Smartphone pupillometry for detection of cerebral vasospasm after aneurysmal subarachnoid hemorrhage.

OBJECTIVES: Vasospasm is a complication of aneurysmal subarachnoid hemorrhage (aSAH) that can change the trajectory of recovery and is associated with morbidity and mortality. Earlier detection of vasospasm could improve patient outcomes. Our objective is to evaluate the accuracy of smartphone-based quantitative pupillometry in the detection of radiographic vasospasm and delayed cerebral ischemia (DCI) after aSAH. MATERIALS AND METHODS: We prospectively collected pupillary light reflex (PLR) parameters from patients with aSAH admitted to a neurocritical care unit at a single hospital twice daily using quantitative smartphone pupillometry recordings. PLR parameters included: Maximum pupil diameter, minimum pupil diameter, percent change in pupil diameter, latency in beginning of pupil constriction to light, mean constriction velocity, maximum constriction velocity, and mean dilation velocity. Two-tailed t-tests for independent samples were performed to determine changes in average concurrent PLR parameter values between the following comparisons: (1) patients with and without radiographic vasospasm (defined by angiography with the need for endovascular intervention) and (2) patients with and without DCI. RESULTS: 49 subjects with aSAH underwent 323 total PLR recordings. For PLR recordings taken with (n=35) and without (n=241) radiographic vasospasm, significant differences were observed in MIN (35.0 ± 7.5 pixels with vasospasm versus 31.6 ± 6.2 pixels without; p=0.002). For PLR recordings taken with (n=43) and without (n=241) DCI, significant differences were observed in MAX (48.9 ± 14.3 pixels with DCI versus 42.5 ± 9.2 pixels without; p<0.001). CONCLUSIONS: Quantitative smartphone pupillometry has the potential to be used to detect radiographic vasospasm and DCI after aSAH.

Cranial and Spinal Cerebrospinal Fluid Leaks: Foundations of Identification and Management.

Cerebrospinal fluid (CSF) leaks may occur at the skull base or along the spinal column and can cause a variety of debilitating neurological symptoms for patients. Recognizing the potential presence of a CSF leak and then identifying its source are necessary for accurate diagnosis and definitive treatment. A standardized workflow can be followed for successful leak localization, which often requires several diagnostic studies, and for definitive leak treatment, which can range from minimally invasive, needle-based approaches to a variety of surgical corrections. This review paper provides an overview of epidemiology, pathophysiology, and diagnostic workup for CSF leaks and introduces available treatment options. An illustrative case of a skull base CSF leak demonstrating diagnosis and surgical correction is provided.

First-In-Human Demonstration of High Frequency Electrical Motor Nerve Block: Case Report.

ABSTRACT: This feasibility study tested the capability of high frequency stimulation (HFS) to block muscle contractions elicited by electrical stimulation of the same nerve proximally. During a tendon lengthening surgery in the forearm, the anterior interosseous nerve (AIN) was exposed. A specialized nerve cuff electrode was placed around the nerve, and a stimulating probe held on the nerve 1 cm proximal to the cuff electrode delivered pulses of current causing the pronator quadratus muscle to contract. Through the cuff electrode, 20 kHz HFS was delivered to the nerve for 10 seconds during proximal stimulation. HFS amplitudes between 5 and 10 mA peak-to-peak were tested to determine which produced complete and partial block of the electrically induced contractions. The minimum HFS amplitude that produced complete block was 8 mA, with lower amplitudes producing partial block. In all trials, muscle contractions resumed immediately after HFS was turned off. This demonstration of high frequency electrical nerve block is a milestone in the road to clinical implementation of HFS mediated motor block for spasticity.

A review of prospective studies regarding percutaneous peripheral nerve stimulation treatment in the management of chronic pain.

