Emergent categorical representation of natural, complex sounds resulting from the early post-natal sound environment.

Cortical sensory representations can be reorganized by sensory exposure in an epoch of early development. The adaptive role of this type of plasticity for natural sounds in sensory development is, however, unclear. We have reared rats in a naturalistic, complex acoustic environment and examined their auditory representations. We found that cortical neurons became more selective to spectrotemporal features in the experienced sounds. At the neuronal population level, more neurons were involved in representing the whole set of complex sounds, but fewer neurons actually responded to each individual sound, but with greater magnitudes. A comparison of population-temporal responses to the experienced complex sounds revealed that cortical responses to different renderings of the same song motif were more similar, indicating that the cortical neurons became less sensitive to natural acoustic variations associated with stimulus context and sound renderings. By contrast, cortical responses to sounds of different motifs became more distinctive, suggesting that cortical neurons were tuned to the defining features of the experienced sounds. These effects lead to emergent "categorical" representations of the experienced sounds, which presumably facilitate their recognition.

Relating speech and swallow function to dropout in a longitudinal study of head and neck cancer.

The relation between functional outcome and dropout from a 12-month follow-up period was examined in a longitudinal study whose objective was to define and quantify the functional effects of oral surgical resection and reconstruction on speech and swallowing in patients with head and neck cancer. In a group of 150 patients recruited to a surgical study in the Cancer Control Science Program in Head and Neck Cancer Rehabilitation, dropout from all causes and dropout from specific causes (medical, patient, and administrative specific) were assessed in relation to longitudinal speech and swallow function. In univariate analysis, better speech articulation was associated with decreased risk of dropout from all causes and from medical-specific causes. Better swallow performance was associated with decreased risk of medical-specific dropout. Multivariate analysis revealed the following: (1) only articulation function was associated with dropout from all causes; (2) the association of speech articulation function with medical dropout was diminished after adjusting for advanced age and surgical resection variables; (3) the association of speech articulation function became significant for patient-specific dropout after adjusting for advanced age and surgical resection variables and indicated that better function decreased the risk of this type of dropout; and (4) swallowing function was not related to dropout. Patients treated for oral or oropharyngeal cancer who have poorer speech outcomes are more likely to drop out from a longitudinal study. Basing study results on only patients who complete a longitudinal study will understate the level of dysfunction experienced.

Factors related to dropout in a study of head and neck cancer patients after surgery.

The extent and nature of dropout was assessed in a longitudinal study whose objective was to define and quantify the functional effects of oral surgical resection and reconstruction on speech and swallowing function in patients with head and neck cancer. Of 150 patients who were enrolled to be followed up with speech and swallow assessments for 1 year after surgery, 113 (75%) dropped out and 37 (25%) returned to complete the study at the final 12-month evaluation point. In general, those completing the study had a smaller resection than the patients who dropped out before the 12-month evaluation. Fifty percent of the dropout was accounted for by medical reasons, 23% by administrative reasons, and 27% by patient-specific reasons (i.e., reasons known only to the patient). Analysis of the dropout categories revealed that higher cancer stage, larger volume of resection, and having a flap surgical closure versus a primary closure or skin graft increased a patient's chance of dropping out. A larger volume of resection was also related to an increased chance of being a patient-specific dropout. Patients who reported no or low alcohol usage had a greater chance of completing follow-up than being a patient-specific dropout.

Surgical variables affecting speech in treated patients with oral and oropharyngeal cancer.

Postoperative speech function may be influenced by a number of treatment variables. The objective of this study was to examine the relationships among various treatment factors to determine the impact of these measures on speech function. Speech function was tested prospectively in 142 patients with surgically treated oral and oropharyngeal cancer 3 months after treatment. Each patient's speech was recorded during a 6- to 7-minute conversation and while performing a standard articulation test, producing speech outcome measures of percent correct consonant phonemes and percent conversational understandability. Correlational analyses were used to determine the relationships among the speech outcome measures and 14 treatment parameters. Speech function was mildly to moderately negatively correlated with most surgical resection variables, indicating that larger amounts of tissue resected were associated with worse speech function. Overall measures of conversational understandability and percent correct consonant phonemes were related to extent of oral tongue resection, floor of mouth resection, soft palate resection, and total volume of tissue resected. These relationships varied depending on the method of surgical closure. Method of surgical reconstruction had a profound impact on postoperative speech function 3 months after treatment and was an important factor in determining how oral tongue resection influenced articulation and intelligibility. The combination of closure type, percent oral tongue resected, and percent soft palate resected had the strongest relationship with overall speech function for patients with surgically treated oral and oropharyngeal cancer 3 months after treatment.

Speech and swallowing function after oral and oropharyngeal resections: one-year follow-up.

