Neurology

Question 1

Define acute vestibular syndrome

Answer 1

Acute, continuous dizziness for ≥24 hours

Without any of:

• hemiparesis
• hemisensory loss
• gaze palsy

Source: http://academiclifeinem.com/paucis-verbis-acute-vestibular-syndrome-and-hints-exam/

Question 2

Causes of acute vestibular syndrome (dizziness continuous ≥24 hours with no hemiparesis, hemisensory loss or gaze palsy). Which are most common?

Answer 2

Peripheral

• vestibulitis

Central

• Vertebrobasilar infarct (most common)
• multiple sclerosis
• “other”

NB: Meniere’s, BPPV do not produce continuous dizziness ≥24 hours

Source: http://academiclifeinem.com/paucis-verbis-acute-vestibular-syndrome-and-hints-exam/

Question 3

Which features on history predict a central cause for acute vestibular syndrome (dizziness continuous ≥24 hours with no hemiparesis, hemisensory loss or gaze palsy)?

Answer 3

Multiple prodromal episodes of dizziness

Head ache or neck pain

Source: http://academiclifeinem.com/paucis-verbis-acute-vestibular-syndrome-and-hints-exam/

Question 4

Which features on physical examination predict a central cause for acute vestibular syndrome (dizziness continuous ≥24 hours with no hemiparesis, hemisensory loss or gaze palsy)?

Answer 4

Truncal ataxia (unable to sit upright with arms crossed)

Severe gait instability

Normal horizontal head impulse test (peripheral lesions result in saccadic rather than tracking movements)

Bilateral gaze-evoked nystagmus

Vertical occular misalignment on alternate cover test

(mnemonic: HINTS — Head Impulse, Nystagmus, Test of Skew)

Source: http://academiclifeinem.com/paucis-verbis-acute-vestibular-syndrome-and-hints-exam/

Question 5

What is the sensitivity and specificity of the HINTS (Head _I_mpulse, _N_ystagmus, _T_est of _S_kew) exam for detecting vertebrobasilar CVA in acute vestibular syndrome?

Answer 5

If any one in three findings suggests central cause:

Sensitivity 100%

Specificity 96%

NB: DW MRI sensitivity is 83%

Sources: Kattah et al, Stroke 2009; http://academiclifeinem.com/paucis-verbis-acute-vestibular-syndrome-and-hints-exam/

Question 6

What are the three brain herniation syndromes in traumatic brain injury?

Answer 6

1. Sub-falcine
2. Trans-tenthorial
3. Tonsillar

Question 7

What structure is likely to be compromised in a sub-falcine herniation and what is the clinical presentation?

Answer 7

Medial frontal cortex (mimics anterior cerebral artery ischaemia)

Question 8

What structure is most commonly compromised in transtentorial herniation and what is the clinical syndrome?

Answer 8

Occulomotor nerve (ipsilateral loss of pupillary constriction)

Question 9

What structure is most likely to be compromised in tonsillar herniation and what is the clinical syndrome?

Answer 9

Medulla (loss of respiratory function)