Transient ischemic attack after hot bath in a patient with Moyamoya disease

Abstract

Hot bath has not yet been reported as a precipitating factor in patients with Moyamoya disease. Here, we report an adult patient with Moyamoya disease presenting transient ischemic attack (TIA) characteristically precipitated by hot bath. A 38-year-old housewife presented with recurrent transient right hemiparesis and difficulty in speech for the past 3 months. These symptoms were developed only during hot bath, especially around the end of bath, and lasted about 5 min and then relieved spontaneously. Her past medical history and neurologic examination were unremarkable. Laboratory tests for associated conditions with vasculopathy were normal. Brain MRI revealed increased cortical vascular markings on the right hemisphere without parenchymal lesion. Brain magnetic resonance angiography revealed bilateral steno-occlusive lesions of the distal internal carotid arteries (ICAs) and the proximal part of the middle cerebral arteries (MCAs) and anterior cerebral arteries (ACAs) (Fig. 1a). Digital subtraction angiography (DSA) demonstrated that extensive collateral flows to the right hemisphere were from basal collaterals, posterior circulation system (Fig. 1b), the external carotid artery via transdural anastomosis, and ethmoidal arteries via ophthalmic artery. However, DSA of left ICA showed only small basal collaterals with delayed filling of the dilated distal left MCA branches (Fig. 1c). Perfusion CT demonstrated increased cerebral blood volume (CBV) in the right hemisphere (Fig. 1d). After acetazolamide challenge, increased CBV in the right hemisphere was more prominent and cerebral blood flow (CBF) was mildly increased (Fig. 1e). However, CBV and CBF changes after acetazolamide were not remarkable in the left hemisphere. Baseline transcranial Doppler showed the increased mean flow velocity (MFV) in both MCAs. Hyperventilation did not cause any changes, but breath holding decreased MFV paradoxically only in the left MCA. After taking hot bath, baseline MFVs of both MCAs were decreased. Breath holding after taking hot bath caused marked drop in MFV of the left MCA (Fig. 1f). The evoked potential (EP) studies were unremarkable at both room temperature (25 C) and heated room temperature (30 C). Breath holding and hyperventilation did not cause any changes in EP studies. However, during hyperventilation for 3 min in electroencephalography (EEG) study, transient right hand shaking movements were developed without EEG changes. She was on antiplatelet agent and educated to avoid hot bath for a long time. After discharge, she experienced TIA after hot bath only once in recent 6 months. Most of precipitating factors of TIA in Moyamoya disease are associated with hyperventilation [1]. The main underlying mechanism is presumed to be hyperventilationinduced vasoconstriction in hemodynamic-compromised cerebral region and subsequent CBF reduction [2]. In our case, hyperventilation during EEG study also induced transient right limb shaking, reflecting decreased vascular reserve in left hemisphere [3]. Interestingly, hot bath in this case was a distinct precipitating factor that affected cerebral hemodynamic status. Electronic supplementary material The online version of this article (doi:10.1007/s10072-013-1468-8) contains supplementary material, which is available to authorized users.