Miller Fisher Syndrome ELECTRODIAGNOSIS

Dr Mohamed ibrahim khalilphysical medicine Rheumatology Alexandria University, EGYPT

To contact Dr M. IbrahimReverie-forever@hotmail.com

History

A 24 year-old female patient , married housewife from el Behira presented with:

• Headache • Gait instability • Right Facial weakness • Squint of Left eye with diplopia• Numbness of both upper and lower limbs • Dysphagia

Of 2 Months Duration

The condition started 2 months ago with subacute onset of :

• Continuous headache: occipital , bursting , awaken the patient from sleep and not responding to analgesic .

• Nausea and vomiting , not related to meal and usually at the peak of headache .

• Blurring of vision • Numbness at the back of the neck and upper

limbs.

A week later , the patient experienced :

• Generalized body numbness

• Difficulty in handling objects by both hands

• Gait instability and difficulty in getting upstairs

** She sought medical advice , CT Brain was done which revealed normal findings , and Fundus examination showed mild papilloedema .

** She received analgesics vitamins and Performed Hagama with No improvement .

After 10 days , she developed • Weakness of Right facial muscles:

1- Inability to close Right eye.

2- Accumulation of food on right side.

3- Drippling of saliva from right side.

4- Deviation of mouth to the left side . • Mild dysphagia for solid food.• Left eye squint with diplopia.

• She was admitted to El-Hadara University Hospital – Neurology

Department

• No history of similar attacks

• No history of head trauma

• No history of fever, common cold or diarrhea

• No history of deafness , tinnitus or vertigo

• No sphincteric disturbance

• No history of change of consciousness

• No history of convulsions

• NO history of involuntary movements

• No history of dysarthria or dysphasia

•

• Past Medical History : NO DM - NO HTN

• Family History : Irrelevant

• Vital signs :

Pulse 95 b/min

Respiration 16 /min

Blood Pressure 125/90

Temperature 37 C

Physical examination

1- Mental or intellectual function:

• The Patient is fully conscious, alert ,well oriented to time , person and place and with intact memory and average intelligence .

2- Speech and articulation : Normal

3- Cranial nerves : Right facial nerve LMNL Left Abducent Palsy other cranial nerves are clinically free

4- Motor examination : • Muscle state : Normal • Muscle Tone :HYPOTONIA in both upper

and lower Limbs • Muscle Power :Grade 5 all over .• No fasiculations • No involuntary movements

5- Reflexes

A) Superficial reflexes :

Abdominal : absent

Planter : FLEXOR

B)Deep Reflexes :

AREFLEXIA In upper and Lower limbs

6- Coordination:

Mildly affected finger to nose test and heel knee test more on the Left side

Dysdiadikokinesia more on the left side

7- No Involuntary movement:

8- Sensory examination :

a) Superficial : Normal in UL and LL

b) Deep:

*Sense of movements : Normal

*Sense of Position : ? Affected at

left side

*Vibration sense : intact

c) cortical sensation : normal

9- Gait :

Gait instability with difficult walking along a straight line

10- Romberg sign : negative

Investigations

• CT Brain Free

• MRI Brain Free

• Cervical MRI Free• MRI and MRV using open Magnet unremarkable

• Fundus examination showed Mild Papilledoema

• CSF Free

• CSF Pressure Increased

Current treatment

• Gabapentin 300 mg / 8h

• Methyl Prednisolone 60 mg daily for 2 w

then tapering

• Vitamin B 6,10,12

• Paracetamol 500 mg if nessecary

• Local treatment for the right eye

SUM UP

PERIPHERAL• Gait instability • Numbness of both UL

and LL • Hypotonia• Areflexia• Flexor Planter• No Sphincteric • Right facial LMNL• Left Abducent

CENTRAL• ↑ ICP , Headache ,

vomiting, Papilledema• Right facial LMNL• Left Abducent• Dysphagia • Incordination• Gait instability

• MRI and CSF FREE

Is there any sure sign of Upper motor neuron Lesion ?Could hypotonia and areflexia be Present early in UMNL ? The Sure LMNL is facial and abducent but can be present in brain stem lesion Could combination of LMNL + UMNL be Present ? DDHow can electrodiagnosis help in solving the Puzzle ?

What is the Role of electrophysiological study ?