BACKGROUND: The purpose of this study was to determine whether the speech and swallowing function of surgically treated oral cancer patients improves between 1 month and 1 year after surgery. METHODS: Speech and swallowing performances were assessed for 28 men and 10 women preoperatively and at 1, 3, 6, and 12 months postoperatively following a standardized protocol. Speech tasks included an audio recording of a brief conversation and of a standard articulation test; swallowing function was examined using videofluoroscopy. Data were also collected on the number and duration of speech/swallowing therapy sessions, as well as the amount and duration of radiotherapy. RESULTS: Statistical analyses revealed that the speech and swallowing function of surgically treated oral and oropharyngeal cancer patients did not improve progressively between 1 and 12 months postsurgery; the level of functioning that these patients demonstrated at the 1- and 3-month posthealing evaluations was characteristic of their status at 1 year after surgery. CONCLUSION: The lack of improvement between 1 and 12 months postsurgery may be related to the relatively small amount of therapy that these patients received during that period. Several outcome variables worsened significantly at the 6-month evaluation; the reversal of function at the 6-month evaluation point could be the effect of postoperative radiotherapy, because irradiated and nonirradiated patients differed in their pattern of recovery on oropharyngeal swallow efficiency and several speech variables.

Surgical variables affecting postoperative swallowing efficiency in oral cancer patients: a pilot study.

This study examined the correlation between swallow function at 3 months postoperatively and surgical variables including volume resected, flap volume, ratio of flap volume to volume resected, percentage of oral tongue, tongue base, and anterior and lateral floor of mouth resected, and whether or not the mandible was preserved in 30 surgically treated oral cancer patients. Swallows of measured amounts of liquid and paste (pudding) materials were examined videofluoroscopically. Nine measures of swallow function were completed for each swallow. A factor analysis of all swallow variables was done for liquid and for paste consistencies to determine whether one measure was statistically representative of all swallow measures. This analysis indicated that oral pharyngeal swallow efficiency (OPSE) represented all measures for both liquid and paste consistencies. Then the correlation between OPSE and surgical variables was defined. Only percentage of oral tongue and percentage of tongue base resected were significantly negatively correlated with OPSE. That is, OPSE decreased for both liquid and paste as percentage of oral tongue or percentage of tongue base resected increased. Results are discussed in terms of diet choices and surgical management.

Speech and swallow function after tonsil/base of tongue resection with primary closure.

Speech and swallowing function was examined in 11 patients who underwent surgical resection of greater than 1 cm of tongue base, tonsil, and faucial arch with mandible resected on the side of the tumor and reconstruction by primary closure. Preoperatively and 1 and 3 months post-healing, high fidelity audio recordings were made of a 6- to 7-minute conversational speech sample, the sentence version of The Fisher Logemann Test of Articulation Competence was administered, and videofluoroscopic assessment of oropharyngeal swallow was conducted. All subjects exhibited changes in speech and swallowing function postoperatively, with little improvement during the study. Patients exhibited greatest difficulty on stop and fricative consonants and bolus propulsion. Comparison with patients who received anterior tongue and floor of mouth resections and distal flap reconstruction revealed consistently better speech performance by the tonsil/base of tongue patients, although the same phonemes were affected. Swallow function was equally affected in the two groups. Results are discussed in terms of locus of surgical resection, nature of reconstruction, and need for swallowing therapy.

Speech and swallowing function after anterior tongue and floor of mouth resection with distal flap reconstruction.

The purpose of this study was to assess the postoperative functioning of oral cancer patients with resections of the anterior tongue and floor of mouth, reconstructed with distal flap closure. Speech and swallowing performance was assessed for 11 men and 5 women preoperatively and at 1 and 3 months postoperatively following a standardized protocol. Speech tasks included an audio recording of a brief conversation and of a standard articulation test; swallowing function was examined using videofluoroscopy. Data were also collected on the number and duration of speech/swallowing treatment sessions, as well as the amount and duration of radiation therapy. Statistical analyses revealed that patients demonstrated a significant and severe impairment in speech and swallow functioning after surgery, with no recovery of function by 3 months post-healing. The degree of impairment in these patients may be related to the adynamic character of the distal flap used for reconstruction. Lack of improvement at the 3-month evaluation may be related to either the timing of postoperative radiation therapy or the low rate (44%) and amount of speech/swallowing treatment provided to these patients.

Lymphedema after groin dissection.

Groin dissection was performed in 67 patients, of whom 40 had superficial groin dissection and 27 had ilioinguinal dissection. The incidence of overall lymphedema of a mild to moderate degree was 21 percent. Lymphedema was observed more frequently (26 percent) in patients with primary lesions in the leg when compared with those with lower trunk lesions (6 percent, p less than 0.001), and in those who did not follow a prophylactic regime of leg elevation and use of a fitted elastic stocking (45.8 percent) when compared with those who adhered to the regime (7 percent, p less than 0.004). Sex, age, wound problems, histologic status of lymph nodes, and the duration of follow-up did not significantly affect the occurrence of lymphedema.