Pure or predominant sensory stroke due to brain stem lesion

Background and Purpose Pure or predominant hemisensory symptoms can be seen in patients with brain stem stroke. However, there have been no reports in which sufficient numbers of patients were studied with detailed descriptions on the sensory patterns and imaging findings. Methods We describe 17 patients presenting with pure or predominant hemisensory symptoms due to brain stem stroke in whom CT scan and/or MRI identified appropriate lesions. Results Eleven patients had an infarct and 6 had a hemorrhage. Aside from sensory deficit, the majority had dizziness and gait ataxia. Fifteen patients had paramedian dorsal pontine lesions associated with pure or predominant lemniscal sensory involvement, often in the cheiro-oral (n=4) or leg dominance (n=4) patterns. The lesions of the former group tended to be located more medially compared with those of other patients, which is in agreement with the sensory topography of the pontine lemniscal sensory tract. Bilateral facial or perioral sensory symptoms were noted in 6 patients. One patient with a dorsolateral pontine lesion had selective spinothalamic modality impairment, while one with a lateral midbrain infarct had sensory deficit of all modalities. Conclusions Pure or predominant brain stem sensory stroke is most often produced by small infarcts or hemorrhages in the paramedian dorsal pontine area and may be differentiated from thalamic pure sensory stroke by the following characteristics: frequent association of dizziness/gait ataxia, predominant lemniscal sensory symptoms, occasional leg dominance or cheiro-oral pattern, and frequent bilateral perioral involvement.