Embolic MCA Stroke Treated With tPA and TICI-3 Mechanical Thrombectomy Complicated by Hemiballismus: A Case Study and Literature Review.

This report examines the etiology of hemiballistic movements that began 24 hours after a 63-year-old male with vascular risk factors received tissue plasminogen activator (tPa) and thrombolysis in cerebral ischemia 3 (TICI3) thrombectomy for a left middle cerebral artery (MCA) ischemic stroke. The clinical course was reviewed from an admission at a large academic institution where assessments included physical exams, head and neck computed tomography angiography (CTA), and head magnetic resonance imaging (MRI) without contrast. The patient's initial physical exam was consistent with a left MCA syndrome and included a National Institute of Health Stroke Scale (NIHSS) of 20. CTA showed an embolic M2 occlusion. After tPA and TICI 3 thrombectomy, NIHSS improved to 3 for dysarthria, facial weakness, and language deficits. MRI showed left insular diffusion restriction. New right-sided hemiballistic movements began 24 hours after treatment. At his six-week follow-up outpatient appointment, the movements were no longer present, and his neurologic exam was unremarkable, including an NIHSS of zero. No prior cases of hemiballism have been reported as a likely complication of treatment with tPa and thrombectomy. The globus pallidus is the suspected origin of the ballistic movements either from a decreased insular signal or embolic event during treatment. As stroke interventions improve, the susceptibility of certain tissues to brief ischemic events during treatment must be assessed.

Smad4 restricts differentiation to promote expansion of satellite cell derived progenitors during skeletal muscle regeneration.

Skeletal muscle regenerative potential declines with age, in part due to deficiencies in resident stem cells (satellite cells, SCs) and derived myogenic progenitors (MPs); however, the factors responsible for this decline remain obscure. TGFß superfamily signaling is an inhibitor of myogenic differentiation, with elevated activity in aged skeletal muscle. Surprisingly, we find reduced expression of Smad4, the downstream cofactor for canonical TGFß superfamily signaling, and the target Id1 in aged SCs and MPs during regeneration. Specific deletion of Smad4 in adult mouse SCs led to increased propensity for terminal myogenic commitment connected to impaired proliferative potential. Furthermore, SC-specific Smad4 disruption compromised adult skeletal muscle regeneration. Finally, loss of Smad4 in aged SCs did not promote aged skeletal muscle regeneration. Therefore, SC-specific reduction of Smad4 is a feature of aged regenerating skeletal muscle and Smad4 is a critical regulator of SC and MP amplification during skeletal muscle regeneration.

Injury depth control from combined wavelength and power tuning in scanned beam laser thermal therapy.

Laser thermal therapy represents a possible method to treat premalignant epithelial lesions of the esophagus. Dynamically conforming the thermal injury profile to a specific lesion boundary is expected to improve the efficacy of such a treatment and avoid complications. In this work, we investigated wavelength tuning as a mechanism to achieve this aimed control over injury depth by using the strong variation of water absorption close to 1900 nm. We developed a numerical model simulating in steps the photon propagation in the tissue, the diffusion of the absorbed heat, and the resulting tissue damage. The model was compared with experimental results on porcine esophageal specimens ex vivo and showed good agreement. Combined with power tuning, the wavelength agility in the range of 1860 to 1895 nm extends the injury range compared to a fixed wavelength source beyond 1 mm, while at the same time improving control over shallow depths and avoiding vaporization at the tissue surface. The combination of two or three discrete wavelengths combined at variable ratios provides similar control, and may provide an improved strategy for the treatment of endothelial lesions.