Paralysis refers to a temporary or permanent loss or impairment of motor or sensory function in a part. The XIIth cranial nerve is one of twelve pairs of nerves connected with the brain. It is the motor nerve to the tongue supplying the ipsilateral muscles which provides tongue movement.

Paralysis may be caused by tumors at the base of the skull and the meninges. Other etiologic factors include: lesions of the nerve or nerve root; brainstem lesions or injury such as motor neuron disease; poliomyelitis; tumors; chronic degenerative disorders such as amyotrophic lateral sclerosis (ALS); and surgical trauma. Deficits of this nerve may be in combination with those of the tenth and eleventh cranial nerves. (See Diagnostic Code: 8210 Tenth [pneumogastric, vagus] cranial nerve-Paralysis of, and Diagnostic Code: 8211 Eleventh [spinal accessory, external branch] cranial nerve-Paralysis of).

Manifestations may include: atrophy and paralysis of half of the tongue muscles; deviation of the tongue to the paralyzed side; fasciculation; dysarthria; and difficulty in eating.

Diagnostic measures may include: complete history; physical and neurological examinations; blood studies; spinal tap; computed tomography (CT) scan; and magnetic resonance imaging (MRI); and electromyography (EMG).

Treatment may be directed to the specific underlying cause and symptoms. Other measures of the treatment plan may include: surgery; medications to treat underlying diseases; nutritional intervention; and physical and speech therapies. Treatments for symptoms of affected neighboring nerves may be indicated.

Regeneration of the nerve may depend on the degree and site of injury. The closer the injury is to the central nervous system (CNS), regeneration of a severely damaged nerve is less likely to occur. Partial paralysis may be progressive and become permanent. Muscle atrophy and fasciculation may develop weeks to months following nerve injury. The nutritional status may decline, and there may be injury to neighboring nerves.

• This disease shall be granted service connection although not otherwise established as incurred in or aggravated by service if manifested to a compensable degree within the applicable time limits under 38 CFR 3.307 following service in a period of war or following peacetime service on or after January 1, 1947, provided the rebuttable presumption provisions of 38 CFR 3.307 are also satisfied [38 CFR 3.309 [Disease subject to presumptive service connection], 38 CFR 3.309(a). [chronic disease].

Notes

•  Dependent upon loss of motor function of tongue.