Miscellaneous

Question 1

Transient Global Amnesia

Answer 1

Abrupt memory difficulty.
Prominent anterograde amnesia usually accompanied by repetitive questions
No antecedent head trauma or LOC
No focal neurological symptoms
Last at least 1 hour and resolve within 24 hours

Question 2

Mononeuritis Multiplex

Answer 2

Vasculitis neuropathy classically presenting as multiple mononeuropathy.
- Peripheral neuropathy that affects two or more non-contiguous nerves.
Presentation
- Acute onset of severe unilateral thigh pain followed rapidly by weakness and atrophy in anterior thigh and loss of patellar reflex
- Can progress to affect other peripheral nerves including upper limb nerves

Question 3

Management of traumatic mononeuropathy (E.g. Saturday night palsy)

Answer 3

Physical therapy
Joint splinting
Pain management
Complete recovery over a mean of 3-4months

Question 4

Management of Trigeminal neuralgia

Answer 4

Carbamazepine MR 100mg PO BD
2nd - Oxcarbazepine 300mg PO BD

Question 5

Management of Peripheral Neuropathy

Answer 5

Amitriptyline 25mg PO Nocte -> 150mg
2nd - Duloxetine 60mg PO OD / Gabapentin 300mg PO OD / Pregabalin 75mg PO BD
Consider use of capsaicin cream as adjunct

Question 6

Upper Motor Neuron vs Lower Motor Neuron Clinical Features

Answer 6

UMN
- Absent wasting
- Reduced power
- Increased spasticity
- Brisk tendon reflexes
LMN
- Marked wasting
- Absent or reduced tone
- Absent or diminished reflexes

Question 7

Motor neurone disease

Answer 7

• Progressive neuromuscular disorder resulting in muscular limb and bulbar weakness due to death of motor neurones in brain
• Sensory system, cranial nerves and eye muscles not involved.
• Genetic - 5-10% with autosomal dominant pattern
• 3 different patterns
  
  • ALS (Lou Gehrig Disease) Combined LMN atrophy with UMN hyper-reflexia
  • Progressive muscle atrophy - Wasting beginning in distal muscles. Widespread fasciculations
  • Progressive bulbar - Wasted fibrillating tongue, weakness in chewing and swallowing, facial muscle weakness.
• Clinical diagnosis
• Progress to death within 3-5 years from ventilatory failure or aspiration pneumonia.

Question 8

Complex Regional Pain Syndrome Overview

Answer 8

Chronic pain syndrome in which severity of pain is disproportionate in time or degree to inciting event.
Inciting events (Trauam, surgery, stroke, wasp sting)
- Pain described as spontaneous burning sensation distrally
- Diagnosis
- At least one symptom in three of four categories
- Sensory - Hyperesthesia or allodynia
- Vasomotor - Temprature assymmetry. Skin colour changes
- Sudomotor - Oedema. Sweating changes
- Motor - Decreased ROM or weakness / dysfunction.

Question 9

Management of Complex Regional Pain Syndrome

Answer 9

Physiotherapy aimed at restoring function to affected limb

Analgesia
- Meloxicam 15mg PO OD
- Gabapentin 100mg PO Nocte / Pregabalin 25mg PO Nocte
- TCA - Amitriptyline / Nortriptyline
- SNRI - Venlafaxine / Duloxetine

Future Prevention - Vitamin C 1g PO OD daily for 50 days following injury. Consider if previous CRPS or Radius fracture.

Question 10

Amaurosis Fugax

Answer 10

Transient Monocular or binocular vision loss
- Causes
- Idiopathic, Giant cell arteritis, Transient ischaemic attack, retinal vasospasm, migraine
- Investigations
-ESR and CRP for GCA review in patients > 50yo
- Carotid duplex Ultrasound and opthamologic examination for all patients

Question 11

Causes of peripheral neuropathy

Answer 11

• Vitamin B12 deficiency
• Hypothyroidism
• Renal disease
• alcohol Consumption
• Diabetic neuropathy

Question 12

Assessment of peripheral neuropathy

Answer 12

Small fibre
- Pinprick sensation
Large Fibre
- Vibration with 128Hz tuning fork
- 10g Monofilament pressue
- Assessment of ankle reflexes

Question 13

Radial Neuropathy (Saturday Night Palsy)

Answer 13

Compression of radial nerve at spiral groove (at medial aspect of humeral shaft from lying on area with head or support self in chair with arm hooked over armrest).

Clinical signs
- Wrist drop (weakness in wrist extensors)
- Weakness in finger extensors and brachioradialis.
- Sensory loss over dorsum of hand, possibly extending up forearm.

Normally a clinical diagnosis
- Can perform Nerve conduction studies to assist with localisation of symptoms and severity of nerve injury.

Treatment
- Physiotherapy
- Wrist splinting (to maintain function)
- Pain management ?NSAIDS, neuropathic pain medications

Complete clinical recovery over a mean of 3-4 months.

Question 14

Wernicke’s Encephalopathy

Answer 14

Thiamine (Vitamin B1 ) Deficiency resulting in encephalopathy. Body has 2-3 weeks of Thiamine reserve before exhaustion if not replaced.
- Results in focal lesions in brain from localised lactic acidosis (pyruvate is not able to broken down in TCA cycle due to lack of thiamine)

Symptoms
- Triad - Opthalmoplegia, ataxia, confusion.

Progression to Korsakoff Psychosis, showing symptoms of confusion, confabulation, impaired memory, psychosis

Treatment
- Prophylaxis for High risk of deficiency? (Large amount of alcohol intake or severely malnourished)
- Thiamine 300mg IV/IM OD x 3 days -> 100mg IV/IM OD or 100mg PO TDS for 1-2 weeks

Wernicke Encephalopathy treatment when diagnosed
Thamine 200-500mg IV TDS x 7 days then taper down.

