Neurology

Question 1

Differentiate between upper and lower motor neuron disease

Answer 1

Upper Motor Neuron
- Minimal muscle atrophy
- increased tone, spasticity
- hyperreflexia
- upgoing plantar response
Lower Motor Neuron Disease
- weakness, muscle atrophy
- decreased tone
- hyporeflexia
- downgoing plantar reflex (normal)

Question 2

List the 8 aspects of the neurological exam

Answer 2

• Mental Status Exam
• Cranial Nerve Exam
• Motor Exam
• Coordination Exam
  - pronator drift
  - nose to finger, finger to nose
  - heel to shin rubbing
• Sensory Exam
• Reflexes
• Testing of stance and Gait
• Special Test

Question 3

List the causes of Ischemic and Hemorrhagic Stroke

Answer 3

Thrombosis
- obstruction of large or small vessel
- large vessel commonly carotid due to arthersclerosis
- small vessel commonly lacunar stroke (small cerebral artery) due to hypertension causing lipohyalinosis
Embolism
- Clot from elsewhere that traveled in blood vessel to brain
- commonly from heart due to AF, rheumatic heart disease, prosthetic valve
Systemic Hypoperfusion
- global decreased blood flow to the brain causing global damage
- common in watershed area
- commonly due to cardiogenic shock
Hemorrhagic
- 20% of stroke and due to bleeding
- intracerebral hemorrhage when have bleeding from small arteries in brain from rupture of microaneurysm from hypertension, trauma, amyloid, vascular malformation or drugs
- sub-arachnoid hemorrhage

Question 4

Discuss the difference between TIA and stroke and common presentation

Answer 4

Definition
- TIA: focal cerebral ischemic event lasting <24hrs followed by full recovery
- usually resolve in minutes to few hours
- Reversible ischemic neurologic deficit: focal cerebral ischemic event with neurological deficit >24hrs followed by full recovery (usually within few weeks)
- Stroke: permanent neurological deficit
Symptoms
- sudden onset focal neurological deficit
- dizziness, n/v
- loss of vision, diplopia
- aphasia, dysarhria
- unilateral weakness/paralysis
- incoordination
- altered LOC, confusion
- dysphasia, aphasia
- facial droop

Question 5

Discuss presentation of stroke by vascular territory

Answer 5

Anterior Cerebral Artery
- frontal lobe affected
- contralateral leg paresis and sensory loss
- gait disturbance
- urinary incontinence
Middle Cerebral Artery
- posterior frontal lobe, temporal lobe, parietal lobe
- contralateral weakness and sensory loss of face and arm
- contralateral homonymous hemianopia or quadantanopia
- left hemipshere: aphasia
- right hemisphere: visual-spatial neglect
Posterior Cerebral Artery
- occipital lobe
- contralateral homonymous hemianopia
- left hemisphere: alexia with agraphia (cannot read but can write)
- right hemisphere: sensory loss, decreased LOC
Basilar Artery
- brainstem
- locked-in syndrome: quadraparesis/quadraplegia, anarthria/dysarthria, impaired horizontal eye movement
Lacunar Infarct
- Deep brain structures
- Pure contralateral hemiparesis or hemisensory loss
- ataxia
- dysarthria-clumsy hand syndrome: dysarthria, facial weakness, dysphagia, mild hand weakness and clumsiness

Question 6

Discuss the acute management of stroke

Answer 6

Stabilize
- ABC
Initial Assessment
- onset of symptoms since last awake and free of symptoms
- rule out differential: hypoglycemia, seizure, migraine, syncope
- hemorrhagic strong headache and vomiting
- NIH Stroke Scale exam
Investigations
- Non-contrast brain CT
- ECG
- CBC, electrolytes, blood glucose, INR/PTT, creatinine, BUN, troponin
Address Underlying Cause
- if hemorrhagic then decrease BP to <140mmHg with IV labetalol and immediate interventional radiology or neurosurgery

