Facial Weakness History
Author – Bharneedharan Surendaran Editor – Dr Karthikeyan Sivaganesh
Last updated 27/08/24
Table of Contents
Introduction
Facial paralysis is the total weakness of facial muscles due to dysfunction of the facial nerve (CNVII). The pattern of weakness depends on where the upper motor neuron (UMN) or lower motor neuron (LMN) of the facial nerve is affected. An UMN lesion spares the forehead (as it receives supply from both hemispheres) but contralateral mouth weakness. A LMN lesion causes ipsilateral weakness of both the forehead and the mouth. Aetiology of facial paralysis can be categorised into:
- LMN lesions (aka peripheral) causes:
- Bell’s Palsy (most common cause)
- Ramsay Hunt syndrome
- Trauma/surgery e.g. parotid gland surgery
- Infections e.g. otitis media, mastoiditis
- Tumours e.g. acoustic neuroma
- Guillain Barre syndrome (GBS)
- UMN lesions (aka central) causes:
- Stroke (most common cause)
- Multiple sclerosis
- Brain tumours
- Infections e.g. encephalitis
- Traumatic brain injury
- Systemic causes such as diabetes, sarcoidosis, amyloidosis, etc.
Common OSCE Scenarios
| Condition | Typical History |
|---|---|
Brain Tumour | Worsening headache with signs and symptoms of raised intracranial pressure e.g. dilated pupil, impaired abduction, headache worse on coughing or lying down, etc and gradual onset, progressive neurological deficits e.g. weakness, sensory changes, dysarthria. Seizures may be present. |
Stroke | Sudden onset, persistent focal neurological deficit e.g. limb weakness, dysarthria, visual disturbances with UMN signs e.g. hyperreflexia, upgoing plantars, etc.
There is often a history of diabetes, hypercholesterolaemia, smoking, cardiovascular disease, hypertension, etc. |
Transient ischaemic attack | Similar presentation and risk factors of stroke. However, the symptoms are milder and resolve within 24 hours. |
Bell’s Palsy | Sudden onset, persistent focal neurological deficit in cranial nerve 7 e.g. dysarthria, inability to taste, facial weakness and inability to raise their eyebrows.
To diagnose Bell’s palsy, we will need to rule out other conditions. |
Motor neuron disease | Gradual onset,UMN signs e.g. hyperreflexia, upgoing plantars, etc. LMN signs e.g. hyporeflexia, downward plantars, fasciculations and fibrillations, etc. No sensory changes will occur. |
Multiple sclerosis | Gradual onset, first presentation will be visual disturbance with a mixture of UMN and LMN signs and sensory changes. Persistent autonomic neurological deficit in end stages of diseases e.g. bladder and bowel dysfunction, etc. |
Ramsay Hunt Syndrome | Viral infection of VSZ. Flu-like symptoms e.g. headache, runny nose, cough tiredness. Ear pain and vesicular rash around the ear. Hearing and balance changes e.g. tinnitus, vertigo and hearing loss |
Otitis Media with Mastoiditis | Sudden onset, with a background history of otitis media.Pain and swelling around the mastoid process with a loss of hearing and taste. |
Vestibular Schwannoma (aka acoustic neuroma) | Gradual onset, progressively worsening neurological deficit e.g. unilateral loss of hearing, tinnitus and facial weakness. Nausea and vomiting due to vertigo. Signs of malignancy (fever, lethargy, anorexia, weight loss and night sweats). Family history of neurofibromatosis may be present. |
Presenting Complaint
Site
- Unilateral
- Mouth involved and forehead spared → UMN lesion e.g. stroke
- Mouth and forehead involved → LMN lesion e.g. Bell’s palsy
- Bilateral → systemic causes e.g. sarcoidosis
Onset
- Sudden → vascular causes e.g. stroke and TIA.
- Chronic → brain tumour, motor neurone disease, multiple sclerosis
Associated symptoms
- Changes in vision and hearing → multiple sclerosis, stroke, vestibular schwannoma, otitis media with mastoiditis
- If the vision changes first → multiple sclerosis and stroke are more likely
- If the hearing changes first → vestibular schwannoma and otitis media with mastoiditis
- Changes in sensation → stroke and multiple sclerosis
- Fits, faints and funny turns → stroke or epileptic seizure
- Changes in speech and swallow → helps to indicate if patient will need speech and language therapy in the future
Background
Past medical history
- Previous infection and fevers → ramsay hunt syndrome, meningitis, encephalitis and otitis media causing mastoiditis
- B symptoms (fatigue, lethargy, anorexia, weight loss and night sweats)→ brain malignancy
- Previous history of falls and trauma → directly damaging facial muscles and nerve
- History of neurological disease e.g. bell’s palsy, motor neurone disease and multiple sclerosis, primary brain tumour
- Hypertension, high cholesterol, diabetes, ischaemic heart disease and previous cerebrovascular disease → Increased risk of stroke
- Immunocompromised → CNS lymphoma or severe manifestation of viral infections e.g. HIV/EBV causing facial paralysis.
- Neurofibromatosis type 2 → vestibular schwannoma/acoustic neuroma
- Cancer → cerebral metastases
Family History
- Stroke at a young age → arteriovenous malformation, cerebral venous sinus thrombosis, thrombophilias
- Neurological conditions → bell’s palsy, motor neurone disease, multiple sclerosis and neurofibromatosis
Drug and Social History
- Blood thinners e.g. apixaban → increase risk of intracranial bleeding
- Recreational drug use e.g. cocaine can cause facial paralysis
- Travel history → leprosy and lyme disease
- Lack of exercise and poor diet → increases risk of diabetes, hypertension, cardiovascular and cerebrovascular disease.
Examination
A full neurological examination is crucial in anyone presenting with weakness. Excluding stroke is the utmost priority as missing it can be fatal. As stroke is an upper motor neuron (UMN) lesion, look for UMN signs e.g. hypertonia. Then identify the pattern of weakness:
- Unable to raise left eyebrow and cheek → Bell’s palsy of left LMN of CNVII
- Unable to raise left cheek but eyebrow spared → Right sided stroke
- Ptosis (droopy eyelid) → 3rd nerve palsy
Sensory loss is more likely present in stroke/multiple sclerosis/polyneuropathy. Assess cerebellar function by doing tests of coordination (e.g. nose-to-finger test) and gait. Presence of DANISH signs suggest cerebellar disease:
- D = dysmetria/dysdiadochokinesia
- A = ataxia
- N = nystagmus
- I = intentional tremor
- S = slurred/scanning speech
- H = hypotonia
MLA Tip 💡
Always exclude the most worrying diagnosis even if they seem less likely as missing it can lead to worse prognosis. For e.g. an elderly man with facial weakness, you must screen for stroke even if the cause is benign.
1. Facial Palsy UK:https://www.facialpalsy.org.uk/causesanddiagnoses/list/ [Accessed 12/8/24]
2. Stroke and TIA NICE CKS: https://cks.nice.org.uk/topics/stroke-tia/ [Accessed 22/08/24]
3. BMJ Best Practice: https://bestpractice.bmj.com/topics/en-gb/118?q=Bell%27s%20palsy&c=suggested [Accessed 22/08/24]