Pure sensory stroke due to brainstem lesion

ABSTRACT

BACKGROUND & OBJECTIVES: Although thalamic stroke is the most frequent cause of pure sensory stroke, non-thalamic strokes have been also occasionally reported to produce pure sensory stroke(PSS). We attempt to characterize the clinical and radiological features of 11 patients with PSS due to brainstem stroke. SUBJECTS AND METHODS: There were eight men and three women and their age ranged from 50 to 71 years. Their risk factors included hypertension in 10, diabetes mellitus in 2, hyperlipidemia in 3, alcohol drinking in 3 and cigarette smoking in 2. All underwent brain computed tomography(n=11) and/or magnetic resonance imaging(n=8). RESULTS: Five patients presented with pure lemniscal sensory deficits(position and vibration sensation); two presented with abnormalities in all sensory modalities but dominantly involving lemniscal sensation; remaining 4 presented with numbness only. Four patients had cheiro-oral syndrome with bilateral perioral involvement. Imaging studies showed that 6 patients had a small infarct in the paramedian pontine tegmentum, which was thought to be caused by small vessel(lacunar) inclusion. One patient had a small infarct in the lateral part of the midbrain which was probably caused by artery-to-artery embolism originated from mid-basilar stenosis. In addition, four patients had small hypertensive hemorrhage affecting the pontine tegmentum. CONCLUSION: Our result confirms that PSS can be caused by small brainstem stroke of various etiopathology, frequently involving the paramedian pontine tegmentum PSS due to braimtem stroke may be characterized by predom inant lemniscal sensory involvement and occasional bilateral perioral symptoms.