The Neurodiagnostic Journal最新文献

Needle-shaped occipital spikes are most often described in children with cortical visual impairment or congenital blindness. We report the case of a 5-year-old child with developmental delay, microcephaly based on an occipitofrontal circumference below the 3rd percentile, and recurrent dystonic movements. Despite the reduced head size, MRI of the brain and spine showed no additional structural abnormalities beyond the microcephaly, and her vision was clinically normal. She underwent ambulatory EEG for episodes of abnormal posturing. The study showed low-voltage, surface-negative spikes maximal at O2 that persisted throughout the recording without associated clinical events, while background activity remained normal. Although these discharges have features that may resemble benign EEG variants, their interpretation should be cautious given the patient's developmental and neurological background. Recognizing such patterns and interpreting them in the full clinical context is essential to prevent misdiagnosis and unnecessary antiepileptic therapy.

Repetitive electrical stimulation of the femoral nerve to record F-waves from the vastus lateralis (VL) muscle can cause significant pain in some participants. This study aimed to develop a method for recording F-waves from the VL with minimal discomfort by adjusting the position of the stimulating electrode. Fifteen healthy participants were recruited. The cathode was positioned at two locations: one at the center of the thigh and the other slightly lateral to it, targeting the physiological motor point of the distal VL. The anode was placed on the lateral thigh, and the recording electrode was placed on the distal VL. F-waves were elicited at each site, with the stimulus intensity set at 1.2 times the level required to elicit the maximum M-wave amplitude. Stimulus duration was 0.2 ms, frequency was 0.2 Hz, and 30 stimuli were delivered per trial. Pain levels were immediately assessed using a visual analogue scale (VAS). The following parameters were analyzed: stimulus intensity, VAS scores, M-wave amplitude, F-wave persistence, F-wave mean latency, F-wave mean amplitude, and F/M amplitude ratio. Stimulation at the lateral site resulted in reduced stimulus intensity, VAS scores, M-wave amplitude, and F-wave persistence compared to the center site. F-wave mean amplitude and the F/M amplitude ratio were higher, while F-wave latency remained unchanged. Shifting the cathode slightly lateral to the center of the thigh enabled F-wave recordings from the VL with lower stimulation intensity and reduced pain. However, changes in M-wave and F-wave parameters were observed.

Background: Spinal cord stimulation (SCS) is a common therapeutic approach for treating intractable chronic pain. A key factor determining SCS efficacy is lead positioning to generate paresthesias in areas of perceived pain. There are two distinct approaches to confirming appropriate coverage. 1) Sedative anesthesia with local anesthetic and intraoperative patient reporting of pain coverage. 2) General anesthesia and intraoperative neurophysiological mapping. Placement guided by neuromonitoring decreases OR times, produces more accurate placement with better pain coverage, less excess paresthesias and adverse events. We aim to determine the prevalence of non-awake SCS placement with neuromonitoring in Canada, given the demonstrated benefits, and to identify possible barriers to implementation.

Methods: A structured questionnaire was designed to assess procedures for SCS implantation in Canada. The survey was distributed via email to members of the Canadian Neuromodulation Society.

Results: 14 responses were received. 36% perform SCS implantation asleep with neuromonitoring where 75% utilize CMAPs and 25% utilize SSEP collisions. 71% have access to a neurophysiologist yet 93% are at centres where neurophysiologists are used for other procedures. Barriers to utilizing neurophysiologist assisted lead placement include familiarity with the awake procedure, and lack of access and awareness.

Conclusion: This survey provides a summary of SCS implantation practice patterns in Canada. Although asleep SCS implantation with neuromonitoring is faster and results in more accurate placement while avoiding downsides of the awake procedure, most neurosurgeons currently do not utilize this protocol in part due to a lack of access to neurophysiologists with expertise in this area.

Epilepsy surgery encompasses a wide range of procedures aimed at reducing or eliminating seizures. In these procedures, there are opportunities to employ intraoperative neurophysiology to map the epileptic focus and accurately identify functional areas of the brain. In cases of drug-resistant epilepsy where onset is diffuse, multifocal, or in an eloquent region of the brain, resection is not possible, and neuromodulation can be considered to reduce the seizure burden. While resective or ablative therapy aims to be curative, neuromodulation techniques for epilepsy are generally considered palliative. The goal of neuromodulation is to use an implantable device with electrodes and a pulse generator to use electrical energy to interfere with the nervous system. Three neuromodulation modalities have been approved by the United States FDA for epilepsy: vagus nerve stimulation, deep brain stimulation of the anterior nucleus of the thalamus, and responsive neurostimulation. While rates of seizure freedom with neuromodulation are lower than with resection of an epileptogenic focus, many patients experience >50% reduction in seizures, and results improve with time, suggesting both acute and chronic benefits with these therapies.

Deep brain stimulation (DBS) has significantly advanced the treatment of moderate to severe motor symptoms in conditions such as Parkinson's disease and essential tremor. Although DBS is generally considered a safe and effective therapy, selecting suitable candidates requires careful diagnostic evaluation and ensuring a stable neuropsychiatric baseline. Effective patient counseling is crucial, as it helps manage expectations regarding the potential benefits, the limitations of DBS, and the typical timeline for symptom improvement. This counseling is as important as the precision in surgical targeting to achieve optimal therapeutic outcomes. Once DBS is implanted, the remaining adjustable component is the programming of the device, which plays a vital role in patient response. Despite the absence of formal programming algorithms, various studies have provided collective insights into best practices, offering guidance on how to approach device programming for improved results. The aim of this review is to equip clinicians with valuable practical knowledge to enhance the management of patients undergoing DBS therapy, ultimately optimizing patient outcomes. By understanding the complexities of patient selection, surgical placement, and ongoing device management, clinicians can better tailor DBS interventions to individual needs and maximize the long-term benefits of the therapy.

Peripheral nerve stimulation (PNS) is defined as the application of electric stimulation to the peripheral nervous system and to a specific nerve. For the most part, the goal of PNS has been treatment of pain. Later, PNS use expanded to indications other than pain including epilepsy and depression, which involves stimulation of the vagus nerve, sleep apnea with stimulation of the hypoglossal nerve, respiratory insufficiency, involving phrenic nerve stimulation, and many others. The overarching peripheral neuromodulation approach involves three modalities: conventional PNS, which implies direct placement of stimulating electrode leads over the affected peripheral nerve(s); percutaneous PNS, which implies insertion of stimulating electrode leads near the target nerve with appropriate guidance; and peripheral nerve field stimulation, which requires placement of electrode leads to stimulate smaller nerves and nerve endings in the affected target area. Monitoring peripheral nerves during surgery through electrophysiological methods is a highly valuable option, offering crucial real-time information to the surgical team. While preoperative testing provides helpful data for decision-making, intraoperative neurophysiological monitoring (IONM) fills in gaps that cannot be addressed by preoperative studies. IONM assesses the nervous system during surgery to prevent potential damage to critical neurological structures. It serves the next main purposes: detecting and minimizing iatrogenic injuries, mapping nervous structures to identify the target nerve, and assessing the functionality of the nerve. In this article we review currently available information about the utilization of IONM during PNS procedures.