Transient Global Amnesia - PowerPoint PPT Presentation

Loading...

PPT – Transient Global Amnesia PowerPoint presentation | free to view - id: 7ef227-N2U3O



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

Transient Global Amnesia

Description:

Transient Global Amnesia Allan B. Wolfson, MD University of Pittsburgh Department of Emergency Medicine Presentation of TGA Clinical features Sudden onset Anterograde ... – PowerPoint PPT presentation

Number of Views:176
Avg rating:3.0/5.0
Slides: 29
Provided by: Computi425
Category:

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: Transient Global Amnesia


1
Transient Global Amnesia
  • Allan B. Wolfson, MD
  • University of Pittsburgh
  • Department of Emergency Medicine

2
Presentation of TGA

3
Clinical features
  • Sudden onset
  • Anterograde amnesia
  • Repetitive questioning
  • Retrograde amnesia
  • (variable, often spotty)
  • Normal alertness, behavior, cognition
  • Non-focal neuro exam
  • Resolution within 24 hrs

4
Reported triggers
  • Emotional upset
  • Sexual activity
  • Vigorous exercise
  • Valsalva

5
Differential Diagnosis
  • Head injury
  • Toxic / metabolic
  • Vascular / TIA posterior circulation
  • Non-convulsive seizure
  • Post-ictal state
  • Migraine
  • Tumor
  • Encephalitis
  • AV fistula
  • Functional

6
Epidemiology of TGA
  • Age group
  • usually over 50, but seen in kids too
  • Family history ?2
  • Incidence
  • 5 - 30 per 100,000
  • Recurrence
  • 5 - 8 per year
  • Apparent triggering factors
  • in 33 - 50

7
TGA -- Criteria for Dx
  • Witnessed onset
  • Antegrade amnesia
  • No clouding of consciousness or loss of personal
    identity
  • No cognitive impairment
  • No focal findings
  • No epileptic features
  • No recent head trauma, no sz within 2 yrs
  • Resolution within 24 hrs

8
Anatomy of Memory
  • What structures subsume memory?
  • Medial temporal lobes (hippocampus)
  • Thalamus
  • Diencephalon
  • Frontal / pre-frontal
  • Deep cortical structures

9
Physiology of Memory
  • Memory acquisition
  • Memory storage or consolidation
  • Memory retrieval
  • 3-compartment model?
  • immediate, recent, remote

10
Emergency Dept Evaluation
  • History
  • Neuro exam
  • Basic labs?
  • Head CT
  • EEG
  • MRI

11
Bedside evaluation of episodic memory
  • Orientation?
  • Remember 3 things for 3 minutes?
  • Remember what happened yesterday?

12
Other types of memory to check on
  • Semantic memory
  • Procedural memory
  • Biographical memory
  • Topographic memory
  • Meta-memory

13
Etiology of TGA?
  • Vascular
  • Seizure
  • Migraine
  • Venous hypertension
  • (Valsalva, paradoxical embolism)

14
Etiology of TGA?
  • Case-control studies show no association with
    stroke or TIA
  • Sub-group with epilepsy excluded by definition
  • Nonconvulsive status epilepticus?
  • Association with migraine
  • Reported precipitating factors

15
Differentiating features
  • Repetitive questioning
  • Complex acts and instructions
  • Memory gap for the event
  • Severity of retrograde amnesia
  • Rapid onset
  • Duration

16
Transient epileptic amnesia
  • Short attacks, multiple attacks
  • No repetitive questioning
  • Anterograde amnesia may be only partial
  • Altered behavior
  • Alteration in consciousness
  • Other features of epilepsy
  • (eg, automatisms, other seizures, EEG,
  • response to anticonvulsants)

17
Functional Amnesia
  • Severe retrograde amnesia
  • Absence of anterograde amnesia
  • Duration often weeks or longer

18
Fancy Diagnostic Studies
  • EEG
  • CT scanning
  • SPECT scanning, PET scanning
  • MRI, DW-MRI, PW-MRI

19
SPECT scanning
  • Some studies have shown decreased perfusion in
    medial temporal lobes, thalamus, or frontal
    lobes
  • Usually returns to normal after attack
  • Reflection of abnormality or cause?

20
Diffusion-weighted MRI
  • Inconsistent findings
  • Sometimes shows abnormalities
  • (esp in left hippocampus)
  • Sensitive for ischemia
  • (decreased diffusibility of water)
  • But also consistent with
  • spreading depression
  • (rapid resolution, unlike ischemia)

21
Diffusion-weighted MRI
  • Sensitive for ischemia
  • (decreased diffusibility of water)
  • But also consistent with
  • spreading depression
  • (rapid resolution, unlike ischemia)

22
What is spreading depression?
  • Wave of depolarization progressing across cortex
    at 3-5 mm/min
  • Associated with aura of migraine

23
Diffusion-weighted MRI in TGA
  • Inconsistent findings
  • Sometimes shows abnormalities,
  • especially in left hippocampus
  • Bilateral or left-sided only
  • Sometimes no changes
  • May be time-dependent

24
Treatment
  • None necessary
  • Migraine therapy?

25
Prognosis
  • Essentially benign
  • Subclinical persistent memory deficits?
  • Associated conditions?

26
Disposition from the ED
  • Theoretically
  • after amnesia resolves, can
  • discharge with neurology follow-up
  • and no immediate testing
  • Actually
  • admission, MRI, EEG

27
Unanswered questions
  • Etiology? Spectrum of causes?
  • True role of precipitating factors?
  • Acute treatment?
  • Physiology of memory?

28
QUESTIONS ???
About PowerShow.com