Question 7

Discuss the NIH Stroke Scale

Answer 7

• level of consciousness
• gaze
• visual fields
• facial palsy
• motor arm
• motor leg
• limb ataxia
• sensory
• language
• dysarthria
• extinction and inattention
  Severity
• 0: no stroke
• 1-4: mild stroke
• 5-15: moderate stroke (>=6 consider tPA)
• 15-20: moderate to severe
• > 21/42 severe

Question 8

Discuss the management for an ischemic stroke

Answer 8

• if within 4.5 hours of symptom onset then candidate for IV rTPA
• if contraindication then asparin 325mg or clopidrogrel
  Absolute Contraindication
• hemorrhagic stroke on CT
• head trauma or prior stroke within last 3 months
• Arterial puncture at non-compressible site in last 7 days
• Any previus intracranial hemorrhage
• Evidence of active bleeding
• Hypertension >185/110 (must lower with IV labetalol first)
• Blood dyscrasia
  - platelet <100
  - heparin use and PTT above normal limit
  - anticoagulant use and INR >1.7
• blood glucose <5
• multilobar infarction >1/3 cerebral hemisphere
  Relative Contraindications
• Minor or rapidly improving stroke symptoms
• Seizure at onset
• Major surgery or serious surgery within previous 2 weeks
• Recent GI or urinary tract hemorrhage in previous 3 weeks
• recent MI in previous 3 months

Question 9

Discuss the risk stratification for a TIA

Answer 9

ABCD2 Score
- Age >60 (1 point)
- Blood pressure >=140/90 (1 point)
- Clinical features of TIA
       - speech impairement without weakness (1 point)
       - unilateral weakness (2 points)
- Duration of TIA
      - 10-59 min (1 point)
      - >60 min (2 points)
- Diabetes (1 point)
Risk Stratification
- <=3 have 1% risk of stroke in following 2 days so can discharge
- >=4 have 4-8% risk of stroke in following 2 days so hospital observation

Question 10

Discuss the secondary prevention for stroke

Answer 10

Anti-Platelet
- aspirin
- aspirin + dipyridamole
- clopidogrel
Symptomatic Carotid Stenosis
- >70% then carotid endarterectomy
- 50-70% then carotid endarterectomy considered
- <50% then not indicated
- best if done within 2 weeks
Atrial Fibrilation
- CHADSVAS
      - Congestive Heart Failure
      - Hypertension
      - Age >=75
      - Diabetes
      - Previous stroke or TIA
      - Vascular disease
      - Age 65-74
      - Sex (female)
Hypertension
- reduce risk of stroke y 40%
Dyslipideia
- target LDL <2
Lifestyle
- reduce alcohol, quit smoking
- stop hormone therapy
- increase physical activity and healthy diet

Question 11

Differentiate between motor, sensory and autonomic neuropathy

Answer 11

Motor
- muscle weakness
- atrophy
- cramps
Sensory
- numbness
- loss of feeling
- tingling paresthesia
- small fibers have more burning pain, large then loss of proprioception
Autonomic
- sweating
- gastroparesis
- bowel/bladder dysfunction
- erectile dysfunction
- orthostatic hypotension

Question 12

Discuss causes of mononeuropathy

Answer 12

Compressive Neuropathy
- carpal tunnel syndrome
- ulnar neuropathy
- radial nerve (saturday night palsy)
- lateral femoral cutaneous nerve
- peroneal neuropathy
Mononeuropathy Multiplex
- diabetes mellitus
- rheumatoid arthritis
- SLE
- vasculitis

Question 13

Discuss causes of polyneuropathy

Answer 13

Axonal Polyneuropathy
- diabetes
- renal failure
- vitamin B12 deficiency
- alcohol
Demyelinating Polyneuropathy
- Guillain-Barre syndrome
              - acute progressive symmetric muscle weakness with hyporeflexia
- Chronic Inflammatory Demyelinating polyneuropathy