Nervous system

Question 1

Upper motor neuron (UMN) lesion where does weakness develop?

Answer 1

Develops in the weaker muscle groups. The extensors in the arms and flexors in the legs.

Question 2

UMN lesion - where does spactisity develop and how does it manifest?

Answer 2

Spasticity develops in the stronger muscle groups (arm flexors and leg extensors). It manifests as increased tone that is velocity-dependent, ie the faster you move the patient’s muscle, the greater the resistance, until it finally gives way (like a ‘clasp-knife’).

Question 3

UMN lesion muscle wasting

Answer 3

Less prominent

Question 4

UMN lesion reflexes

Answer 4

• There is hyperreflexia: reflexes are brisk
• Plantars are upgoing (+ve Babinski sign)
• ± clonus (elicited by rapidly dorsiflexing the foot; ≤3 rhythmic, downward beats of the foot are normal)

Question 5

UMN lesion fine motor skills

Answer 5

Loss of skilled fine finger movements may be greater than expected from the overall grade of weakness.

Question 6

Where do lower motor neurone (LMN) lesions exist?

Answer 6

Anywhere from the anterior horn cells distally, including the nerve roots, plexuses, and peripheral nerves.

Question 7

LMN lesion pattern of weakness

Answer 7

The pattern of weakness corresponds to the muscles supplied by the involved neurons.

Question 8

LMN lesion muscle wasting

Answer 8

Affected muscles show wasting ± fasciculation

Question 9

LMN lesion tone

Answer 9

There is hypotonia/flaccidity: the limb feels soft and floppy, providing little resistance to passive stretch.

Question 10

LMN lesion reflexes

Answer 10

Reflexes are reduced or absent; the plantars remain flexor.

Question 11

Muscle weakness grading (MRC classification)

Answer 11

• Grade 0 - No muscle contraction
• Grade 1 - Flicker of contraction
• Grade 2 -Some active movement
• Grade 3 - Active movement against gravity
• Grade 4 - Active movement against resistance
• Grade5 - Normal power (allowing for age)

Question 12

Questions to ask about headaches

Answer 12

• Onset
• Character
• Frequency
• Duration
• Associated features
• Precipitating cause
• Drug history
• Social history

Question 13

Rapid onset headache differential diagnosis

Answer 13

• Subarachnoid haemorrhage
• Meningitis
• Encephalitis
• Post-coital headache

Question 14

Symptoms of subarachnoid haemorrhage

Answer 14

• sudden-onset
• ‘worst ever’ headache
• often occipital
• stiff neck
• focal signs
• decreased consciousness

Question 15

Character - tight band

Answer 15

Think tension headache

Question 16

Character - throbbing/pulsatile/lateralising

Answer 16

Migraine

Question 17

What do recurring headaches suggest?

Answer 17

Headaches that recur tend to be benign.

• Migraine
• Cluster headache
• Trigeminal neuralgia
• Recurrent meningitis

Question 18

Why is drug history important in headaches?

Answer 18

Exclude medication overuse (analgesic rebound) headache: Culprits are mixed analgesics (paracetamol+codeine/opiates), ergotamine, and triptans.

Question 19

Symptoms of cluster headaches

Answer 19

• Rapid-onset of excruciating pain around one eye that may become watery and bloodshot with lid swelling, lacrimation, facial flushing, rhinorrhoea, miosis ± ptosis (20% of attacks)
• Pain is strictly unilateral and almost always affects the same side
• It lasts 15–180min, occurs once or twice a day, and is often nocturnal
• Clusters last 4–12wks and are followed by pain-free periods of months or even 1–2yrs before the next cluster

Question 20

Cluster headache treatment

Answer 20

• Acute
  
  • give 100% O2 for ~15min via non-rebreathable mask (not if COPD)
  • sumatriptan SC 6mg at onset
• Preventative
  
  • avoid triggers
  • corticosteroids (short term only)
  • verapamil
  • lithium