The maximum length of the thalamus is 3.8 cm, the width is 1.5 cm, and the height is 1.9 cm. According to the aforementioned estimation formula, the volume is 5.5 ml. The large size of the hematoma is bound to cause direct damage to adjacent structures such as the hypothalamus and midbrain, and coupled with the occupying effect of the hematoma, the consequences are serious. If the hypothalamus is involved, the symptoms may include high fever, gastrointestinal bleeding, and hyperglycemia in addition to impaired consciousness. It is mainly caused by rupture of the thalamic penetrating artery. A moderate or large amount of thalamic hemorrhage often causes hemiparesis or hemianesthesia contralateral to the lesion due to compression or damage to the internal capsule. Sensory deficits are more severe, with both deep and superficial senses involved, but deep sensory deficits are evident and may be accompanied by hemiplegic spontaneous pain and hyperalgesia. Patients with hemorrhage in the dominant hemisphere may present with aphasia, and with non-dominant hemisphere involvement, there may be somatosensory image disturbance and hemianesthesia. Thalamic hemorrhage may present with psychiatric disorders, manifested as emotional apathy, phantom vision and depression, as well as thalamic language and thalamic dementia. If the thalamic hemorrhage extends down to the hypothalamus or upper midbrain, it may cause some eye position abnormalities such as vertical gaze or lateral gaze palsy, binocular dissociative strabismus, strabismus nasalis, dull pupillary reflex to light, pseudo-extensor nerve palsy and convergence disorder. When the hematoma spreads to the lower thalamus or breaks into the third ventricle, it shows symptoms such as deepening of consciousness, pupil narrowing, central hyperthermia and decortical tonicity. According to the above, thalamic hemorrhage causing tetraplegia may be de-cortical tonic or de-cerebral tonic . Contralateral paralysis caused by thalamic lesion on the home side: If the activity of the midbrain is greater, the brainstem may be pushed by the medial temporal lobe of the affected side, the contralateral cerebral peduncle is pressed against the free edge of the sharp cerebellar curtain, and the pupil dilatation side and the sign of motor neuron paralysis on the limb are on the same side, and other clinical manifestations such as impaired consciousness caused by the two causes are different.