Note: Give thiamine before glucose for hypoglycaemia.

Question 15

Medication Overuse headaches

Answer 15

Occur as dose of medication wears off.
- Associated analgesics - Opioids, Paracetamol, Triptans, ergots, NSAIDS

Rx
- Opioid withdrawal, replace with either
1- Naproxen MR 750mg PO OD x 5 days then 4 days per week for 2 weeks then stop
2- Prednisolone 50mg PO OD x 3 days -> Taper over 7-10 days then stop.

Question 16

Migraine Prophylaxis

Answer 16

Trial 8-12 weeks of drug to review efficacy. All 1st line. Selection including following:

• Topiramate 25mg PO OD
• Pizotifen 0.5mg PO OD
• Propranolol 20mg PO OD
• Sodium valproate 200mg PO OD
• Verapamil SR 90mg PO OD
• Nortriptyline 10mg PO OD
• Amitriptyline 10mg PPO OD
• Candesartan 4mg PO OD

Select based upon potential co-morbidities

Question 17

Restless legs syndrome

Answer 17

Periodic limb disorder
- Sx - Twitching / prickling / creeping of lower limbs and sometimes upper limbs
- Disruption of sleep and of relaxing activities
- Underdiagnosed as patients do not complain of symptoms to doctor.

Risk
- Age > 45
- F > M
- Pregnancy

Secondary causes
- Anaemia
- Iron Deficiency
- Uraemia
- Hypothyroidism
- Pregnancy
- Drugs (Sedating Antihistamines, antiemetics, Antidepressants, Lithium, anti-hypertensives)

Ix
- FBC, Iron, EUC, TSH

Management
- Iron Replacement with vitamin C
- Modest amount of walking before bedtime
- Cease any medications that could be contributing
- Good sleep hygiene. (Regular sleeping hours, gradual relaxation at bedtime.)
- Avoid caffeine, alcohol, smoking
- Keep legs cooler than the body for sleeping.
- Gentle stretching of hamstrings and calf muscles for at least 5 minutes prior to sleep.

Pharmacological Therapy
- Levodopa + Benserazide 100+25 PO Nocte as needed
- Levodopa + Carbidopa 100+25mg PO Nocte as needed.

More severe symptoms? Use Gabapentin or Pregabalin.

Can also consider dopamine agonist
- Pramipexol 0.125mg PO OD 2 hours prir to sleep
- Ropinirole 0.25mg PO 50mins prior to sleep
- Rotigotine 1mg transfermal once daily for 24 hours.

Question 18

Myasthenia Gravis

Answer 18

Most common disorder of neuromuscular transmission.
- Fluctuating degree and variable combination of weakness in ocular, bulbar, limb and respiratory muscles.
- Antibody-mediated T cell-dependent immunologic attack directed at proteins in the postsynaptic membrane of the neuromuscular junction (Acetylcholine receptors)
- Will not cause sensory loss, sphincter disturbance or loss of reflexes. If present consider other differential.

Diagnosis
- Clinical presentation and serological testing
- ACh-R antibodies (present in 85% of cases)
- Muscle specific tyrosine kinase (MuSK) antibodies less commonly.
- Antibodies not detected in some cases.
- Additional tests: Perform TFTs and vit B12, Also review for Thymoma with CT chest.

Epidemiology
- Bimodal distribution of age of onset. Early peak in 20-30yo and late peak in 60-80yo.
- F > M for early peak and M > F for late peak.

Clinical features
- Fluctuating skeletal muscle weakness with true muscle fatigue (worsening contractile force of muscle)
- Weakening worse after exercise or later in the day. Variable weakness important distinguishing factor from other differentials such as motor neuron disease or myopathy.

Treatment
- Pyridostigmine 30mg PO TDS -> Uptitrate to max 120mg PO 3-6x per day

Immunosuppression with prednisolone 5mg PO Daily + Azathioprine / mycophenolate

Crisis? Consider IvIg or plasma exchange.

Question 19

Guillain-Barre Syndrome

Answer 19

Acute inflammatory polyradiculoneuropathy
- Widespread weakness and sensory disturbance.
- Rapid progression
- Starts peripherally with impaired or lost tendon reflexes.
- Associated autonomic instability (BP variation, cardiac arrhythmia, urinary retention)

Triggers
- Infection (campylobacter enteritis, mycoplasma pneumoniae, EBV, CMV)

Ix
- CSF review for raised protein concentration with absent or minimal cellular response.

Rx
- Hospital management. Monitor vital capacity 4 hourly. If falls to < 20ml/kg, admit to ICU.
- IVIg and plasma exchange.

Question 20

Trigeminal Neuralgia

Answer 20

Clinical Features
- Trigeminal distribution
- Paroxysmal, electric, shock-like or stabbing pain lasting seconds then relieving spontaneously. Frequency of 0 to >50x per day.
- Can be triggered by lightly touching affected zone.
- Autonomic symptoms - Lacrimation, conjunctival injection, rhinorrhoea.
- Can also be triggered by talking, having are move across face. Following trigger, refractive period of approximately 60 seconds during which time repeated trigger does not cause response.

Rx
- Carbamazepine MR 100mg PO BD
- 2nd - Oxcarbazepine 300mg PO BD
- 3rd - Baclofen, Gabapentin, Lamotrigine, Phenytoin.

Question 21

Ramsay Hunt Syndrome Treatment

Answer 21

• Prednisolone 1mg/kg (Max 75mg) PO Od x 7 days
• Valaciclovir 1g PO TDS x 7 days