachnoid shunting for syringomyelia in patients whose DCs have an intact function.

T1-nerve root neuroma presenting with apical mass and Horner's syndrome.

BACKGROUND: The appearance of dumbbell neuroma of the first thoracic root is extremely rare. The extradural component of a T1-dumbbell neuroma may present as an apical mass. The diagnosis of hand weakness is complex and may be delayed in T1-neuroma because of absence of the palpable cervical mass. One-stage removal of a T1-root neuroma and its intrathoracic extension demanded an extended posterior midline approach in the sitting position. CASE PRESENTATION: A 51-year old man had suffered a traumatic partial tendon rupture of his wrist flexor muscles 6 years ago. Since the incident he occasionally felt fullness and tenderness in the affected forearm with some tingling in his fingers bilaterally. During the last two years the hand weakness was continuous and hypotrophy of the medial flexor and intrinsic hand muscles had become apparent. Electrophysiological studies revealed an ulnar neuropathy in addition to mild median and radial nerve dysfunction, including a mild contralateral carpal tunnel syndrome. The diagnostic work-up for multiple mononeuropathy in the upper extremity was negative. Repeated electrophysiological studies revealed fibrillations in the C7 paravertebral muscles on the affected side. Chest x-ray revealed a large round apical mass on the affected side. A Horner's syndrome was noted at this point of diagnostic work-up. MRI of the cervical and thoracic spine revealed a dumbbell T1 neuroma enlarging the intervertebral foramen at T1-2 and a 5 cm large extradural tumor with extension into the apex of the ipsilateral lung. The patient underwent surgery in sitting position using a left dorsal midline approach. Although the T1 root could not be preserved, the patient's neurological condition was unchanged after the surgery. CONCLUSION: Extended posterior midline exposure described here using hemilaminectomy, unilateral facetectomy and costo-transversectomy is efficient and safe for one-stage removal of dumbbell tumors at the T1 level with a predominantly extraforaminal component in the apex of the lung extending up to 6-7 cm laterally. Horner's syndrome, if present and observed, may significantly narrow the differential diagnosis of hand weakness caused by T1-root tumors.

Continuous wavelet transform of laser-Doppler signals from facial microcirculation reveals vasomotion asymmetry.

Facial laser Doppler flux (FLDF) consists of a mean value and complex oscillatory components called vasomotion. Vasomotion can be expressed as spectral amplitudes (SA) after the application of continuous wavelet transform. Vasomotion is influenced by cardiac activity (frequency interval I), respiration (interval II), intrinsic myogenic activity (interval III), neural mechanisms (interval IV) and endothelial mechanisms (intervals V and VI). Asymmetry of FLDF mean value was previously documented and hereby we present homogeneity assessment for FLDF vasomotion. Mean FLDF (p<0.001), total SA (p<0.001) and SA within frequency intervals I-VI were significantly higher in both cheeks compared to forehead. Total SA (p=0.009) and SA within frequency intervals I (p=0.041), II (p=0.005), III (p=0.009), IV (p=0.001) and V (p=0.036) were significantly higher in right than in left forehead. Human face is a heterogeneous microvascular region. Angiographic characteristics of deep horizontal sub-dermal plexus, endothelial and vascular smooth muscle cell heterogeneity, and plasticity of the microvasculature, autonomic asymmetry and facial neuropsychological asymmetry are possible causes of microvascular asymmetry. The origin and significance of microvascular imbalance need to be elucidated further.

Laser-Doppler flowmetry and Horner's syndrome in patients with complete unilateral damage to the parasellar sympathetic fibers during cavernous sinus surgery.

AIM: To determine ocular, sudomotor, and vasomotor components of Horner's syndrome resulting from complete unilateral intraoperative damage to the parasellar sympathetic fibers during cavernous sinus surgery. METHODS: Complete damage to the parasellar sympathetic fibers was found in four patients operated for central skull base lesions. Pupilometry, eyelid fissure measurement, Hertel's exophthalmometry, starch iodine sweat test, and laser-Doppler perfusion assessment of bilaterally symmetrical forehead and cheek areas were performed. RESULTS: Pupil diameter was smaller and the eyelid fissure was >2 mm narrower on the affected side in all four patients. Exophthalmometry after the operation never revealed >1 mm difference. Anhydrosis was localized to the medial forehead in three and to the entire forehead in one patient. Average perfusion did not significantly differ between the affected and opposite side of the forehead or cheek. CONCLUSIONS: The parasellar sympathetic fibers exclusively innervate the orbit and variably innervate the forehead sweat glands. No conclusion regarding their contribution to the facial vasomotor control could be established.

H wave and spinal root potentials in neuromonitoring of S1 root function during evacuation of herniated disc: preliminary results.

AIM: To determine the changes in the tibial H reflex and spinal nerve root potentials (SRPs) of the S1 root during posterior discectomy and the effects of surgical manipulation. METHODS: Tibial H reflex responses (M and H waves) were intermittently recorded from the soleus muscle by surface electrodes during different stages of surgery in 5 patients with S1 radiculopathy. All patients had Achilles reflex preserved bilateraly and no paresis on manual strength testing preoperatively. SRPs were additionally obtained by direct epidural recordings from the surgically exposed S1 root in 2 of them. RESULTS: The variations in the amplitude of H wave were minor and reversible upon the cessation of surgical manipulation of the root, but the H reflex was not lost either temporarily or permanently in any of the patients. Prolongation of H wave latency by up to 18% at the end of surgery in comparison with preoperative value was noticed in 4 patients. However, there was increased degree of desynchronization of the SRP in some phases of the spinal root manipulation, such as root mobilization before the disc incision and retraction during the disc evacuation. H waves and SRPs were continuously present during the surgery. Ankle jerks were preserved postoperatively in all 5 patients. CONCLUSION: Unremarkable variations in H wave latency may be followed by increased SRP desynchronization. Monitoring of the epidurally recorded SRPs seems to be more sensitive to surgical manipulations of the spinal nerve root than the tibial H reflex recordings from the soleus muscle.

Left-right asymmetry of the facial microvascular control.

Facial blood flow and temperature were significantly higher on the right side of the forehead compared to the left. This asymmetry implies that the hemispheric autonomic control of the face differs and could influence the expression of emotion.