Denervation pattern of three mimic muscles in Bell's palsy

Ultrasonographic findings of facial muscles in patients with severe facial palsy who showed no improvement for more than 3 months on acute stage

INTRODUCTION/AIMS

The study aimed to visualize the changes in the facial muscles of patients with severe facial palsy who showed no improvement for more than 3 months on acute stage.

METHODS

The 102 patients with severe facial palsy over House-Brackmann grade IV or an 80% degenerative ratio on ENoG at the initial examination, who showed no improvement for more than 3 months on acute stage were indicated to undergo ultrasonography of the face to evaluate the facial muscles.

RESULTS

Muscular degeneration was observed in 537/918 muscles (58.5%). Muscle volume shrinkage was observed in 209/918 muscles (22.8%). Fascial adhesions were observed in 209/918 muscles (22.7%). Among all the muscles assessed for degenerative changes, zygomaticus major/minor was the most affected by degenerative changes (91.2%). Degenerative changes were observed in the levator labii superioris muscle in 84.3% patients. The shrinkage was most frequently observed in the zygomaticus major muscle (61/102 patients [59.8%]), followed by the zygomaticus minor muscle (43.1%). Shrinkage of the levator labii suprioris was observed in 24.5% patients. The zygomaticus major/minor muscle had the highest proportion of fascial adhesions in 61.8% and 66.7% patients respectively. The levator labii suprioris muscle showed the lowest proportion of fascial adhesions, with only 7.8% patients being affected.

DISCUSSION

This study confirmed that the zygomaticus major, zygomaticus minor, and levator labii suprioris muscles, which raise the corner of the mouth, are the first to degenerate in patients with severe facial paralysis. This study demonstrated that ultrasonography is a simple and non-invasive examination for facial paralysis.

Correlations between the clinical, histological and neurophysiological examinations in patients before and after parotid gland tumor surgery: verification of facial nerve transmission

Parotid gland tumor surgery sometimes leads to facial nerve paralysis. Malignant more than benign tumors determine nerve function preoperatively, while postoperative observations based on clinical, histological and neurophysiological studies have not been reported in detail. The aims of this pilot study were evaluation and correlations of histological properties of tumor (its size and location) and clinical and neurophysiological assessment of facial nerve function pre- and post-operatively (1 and 6 months). Comparative studies included 17 patients with benign (n = 13) and malignant (n = 4) tumors. Clinical assessment was based on House-Brackmann scale (H-B), neurophysiological diagnostics included facial electroneurography [ENG, compound muscle action potential (CMAP)], mimetic muscle electromyography (EMG) and blink-reflex examinations (BR). Mainly grade I of H-B was recorded both pre- (n = 13) and post-operatively (n = 12) in patients with small (1.5-2.4 cm) benign tumors located in superficial lobes. Patients with medium size (2.5-3.4 cm) malignant tumors in both lobes were scored at grade I (n = 2) and III (n = 2) pre- and mainly VI (n = 4) post-operatively. CMAP amplitudes after stimulation of mandibular marginal branch were reduced at about 25 % in patients with benign tumors after surgery. In the cases of malignant tumors CMAPs were not recorded following stimulation of any branch. A similar trend was found for BR results. H-B and ENG results revealed positive correlations between the type of tumor and surgery with facial nerve function. Neurophysiological studies detected clinically silent facial nerve neuropathy of mandibular marginal branch in postoperative period. Needle EMG, ENG and BR examinations allow for the evaluation of face muscles reinnervation and facial nerve regeneration.

Which electrophysiological measure is appropriate in predicting prognosis of facial paralysis?

OBJECTIVE

The prognostic value of electrophysiology and its significance in the prediction facial function outcome in facial palsy patients remains unclear because of the different methodologies used in previous studies. We aimed to establish the prognostic value of electrophysiological testing in a group of patients with facial palsy.

METHODS

We prospectively analyzed facial nerve electrophysiology results and compared them with the House-Brackmann scale in 65 patients. The treatment consisted of a standard corticosteroid plus antiviral regimen. Clinical evaluation comprised the House-Brackmann grading system and electrophysiological tests (nerve excitability, nerve conduction study (NCS), needle electromyography (EMG), and blink reflex) conducted on the 5th, 20th, and 90th days after paralysis onset.

RESULTS

In predicting the prognosis, the nerve excitability test in the acute phase, NCS in the subacute phase, blink reflex in the acute and subacute phases and needle EMG in the subacute phase provided statistically significant results.

CONCLUSION

Prognosis can be determined, and excessive tests can be eliminated with proper timing and electrophysiological testing.

SIGNIFICANCE

In determining the prognosis of facial paralysis, the nerve excitability test should be used in the acute phase, and NCS and needle EMG should be used in the subacute phase. Blink reflex studies are helpful in both the acute and subacute phases.