Cranial Nerve XII: The Hypoglossal Nerve
ABSTRACT The hypoglossal nerve provides motor innervation to the tongue, and may be affected by pathology at multiple locations along its pathway. Knowledge of its anatomy and careful examination of the tongue are important in the diagnosis of lesions and determination of appropriate testing. The hypoglossal nerve anatomy and physiology, clinical disorders, and the evaluation of the hypoglossal nerve are reviewed.
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ABSTRACT: Tonsillectomy is a common procedure in the ENT department but unusual complications related to nerve injury might be associated with the surgery. We report a case of permanent hypoglossal nerve palsy following tonsillectomy in a 33-year-old female patient. The findings from the neurologic examination were unremarkable except for tongue deviation to the left, hemiatrophy of the tongue and associated dysarthria. Forceful pressure and stretch of hypoglossal nerve during surgery can explain the cause of injury. To avoid nerve compression, intermittent release of the mouth gag and avoidance of neck hyperextension are suggested especially when long operation time would be expected. Although rare, having knowledge of the existence of hypoglossal nerve injury complicating tonsillectomy is important when counseling patients.01/2010; 53(3). DOI:10.3342/kjorl-hns.2010.53.3.172
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ABSTRACT: Since its introduction in 1960, The Wada test has been considered the gold standard for language lateralization prior to ablative brain surgery. Due to the invasive nature of The Wada test several non-invasive techniques have been alternatively adopted. Recently, it has been suggested that the tongue deviates toward the language dominant cerebral hemisphere on full protraction. This suggestion is based on the important role the tongue plays in articulation and on the close anatomical relationship between the cortical tongue motor area and the motor speech area. It was proposed that this phenomenon could serve as a reliable and simple method for language brain lateralization. However, this hypothesis is still open for verification. In an attempt to correlate tongue deviation and language cerebral dominance we present and discuss in this paper the results of a study conducted on 339 free adult Jordanian volunteers. Tongue deviation and handedness were determined and statistically correlated. Our results showed that 62% of test subjects did not show any tongue deviation on full protrusion. Additionally, 9% of test subjects showed left-sided tongue deviation on full protraction in spite of 90% right handedness with presumed left language dominant cerebral hemisphere. We conclude that, at least in Jordanians, tongue deviation cannot be considered as a reliable indicator for language lateralization.Medical Hypotheses 09/2014; DOI:10.1016/j.mehy.2014.05.014 · 1.15 Impact Factor
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ABSTRACT: Intraoperative nerve monitoring (IONM) has many applications in different surgical fields. In head and neck surgery, IONM has been used to perform surgery of the parotid, thyroid and parathyroid glands, preserving the facial and recurrent nerves. However, hypoglossal nerve neuromonitoring has not been addressed with such relevance. A retrospective review of surgeries performed on patients with special tongue and floor of mouth conditions was undertaken to examine the indications that prompted its use. Particular attention was given to the pathology, intraoperative findings and the final outcome of each patient. Four patients, aged between 6 years and 68 years, with complex oral tongue and floor of mouth lesions were reviewed. Three patients were male, aged 22 years and younger, and two of these patients had oral tongue cancers with previous surgery. Oral tongue and neck conditions are challenging since the functions of the hypoglossal nerve are put at risk. The use of IONM technology allowed us to preserve nerve functions, speech and swallowing. Although IONM of the hypoglossal nerve is not a common indication in tongue and floor of mouth lesions, under special conditions its application can be extrapolated to challenging surgical cases, like the ones described.World Journal of Surgical Oncology 09/2013; 11(1):225. DOI:10.1186/1477-7819-11-225 · 1.20 Impact Factor