In this simplified brain circuit, damage to orexin-secreting neurons in the hypothalamus can lead to inhibition of motor neurons, thus lowering muscle tone.<unk>  is considered secondary when it is due to specific lesions in the brain that cause a depletion of the hypocretin neurotransmitter. Secondary<unk>  is associated with specific lesions located primarily in the lateral and posterior hypothalamus.<unk>  due to brainstem lesions is uncommon particularly when seen in isolation. The lesions include tumors of the brain or brainstem and arterio-venous malformations. Some of the tumors include astrocytoma, glioblastoma, glioma, and subependynoma. These lesions can be visualized with brain imaging, however in their early stages they can be missed. Other conditions in which<unk>  can be seen include ischemic events, multiple sclerosis, head injury, paraneoplastic syndromes, and infections such as encephalitis.<unk>  may also occur transiently or permanently due to lesions of the hypothalamus that were caused by surgery, especially in difficult tumor resections. These lesions or generalized processes disrupt the hypocretin neurons and their pathways. The neurological process behind the lesion impairs pathways controlling the normal inhibition of muscle tone drop, consequently resulting in muscle atonia. Theories for episodes A phenomenon of REM sleep, muscular paralysis, occurs at an inappropriate time. This loss of tonus is caused by massive inhibition of motor neurons in the spinal cord. When this happens during waking, the victim of a cataplectic attack loses control of his or her muscles. As in REM sleep, the person continues to breathe and is able to control eye movements. Hypocretin The hypothalamus region of the brain regulates basic functions of hormone release, emotional expression and sleep. A study in 2006 in "Tohoku Journal of Experimental Medicine" concluded that the neurochemical hypocretin, which is regulated by the hypothalamus, was significantly reduced in study participants with symptoms of<unk> . Orexin, also known as Hypocretin, is a primary chemical important in regulating sleep as well as states of arousal. Hypocretin deficiency is further associated with decreased levels of histamine and epinephrine, which are chemicals important in promoting wakefulness, arousal and alertness.
Cataplexy
Catatonia
Apoplexy
Paratonia
Metamorphopsia
Abnormal posturing
Catalepsy
Diplophonia