In April 2009, a 71-year-old gentleman presented with a four-month history of difficulty in walking. While walking for short distances, which would vary, he used to develop involuntary jerky movements in his right leg. Occasionally, the movement also spread to his right hand. He had to clutch nearby objects to prevent the fall. These episodes occurred invariably during walking but never at rest or simply standing. The episodes would last for 1-2 minutes and were relieved by rest – either by sitting or lying down. During his visit he was having 3-4 episodes per day with significant disability. Additionally, he also had two episodes of transient right hemiparesis lasting for 20 minutes with spontaneous improvement. His medical history revealed relatively well controlled diabetes and hypertension for last 20 years and he was a chronic smoker (Two packs per day for last 30 years).
On examination his pulses were regular with blood pressure of 120/70 mm Hg without any orthostatic hypotension. The carotid pulses were feeble bilaterally without any bruit and he had subtle right hemiparesis. Walking for a short distance, he developed sudden tremulousness of the right leg with a tendency to fall towards his right. The rest of his examination was normal.
Interictal electroencephalogram (EEG) was normal. Magnetic resonance imaging (MRI) of brain revealed sub-acute infarcts in left periventricular region and centrum semiovale. MR angiography showed bilateral proximal internal carotid artery (ICA, 80-90%) and bilateral vertebral artery stenosis . The rest of the investigations, including echocardiogram were normal. These features suggested a diagnosis of “Limb-shaking transient ischemic attack (TIA)” or low flow TIA.
Figure 1 (a-b) MRI Brain (Axial section FLAIR sequence) showing infarcts in left periventricular region and centrum semiovale, (c) contrast MR angiography showing bilateral proximal internal carotid artery stenosis [(R) ICA – arrowhead, (L) ICA – (more ...)
The patient refused to undergo cerebral angiography and further intervention due to personal reservations about the risk of procedures. He was treated conservatively with anti-platelet and lipid-lowering medications. In view of possible low flow state, his antihypertensive medications were withdrawn. He had significant reduction in the severity and frequency of attacks at resting blood pressure of 130-140/80-90 mm Hg.