Stroke recovery and lesion reduction following acute isolated bilateral ischaemic pontine infarction: a case report

BMC Research Notes, Dec 2014

Background Although pontine strokes account for a small percentage of all ischaemic events, they can be associated with significant initial disability. These lesions may be missed on computed tomography and therefore magnetic resonance imaging is generally preferred for the assessment of brainstem strokes. The aetiopathogenesis of isolated pontine infarcts, not due to a significant compromise (occlusion or dissection) in the vertebrobasilar territory, still remains to be fully characterised. These strokes present with different symptoms, depending on the lesion location and size, partly reflecting the anatomical variability of the vertebrobasilar vessels. Progressive neurological deterioration is relatively common and has been associated with the extension of such lesions. However, many patients with significant infarcts in the pons will do well in the future and initial diffusion-weighted imaging may not add useful prognostication to the clinical assessment. We discuss here a case where an initially progressive presentation was associated with a marked improvement in both clinical and radiological assessments at 42 days. Case presentation A 49-year-old white British man presented with left-sided weakness, incoordination, unsteadiness, cerebellar ataxic dysarthria and dysphonia. A baseline magnetic resonance imaging scan with diffusion-weighted imaging, T1-weighted and T2-weighted sequences showed an acute bilateral pontine infarct. On a repeat scan at 42 days, there was a 57.5% decrease in the size of the lesion on the high-resolution three-dimensional T1-weighted image and a corresponding improvement in the symptoms and the clinical assessments of this patient. The reduction in infarct size was also comparable to the decrease calculated between the baseline diffusion-weighted and the follow-up fluid attenuated inversion recovery sequences. Conclusion This case report discusses the significant clinical improvement and corresponding lesion reduction in a patient that presented with worsening neurological symptoms and was diagnosed with acute bilateral ischaemic pontine infarction. Further studies, utilising structural and functional magnetic resonance imaging with follow-up scans, are needed to provide better insights into the underlying aetiopathology and recovery mechanisms of pontine stroke. These will help define the relationship between imaging parameters and outcome allowing for better prognosis along with the development of relevant rehabilitation programs for this group of patients.

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Stroke recovery and lesion reduction following acute isolated bilateral ischaemic pontine infarction: a case report

BMC Research Notes Stroke recovery and lesion reduction following acute isolated bilateral ischaemic pontine infarction: a case report Ourania Varsou 0 Michael S Stringer 0 Catarina Dinis Fernandes 0 Christian Schwarzbauer 0 Mary Joan MacLeod 1 0 Aberdeen Biomedical Imaging Centre, University of Aberdeen , Foresterhill, Aberdeen AB25 2ZD , UK 1 Department of Medicine and Therapeutics, University of Aberdeen , Foresterhill, Aberdeen AB25 2ZD , UK Background: Although pontine strokes account for a small percentage of all ischaemic events, they can be associated with significant initial disability. These lesions may be missed on computed tomography and therefore magnetic resonance imaging is generally preferred for the assessment of brainstem strokes. The aetiopathogenesis of isolated pontine infarcts, not due to a significant compromise (occlusion or dissection) in the vertebrobasilar territory, still remains to be fully characterised. These strokes present with different symptoms, depending on the lesion location and size, partly reflecting the anatomical variability of the vertebrobasilar vessels. Progressive neurological deterioration is relatively common and has been associated with the extension of such lesions. However, many patients with significant infarcts in the pons will do well in the future and initial diffusion-weighted imaging may not add useful prognostication to the clinical assessment. We discuss here a case where an initially progressive presentation was associated with a marked improvement in both clinical and radiological assessments at 42 days. Case presentation: A 49-year-old white British man presented with left-sided weakness, incoordination, unsteadiness, cerebellar ataxic dysarthria and dysphonia. A baseline magnetic resonance imaging scan with diffusion-weighted imaging, T1-weighted and T2-weighted sequences showed an acute bilateral pontine infarct. On a repeat scan at 42 days, there was a 57.5% decrease in the size of the lesion on the high-resolution three-dimensional T1-weighted image and a corresponding improvement in the symptoms and the clinical assessments of this patient. The reduction in infarct size was also comparable to the decrease calculated between the baseline diffusion-weighted and the follow-up fluid attenuated inversion recovery sequences. Conclusion: This case report discusses the significant clinical improvement and corresponding lesion reduction in a patient that presented with worsening neurological symptoms and was diagnosed with acute bilateral ischaemic pontine infarction. Further studies, utilising structural and functional magnetic resonance imaging with follow-up scans, are needed to provide better insights into the underlying aetiopathology and recovery mechanisms of pontine stroke. These will help define the relationship between imaging parameters and outcome allowing for better prognosis along with the development of relevant rehabilitation programs for this group of patients. Acute stroke; Pontine stroke; Pons; Magnetic resonance imaging; MRI Background Pontine strokes account for approximately 7% of all ischaemic events [ 1 ] and may present with progressive symptoms that cause clinical concern. Patients tend to do generally well, if a bilateral lesion is not present [ 2 ]. In addition, pontine infarcts may be missed when computed tomography (CT) is the imaging modality used and clinicians should have a high index of suspicion in patients with pure motor symptoms [ 3 ]. The aetiopathogenesis of pontine infarction in the absence of vertebrobasilar occlusion or dissection is still not fully characterised. [ 4 ]. Both small vessel (lipohyalinosis) and large vessel disease (atherosclerosis), especially of the basilar artery branches in the latter case, have been proposed as possible causes of pontine ischaemic strokes [ 2,4-6 ]. An imaging study also suggested basilar artery stenosis as a potential aetiology for this condition [7]. Patients with isolated pontine infarcts can present with a wide range of different symptoms, depending on the portion of the pons that has been affected and the size of the lesion, partly reflecting the highly variable vertebrobasilar vessel anatomy [ 8 ]. Furthermore, neurological deterioration is relatively common even in the absence of a basilar thrombus, and has been associated with the enlargement of the pontine lesions. This is most likely a dynamic process with interacting haemodynamic, metabolic, inflammatory and cellular factors [ 4 ]. Case presentation A 49-year-old, right-handed white British, conscious man arrived at the emergency department (ED) in the summer of 2013. He gave a history of waking up the previous day with mild left-sided weakness, affecting both his upper and lower limbs, along with a minor degree of unsteadiness on his feet. At that point, he did not experience any facial weakness, sensory symptoms, seizures or a headache. The left-sided weakness had somewhat improved on th (...truncated)


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Ourania Varsou, Michael S Stringer, Catarina Dinis Fernandes, Christian Schwarzbauer, Mary Joan MacLeod. Stroke recovery and lesion reduction following acute isolated bilateral ischaemic pontine infarction: a case report, BMC Research Notes, 2014, pp. 728, Volume 7, Issue 1, DOI: 10.1186/1756-0500-7-728