Recurrent nerve

Varizella zoster vitus (VZV) is a highly contagious herpesvirus causing chickenpox upon primary infection. After recovery, the vims stays dormant in nerve roots. Weakening of the immune system, e.g. in people over the age of 60 or under immunosuppressive therapy, can lead to reactivation of VZV. This recurrence causes shingles (herpes zoster), a painful rash that develops in a well-defined band corresponding to the area enervated by the affected nerve cells. 

In a recent study 19 of recurrent laryngeal nerves based on the dissection of 100 cadavers, it was found that of the 200 nerves 57 per cent entered the larynx without having branched at any point, whereas 43 per cent were divided trunk nerves with from two to as many as six branches. Furthermore, in 35 per cent of the cadavers, both recurrent laryngeal nerves were single-trunk nerves in 24 per cent, both were divided-trunk nerves and in 41 per cent, one nerve had a divided trunk and the other did not. No consistency of patterns between the right and left sides was found. 

If we dehne a mood stabilizer as a medication that is both an effective anti-manic and antidepressant, then lithium arguably remains to this day the prototypical mood stabilizer. Lithium not only reduces the symptoms of acute BPAD, it also prevents the recurrence of additional mood episodes. Despite the fact that lithium has revolutionized the treatment of BPAD and remains nearly 50 years after its introduction as the single best treatment for many patients with BPAD, there is still no consensus as to how it works. Lithium exerts effects on several neurotransmitter systems (e.g., serotonin, dopamine, norepinephrine, acetylcholine), on second messenger systems inside the nerve cell, and on nerve cell gene expression. Yet, precisely how these varied effects produce lithium s therapeutic benefit remains unclear. 

Sarcomas are tumors of mesenchymal origin, arising in skeletal tissues and extra-skeletal connective tissues including the nerves. They are very rare and mainly effect a younger population. Sarcomas of soft tissues are relatively insensitive to drug treatment and are therefore not discussed in detail in this chapter. A systematic review of fourteen trials of doxorubicin-based adjuvant chemotherapy for the treatment of soft tissue sarcomas involving 1568 patients concluded Doxorubicin-based adjuvant chemotherapy appears to significantly improve time to local and distant recurrence and overall recurrence-free survival in adults with localised resectable soft tissue sarcoma. There is some evidence of a trend towards improved overall survival (see Sarcoma Meta-analysis Collaboration, 1999). 

The complications following surgery include haemorrhage, wound infection, recurrent laryngeal nerve damage, and transient (up to 20% of cases) or permanent (2%) hypocalcaemia. After near-total thyroidectomy relapse of hyperthyroidism should be rare, and this operation has largely replaced the older approach of sub-total thyroidectomy which had higher relapse rates. 

Wetzel H, Heuser I, Benker O. Stupor and affective state alleviation of psychomotor disturbances by lorazepam and recurrence of symptoms with RO 15-1788. J Nerv Ment Dis 1987 175 240-242. 

Central and/or peripheral nervous system involvement is one of the most frequent features, often resulting in the neonatal period in drowsiness, poor sucking, severe hypotonia, abnormal movements, seizures, respiratory distress, and fatal keto-acidotic coma with lactic acidosis [3]. To these severe conditions echo late-onset diseases now frequently attributed to or associated with mitochondrial OXPHOS defects, such as Alzheimer s or Parkinsons disease [10]. Major neurological symptoms, in variable combinations, involve trunk hypotonia, cranial nerve and brainstem involvement (with abnormal eye movements, ophthalmoplegia, recurrent apneas), cerebellar ataxia, myoclonia, seizures, pyramidal syndrome, peripheral neuropathy, poliodystrophy, and leukodystrophy infections [27,28]. A diffuse impairment of the cerebral white matter (leukodystrophy) mostly results in motor disturbance with mental retardation and low incidence of seizures. 

Both types of latent HSV are thought to be reactivated by many factors, including UV exposure, trauma, stress, extreme temperatures, immunosuppression, and menstruation. When activated, the virus travels along the sensory nerve to peripheral tissue to cause recurrent HSV infection. An estimated 300,000 cases of primary and recurrent HSV infections develop each year. 

One girl in her third year, who had been immunized against tuberculosis at birth, developed an abscess of the associated lymph nodes (which were extirpated) and some weeks later developed intestinal BCG dissemination, which appeared to be cured by tuberculostatic treatment. Despite this, at the age of 22 years she developed a leftsided hemiplegia due to aneurysms and thrombosis of cerebral arteries, and 4 years later an oculomotor nerve paralysis was diagnosed. She died at 26 from recurrent intestinal BCG dissemination, which developed at the end of a pregnancy (a healthy premature child was bom). 

Brachial plexus paresis has been reported (358). Accidental block of the recurrent laryngeal nerve can cause hoarseness and occasionally aspiration of saliva (359). 

Harris RJ, Benveniste G. Recurrent laryngeal nerve blockade in patients undergoing carotid endarterectomy under cervical plexus block. Anaesth Intensive Care 2000 28(4) 431-3. 

A 13-month-old girl developed a recurrent sixth nerve palsy 1 week after MMR immunization. This resolved completely over 8 weeks and recurred 15 weeks after initial onset. Other causes for the sixth nerve palsy were excluded. 

McCormick A, Dinakaran S, Bhola R, Rennie IG. Recurrent sixth nerve palsy following measles mumps rubella vaccination. Eye 2001 15(Pt 3) 356-7. 

There have been several reports of isolated vincristine-induced recurrent laryngeal nerve paralysis (38,43-47). 

Manelis G, Aderka D, Manelis J, Horn I. [Recurrent laryngeal nerve palsy and dysphagia for liquids due to vincristine.] Harefuah 1976 91(3 ) 84-5. 

Tobias JD, Bozeman PM. Vincristine-induced recurrent laryngeal nerve paralysis in children. Intensive Care Med 1991 17(5) 304-5. 

Whittaker JA, Griffith IP. Recurrent laryngeal nerve paralysis in patients receiving vincristine and vinblastine. BMJ 1977 l(6071) 1251-2. 

The parasympathetic division is the dominant portion of the pulmonary autonomic nervous system in all mammals. Airway smooth muscle is richly supplied with muscarinic receptors and stimulation of M3 receptors results in smooth muscle contraction and bronchoconstriction. Cholinergic stimulation is the primary mechanism of bronchospasm in horses with recurrent airway obstruction (Robinson et al 1996). Parasympathetic innervation can be demonstrated throughout the tracheobronchial tree of the horse but smooth muscle contraction evoked by stimulation of cholinergic nerves is more pronounced in the trachea than in the smaller bronchi. It is expected that parasympathetic blockade with a muscarinic antagonist will have the greatest effect in large, central airways. 

---