Voice and Swallowing Disorders After Thyroid Surgery.

OBJECTIVE: The aim of the study was to evaluate voice and swallowing function following thyroid surgery, to identify dynamic changes during the follow-up period of 12-18 month and to find possible indicative signs of permanent or temporary vocal fold palsy. METHODS: All participants (N = 110) were prospectively enrolled from the preoperative thyroid surgery patients between September 2013 and December 2016. All subjects underwent preoperatively, first week and 12-18 month postoperatively videolaryngostroboscopy, filled in subjective evaluation of voice (voice handicap index, [VHI]) and swallowing (swallowing impairment score) complaints. Acoustic voice analysis (AVA), maximum phonation time (MPT) measurement and perceptual voice evaluation were conducted. In the presence of laryngeal damage, additional first and sixth-month follow-up visits were planned. Patients, whom we suspected laryngeal nerve damage, underwent laryngeal electromyography 4 weeks after the operation. RESULTS: On first postoperative week evaluation, no objective voice changes within patients with postoperatively intact laryngeal nerves were found. Subjective evaluations showed decline in VHI physical domain and increased strain in postoperative voice. Patients with postoperative nerve damage had a drastic decline in subjective voice quality (VHI all subscales and total score), AVA parameter jitter, MPT and perceptual voice quality. Subjective evaluation of swallowing revealed disturbances in all patients regardless of the nerve damage. We noticed remarkable differences in first week and first month visits between patients with permanent and temporary palsy in VHI total score and physical domain, MPT and perceptual breathiness and asthenia in voice. Regardless of the nerve injury, by the end of the follow-up period all changes had become statistically insignificant with the exception of perceptual evaluation of voice quality. CONCLUSIONS: Patients with postoperative laryngeal nerve damage experience substantial deterioration of both subjective and objective voice quality with more extensive impairment in patients with permanent paralysis. Thyroid surgery causes subjective swallowing changes irrespective of laryngeal nerve damage. In patients without laryngeal nerve damage, swallowing function improves following thyroidectomy. Possible indicators for permanent paralysis are delayed recovery in the values of MPT and jitter and persistent perceptual breathiness and asthenia.

Constitutional risk factors for focal neuropathies in patients referred for electromyography.

BACKGROUND AND PURPOSE: It is well established that patient-related constitutional features predispose to focal peripheral neuropathies. Some of these risk factors were investigated in common focal neuropathies encountered in patients referred for electromyography. METHODS: Gender, age, height and body mass index (BMI) were analysed retrospectively as risk factors for 11 focal neuropathies. In all, 9686 patients (age range 18-96 years; 58% women) were included from three different centres, with identical methods and equipment. RESULTS: High BMI was related to carpal tunnel syndrome (CTS), ulnar neuropathy at the elbow (UNE), combined CTS and UNE, meralgia paraesthetica and lumbar radiculopathy. In women, CTS and Morton's metatarsalgia were more common, whilst long thoracic neuropathies, suprascapular neuropathies and UNE were more common in men. Older age increased the risk for CTS, UNE, Morton's metatarsalgia and radiculopathies. CONCLUSIONS: Age, gender and BMI are important risk factors for many common focal neuropathies.

Reference values for F wave parameters in healthy 3-20 year old subjects.

OBJECTIVE: To create a reference value database for F wave parameters from healthy subjects aged 3-20 yr. METHODS: We studied the following parameters: minimum F wave latency minus distal motor latency (FMINLAT), number of F waves/20 stimuli (FNUMBER) and F wave dispersion (FDISP). The median, ulnar, peroneal and tibial nerves were studied. All four nerves were not analyzed in all subjects, the number of subjects varied from 78 to 118 in each nerve. RESULTS: Age explained 71-87% of the variability of FLATMIN while height explained 80-95% of the variability. The FMINLAT increases by 0.12 ms/cm of height in the upper limb nerves and by 0.28 ms/cm in the lower limb nerves. Gender did not influence the FMINLAT. FDISP was not related with age, height or gender. FNUMBER was not related with age or height, it was somewhat larger in males than females but the difference was not significant in all nerves. CONCLUSIONS: The best model for FMINLAT was a linear regression model with height as an independent variable. FDISP and FNUMBER are not related to age, height or gender between the ages of 3 and 20 yr. SIGNIFICANCE: We have constructed clinically useful reference values for F wave parameters in healthy subjects aged 3-20 yr for the main motor nerves commonly studied.

