Because of this, people with Bells palsy may present with loss of taste sensation in the anterior 2⁄3 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 Bells palsy 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". Cause
The cause of Bells palsy is unknown. Risk factors include diabetes, a recent upper respiratory tract infection, and pregnancy.Some viruses are thought to establish a persistent (or latent) infection without symptoms, e.g., the varicella zoster virus and the Epstein–Barr virus, both of the herpes family. Reactivation of an existing (dormant) viral infection has been suggested as a cause of acute Bells palsy. As the facial nerve swells and becomes inflamed in reaction to the infection, it causes pressure within the Fallopian canal, resulting in the restriction of blood and oxygen to the nerve cells. Other viruses and bacteria that have been linked to the development of Bells palsy include HIV, sarcoidosis and Lyme Disease. This new activation could be triggered by trauma, environmental factors, and metabolic or emotional disorders.Familial inheritance has been found in 4–14% of cases.
Both heads of the biceps join in the middle upper arm to form a single muscle mass usually near the insertion of the deltoid to form a common muscle belly, although several anatomic studies have demonstrated that the muscle bellies remain distinct structures without confluent fibers. As the muscle extends distally, the two heads rotate 90 degrees externally before inserting onto the radial tuberosity. The short head inserts distally on the tuberosity while the long head inserts proximally closer to the apex of the tuberosity. The bicipital aponeurosis, also called the lacertus fibrosus, is a thick fascial band that organizes close to the musculotendinous junction of the biceps and radiates over and inserts onto the ulnar part of the antebrachial fascia.The tendon that attaches to the radial tuberosity is partially or completely surrounded by a bursa, the bicipitoradial bursa, which ensures frictionless motion between the biceps tendon and the proximal radius during pronation and supination of the forearm.Two muscles lie underneath the biceps brachii. These are the coracobrachialis muscle, which like the biceps attaches to the coracoid process of the scapula, and the brachialis muscle which connects to the ulna and along the mid-shaft of the humerus. Besides those, the brachioradialis muscle is adjacent to the biceps and also inserts on the radius bone, though more distally.