Differentiating Bell’s palsy from acute stroke
| Initial assessment of any patient must involve establishing the onset characteristics and duration of the facial palsy. Here, the timing and progression of Bell’s palsy helps distinguish it from an acute cause such as stroke. A key feature is the progressive nature of Bell’s palsy, which can be elucidated by detailed history taking.9 The history must also check for recent trauma, surgery or infection. |
| Table 2 summarises the common differences between Bell’s palsy and acute stroke. |
| Determining whether the facial nerve paralysis is central or peripheral is therefore key to diagnosis. Central lesions will cause paralysis of the lower face alone, sparing the forehead; however, clinicians must ensure they ask about the duration and nature of symptoms including the presence of associated symptoms such as hyperacusis, posterior auricular pain, taste and lacrimal changes in their history.10,11 A full cranial nerve examination as well as ocular, otologic and oral examinations must be carried out in all patients presenting with a facial palsy. |
| Neuroimaging should really be reserved for those patients with other associated physical findings suggestive of a central lesion (such as paralysis of other cranial nerves, associated limb weakness or ataxia) or those whose symptoms have not resolved despite appropriate treatment. Certainly, in cases where there is a history of trauma, computed tomography will adequately demonstrate any disruptions to the temporal bone and structures surrounding cranial nerve VII. |
| Treatment of Bell’s palsy in the acute stage includes early initiation of steroids and eye protection on the effected side to avoid exposure keratitis (in some cases of complete inability to close the eye, urgent ophthalmology assessment is required).12 Referral to ear, nose and throat specialists can be considered for those who do not respond to or have persistent symptoms despite treatment.10 |