Clinical and laboratory-reconfirmed myasthenia gravis: a population-based study.

The aim of this study was to compare the clinically based prevalence of myasthenia gravis (MG) with the prevalence of laboratory-confirmed cases. All patients with a diagnosis of MG living in Estonia as on 1 January 1997 were asked to participate in re-examination. The criteria for laboratory-supported MG were weakness and rapid fatigue and a positive outcome of at least one of three laboratory tests: (i) blinded acetylcholinesterase inhibitor test; (ii) determination of antibodies to acetylcholine receptor and (iii) neurophysiological examination using repetitive nerve stimulation and single-fibre EMG. Eighty-nine patients were re-examined and 70 patients (79%) fulfilled the criteria of laboratory-supported MG. The corrected prevalence ratio was 78 per million. In the non-confirmed MG group, there was more women (92%) than men (43%) whose diagnosis was established within 1 year from onset of symptoms (P = 0.016). In all women with non-confirmed MG the diagnosis was established within 1 year from referral to the physician, whereas 68% of women with confirmed MG was diagnosed within 1 year (P < 0.0001). Thus, we conclude that, in Estonia the prevalence of MG based on medical records seems overestimated by 21% and women are at higher risk of obtaining an uncertain diagnosis of MG.

Motor neurone disease in South Estonia. Diagnosis and incidence rate.

The current study evaluated the diagnostic standards of MND and epidemiological markers of MND in Estonia. A total of 108 patients were referred to the University Hospital from 1986 to 1995 with the first suggested diagnosis or final diagnosis of amyotrophic syndrome, amyotrophic lateral sclerosis (ALS), progressive bulbar paralysis (PBP) or progressive muscular atrophy (PMA). In addition neurologists of the region and the National Society of Neuromuscular disorders were contacted. Some 94 patients satisfied the diagnostic criteria. The annual incidence rate in South Estonia and in the city of Tartu ranged from 0.5 to 2.8 per 100,000. The mean annual incidence rate in Tartu is 1.98 and in South Estonia in general 1.3. The highest incidence rate was 8.3 for men in the age group 60 to 64 years and 7.49 in the age group 70-74; among female patients the highest incidence rate -4.6 was in the age group from 65 to 69.

Significance of A-waves recorded in routine motor nerve conduction studies.

The occurrence of A-waves during routine F-wave studies was investigated in 556 consecutive patients referred to the Department of Clinical Neurophysiology at the University Hospital in Uppsala for various neuromuscular disorders. Altogether, 2367 nerves in the upper and lower extremities were studied. An A-wave, with a nearly constant latency and a uniform shape on consecutive stimulations, could be recorded in 184 nerves (7.8%) out of 124 patients (22.3%). More than 50% of patients with A-waves had various types of polyneuropathies. Of all patients with polyneuropathy, 65% had at least one nerve with A-waves. A-waves occurred somewhat less frequently in patients with radiculopathies. In other proximal local nerve lesions they were found less often and only exceptionally in patients with distal nerve lesions. A-waves were present in 6 out of 10 patients with motor neurone diseases. There was no correlation between the number of A-waves found in one nerve or the number of nerves in a given patient with A-waves and the aetiology or severity of the underlying disease. A-waves were found in 11 patients referred for various neurological symptoms in whom other neurophysiological findings were normal. This might be interpreted as an early sign of underlying disease because in 100 healthy controls no A-waves could be elicited, with the exception of 3 subjects who had A-waves in the abductor hallucis muscle when the tibial nerve was stimulated. We conclude that the appearance of A-waves should be considered a sign of either a local nerve lesion or a generalised neuropathy in all other nerves except for the tibial nerve.