Anandan, Charenya

Abstract General anesthesia increasingly facilitates asleep deep brain stimulation (DBS) surgery but suppresses spontaneous electrophysiological signals used to guide lead placement. Here, we investigated whether evoked resonant neural activity (ERNA), a stimulation-evoked biomarker of basal ganglia circuitry, remains informative during asleep DBS. We analyzed intraoperative recordings from a multisite cohort of 45 patients (86 hemispheres) undergoing subthalamic nucleus or globus pallidus internus DBS under awake and anesthetized conditions. Anesthesia markedly attenuated spontaneous beta and high-frequency oscillatory activity. Although ERNA amplitude was reduced at matched stimulation intensities, increasing stimulation current restored high-amplitude, spatially localized responses while preserving anatomical specificity. Across both targets, ERNA spatial distributions remained stable across awake and anesthetized states, co-localized with established motor-network biomarkers, and retrospectively identified electrode levels associated with the greatest postoperative therapeutic window. These retrospective findings position stimulation-evoked circuit interrogation as a complement to imaging for physiology-guided asleep DBS and as a candidate signal for contact prioritization. Prospective studies are warranted to determine whether ERNA-guided decisions improve placement, programming efficiency and clinical outcomes.

ABSTRACT Introduction: Recessive mutations in the anoctamin‐5‐encoding gene (ANO5) cause muscular dystrophy of various phenotypes. Intramuscular interstitial amyloid deposits were detected in a few patients with anoctaminopathy‐5, some with cardiac involvement. The frequency of amyloid deposition in anoctaminopathy‐5 and its impact on phenotype are unknown. Methods: We retrospectively identified patients with genetically proven anoctaminopathy‐5 who had undergone muscle biopsy and reviewed their clinical and laboratory data. Results: Eight of 15 patients with anoctaminopathy‐5 had intramuscular interstitial amyloid deposits. The median age at onset of weakness was 40 and 45 years in the amyloidosis and nonamyloidosis groups, respectively. Mutations occurred throughout the entire gene in the amyloidosis group. Atrial arrhythmia was noted in 4 patients with amyloidosis and in 4 patients without amyloidosis. The latter group also had premature ventricular contractions. One nonamyloidosis patient had septal hypokinesia. Discussion: Intramuscular amyloidosis occurred in 53% of patients with anoctaminopathy‐5 who underwent muscle biopsy and had no impact on the phenotype. Muscle Nerve 59:133–137, 2019

Background and purposeCACNA1S encodes Cav1.1, a voltage sensor for muscle excitation−contraction coupling, which activates the ryanodine receptor 1 (RYR1) leading to calcium release from the sarcoplasmic reticulum. CACNA1S mutations cause hypokalemic periodic paralysis, malignant hyperthermia and congenital myopathy. RYR1 mutations result in congenital myopathy, malignant hyperthermia and rhabdomyolysis.MethodsThe aim was to describe a novel phenotype associated with a CACNA1S variant at a site previously linked to hypokalemic periodic paralysis.ResultsThe patient presented with fluctuating asymptomatic creatine kinase elevation after an episode of rhabdomyolysis but has no history of periodic paralysis. His muscle biopsy showed core‐like structures occurring mainly in type 2 fibers. He carries a novel Cav1.1 variant (p.Arg528Leu) affecting a highly conserved amino acid. Different mutations at the same location cause hypokalemic periodic paralysis.ConclusionThis case underscores the similarity between the phenotypes caused by mutations in two functionally linked proteins, RYR1 and Cav1.1.