The alterations of inducible nitric oxide synthase in the mouse brainstem during herpes simplex virus type 1-induced facial palsy.

OBJECTIVE: We sought to study the alterations of inducible nitric oxide synthase (iNOS) in the mouse brainstem during facial paralysis induced by herpes simplex virus type 1 (HSV-1) and the inhibitory effects of glucocorticoids. METHODS: HSV-1 was inoculated into the surface of posterior auricle of mouse to set up an animal model. The paralyzed mice were divided in three groups as detailed in text. Mice, in one group, were killed at different time points and, in other two groups, were injected daily for 2 days with methylprednisolone sodium succinate (MPSS) or with combined administration of MPSS and glucocorticoid receptor blocker (RU486). Morphological changes were evaluated by means of hematoxylin and eosin (H&E) staining and improved trichrome staining. The expression and location of iNOS in the facial nucleus of brainstem was detected by reverse transcription-polymerase chain reaction (RT-PCR), western blot, and immunohistochemistry. RESULTS: After inoculated by HSV-1, 49·09% of mice developed unilateral facial paralysis. Injuries in response to HSV-1 infection in the facial nerves and facial nucleus of paralyzed mice were observed by morphological methods. Besides, we found that iNOS was present in normal glial cells and motor neurons at low levels and was upregulated dramatically after facial paralysis, which could be inhibited by MPSS. RU486, a glucocorticoid receptor inhibitor, could block the inhibitory effects of MPSS. DISCUSSION: The present study demonstrates that the enhanced activity of iNOS in the early phase represents an important mechanism in HSV-1-induced facial paralysis. MPSS can effectively attenuate HSV-1-mediated damages in nerve system, which is closely associated to its inhibitory effect on expression of iNOS.

SOD1 (A4V)-mediated ALS presenting with lower motor neuron facial diplegia and unilateral vocal cord paralysis.

Amyotrophic lateral sclerosis (ALS) is a progressive degenerative neuromuscular disease that presents with upper and lower motor neuron signs. Although the majority of ALS cases are sporadic, 10% are familial, of which 20%-25% result from mutations in the superoxide dismutase (SOD1) gene. We describe a novel case of SOD1 (A4V)-mediated ALS that presented with lower motor neuron facial diplegia and unilateral vocal cord paralysis. This case expands the phenotypic expression of the A4V mutation.

[Effects of aminoguanidine on the expression of NOS in facial nerve and surrounding tissues of traumatic facial paralysis rats].

OBJECTIVE: To study the effects of inducible NOS inhibitor aminoguanidine on the expression of NOS in facial nerve and surrounding tissue of traumatic facial paralysis rats. METHODS: A small dose of aminoguanidine were intraperitoneally injected into rats before and after facial paralysis. The facial nerve and surrounding tissues were cut at different time point. Immunohistochemical ABC method was used to study the changes of NOS expression in facial nerve and surrounding tissues. RESULTS: The inducible NOS immunoreactivity was obvious inhibited in the facial nerve and surrounding tissues in aminoguanidine group. CONCLUSION: Aminoguanidine chronic treatment can obvious inhibit the inducible NOS expression in the facial nerve and surrounding tissues. Aminoguanidine can improve the regeneration of facial nerve and the recovery of traumatic tissues.

Involvement of nitric oxide synthase in the physiology and pathophysiology of facial nerve function and dysfunction.

To date few reports have discussed the presence and function of nitric oxide (NO) in structures of the facial nerve. We performed nicotinamide adenine dinucleotide phosphate (NADPH-d)-diaphorase-histochemistry and immunohistochemistry on the intratemporal portion of the facial nerve, including the geniculate ganglion, of guinea pigs using specific antibodies to the three known isoforms of NO synthase and soluble guanylyl-cyclase (sGC). Normal facial nerves were compared to those treated intratympanically with bacterial lipopolysaccharides (LPS) and tumor necrosis factor-alpha (TNF-alpha). Both constitutive NOS isoforms and sGC could be detected in the bipolar ganglion cells of normal animals, while the inducible isoform (iNOS or NOS II) was not found. Endothelial NOS (NOS III) and sGC were present in blood vessels and were predominantly found in the perineurial sheath and less in the endoneurium. sGC could be detected in all fibers in a cross section of the facial nerve. LPS and TNF treatment led to the detection of iNOS in the perikaryia of the geniculate ganglion and the perineural sheath. These findings imply that NO may be involved in neurotransmission at least in the visceroafferent system. NO regulates vascular tone of nutrient blood vessels in the perineural sheath and endoneurium. The presence of sGC indicates that NO acts via its second messenger cGMP. NOS II expression may be a contributing factor to facial nerve palsy via two different mechanisms: NOS II-generated NO may lead to an overstimulation of the visceroefferent nerve fibers and motor fibers of the facial nerve. Dysregulation in facial nerve blood vessels could lead to edema and elevated pressure on the nerve within its osseous canal.

Impaired Ranvier node sodium-potassium adenosine triphosphatase may induce facial palsy.

To clarify the part of the neuron essential for myelinated nerve conduction, the cytochemical localization of potassium ion (K+)-dependent p-nitrophenylphosphatase (K-NPPase) activity was investigated in the normal and reserpine-treated facial nerve of guinea pigs. In the normal animals, K-NPPase activity was localized to the internodal axolemma and Schmidt-Lanterman incisures. In the Ranvier nodes, enzyme activity was observed along the paranodal and nodal axolemma. In reserpinized nerves, K-NPPase activity was absent along the internodal axolemma and Schmidt-Lanterman incisures. In the Ranvier nodes, however, enzyme activity was detectable only in the nodal axolemma. The reserpinized animals demonstrated no evidence of facial palsy. Because K-NPPase is essential for nerve conduction, these results indicate that the location of enzyme activity in reserpinized animals, namely the nodal axolemma, may be of prime importance in saltatory nerve conduction.

