Diseases Of The Nose Throat And Ear

INVESTIGATION OF LARYNGEAL DISEASE

151

part of the larynx, the epiglottis and the anterior commissure, Is seen towards
the top of the mirror and the posterior part, the arytenoids and the posterior
commissure, is seen at the lower portion of the mirror. The patient's right
vocal cord is on the left side of the mirror as the examiner looks at it. The
patient is asked to continue to breathe gently through the mouth so that the
form and colour of all parts of the larynx may be examined (Fig. 70). One first

Fig. 70, The laryngeal image on indirect laryngoscopy. 1, Dorsum of tongue; 2, Vallecula; 3, Epiglottis;
4, Vestibular fold; 5, Vocal fold (cord); 6, Pyriform fossa; 7, Ary-epiglottic fold; 8, Arytenoid cartilage.

examines the vallecula and the tip of the epiglottis, and then the ary-epiglottic
folds and the pyriform fossae on each side, and from there attention is
directed medially to the mouth of the oesophagus and the arytenoids. The
false cords (ventricular folds) and the normally white vocal cords (vocal folds)
are next inspected. It is sometimes possible to see the upper few centimetres of
the trachea through the glottis. Finally, the movements of the vocal cords are
studied by asking the patient to phonate 'ee* several times, when the glottis
should normally close.

It may not be possible to do an indirect laryngoscopy on some patients due
to an overactive gag reflex. In these cases the soft palate and uvula may be
painted with 5 per cent cocaine hydrochloride, and the larynx may be similarly
sprayed. In spite of this it may still be necessary to give some patients a
general anaesthetic in order to examine the larynx, especially if there is an
overhanging epiglottis.

LABORATORY INVESTIGATIONS. These do not form a major part of the
investigation of laryngeal disease but in appropriate cases blood may be taken
for blood counts, thyroid function tests, serological tests, rheumatoid
arthritis factor tests and monospot tests. In cases of suspected tuberculosis a
Mantoux test may be done.

RADIOLOGY.

1. Plain Radiographs. Radiographs of the chest and neck may be of use in
demonstrating the presence of air as, for example, in surgical emphysema or a
laryngocele. The state of ossification of the cricoid and thyroid cartilage can
be assessed and any displacement of the trachea will be seen. Mediastinal
masses causing recurrent laryngeal nerve paralysis are usually obvious.

2. Tomography. Tomography of the larynx (Fig. 71) is a most useful
investigation in assessing the extent of a laryngeal tumour especially an