Facial nerve paralysis is a common problem that involves the paralysis of any structures innervated by the facial nerve. The pathway of the facial nerve is long and relatively convoluted, so there are a number of causes that may result in facial nerve paralysis. The most common is Bells palsy, a disease of unknown cause that may only be diagnosed by exclusion of identifiable serious causes. Signs and symptoms
Facial nerve paralysis is characterised by facial weakness, usually only in one side of the face, with other symptoms possibly including loss of taste, hyperacusis and decreased salivation and tear secretion. Other signs may be linked to the cause of the paralysis, such as vesicles in the ear, which may occur if the facial palsy is due to shingles. Symptoms may develop over several hours. : 1228  Acute facial pain radiating from the ear may precede the onset of other symptoms. : 2585

Causes
Bells palsy
Bells palsy is the most common cause of acute facial nerve paralysis. There is no known cause of Bells palsy, although it has been associated with herpes simplex infection. Bells palsy may develop over several days, and may last several months, in the majority of cases recovering spontaneously. It is typically diagnosed clinically, in patients with no risk factors for other causes, without vesicles in the ear, and with no other neurological signs. Recovery may be delayed in the elderly, or those with a complete paralysis. Bells palsy is often treated with corticosteroids.
A left posterior fascicular block (LPFB), also known as left posterior hemiblock (LPH), is a condition where the left posterior fascicle, which travels to the inferior and posterior portion of the left ventricle, does not conduct the electrical impulses from the atrioventricular node. The wave-front instead moves more quickly through the left anterior fascicle and right bundle branch, leading to a right axis deviation seen on the ECG. Definition
The American Heart Association has defined a LPFB as:
Frontal plane axis between 90° and 180° in adults
rS pattern in leads I and aVL
qR pattern in leads III and aVF
QRS duration less than 120 msThe broad nature of the posterior bundle as well as its dual blood supply makes isolated LPFB rare. See also
Left bundle branch block
Left anterior fascicular block

References
Further reading
Ma FS, Ma J, Tang K,  et al. (March 2006). "Left posterior fascicular block: a new endpoint of ablation for verapamil-sensitive idiopathic ventricular tachycardia". Chin. Med. J. 119 (5): 367–72. doi:10.1097/00029330-200603010-00003. PMID 16542578. == External links ==