“You get to use the word ‘dizzy’ once.” Andrew Asimos
Categories of Dizziness
Posterior Circulation Anatomy
Supplies:
1) Brainstem
2) Cerebellum
3) Thalamus
4) Auditory/vestibular structures
5) Visual occipital cortex
Neuro Exam for Posterior Circulation
Bias
Categories of Dizziness
- Vertigo
- = Perception of movement
- Due to dysfunction of an aspect of the visual, vestibular or proprioceptive systems
- Need to distinguish if peripheral or central etiology
- Peripheral causes:
- BPPV, Vestibular neuritis/labyrinthitis, Perilymph fistula, Meniere’s disease
- Central causes:
- CVA/TIA, Head/Neck trauma (think dissection!), Vertebrobasilar insufficiency, Multiple Sclerosis, Mass, Chiari malformations, Migraine
- Miscellaneous:
- Drug-induced
- Peripheral causes:
- BPPV accounts for the majority of cases BUT must have:
- Short duration (<1min)
- Triggered by head movement
- If does not fit these criteria, consider other diagnoses and dig deeper.
- Key questions: Timing, trigger, and duration
- Ask about associated symptoms such as vision changes, headache, ameliorating/aggravating factors, preceding illness
- Cranial nerve exam (particularly CN II and III), cerebellar exam, and gait important
- Disequilibrium
- = Unsteadiness, imbalance, usually while walking
- Due to dysfunction of sensory, motor control, or proprioception systems
- More common in old people
- Most commonly multisensory deficit e.g. diabetic neuropathy
- Differential is broad (* below is not exhaustive):
- Vascular: CVA/TIA, dissections, hypertensive emergency
- Infectious: Syphilis
- Metabolic/Pharm: EtOH, drug-induced
- Endo: DM, hypothyroidism
- Neuro: Tumor, Parkinson’s, Cerebellar ataxia, MS, neuropathies
- A word about Romberg. It is influenced first by cerebellum, then visual, proprioceptive, and vestibular systems… You must have an intact cerebellum test other systems. If positive with eyes closed and open, cerebellum is not intact.
- Presyncope
- Sense of impending loss of consciousness
- Distinguish if patient actually syncopized
- Ddx: Vascular, autonomic dysfunction, cardiac
- Sense of impending loss of consciousness
- Lightheaded/Psychogenic Dizziness
- NOT vertigo, presyncope or disequilibrium
- Difficult for patients to articulate
- Diagnosis of exclusion.
- DDx includes hyperventilation, psychogenic, anemia, thyroid
Posterior Circulation Anatomy
Supplies:
1) Brainstem
2) Cerebellum
3) Thalamus
4) Auditory/vestibular structures
5) Visual occipital cortex
Neuro Exam for Posterior Circulation
- Cranial Nerves
- Key part of exam à localizes to the brain stem
- Describe what you did:
- Not “CNII-CNXII intact”
- “EOMI, Palate elevates symmetrically, etc”
- Visual fields are key
- Why? Field loss can be the only physical exam feature of CVA
- Test UPPER and LOWER quadrants
- Cerebellum
- Subtle findings!
- Think ATAXIA
- Limb
- Localizes to lateral cerebellum
- Pick one exam: finger to nose, dysmetria, heel to shin
- Truncal
- Localizes to midline cerebellum
- Ask to sit up in bed without aid of arms
- Eye
- Localizes to inferior cerebellum
- Look for pathologic nystagmus
- Vertical
- Direction changing
- Limb
- Gait
Bias
- We are all human, therefore we all have intrinsic biases
- Stop points are critical and are an opportunity for executive override to protect against bias
- Pick stop points that work for you and your work flow:
- One-liners
- Before finishing orders
- Before landing on a discharge diagnosis: “What am I missing?”
- Before discharge: “Is this hospital course consistent with diagnosis?”
- Pick stop points that work for you and your work flow: