What is the most likely diagnosis for a 30-year-old female with facial hemiplegia and altered sense of taste, with a history of hypertension?

Most Likely Diagnosis: Bell's Palsy

The most likely diagnosis for this 30-year-old female with acute unilateral facial hemiplegia and altered taste is Bell's palsy, given the rapid onset (<72 hours), combination of facial weakness with taste disturbance, and absence of other identifiable causes. 1

Clinical Reasoning

Why Bell's Palsy is Most Likely

• Bell's palsy is defined as acute unilateral facial nerve paresis or paralysis with onset in less than 72 hours without an identifiable cause 1
• The 4.5-hour timeframe fits the acute onset criterion (<72 hours) that distinguishes Bell's palsy from other conditions 1
• Altered taste is a classic associated feature of Bell's palsy because the facial nerve (cranial nerve VII) carries taste fibers from the anterior two-thirds of the tongue via the chorda tympani branch 1
• Bell's palsy is the most common acute mononeuropathy and the most common diagnosis associated with facial nerve weakness/paralysis 1
• The condition is more common in those 15 to 45 years old, which includes this 30-year-old patient 1

Critical Differential Considerations

However, stroke must be urgently excluded in this hypertensive patient before confirming Bell's palsy as the diagnosis. The presence of hypertension raises concern for:

Stroke (Must Rule Out First)

• Focal neurological deficits with hypertension should immediately raise suspicion for intracranial hemorrhage or ischemic stroke 2
• Altered taste can occur with stroke affecting specific brain regions, including thalamic infarcts, pontine infarcts, or cortical taste areas 3, 4, 5
• Non-contrast head CT must be obtained immediately to exclude intracranial hemorrhage, followed by MRI if CT is negative 2

Key Distinguishing Features

• Bell's palsy affects the facial nerve peripherally, causing weakness of ALL facial muscles on one side, including the forehead (patient cannot wrinkle forehead or close eye on affected side) 1
• Stroke affecting the facial motor cortex causes central facial weakness, typically SPARING the forehead (patient can still wrinkle forehead and close eye) because of bilateral cortical innervation of upper facial muscles
• The term "facial hemiplegia" in the question is somewhat ambiguous but typically suggests complete one-sided facial paralysis, which is more consistent with Bell's palsy 1

Immediate Diagnostic Approach

Essential Clinical Examination

• Assess whether forehead movement is preserved (suggests central/stroke) or lost (suggests peripheral/Bell's palsy) 1
• Check for other focal neurological deficits (limb weakness, speech disturbance, visual field defects) that would indicate stroke rather than isolated cranial neuropathy 2
• Examine for bilateral involvement, which would make Bell's palsy rare and suggest alternative diagnoses 1

Imaging Requirements

• If ANY concern for stroke exists (hypertension, atypical features, other neurological signs), obtain immediate non-contrast head CT 2
• If imaging excludes stroke and clinical examination confirms peripheral facial nerve pattern, Bell's palsy becomes the diagnosis by exclusion 1

Management if Bell's Palsy is Confirmed

Pharmacological Treatment

• Oral corticosteroids should be offered within 72 hours of symptom onset 1
• Oral antiviral therapy may be offered in addition to oral steroids within 72 hours 1

Eye Protection (Critical)

• The inability to close the eyelid can lead to potential eye injury and requires immediate protective measures 1
• Artificial tears, eye lubricants, and eye taping at night are essential 1

Prognosis

• Bell's palsy is typically self-limited, with most patients experiencing significant recovery 1
• Treatments are designed to improve facial function and facilitate recovery 1

Clinical Pitfalls to Avoid

• Never diagnose Bell's palsy without first excluding stroke in a hypertensive patient with acute neurological symptoms 2
• Do not assume peripheral facial palsy without confirming forehead involvement 1
• Bilateral facial weakness is rare in Bell's palsy and should prompt investigation for alternative diagnoses (Lyme disease, sarcoidosis, Guillain-Barré syndrome) 1
• Remember that taste disturbance can occur with both Bell's palsy (peripheral) and stroke (central), so this feature alone does not distinguish between them 3, 4, 5