HSC Section 3 - Trauma, Critical Care and Sleep Medicine

Medical Management of Acute Facial Paralysis

outcomes following BP. In these patients, FP may be unilateral or bilateral. 53 Treat- ment involves glucose regulation with lifestyle changes and medication. Steroid and antiviral medications are indicated in the acute setting. Care should be taken to not exacerbate hyperglycemia.

VASCULAR

Hypertension increases the risk of FP. 53 The pathogenesis is not completely clear and may be related to vasculitis or thrombus formation of the vasa nervosum leading to ischemia of the nerve. Cerebrovascular Accidents/Infarcts/Stroke-Central Hemispheric strokes can cause multiple cranial nerve deficits as well as unilateral body weakness. Immediate neurologic evaluation with imaging is indicated. Treat- ment depends on the mechanism of the stroke as well as other comorbidities. Medical treatment to prevent a repeat ischemic event should be initiated. If an embolic or ischemic stroke occurs within a window of 4 to 6 hours in a larger vessel, thrombec- tomy or medical thrombolytics may be used. Cerebrovascular Accidents/Infarcts/Stroke-Brainstem Although very rare, infarcts of the dorsal pons can lead to isolated FN palsy. 54–56 Risk factors for these isolated dorsal pons infarcts include diabetes and hypertension. 56 Other cranial nerves in the local vicinity also may be involved. The intrapontine segment of the seventh cranial nerve is primarily supplied by branches of the long penetrating basilar artery. There is also collateral circulation from the circumflex pontine arteries and the anterior inferior cerebellar artery. A thrombotic or embolic event of the basilar artery may solely affect the seventh nerve because other areas may be perfused by collateral circulation. 56 Diffusion MRI will help locate small vessel occlusion. Treatment is similar to central strokes and includes medical as well as endovascular intervention. Although congenital etiologies are typically not considered in a discussion of the causes of acute FP, there are several congenital vascular malformations that are pre- sent at birth but manifest acutely later in life. The natural history of these lesions is to expand and grow throughout a patient’s lifetime. Their growth may be influenced by intrinsic factors such as trauma or hormonal surges ( www.ISSVA.org/ classification ). 57 Geniculate ganglion venous malformations (previously known as geniculate ganglion “hemangiomas”) Congenital intraosseous venous malformations of the temporal bone adjacent to the geniculate ganglion or the intraosseous facial nerve characteristically enlarge throughout the patient’s life and can exert direct pressure on the nerve. Imaging reveals expanded bone with bony spicules adjacent to the nerve. These patients may present with acute or recurrent FP. 58 Because the natural history of all vascular malformations is to expand over time, surgical exploration is warranted in the presence of FP. Excision with facial nerve continuity may often be achieved. 59 If this is not possible, a cable graft or combined nerve substitution pro- cedure is indicated. CONGENITAL (VASCULAR)

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