Guillain-Barré + Bell’s palsy + Essential tremor

Question 1

What is Guillain-Barré syndrome?

Answer 1

Guillain-Barré syndrome (GBS) is an autoimmune, rapidly progressive demyelinating condition of the peripheral nervous system, often triggered by infection.

Question 2

Typical presentation of Guillain-Barré syndrome

Answer 2

Symmetrical muscle weakness usually affecting the lower extremities before the upper extremities (ascending weakness), with a history of infection in the preceding 6 weeks.

The progression is subacute with peak symptoms occurring within 2-3 weeks of disease onset.

Question 3

Symptoms of Guillain-Barré syndrome

Answer 3

• Tingling and numbness in hands and feet often precedes muscle weakness
• Symetrical, progressive, ascending weakness
• Unsteady when walking
• Back and leg pain
• Shortness of breath
• Facial weakness and speech problems

Question 4

Signs of Guillain-Barré syndrome

Answer 4

• Reduced sensation in affected limbs: sensory findings are usually mild
• Symmetrical weakness in lower extremities first, progressing to the upper limbs: proximal muscles are affected earlier than distal muscles
• Ataxia with hyporeflexia (or areflexia) in affected limbs
• Autonomic dysfunction eg tachycardia, hypertension, postural hypotension, urinary retention
• Respiratory distress: shortness of breath, respiratory muscle weakness requiring mechanical ventiallation in severe cases
• Cranial nerve involvement and bulbar dysfunction eg diplopia or facial droop

Question 5

Although GBS is predominantly a clinical diagnosis evidenced by progressive weakness and areflexia in the weaker limbs, investigations are mainly performed to exclude other causes.

What are the primary investigations?

Answer 5

• Bloods
  
  • U&Es: electrolyte abnormalities resulting in neuropathic symptoms
  • B12 and folate: deficiency associated with neurological features
  • TFTs: to exclude hypothyroidism as a cause of weakness
  • LFTs: elevation of hepatic enzymes is associated with more severe disease
  • Anti-ganglioside antibodies: can be used to differentiate GBS variants
• Cultures: stool or sputum if there are ongoing infective features, eg gastroenteritis
• Lumbar puncture: raised protein with normal WBC count is typical, although an initial normal protein level does not exclude GBS
• Spirometry: to monitor respiratory function as 20% of patients require mechanical ventilation at some stage

Question 6

Investigations to consider for GBS

Answer 6

• Nerve conduction studies: not required for diagnosis; findings will typically be suggestive of demyelination eg reduced conduction velocity
• MRI brain and spinal cord: to differentiate between GBS and other possible neurological causes eg transverse myelitis

Question 7

First line management of GBS

Answer 7

• IV immunoglobulins (IVIg): 5 day treatment course commenced within the first 2 weeks of symptom onset OR
• Plasma exchange: 5 treatments of 2-3L over 2 weeks commenced within the first 4 weeks of symptom onset

Question 8

Complications of GBS

Answer 8

• Type 2 respiratory failure: may require mechanical ventilation in intensive care
• Impaired mobility: may persist for months to years after the initial onset of GBS
• Pulmonary complications: including infections due to intubation, or pulmonary emboli due to immobility and pro-inflammatory state
• Autonomic dysfunction: ileus and urinary retention may occur, as may arrhythmias
• Psychiatric impact: depression, post-traumatic stress disorder and anxiety are all associated with GBS

Question 9

Where does the facial nerve exit the brainstem and which structures does it pass through on its way to the face?

Answer 9

The facial nerve exits the brainsten at the cerebellopontine angle. On its journey to the face it passes through the temporal bone and parotid gland.

Question 10

The facial nerve divides into five branches that supply different areas of the face. Name them.

Answer 10

• Temporal
• Zygomatic
• Buccal
• Marginal mandibular
• Cervical

Question 11

Function of the facial nerve

Answer 11

There are three functions of the facial nerve: motor, sensory and parasympathetic.

Motor: Supplies the muscles of facial expression, the stapeidus in the inner ear and the posterior digastric, stylohyoid and platysma muscles in the neck

Sensory: carries taste from the anterior 2/3 of the tongue

Parasympathetic: it provides the parasympathetic supply to the submandibular and sublingual salivary glands and the lacrimal gland

Question 12

Why is it important to disstinguish between and upper motor neurone and lower motor neurone facial nerve palsy.

Answer 12

A patient with a new onset upper motor neurone facial nerve palsy should be referred urgently with a suspected stroke, whereas patients with lower motor neurone facial nerve palsy can be reassured and managed in the community.

Question 13

How would you differentiate between an upper motor neurone and lower motor neurone facial nerve palsy?

Answer 13

In an upper motor neurone lesion, the forehead will be spared and the patient can move their forehead on the affected side.

In a lower motor neurone lesion, the forehead will not be spared and the patient cannot move their forehead on the affected side.

Question 14

Causes of upper motor neurone facial nerve palsy

Answer 14

Unilateral upper motor neurone lesions:

• Cerebrovascular accidents (strokes)
• Tumours

Bilatera upper motor neurone lesions:

• Pseudobulbar palsies
• Motor neurone disease

Question 15

What is Bell’s palsy?

Answer 15

It is a relatively common, idiopathic condition. It presents as a unilateral lower motor neurone facial nerve palsy.

The majority of patients fully recover over several weeks but recovery may take up to 12 months. A third are left with some residual weakness.

Question 16

Management of Bell’s palsy

Answer 16

If patients present within the 72 hours of developing symptoms you may treat with prednisolone.

Lubricating eye drops

Question 17

How does Ramsay-Hunt syndrome present?

Answer 17

• Unilateral lower motor neurone facial nerve palsy
• Painful and tender vesicular rash in the ear canal, pinna and around the ear on the affected side

Question 18

Cause of Ramsey Hunt syndrome

Management of Ramsey Hunt syndrome

Answer 18

Ramsey-Hunt syndrome is caused by the varicella zoster virus.

Treatment should ideally be initiated within 72 hours:

• Prednisolone
• Aciclovir

Patiet also require lubricating eye drops

Question 19

Other causes of lower motor neurone facial nerve palsy

Answer 19

• Infection
  
  • Otitis media
  • Malignant otitis externa
  • Lyme’s disease
• Systemic disease
  
  • Sarcoidosis
  • Guillain-Barré
• Tumours
  
  • Acoustic neuroma
  • Parotid tumour
  • Cholesteatoma
• Trauma
  
  • Direct nerve trauma
  • Damage during surgery
  • Base of skull fractures

Question 20

Which parts of the body does a benign essential tremor affect?

Answer 20

It affects all the voluntary muscles. It is most notable in the hands but affects many other areas, for example a head tremor, jaw tremor and vocal tremor.

Question 21

Describe the features of a benign essential tremor

Answer 21

• Fine tremor
• Symmetrical
• More prominent on voluntary movement
• Worse when tired, stressed or after caffeine
• Improved by alcohol
• Absent during sleep

Question 22

Differential diagnosis of a tremor

Answer 22

• Parksinson’s disease
• Multiple sclerosis
• Huntington’s Chorea
• Hyperthyroidism
• Fever
• Medications eg antipsychotics

Question 23

Management of benign essential tremor

Answer 23

The tremor is not harmful and does not require treatment if not causing functional or psychological problems.

• Propanol (a non-selective beta blocker)
• Primidone (a barbiturate anti-epileptic medication)