Mid Brain Brain stem Anterior view Brain stem Posterior view Section of Mid Inferior colliculus Section of Mid Superior colliculus At Superior colliculus Tectum of Mid Brain (Quadrigemial bodies) Cranial Nerve Nuclei Ventromedial Superior Midbrain Syndrome (Webers Syndrome) Contralateral Pralysis of face, arm and leg Ipsilateral III palsy (fascicular) Artery Paramedian perforators of terminal basilar, or peduncular perforating branches of posterior cerebral artery Paracentral (Tegmental) Superior Midbrain Syndromes (Claudes and Benedikts syndromes) Contralateral ataxia with tremor (red nucleus) hemichorea (subthalamic nucleus) Ipsilateral III fascicular palsy Artery Paramedian perforators of terminal basilar, or Interpeduncular branches of Posterior Cerebral Artery A 65 year old women suddenly remarked that she was seeing double and felt a weakness in his left arm and leg. her husband noticed that her right eyelid was drooping. At the hospital, she was awake, oriented, and articulate. her visual fields were normal but her right eye deviated to the right. On attempted lateral gaze to the left only the left eye responded; only the left eye constructed in response to light. Upon smiling, there was a minor weakness on the left. The gag, corneal, and jaw jerk reflexes were normal as were the sensory examinations of the face and body. Motor strength was normal in the extremities on the right but reduced on the left especially in the arm while there was a heightened biceps reflex and resistance to passive stretch. A usually alert 65 year old women lost consciousness. Upon awakening she complained of double vision and a tremor in her left arm. Mental status was good and speech was articulate and appropriate. The right eye had a dilated pupil and a lateral strabismus. On attempted lateral gaze to the left, the right eye would not proceed across the midline. Although vision was normal the right pupil did not constrict in either the direct or consensual pupillary light reflexes. Hearing was normal as were CN Pain and temperature sensation from the body and face were normal bilaterally. There was diminihed vibratory sense and muscle strength on the left. The left arm showed an intention tremor, dysmetria and occasional involuntary movements.