Not Feeling the Heat

75 years old man attended neurology clinic for 9 months lasting sensory symptoms in the left side of the body. He reported loss of temperature sensation down the left side of his body, mainly in the left arm and left leg (struggled to differentiate water temperature in the bath etc.). He felt that problems started abruptly. It all started when he developed an episode of dizziness/vertigo with nausea and unstable gait that came on suddenly and then a month later after these symptoms had resolved he noticed that the left side of his body could no longer discriminate temperatures.