Neurology
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To investigate the effect of sympathetic arousal on pain and vasomotor responses in healthy control subjects and patients with complex regional pain syndrome (CRPS), and to determine whether pain increases in patients with particular symptoms. ⋯ Normal inhibitory influences on pain during sympathetic arousal are compromised in the majority of patients with CRPS. The augmented vasoconstrictor response in the symptomatic limb during sympathetic arousal is consistent with adrenergic supersensitivity. An adrenergic sensitivity in nociceptive afferents might contribute to pain and hyperalgesia during sympathetic arousal in certain patients with CRPS.
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Recent natural history studies have suggested that unruptured intracranial aneurysms smaller than 1 cm have a low risk of rupture. Symptomatic aneurysms may be underrepresented in natural history studies because they are preferentially treated. The authors compared the number of patients with symptoms caused by unruptured intracranial aneurysms smaller than 1 cm treated surgically at their institution with similar patients enrolled in the International Study of Unruptured Intracranial Aneurysms (ISUIA) from their institution over the same time period. ⋯ Unruptured intracranial aneurysms smaller than 1 cm occasionally present with neurologic symptoms. These symptoms are typically owing to mass effect on the second and third cranial nerves or cerebral ischemia as a result of emboli originating from within the aneurysm. Patients with symptomatic unruptured aneurysms less than 1 cm at the Mayo Clinic were preferentially treated. Although existing natural history data may be applied to most unruptured aneurysms, small symptomatic aneurysms may be underrepresented in natural history studies.