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Objective: The precision of neuronavigation systems relies on the correct registration of the patient's position in space and aligning it with radiological 3D imaging data. Registration is usually performed by the acquisition of anatomical landmarks or surface matching based on facial features. Another possibility is automatic image registration using intraoperative imaging. This could provide better accuracy, especially in rotated or prone positions where the other methods may be difficult to perform. The aim of this study was to validate automatic image registration (AIR) using intraoperative cone-beam computed tomography (CBCT) for cranial neurosurgical procedures and compare the registration accuracy to the traditional surface matching (SM) registration method based on preoperative MRI. The preservation of navigation accuracy throughout the surgery was also investigated. Methods: Adult patients undergoing intracranial tumor surgery were enrolled after consent. A standard SM registration was performed, and reference points were acquired. An AIR was then performed, and the same reference points were acquired again. Accuracy was calculated based on the referenced and acquired coordinates of the points for each registration method. The reference points were acquired before and after draping and at the end of the procedure to assess the persistency of accuracy. Results: In total, 22 patients were included. The mean accuracy was 6.6 ± 3.1 mm for SM registration and 1.0 ± 0.3 mm for AIR. The AIR was superior to the SM registration (p < 0.0001), with a mean improvement in accuracy of 5.58 mm (3.71–7.44 mm 99% CI). The mean accuracy for the AIR registration pre-drape was 1.0 ± 0.3 mm. The corresponding accuracies post-drape and post-resection were 2.9 ± 4.6 mm and 4.1 ± 4.9 mm, respectively. Although a loss of accuracy was identified between the preoperative and end-of-procedure measurements, there was no statistically significant decline during surgery. Conclusions: AIR for cranial neuronavigation consistently delivered greater accuracy than SM and should be considered the new gold standard for patient registration in cranial neuronavigation. If intraoperative imaging is a limited resource, AIR should be prioritized in rotated or prone position procedures, where the benefits are the greatest. [ABSTRACT FROM AUTHOR]

Epilepsy surgery should be considered for individuals with drug-resistant focal epilepsy. The pre-surgical evaluation is highly multi-disciplinary and performed by a team consisting of neurologists, neurophysiologists, neurosurgeons, neuroradiologists, neuropsychologists, biomedical scientists, speech-language pathologists and nursing staff. The evaluation comprises of a meticulous medical history with focus on seizure semiology, a 3 Tesla MRI, ictal video-EEG, neuropsychological evaluation and sometimes also MEG, nTMS, fMRI, PET or SISCOM/ictal SPECT. Occasionally, invasive monitoring with intracranial electrodes is necessary. Surgical options in treatment of epilepsy range from open resections of epileptogenic areas to focal ablations and neurostimulation. There is evidence of epilepsy surgery being an effective treatment in carefully selected cases. Epilepsy surgery seems underutilized in Sweden and referrals for epilepsy surgery work-up need to increase.

Laser Interstitial Thermal Therapy (LITT) is used to treat patients with intracranial lesions such as epileptogenic foci, radiation necrosis, cavernomas and brain tumors in the United States. The approval for this treatment in Europe has first been granted in 2018, with the first treatment(s) in the Nordic countries - in the form of 3 brain tumor patients - performed at the Karolinska University Hospital in 2019. In this article we briefly describe our initial experience in the context of current literature.

The diagnosis of a malignant brain tumour is often associated with a poor prognosis. Current treatment is surgical resection followed by radio-chemotherapy. Surgical resection is most favourable in relation to survival time. Unfortunately, many patients are not suitable for surgical resection, due to inoperable tumour location or the patients' poor state. Minimally invasive thermal ablation may pose an interesting new treatment alternative. In this review, we describe the evolution, the underlying physiology and the clinical applications of cryo- and laser-induced thermal therapy of primary and secondary brain tumours.

Background and Importance: Stereotactic brain biopsy (SB) is an important part of the neurosurgical armamentarium, with the possibility of achieving histopathological diagnosis in otherwise inaccessible lesions of the brain. Nevertheless, the procedure is not without the risk of morbidity, which is especially true for lesions in eloquent parts of the brain, where even a minor adverse event can result in significant deficits. Navigated transcranial magnetic stimulation (nTMS) is widely used to chart lesions in eloquent areas, successfully guiding maximal safe resection, while its potential role in aiding with the planning of a stereotactic biopsy is so far unexplored., Clinical Presentation: Magnetic resonance imaging of a 67-yr-old woman presenting with dysphasia revealed a noncontrast enhancing left-sided lesion in the frontal and parietal pars opercularis. Due to the location of the lesion, nTMS was used to chart both primary motor and language cortex, utilizing this information to plan a safe SB trajectory and sampling area according to the initial work-up recommendations from the multidisciplinary neuro-oncology board. The SB was uneventful, with histology revealing a ganglioglioma, WHO I. The patient was discharged the following day, having declined to proceed with tumor resection (awake surgery) due to the non-negligible risk of morbidity. Upon 1- and 3-mo follow-up, she showed no signs of any procedure-related deficits., Conclusion: nTMS can be implemented to aid with the planning of a stereotactic biopsy procedure in eloquent areas of the brain, and should be considered part of the neurosurgical armamentarium., (Copyright © 2018 by the Congress of Neurological Surgeons.)