Question

Bell's palsy: Discuss the pathophysiology, signs & symptoms.

Answer 1

Bells's palsy-  It is a type of facial paralysis that results in an inability to control the facial muscles on the affected side.

Pathophysiology:-

• Bell's palsy occurs due to a malfunction of the facial nerve(VII), which controls the muscles of the face. This palsy is characterised by the inability to control movement in the muscles of facial expression. The paralysis is of the infranuclear/lower motor neuron type.
• It may also be due to inflammation of the facial nerve. When pressure is produced on the nerve where it exits the skull within its bony canal (the stylomastoid foramen), it blocks the transmission of neural signals or damaging the nerve.
• Patients with facial palsy for which an underlying cause can be found are not considered to have Bell's palsy per se. Possible causes include tumour, meningitis, stroke, diabetes mellitus, head trauma and inflammatory diseases of the cranial nerves (such as sarcoidosis). In these conditions, the neurologic findings are rarely restricted to the facial nerve.
• Children can be born with facial palsy.
• In a few cases, bilateral facial palsy has been associated with acute HIV infection.

Signs and symptoms:-

• Droopy appearance on one side of the face
• The inability to open or close your eye on the affected side
• Drooling of saliva
• Difficulty in eating and drinking
• An inability to make facial expressions, such as smiling or frowning
• Facial weakness
• Muscle twitches in the face
• Dry eye and mouth
• Headache
• Sensitivity to sound
• Irritation of the eye on the involved side