Bell Palsy Differential Diagnoses

Updated: May 04, 2021
  • Author: Danette C Taylor, DO, MS, FACN; Chief Editor: Selim R Benbadis, MD  more...
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Diagnostic Considerations

In most cases, the diagnosis of Bell palsy is straightforward as long as the patient has undergone a thorough history and physical examination. Failure to recognize structural, infectious, or vascular lesions leading to seventh cranial (facial) nerve damage may result in further deterioration of the patient’s condition. For example, if other cranial nerve, motor, or sensory symptoms are present, then other neurologic diseases should be considered (eg, stroke, Guillain-Barré syndrome, basilar meningitis, cerebellar pontine angle tumor).

Symptoms associated with seventh nerve neoplasm include slowly progressive paralysis, facial hyperkinesis, severe pain, recurrent palsy, and other cranial nerve involvement. Cerebellopontine tumors may affect the seventh, eighth, and fifth cranial nerves simultaneously. Patients with a progressive paralysis of the facial nerve lasting longer than 3 weeks should be evaluated for neoplasm.

Recurrent ipsilateral facial paralysis must raise the suspicion of a tumor of the facial nerve or parotid gland. Tumors in the temporal bone, such as facial nerve neuromas, meningiomas, hemangiomas, and malignant primary and metastatic lesions, should be considered as well.

If a patient is from the Northeast United States, Lyme disease should be considered as a cause of facial paralysis, and serologic testing should be performed. Approximately 5-10% of untreated Lyme patients may have a peripheral facial nerve palsy.

If a patient reports the sudden onset of hearing loss and severe pain with the onset of facial paralysis, Ramsay Hunt syndrome must be considered. Typically, these patients will also have an erythematous vesicular rash involving the ear canal, auricle, and/or oropharynx.

Other problems to be considered include the following:

  • Acoustic neuroma and other cerebellopontine angle lesions

  • Acute or chronic otitis media

  • Amyloidosis

  • Aneurysm of vertebral artery, basilar artery, or carotid arteries

  • Autoimmune syndromes

  • Botulism

  • Carcinomatosis

  • Carotid disease and stroke - Including embolic phenomenon

  • Cholesteatoma of the middle ear

  • Congenital malformation

  • Facial nerve schwannoma

  • Geniculate ganglion infection

  • Glomus tumors

  • Guillain-Barré syndrome

  • Herpes zoster

  • Human immunodeficiency virus (HIV) infection

  • Leukemia/lymphoma

  • Leukemic meningitis

  • Malignant otitis externa

  • Melkersson-Rosenthal syndrome

  • Meningitis

  • Mycoplasma pneumonia

  • Nasopharyngeal carcinoma

  • Osteomyelitis of the skull base

  • Otitis media

  • Parotid gland disease or tumor

  • Pontine lesions

  • Sarcoma

  • Skull base tumor

  • Teratoma

  • Tuberculosis

  • Viral syndromes

  • Wegener granulomatosis

  • Wegener vasculitis

In the setting of an appropriate history, additional considerations include the following:

  • Alcoholic neuropathy

  • Anesthesia nerve blocks

  • Basal skull fractures

  • Barotrauma

  • Benign intracranial hypertension

  • Birth trauma

  • Carbon monoxide exposure

  • Diphtheria

  • Facial injuries

  • Facial trauma (blunt, penetrating, iatrogenic)

  • Forceps delivery

  • Iatrogenic - As in otologic, neurotologic, skull base, or parotid surgery

  • Infectious mononucleosis

  • Kawasaki disease

  • Leprosy

  • Metastatic disease

  • Mumps

  • Polyneuritis

  • Temporal bone fracture

  • Tetanus

  • Thalidomide exposure

  • Toxic

Bilateral cases

Bilateral simultaneous Bell palsy is a rare occurrence; the rate of such cases is less than 1% of that of unilateral facial nerve palsy, [27, 28] and it accounts for only 23% of bilateral facial paralysis cases. The majority of patients with bilateral facial palsy have Guillain-Barré syndrome, sarcoidosis, Lyme disease, meningitis (neoplastic or infectious), or bilateral neurofibromas (in patients with neurofibromatosis type 2).

Differential Diagnoses