Conventionally, peripheral nerve stimulation (PNS) for treatment of chronic pain has involved a two-stage process: a short-term (e.g., 7 days) trial and, if significant pain relief is achieved, a permanent PNS system is implanted. A percutaneous PNS treatment is now available where a coiled lead may be implanted for up to 60 days with the goal of producing sustained relief. In the present review, published prospective trials using percutaneous PNS treatment were identified and synthesized. The collected evidence indicates that percutaneous PNS treatment for up to 60 days provides durable clinically significant improvements in pain and pain interference. Similar efficacy across diverse targets and etiologies supports the broad applicability for use within the chronic pain population using this nonopioid technology.

What is this review about? This review looks at a drug-free way to treat chronic pain called percutaneous peripheral nerve stimulation (PNS). Percutaneous means it is placed through the skin. PNS applies small amounts of electricity to the nerves to reduce chronic pain. Most PNS systems involve a two-step process. A short trial is first performed to see if a patient has pain relief. A permanent system is then placed if the person had pain relief. Percutaneous PNS treatments are different. They use a thin wire called a lead placed in the body for up to 60 days. The lead is taken out at the end of the treatment period. Studies have shown that this type of PNS treatment can reduce chronic pain even after the treatment is over. No previous article has collected all these studies of percutaneous PNS in one place.What evidence was gathered? This review found evidence from studies on treatment of chronic pain. Pain types included shoulder pain, neuropathic pain and low back pain. It found that percutaneous PNS treatment for up to 60 days can reduce pain and how pain interferes with daily life.How can these data lead to better care for patients? These findings mean that percutaneous PNS treatments could be a useful, non-drug option for many types of chronic pain.

Innovations in Stroke Recovery and Rehabilitation: Poststroke Pain.

Pain can be a significant barrier to a stroke survivors' functional recovery and can also lead to a decreased quality of life. Common pain conditions after stroke include headache, musculoskeletal pain, spasticity-related pain, complex regional pain syndrome, and central poststroke pain. This review investigates the evidence of diagnostic and management guidelines for various pain syndromes after stroke and identifies opportunities for future research to advance the field of poststroke pain.

Intraoperative occipital to C2 angle and external acoustic meatus-to-axis angular measurements for optimizing alignment during posterior fossa decompression and occipitocervical fusion for complex Chiari malformation.

Background: Excess flexion or extension during occipitocervical fusion (OCF) can lead to postoperative complications, such as dysphagia, respiratory problems, line of sight issues, and neck pain, but posterior fossa decompression (PFD) and OCF require different positions that require intraoperative manipulation. Objective: The objective of this study was to describe quantitative fluoroscopic morphometrics in Chiari malformation (CM) patients with symptoms of craniocervical instability (CCI) and demonstrate the intraoperative application of these measurements to achieve neutral craniocervical alignment while leveraging a single axis of motion with the Mayfield head clamp locking mechanism. Methods: A retrospective cohort study of patients with CM 1 and 1.5 and features of CCI who underwent PFD and OCF at a single-center institution from March 2015 to October 2020 was performed. Patient demographics, preoperative presentation, radiographic morphometrics, operative details, complications, and clinical outcomes were analyzed. Results: A total of 39 patients met the inclusion criteria, of which 37 patients (94.9%) did not require additional revision surgery after PFD and OCF. In this nonrevision cohort, preoperative to postoperative occipital to C2 angle (O-C2a) (13.5° ± 10.4° vs. 17.5° ± 10.1°, P = 0.047) and narrowest oropharyngeal airway space (nPAS) (10.9 ± 3.4 mm vs. 13.1 ± 4.8 mm, P = 0.007) increased significantly. These measurements were decreased in the two patients who required revision surgery due to postoperative dysphagia (mean difference - 16.6°° in O C2a and 12.8°° in occipital and external acoustic meatus to axis angle). Based on these results, these fluoroscopic morphometrics are intraoperatively assessed, utilizing a locking Mayfield head clamp repositioning maneuver to optimize craniocervical alignment prior to rod placement from the occipital plate to cervical screws. Conclusion: Establishing a preoperative baseline of reliable fluoroscopic morphometrics can guide surgeons intraoperatively in appropriate patient realignment during combined PFD and OCF, and may prevent postoperative complications.