Transient speech compromise following sublabial transsphenoidal surgery: A case report and findings of a small preliminary study

Ear, Nose & Throat Journal, April, 2000 by Nagalapura S. Viswanath, David B. Rosenfield, David S. Baskin, Sandra J. Wieber

Abstract

Sublabial transsphenoidal surgical removal of pituitary tumors is a common procedure with minimal complications. Although many investigators have reported oral sensory compromises following surgery, none has reported any postoperative compromise in speaking ability. In this article, we describe the case of a 33-year-old woman who developed transient but severe speech symptoms after she underwent sublabial transsphenoidal surgery. This case prompted us to undertake a brief retrospective analysis of our experience with this procedure in other patients, which revealed that speech compromise is far more common than heretofore realized.

Introduction

It is well documented that several oral complications can arise following sublabial transsphenoidal surgical removal of a pituitary tumor. [1-3] Investigators have reported complications such as dysesthesia, pain, and numbness of the upper lip, as well as numbness of the upper teeth and alveolar region. Although these symptoms generally abate, some do persist. [1,3] Prior to now, there have been no reports of postsurgical speech disturbance.

One might expect to observe speech disturbances following sublabial transsphenoidal surgery for at least two reasons. First, to varying extents, the precision of ongoing speech is dependent on movement-generated afferent feedbacks (tactile, kinesthetic, and auditory). [4-6] Therefore, any surgery that directly involves the sensory innervations in the upper lip, teeth, and alveolar region could be expected to have adverse consequences on speech. Second, postsurgical swelling and the presence of sutures can interfere mechanically with the physical movements that control speech. Another factor that can complicate matters is the way in which a patient copes with the primary symptoms of speech compromise. The coping maneuvers themselves can introduce abnormal dimensions to speech and possibly prolong symptoms.

With these considerations in mind, we report the case of a patient who experienced sensory disturbances in the upper lip, teeth, and alveolar region following sublabial transsphenoidal surgery. These symptoms were accompanied by a transient but severe deterioration in speech. This case motivated us to conduct a retrospective study of 10 other patients who had undergone the same surgery at the Methodist Hospital in Houston in the recent past.

Case report

On March 13, 1998, a 33-year-old woman underwent sublabial transsphenoidal surgery of the pituitary gland following the detection of high levels of prolactin. One week postoperatively, the woman noticed a deterioration in the quality of her speech. Her speech disturbance took on an episodic character, as there were several days when her speech returned to normal.

Three months following her surgery, the patient sought medical treatment for her speech disturbance, and she immediately underwent an initial speech examination. At that time, her speech had been disturbed for more than 4 weeks. The patient described a "funny feeling" in her upper lip and numbness of her upper teeth and alveolar region. Speech and nonspeech tests did not reveal any weakness in the muscles of her lips, tongue, soft palate, or mandible.

The patient was recorded on audiotape with a high-quality microphone as she conversed and read a story aloud. Samples of her recorded speech were submitted for waveform and spectrographic analysis. These samples were also analyzed perceptually for possible phonemic (articulatory) errors.

The patient read in a labored fashion (almost one word at a time) and made many sound errors (mostly distortions of sounds rather than substitutions or deletions). As expected, the sounds that are articulated at the front of the oral cavity--the bilabial (/p/, /b/), dental and alveolar (/d/, /t/, /th/), and fricative (/s/) sounds--were mispronounced, albeit inconsistently. Her voice generally sounded weak and exhibited very little modulation of fundamental frequency (pitch) and very little energy in the midrange and higher harmonics ([greater than] 2.5 kHz).

As a result of her initial examination, the woman was started on the benzodiazepine clonazepam, but she failed to show any improvement. Once she was switched to the anticonvulsant gabapentin (100 mg bid), she experienced a dramatic improvement. When the patient made a return visit 3 weeks following the initial visit, she related that the gabapentin had been prescribed on a Thursday and she had greatly improved by the following Monday. Also, the funny feeling in her upper lip had disappeared, although she still experienced numbness in her upper teeth and alveolar region. During this return visit, we again recorded her while she read aloud the passage she had read during the initial examination. Then we compared her pre- and postmedication speech samples, both perceptually and acoustically.

The postmedication recording revealed that the patient had indeed experienced a dramatic improvement in both her speech and voice. Not surprisingly, the acoustic analysis confirmed the perceptual judgment. Specifically, acoustic analysis showed that the woman's utterances were significantly shorter, more variable in terms of fundamental frequency, and produced with fewer pauses between words. Moreover, her fundamental frequency was generally lower, and she displayed more energy in the upper harmonics. Finally, the phonemic errors disappeared. All these changes were accompanied by a significant change in the patient's mood--from distraught during the first examination to cheerful during the final visit.