Monogenic disorders offer a possibility for studies of genetic disturbances in hearing impairment—a knowledge which could be essential for development of future treatment options. In this thesis, the underlying genetic disturbances in neurofibromatosis 2 (NF2) and familial Meniere’s disease (FMD) were evaluated, and familial X-linked hearing impairment was described from a clinical point of view. In paper I, constitutional DNA from 116 individuals with NF2 of variable severity was studied using the array-CGH method focusing on a 7.6-Mb area surrounding the NF2 gene on chromosome 22q. Deletions were found in 20.7% of samples. In mild NF2, the deletions were small, but variable sizes of deletions were found in cases that were moderately or severely affected. Disease phenotype could not be predicted from the size of the deletions. In papers II and III, a single five-generation family with autosomal dominant FMD was described. Anticipation concerning age of onset was observed. Genome scan revealed five candidate gene regions with a LOD score of > 1. Two additional families with autosomal dominant MD were analyzed for linkage to these five regions. A cumulative Zmax of 3.46 was obtained for a single 463-kb region on chromosome 12p12.3, containing only one known gene: PIK3C2G. This encodes a protein with a proposed role in hair cell regeneration in mammalian ears. No mutations were found in protein-coding sequences or exon-intron borders. In two of the three families, a shared haplotype, suggested common ancestry, was found to extend over 1.7 Mb, which could be a genomic region of importance for FMD. In paper IV, a family in which five males displayed progressive low- and mid-frequency hearing impairment from the first or second decade was described. Female carriers were affected by a high-frequency hearing impairment from the fourth decade. The family could represent a novel X-linked dominant audiophenotype.

The main aim of this thesis was to evaluate the effect of prednisolone and valaciclovir in a large number of Bell's palsy patients. The incidence and intensity of pain around the ear, in the face or in the neck during the first two months of palsy, and its prognostic value, was also assessed. We also investigated how study design and choice of analysis method affect the rate of facial recovery. Furthermore, the agreement between the Sunnybrook, House-Brackmann and Yanagihara facial grading systems was evaluated. From May 2001 to September 2007, a prospective, randomised, double-blind, placebo-controlled, multicentre trial with 12-month follow-up was performed in patients with Bell's palsy. Of 839 randomised patients, 829 were included in the intention-to-treat analysis; 206 received placebo plus placebo, 210 prednisolone plus placebo, 207 valaciclovir plus placebo, and 206 prednisolone plus valaciclovir. Time to recovery was significantly shorter in the 416 patients who received prednisolone compared with the 413 who did not (p<0.0001). At 12 months, 300 of 416 patients (72%) in the prednisolone group had recovered compared with 237 of 413 patients (57%) in the no prednisolone group (p<0.0001). Valaciclovir was not found to affect time to facial recovery or outcome at 12 months. Prednisolone and/or valaciclovir did not affect the incidence or intensity of pain. Presence of pain at day 11 to 17 indicated a worse prognosis for facial recovery at 12 months. We also found that recovery rates in a Bell's palsy trial are substantially affected by the choice of analysis method and definition of facial recovery. We used weighted Kappa statistics in 100 examinations of patients with facial palsy to assess the agreement between the Sunnybrook, House-Brackmann and Yanagihara scales. The highest agreement was found between the regional Sunnybrook and Yanagihara scales. An evaluative difference between the Sunnybrook and House-Brackmann systems was observed.

<p><b>Aims</b></p><p>The aims of the thesis were to validate investigation instruments for stroke patients with dysphagia, and to improve oropharyngeal dysphagia therapies.</p><p><b>Methods/Results</b></p><p>A Lip Force Meter, LF 100, affirmed excellent intra- and inter-reliability, sensitivity and specificity. Controls had significantly stronger lip force (LF) and swallowing capacity (SC) than stroke patients. A normal lower limit of LF was set to 15 Newton. Dysphagia symptoms improved in 7 stroke patients after a 5-week sensorimotor stimulation therapy comprising manual body and facial regulation in combination with palatal plate application. Impaired LF and impaired SC were parallel phenomena in 22 acute stroke patients and did not differ regardless of presence or absence of facial palsy. LF and SC improved and were parallel phenomena in 30 stroke patients and did not differ regardless of presence or absence of facial palsy, time lag between stroke attack and start of treatment, or age. SC was normalized in 19 of 30 dysphagia patients after a 5-8-week daily lip muscle self-training with an oral screen. </p><p><b>Conclusions</b></p><p>LF100 is an appropriate and reliable instrument for measuring lip force. Dysphagia improvement, by body and facial sensorimotor stimulation in combination with palatal plate application, or by training with an oral screen is excellent examples of brain plasticity and cortical reorganisation. . Swallowing capacity and lip force in stroke patients are parallel phenomena. A sub clinical facial paresis seems to be present in most stroke patients. Training with an oral screen can improve LF and SC in stroke patients with oropharyngeal dysphagia. </p>

<b>Aims</b> The aims of the thesis were to validate investigation instruments for stroke patients with dysphagia, and to improve oropharyngeal dysphagia therapies. <b>Methods/Results</b> A Lip Force Meter, LF 100, affirmed excellent intra- and inter-reliability, sensitivity and specificity. Controls had significantly stronger lip force (LF) and swallowing capacity (SC) than stroke patients. A normal lower limit of LF was set to 15 Newton. Dysphagia symptoms improved in 7 stroke patients after a 5-week sensorimotor stimulation therapy comprising manual body and facial regulation in combination with palatal plate application. Impaired LF and impaired SC were parallel phenomena in 22 acute stroke patients and did not differ regardless of presence or absence of facial palsy. LF and SC improved and were parallel phenomena in 30 stroke patients and did not differ regardless of presence or absence of facial palsy, time lag between stroke attack and start of treatment, or age. SC was normalized in 19 of 30 dysphagia patients after a 5-8-week daily lip muscle self-training with an oral screen. <b>Conclusions</b> LF100 is an appropriate and reliable instrument for measuring lip force. Dysphagia improvement, by body and facial sensorimotor stimulation in combination with palatal plate application, or by training with an oral screen is excellent examples of brain plasticity and cortical reorganisation. . Swallowing capacity and lip force in stroke patients are parallel phenomena. A sub clinical facial paresis seems to be present in most stroke patients. Training with an oral screen can improve LF and SC in stroke patients with oropharyngeal dysphagia.