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Facial synkinesis is one of the most distressing consequences of facial paralysis. Synkinesis refers to the abnormal involuntary facial movement that occurs with voluntary movement of a different facial muscle group. The pathophysiologic basis of facial synkinesis is likely multifactorial although the predominant mechanism appears to be aberrant regeneration of facial nerve fibers to the facial muscle groups after facial nerve injury. Patients experience hypertonic contractures and synkinetic movements such as eye closure with volitional movement of the mouth or midfacial movement during volitional or reflexive eye closure. Synkinesis can cause functional limitation with activities such as eating, drinking, smiling, and may even lead to social isolation. Evaluation of synkinesis is primarily subjective with facial grading scales such as the Sunnybrook scale. Objective measures of synkinesis using computerized video analysis show promise although no objective techniques are currently widely used. The most common therapeutic modalities for the treatment of facial synkinesis include (1) botulinum toxin type A (BTX-A) injections for selective chemodenervation of affected muscle groups and (2) facial neuromuscular retraining. Biofeedback using mirrors or electromyography has been used both for the treatment and prevention of facial synkinesis. Other treatment options include surgical therapies, such as selective neurolysis or myectomy, although these have been rendered nearly obsolete with the advent of BTX-A.

Type 2 innate lymphoid cells (ILC2s) have recently been identified in human nasal polyps, but whether numbers of ILC2s differ by polyp endotype or are influenced by corticosteroid use is unknown. Here, we show that eosinophilic nasal polyps contained double the number of ILC2s vs. non-eosinophilic polyps. Polyp ILC2s were also reduced by 50% in patients treated with systemic corticosteroids. Further, using a fungal allergen challenge mouse model, we detected greatly reduced Th2 cytokine-producing and Ki-67+ proliferating lung ILC2s in mice receiving dexamethasone. Finally, ILC2 Annexin V staining revealed extensive apoptosis after corticosteroid treatment in vivo and in vitro. Thus, ILC2s are elevated in the eosinophilic nasal polyp endotype and systemic corticosteroid treatment correlated with reduced polyp ILC2s. Finally, allergen-challenged mice showed reduced ILC2s and increased ILC2 apoptosis after corticosteroid treatment suggesting that ILC2 may be responsive to corticosteroids in eosinophilic respiratory disease.

The Cdc25 phosphatases play key roles in cell-cycle progression by activating cyclin-dependent kinases. The latter are absent from neurons that are terminally differentiated in adult brain. However, accumulation of mitotic phosphoepitopes, and re-expression and activation of the M phase regulator, Cdc2/cyclin B, have been described in neurons undergoing degeneration in Alzheimer's disease (AD). To explain this atypical mitotic activation in neurons we investigated the Cdc2-activating Cdc25A phosphatase in human brain. The structural hallmarks of AD neurodegeneration, neurofibrillary tangles and neuritic plaques, were prominently immunolabeled with Cdc25A antibodies. In addition numerous neurons without visible structural alterations were also intensely stained, whereas control brain was very weakly positive. After immunoprecipitation from control and AD tissue, we found that the tyrosine dephosphorylating activity of Cdc25A against exogenous Cdc2 substrate was elevated in AD. Accordingly, Cdc25A from AD tissue displayed increased immunoreactivity with the mitotic phosphoepitope-specific antibody, MPM-2, and co-localized with MPM-2 immunoreactivity in AD neurons. These data suggest that Cdc25A participates in mitotic activation during neurodegeneration. The involvement of Cdc25A in cellular transformation, modulation of the DNA damage checkpoint, and linkage of mitogenic signaling to cell cycle machinery, also implicates one of these cell-cycle pathways in AD pathogenesis.

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