1. Assess LMNL ( NCS , F wave , H reflex and EMG ) , to Diagnose Guillian barre syndrome , CIDP and Miller Fisher syndrome

** Assess Ia afferent fibers conduction

1. Exclusion of UMNL ( H/M < 50 % )

2. Assess central and Posterior column Lesion ( SEP )

3. Examine the functional integrity Brain stem ( Blink Reflex)

4. Assess the nature of facial neuropathy and possibility of trigeminal neuropathy ( Blink Reflex and facial NCS / EMG )

Differential diagnosis

1. Miller Fisher syndrome associated with Benign intracranial hypertension

2. Bickerstaff brainstem encephalopathy

3. Gillian barre syndrome associated with cranial neuropathy

4. CIDP

5. Central Lesion ( brain stem – cerebellar )

6. ? Imflamatory , ? Demylinating

7. Idiopathic intracranial hypertension

(5)

(7)

(5)

(7)

(6) (6)

• NB :

• 1- Negative rombergism

• 2- Increased Intracranial Pressure

• 3- Numbness of both UL and LL

1. Submaximal stimulation

2. Low Gain

3. Voluntary movement

4. Average analysis

Sensory 1a afferent new technique for electrodiagnosis

• Follow up assessment after 4 days

What causes Lost H reflex Bilateral with normal Peripheral nerve conduction ?

Electrodiagnosis Results

1. Normal sensory and motor conduction and F waves against the diagnosis of GBS or CIDP

2. Abnormal conduction of the Ia afferent fibers

3. Right Facial and Trigeminal axonal neuropathy

4. Lost H reflex on left side , Decreased amplitude on right side .

5. The intact Left R1 ( with clinical evidence of left abducens neuropathy ) is suggestive of intact brain stem

6. Decreased SEP Amplitude (? ICP , ? Central Lesion)

Diagnosis

• The Multiple cranial neuropathy , ophthalmoplegia (with Free MRI study of the brain ) associated with abnormal Ia afferent conduction is highly suggestive of :

Miller Fisher Syndrome

Associated with Benign intracranial hypertension

Explanation

• Sensory Ia afferent affection explains the Hypotonia , Areflexia , lost H Reflex , the Gait instability and Limb incoordination

• Abnormal SEP is attributed mostly to ↑ ICP rather than central Lesion

• Blink Reflex Pattern of right Trigeminal facial neuropathy rather than Pontine Lesion

• H reflex changes attributed to abnormal Ia afferent conduction , no evidence of UMNL

Lost H Reflex in Miller fisher Syndrome

• Sensory Ia afferent affection explains the Hypotonia , Areflexia , lost H Reflex , the Gait instability and Limb incoordination

• A Reflexia in Miller fisher syndrome

• Sensory Ia afferent affection explains the Hypotonia , Areflexia , lost H Reflex , the Gait instability and Limb incoordination

• Ataxia in Miller fisher syndrome

• Sensory Ia afferent affection explains the Hypotonia , Areflexia , lost H Reflex , the Gait instability and Limb incoordination

• ?? Effect of steroid therapy on the Results of electrodiagnosis

Pathophysioly of MFS

• Hypothesis of molecular mimicry

• Infection by C. jejuni if also implicated in the development of MFS by the same mechanism of molecular mimicry. MFS patients present with symptoms similar to other forms of GBS along with problems controling eye movements, or ophthalmoplegia. Autoantibodies have been isolated from these patients that bind to human ganglioside GQ1b as well as the GQ1b epitope present within the LOS of C. jejuni isolated from MFS patients. Also, the dominant C. jejuni serotypes associated with MFS were HS:2 and HS:4. The gene polymorphism associated with the development of anti-GD1b autoantibodies was found to be cstII(Asn51) (Koga et al., 2006). This provides a clear link to the clincal presentation of MFS since the GQ1b ganglioside is found predominantly in human oculomotor nerves (Ang et al., 2004; Kuwabara, 2004).

GQ1b Antibody

Bickerstaff brain stem encephalitis ( BBSE)

• Pathophysiology :

BBSE is caused by Autoimune Response against CNS• Clinical Picture :• Acute oncet of ophthalmopligia , Ataxia , Areflexia usually associated

with bilateral facial Palsy• Drowziness or Lost consiousness with affection of the Glasco coma

scale• In the Shock stage : Hypotonia , Areflexia and Lost H Reflex –( DD .

Miller Fisher syndrome ) • After few days UMNL signs appear : Hyperreflexia , extensor Planter

Response • Free MRI Brain , CSF may show Increased Albumen : Low cell Ratio • Lab : GQ1b antibody in serum and CSF• Good Prognosis and Recovery with Plasmaphareses and IVIG

Electrodiagnosis

• Lost H Reflex • Decrease in the Somatosensory evoked Potentials

Amplitude • Blink Reflex showing Poor response • Peripheral sensory and motor conduction is usually

normal or very mild affection in the form of decreased amplitude unrelated to SCV

• Affection of the sensory Ia afferent• NB : Recent studies showed affection of the cerebellum