Facial Asymmetry: Causes, Diagnosis and Differential Diagnosis, Ayurveda Understanding

Article by Dr Raghuram Y.S. MD (Ay) & Dr Manasa S, B.A.M.S

 In some neurological diseases, there is facial deviation. Since the symmetry between both sides of the face is lost, it is called ‘Facial Asymmetry’. It is also called Facial Droop.

Why it happens – Facial asymmetry occurs due to facial deviation, when the muscles on one side of the face get paralyzed or weakened. Facial deviation results in asymmetry of face, drooping at the corner of the mouth or inability to fully close one eye.

Causes – Facial Asymmetry generally occurs due to either –

1. Upper Motor Neuron Lesions (UMN) or
2. Lower Motor Neuron Lesions (LMN)

The other common conditions which cause facial asymmetry are (commonly diagnosed) –

1. Bell’s Palsy – the most common cause for facial deviation (also a LMN Lesion)
2. Stroke – a life-threatening condition which would cause facial deviation (also a UMN Lesion)

The main goal will be to differentially diagnose these conditions and label them properly, especially UMN and LMN lesions.

Differentiating the conditions causing Facial Asymmetry

First of all let us start with differentiating UMN and LMN Lesions, which is very important in this direction so as to rule them in or out.

Do Not Miss the FOREHEAD – In differentiating between UMN and LMN Lesions causing facial deviation, it is very important to start with the ‘FOREHEAD’. This ‘Forehead Test’ quickly helps us to narrow down the cause of facial deviation.

Golden Rule – ‘LOOK AT HOW MUCH THE FACE IS AFFECTED’

1. UMN Lesions – Central Causes – FOREHEAD IS SPARED

There is deviation of only the LOWER HALF of the face while the forehead usually still moves.

Reason – The upper half of the face receives the nerve signals from both sides of the brain.

To keep it short – Forehead is unaffected. There is paralysis and deviation of the lower half of the face.

UMN Causes to look out for – They have their origin in the brain, usually indicating a CNS (central nervous system) issue. These conditions will present with no or minimal facial deviation (asymmetry) or weakness.

The UMN causes to consider facial asymmetry are –

1. Stroke / CVA (Cerebrovascular accident) – There is no forehead weakness. Facial droop in stroke is sudden. It is often accompanied by arm or leg weakness, difficulty in speech (slurred speech) and loss of balance.
2.   Transient Ischemic Attack (TIA) – The symptoms are identical to a stroke but they resolve within 24 hours or so.
3. Multiple Sclerosis (MS) – Marked by intermittent episodes of facial weakness caused due to central pathways being affected by demyelinating plaques and is often accompanied by numbness or vision problems.
4.   Intracranial Tumors or Lesions / Brain Tumor – The tumors compress the motor cortex or brainstem. In this, there may be a slow onset of facial weakness. Associated features include balance issues, vision changes or chronic headaches.

2. LMN Lesions – Peripheral Causes – FOREHEAD and ENTIRE FACE (One Side) is AFFECTED

There is paralysis and hence deviation of the whole ONE SIDE of the face including the forehead.

Reason – The entire same side of the face is controlled by LMN.

To keep it short – Forehead is affected. One half of the face along with the forehead of that side are paralyzed and deviated.

LMN Causes to look out for – They affect the facial nerve after the nerve has left the brain stem. These conditions will definitely present with facial deviation or weakness.

The LMN causes to look out for in facial asymmetry cases are –

1. Bell’s Palsy – This is the most common (60-75% of cases) cause for facial deviation / asymmetry. The disease is characterized by sudden onset of unilateral facial paralysis. The condition is idiopathic. There is rapid onset and the symptoms peak usually within 48 hours.
2.   Ramsay Hunt Syndrome / Herpes Zoster Oticus – This condition is caused by reactivation of shingles virus. The physician needs to look out for painful blisters in the ear canal or mouth roof. The condition presents with severe pain in the ear, a vesicular rash in the ear canal or mouth and also issues with hearing and balance.
3. Lyme Disease – The cause is a ‘tick bite’ (Borrelia burgdorferi tick). It obviously starts off with a rash (bull’s eye rash) which is followed by facial palsy. The palsy can be bilateral – facial diplegia.
4.   Tumors – Mainly look out for a parotid gland tumor or acoustic neuroma as the chief cause. There is slow and progressive weakness of one side of the face and is often accompanied by a palpable lump near the jawline. Localized twitching or hearing loss may also be associated.
5. Trauma / Iatrogenic – Direct injury to the face as occurs in accidents or a temporal bone fracture are often causal. Nerve damage from dental work or surgeries including parotid gland or mastoid are also causa.

Other Rare Systemic and Autoimmune Causes

1. GBS (Guillain Barre Syndrome) – Bilateral facial paralysis is a feature in this autoimmune disorder. The disease has a rapid onset and often starts off with leg weakness. The disease is progressive and would involve progressive symmetrical limb weakness, areflexia. 
2. Sarcoidosis – It is an inflammatory disease which can affect the facial nerve. It can cause bilateral palsy or parotid enlargement (Heerfordt Syndrome) when the disease affects the facial nerve.
3. Melkersson Rosenthal Syndrome – It is a rare genetic condition which causes recurring facial palsy. There may also be associated lip swelling and a fissured tongue. MRS Triad includes – recurring facial palsy, fissured tongue and facial / lip swelling.
4. Infections Meningitis or Otitis Media – In this condition, there is direct spread of bacterial or viral infections affecting the nerve within the temporal bone.