[2'-5' olygoadenylate synthetase activity in peripheral facial paralysis].

Interferons are produced in response to viral infection and play an important part in defense by their antiviral effects. An interferon-induced enzyme, 2'-5' oligoadenylate synthetase (2-5AS) also takes an important part of the system of defense against viral infections, and its activity elevates in nonspecific viral infections. This study was designed to evaluate the usefulness of examining serum 2-5AS activity and peripheral blood WBC 2-5AS (WBC 2-5AS) as diagnostic aids of viral infections that cause facial paralysis. Samples were obtained from 83 patients with Bell's palsy, 20 with Ramsay Hunt syndrome, 74 healthy individuals, and a total of 177 subjects. In 177, we measured serum 2-5AS level in 123 subjects, WBC 2-5AS level in 57, and both in 25. Serum 2-5AS levels in Bell's palsy (60 cases) ranged from 20 to 146 pmol/dl (average: 38.5). The range in Ramsay Hunt syndrome (13) was 20-333 (average: 59.0), and in healthy controls (50), it was 20-128 (average: 41.4). WBC 2-5AS level ranged from 20 to 5900 pmol/dl (average: 733.2) in Bell's palsy (23 cases), from 20-4540 (average: 1371.4) in Ramsay Hunt syndrome (7), and from 20-903 (average: 294.5) in healthy individuals (24). There were no statistically significant differences in serum 2-5AS activities. Otherwise, there was significant difference (p < 0.01) between healthy individuals and Patients with Ramsay Hunt syndrome in WBC 2-5AS activity. In Bell's palsy, 3 cases (13.0%) with markedly high WBC 2-5AS levels existed.(ABSTRACT TRUNCATED AT 250 WORDS)

[Experimental validation of the use of the masseter muscle in treating paralysis of the mimetic muscles]. / Eksperimental'noe obosnovanie ispol'zovaniia zhevatel'noi myshtsy pri lechenii paralichei mimicheskikh myshts.

In 15 rabbits the distal end of masseter muscle was surgically transposed to perioral region. After 90, 120 and 180 days the altered muscle position and reduction of functional load did not cause its degeneration. Rather, these conditions elicited a functional reordering evidenced by reduction of muscular fibers' cross-sectional area, the number of surrounding capillaries, decrease in the succinate dehydrogenase activity and increase in connective tissue layer.

Morphology of denervated human facial muscles.

17 biopsies of denervated facial muscles, the zygomatic, the orbicularis oris and the levator labii muscles, showed atrophic myofibers in most cases. There was loss of fiber typability when applying the NADH, the MAG and the alkaline ATPase reactions. The acid ATPase preparations allowed differentiation of myofibers into type I and type II without subtypes. Contrary to normal facial muscles that are richly endowed with motor endplates, no neuromuscular junctions were observed in denervated muscle fibers except one example which might have been obtained by false sampling from the marginal area of denervation or might be the result of partial reinnervation due to sprouting axons from the neighborhood. There was no correlation between the degree of muscle fiber atrophy and the duration of the paralysis. However, fibrosis corresponded to length of denervation. The presence of highly atrophic muscle fibers even 36 years after denervation indicates that the final aim of facial nerve surgery, namely the reinnervation of denervated facial musculature may still be achievable. However, endomysial and perimysial fibrosis may have a considerable impact on the final outcome of such facial nerve surgery. Unsatisfactory correlation between morphological and clinical as well as electromyographical findings in denervated facial muscles requires individual morphological study of each biopsy to assess the probable outcome of reconstructive facial nerve surgery. It therefore appears reasonable even in long-standing facial paralysis, to biopsy denervated facial muscles before or during surgical reanastomosation of the facial nerve. This study provides hints that morphological examination of denervated facial muscles may supplement clinical, electrophysiological, and possibly biochemical diagnostic findings.

Myoadenylate deaminase deficiency in a patient with facial and limb girdle myopathy.

Absence of AMP-deaminase was demonstrated by histochemical and biochemical methods in a muscle biopsy of a 25-year-old woman with facial and limb girdle myopathy. Venous ammonia failed to rise after ischaemic exercise. This patient further contributes to the variety of clinical pictures associated with AMP-deaminase deficiency. Whereas AMP-deaminase has been shown to play an essential role in the regulation of adenine nucleotide metabolism in the liver, its physiological function in muscle remains uncertain.

[Clinico-enzymologic correlations in trophic disorders of the buccal mucosa in patients with peripheral lesions of the facial nerve]. / Kliniko-énzimologicheskie sopostavleniia pri troficheskikh narusheniiakh slizistoi obolochki shcheki u bol'nykh s perifericheskimi porazheniiami litsevogo nerva.

The paper deals with trophic disorders of the buccal mucosa in 30 patients with Bell's paralysis. The character of the found changes was judged by the results of an examination of the mucosa and chemical and histochemical studies of the bioptate, obtained by aspirational biopsy. The examinations demonstrated trophical disorders in the buccal mucosa which was testified to by a slight edema and enzymatic-metabolic disorders in the form of an increased activity of the acid and alkaline phosphotase as well as asparagine and alanine aminotranspherase. These changes to a certain extent confirm the existence of vegetative filaments in the facial nerve, an affection of which leads to metabolic-trophical changes. Such data should be taken into consideration in an attempt to explain the mechanisms of distrophical processes and may be utilized as some indices in the judgment of the dynamics in the process of treatment.