<unk>  is characterized by a one-sided facial droop that comes on within 72 hours. In rare cases (<1%), it can occur on both sides resulting in total facial paralysis. The facial nerve controls a number of functions, such as blinking and closing the eyes, smiling, frowning, lacrimation, salivation, flaring nostrils and raising eyebrows. It also carries taste sensations from the anterior two-thirds of the tongue, through the chorda tympani nerve (a branch of the facial nerve). Because of this, people with<unk>  may present with loss of taste sensation in the anterior of the tongue on the affected side. Although the facial nerve innervates the stapedius muscle of the middle ear (through the tympanic branch), sound sensitivity, causing normal sounds to be perceived as very loud (hyperacusis), and dysacusis are possible but hardly ever clinically evident. Although defined as a mononeuritis (involving only one nerve), people diagnosed with<unk>  may have "myriad neurological symptoms" including "facial tingling, moderate or severe headache/neck pain, memory problems, balance problems, ipsilateral limb paresthesias, ipsilateral limb weakness, and a sense of clumsiness" that are "unexplained by facial nerve dysfunction".
Bell's palsy
Lyme disease
Erb's palsy
Stroke
Horner's syndrome
Ramsay Hunt syndrome type 2
Todd's paresis
Brain tumor