Panic Anxiety in Humans with Bilateral Amygdala Lesions: Pharmacological Induction via Cardiorespiratory Interoceptive Pathways.
Level 4 - case-series / case-control
Placebo-controlled experimental case series in two patients with rare focal bilateral amygdala lesions
PubMed 27013684 · doi:10.1523/JNEUROSCI.4109-15.2016
What was done
Two monozygotic twin patients (B.G. and A.M.) with rare focal bilateral amygdala lesions received bolus intravenous infusions of either isoproterenol (a peripheral beta-adrenergic agonist) or saline. Testing occurred across two conditions: panic induction and an assessment of cardiorespiratory interoception. Participants provided self-report ratings of their affective and sensory experiences.
What was found
The abstract reports no numerical values or statistical comparisons. Isoproterenol induced heightened anxiety in both patients and a full-blown panic attack in patient B.G. Both patients showed signs of diminished cardiac awareness, while patient A.M. (who did not panic) reported a complete absence of dyspnea awareness.
Why it matters
This study provides evidence that the conscious experience of fear and panic triggered by non-chemosensory, cardiorespiratory interoceptive pathways does not require an intact amygdala.
Limits
The study is limited to a sample size of two individuals from a single twin pair, restricting generalizability. No quantitative measures, dosage details, or statistical analyses are reported in the abstract.