Alarming Signs

One should consider facial deviation as a clinical emergency when it is accompanied with other warning signs as below mentioned (any of them( –

–        Limb weakness

–        Numbness

–        Difficulty in walking

–        Slurred speech

–        Concussion

–        Blisters around the ear

–        Severe vertigo

–        Double vision

Diagnostic Approach

Proper and timely evaluation is very essential in facial deviation conditions since it may indicate a medical emergency or a serious systemic infection. It shall be assessed with the help of one or more of the below mentioned diagnostic tools

–        Neurological examination – a thorough test of cranial nerves with special emphasis towards 7th cranial nerve i.e. facial nerve

–        Otoscopy – for vesicles (to rule out Ramsay Hunt Syndrome)

–        Imaging – when the cause is not clear and if there is slow progression of weakness over many weeks or when a tumor / central lesion is suspected as causal for facial deviation, MRI or CT scans are suggested

–        Blood Work – is done to test for inflammatory markers, Lyme antibodies and HIV etc.

Conditions described in Ayurveda depicting ‘Facial Deviation’ or ‘Facial Asymmetry’

Facial Deviation or Facial Asymmetry, according to Ayurveda is a condition caused by aggravated Vata. It is also a Vata Nanatmaja Vyadhi – a special condition caused by aggravation of only Vata.

Ardita, a condition described in Ayurveda treatises resembles the description of facial paralysis / palsy or Bell’s Palsy wherein facial deviation, asymmetry or crookedness of the face (vakram bhavati vaktra ardham) has been clearly mentioned amongst the symptoms.

Another condition which needs to be considered herein is Pakshavadha or Pakshaghata. Though Pakshavadha describes hemiplegia, the weakness of half face and its deviation too shall be considered. The description of Pakshavadha also includes Ekanga Vata and Sarvangna Vata (aggravated vata affecting half or full body respectively), which are also said to be the synonyms of Pakshavadha.

Therefore, this Ardita-Pakshavadha condition in totality describes every single condition described in the differential diagnosis of facial deviation above.

Related Reading 

Paralysis – Ayurveda Understanding – Easy Ayurveda Article

Charaka Samhita – Vata Vyadhi Chikitsa by Easy Ayurveda

Facial Paralysis – Easy Ayurveda Article

Madhava Nidana – Vata Vyadhi Nidanam

AIAPGET Questions

1. Facial deviation associated with inability to wrinkle the forehead suggests:

1. Upper motor neuron lesion
2. Lower motor neuron facial palsy
3. Trigeminal neuropathy
4. Glossopharyngeal palsy

Answer: B. Lower motor neuron facial palsy

Explanation: Bell’s palsy affects the entire ipsilateral face including forehead muscles.

2. Which of the following symptoms is least likely in Ardita?

1. Deviation of Face
2. Speech Difficulty
3. Deviation of nose
4. Complete loss of consciousness

Answer: D. Complete loss of consciousness

Explanation: Consciousness remains intact in Ardita.

3. In modern neurology, preservation of forehead movements with facial deviation indicates:

1. Bell’s palsy
2. LMN facial nerve lesion
3. UMN lesion above facial nucleus
4. Trigeminal neuralgia

Answer: C. UMN lesion above facial nucleus

Explanation: Forehead receives bilateral cortical innervation.

4. A patient presents with facial asymmetry, hyperacusis, reduced lacrimation, and loss of taste in anterior 2/3 of tongue. The lesion is most likely in:

1. Trigeminal nerve
2. Facial nerve proximal to chorda tympani
3. Hypoglossal nerve
4. Oculomotor nerve

Answer: B. Facial nerve proximal to chorda tympani

Explanation: Facial nerve carries taste fibers and supplies stapedius.

5. Which Nidana is specifically mentioned for Ardita in classical texts?

1. Excessive exposure to cold wind
2. Excessive blood loss
3. Excessive fasting alone
4. Excessive sleep alone

Answer: A. Excessive exposure to cold wind

Explanation: Sheeta, Ativata-sevana, and exposure to cold are important Vata-provoking causes.

6. Facial deviation occurring along with contralateral hemiplegia is classically suggestive of:

1. Bell’s palsy
2. Isolated facial neuropathy
3. Central facial palsy due to stroke
4. Trigeminal neuropathy

Answer: C. Central facial palsy due to stroke

Explanation: UMN lesions often produce facial weakness with hemiplegia.

7. The most appropriate Ayurvedic Panchakarma procedure in chronic Ardita dominated by Vata-Kapha is:

1. Virechana only
2. Raktamokshana only
3. Nasya Karma
4. Tikta Kshira Basti only

Answer: C. Nasya Karma

Explanation: Nasya is considered the prime therapy for diseases above the clavicle (Urdhvajatrugata Vikaras), including Ardita.

8. Intermittent episodes of facial weakness in Multiple Sclerosis is characteristic of –

1.   Upper Motor Neuron Lesion
2.   Lower Motor Neuron Lesion
3.   Both
4.   None

Ans – Upper Motor Neuron Lesion.

Explanation – The involvement of the forehead is spared.

9. Facial deviation in Ramsay Hunt Syndrome is characteristic feature of –

1.   Lower Motor Neuron Lesion
2.   Upper Motor Neuron Lesion
3.   Both
4.   None

Ans – A. Lower Motor Neuron Lesion.

Explanation – The forehead is also involved.

10. When facial deviation occurs following surgery of parotid gland, it reflects –

1.   Upper Motor Neuron Lesion
2.   Lower Motor Neuron Lesion
3.   Both
4.   None

Ans – B. Lower Motor Neuron Lesion.

Explanation – The forehead is also involved.