Seppo Karjalainen

Auditory brainstem latencies in type I (insulin-dependent) diabetic patients☆

INTRODUCTION This study was undertaken to compare auditory brainstem response latencies in insulin-dependent diabetics, and to compare these findings with metabolic control, microangiopathy, neuropathy, and the duration of diabetes. METHODS Auditory brainstem latencies were studied in 53 type I diabetic patients and 42 randomly selected nondiabetic control subjects, aged between 20 and 40 years. Three different stimulus repetition rates (10, 30, and 50 Hz) were used. All subjects had normal hearing ability. RESULTS Wave V latencies were longer in diabetic patients when compared with those of control subjects at all repetition rates. At repetition rates of 10 and 50 Hz, diabetic patients had a prolonged I-V interwave latency, and at a repetition rate of 50 Hz, diabetics had a longer III-V interwave latency than control subjects. These findings indicate a central disturbance in the auditory pathway. Microvascular complications (retinopathy, nephropathy) and the duration of diabetes were associated with the prolongation of auditory brainstem latencies. In contrast, poor metabolic control (high fasting blood glucose and glycated hemoglobin A1c) at the time of the present study was only marginally associated with prolonged auditory brainstem latencies. The changes in auditory brainstem latencies associated with diabetic neuropathy (measured with five cardiac autonomic nervous function tests) appeared simultaneously with microvascular complications and in patients with diabetes of long duration, and thus a causative role of diabetic neuropathy in the pathogenesis of prolonged auditory brainstem latencies remains unsolved. CONCLUSION Delayed auditory brainstem latencies in type I diabetic patients are probably caused by the long duration of diabetes and the microvascular complications associated with it.

Factors influencing sensorineural hearing loss in chronic otitis media.

Sensorineural hearing loss was studied in 874 chronically infected ears and was found to occur more frequently in cases of cholesteatoma and in the presence of discharge. Sensorineural hearing loss is not dependent on the type of causative microorganism. Older patients exhibited sensorineural hearing loss more often than did younger patients, this disorder being more common in affected ears than in control ears (the contralateral ear in unilateral cases).

Improvement of metabolic control does not normalize auditory brainstem latencies in subjects with insulin-dependent diabetes mellitus

INTRODUCTION In our previous study (Am J Otolaryngol 14:413-418, 1993), we reported that prolonged auditory brainstem response latencies are associated with microvascular complications and the duration of diabetes in patients with insulin-dependent diabetes mellitus (IDDM). To investigate whether short-term improvement in metabolic control also affects ABR-responses, we compared ABR-latencies in subjects with IDDM before and after intensified insulin and diet therapy. MATERIALS AND METHODS Auditory brainstem latencies were measured in 13 subjects with IDDM (mean age: 25 years) before and after intensified insulin and diet therapy. The acoustic stimulus was a half sine wave with a duration of 0.250 millisecond and a frequency of 2,000 Hz. The stimulus was presented monaurally with fixed polarity through shielded headphones TDH-39 at repetition rate of 10 Hz and at 90 dB hearing level. All subjects had normal hearing ability. Glycated hemoglobin A1C (GHbA1C), blood glucose immediately before ABR-measurements, and mean blood glucose during 24 hours before auditory studies were measured before and after intensified therapy. RESULTS During intensified insulin therapy, GHbA1C improved significantly (P < .05) in study subjects. However, no changes were observed in ABR-latencies. We also studied those 10 patients whose blood glucose improved during intensified insulin therapy. Although blood glucose was significantly lower (P < .01) after intensified insulin therapy compared with that at baseline, no changes were observed between ABR-latencies at baseline and follow-up. CONCLUSION ABR-latencies were not affected by improvement in metabolic control in patients with IDDM. Our finding suggests that delayed ABR-latencies found in patients with IDDM are not caused by poor metabolic control of diabetes but rather by other mechanisms, for example, microvascular complications.

The KID‐syndrome in Finland A report of four cases

Abstract. We describe a rare syndrome in a Finnish family, in which the father and his two sons are congenitally deaf and also exhibit corneal vascularization, and hyperkeratosis of the skin of the palms, soles, elbows and knees. In addition, all 3 suffer from fungal infections of the skin and nails. We also describe a fourth, sporadic case of a 9‐year‐old girl with the same disease. The KID (k = keratitis, i = ichthyosis, d = deafness) syndrome is an ectodermal dysplasia that probably arises through mutation, and is transmitted as an autosomal dominant in the family described by us.

Progressive Hearing Loss in Usher's Syndrome

In 18 patients with Ushers syndrome, progressive hearing loss was verified audiologically in eight cases. Despite poor auditory threshold values and low speech discrimination scores, there was only one patient who could not communicate with speech. The possibility of hearing impairment being mainly progressive in Ushers syndrome is discussed.

Auditory Disorders Following Head Injury in Children

199 children with blunt head injury were examined. Eighteen fractures of the temporal bone were found, two of which were transverse. In both cases the damaged ear remained completely deaf. Of the 16 longitudinal fracture patients, one was left with a persistent 27 dB conductive hearing loss. In another, surgery revealed fractures of the stapedial crura. Persistent sensorineural hearing loss (greater than or equal to 30 dB) at high frequencies (4 to 8 kHz) was observed in 7% of patients. The results of the audiological tests led to the conclusion that sensorineural hearing loss in association with head injury is generally located in the inner ear. The auditory sequelae after head injury in children were found to be similar to those reported earlier in adults.

HEARING THRESHOLDS IN INSULIN-DEPENDENT DIABETIC PATIENTS

Hearing thresholds were studied in 53 patients with insulin-dependent diabetes mellitus (IDDM) and 42 randomly selected non-diabetic control subjects, aged between 20 and 40 years. The hearing level tended to be worse in diabetic patients than in control subjects, but the differences were statistically significant only at frequencies of 6,000 and 8,000 Hz. Microvascular complications (retinopathy and nephropathy), and the duration of diabetes were associated with the elevated hearing thresholds. In contrast, poor metabolic control (high fasting blood glucose and glycated haemoglobin A1c) was not associated with increased hearing thresholds. The changes caused by diabetic neuropathy appeared simultaneously with microvascular complications and a long duration of the diabetes, and thus a causative role of diabetic neuropathy in the pathogenesis of elevated hearing thresholds remained unsolved. It was concluded that elevated sensorineural hearing thresholds at the frequencies of 6,000 and 8,000 Hz in patients with IDDM are probably caused by the long duration of diabetes and the microvascular complications associated with it.

Vestibular disorders following head injury in children

One hundred and ninety-nine child patients with blunt head injury were examined. Spontaneous and/or positional nystagmus (greater than or equal to 7 degrees/s) was observed immediately after trauma in 46% of cases, 6-12 months (average 10.2 months) later in 20%, and 2-8 years (average 4.7 years) later in 18%. Central ENG disturbances were found immediately after trauma in 43% of cases, 6-12 months later in 24%, and 2-8 years later in 12%. Only 1.5% of the child patients suffered from vertigo more than 6 months after trauma. The results of the study led to the conclusion that head injuries cause about as many similar objective vestibular lesions in children as in adults but fewer subjective symptoms.

Failures in myringoplasty

SummaryWe analyzed those failures occurring in 417 myringoplasties. Forty-four drum re-perforations were found (10.6%), half of which occurred immediately after operation. Causes of these early failures included necrosis in the middle of the graft without infection (10 ears) and blunting of the anterior margins of the graft (7 ears). Infection was the most common cause of re-perforations in the later failures. Re-perforations also occurred more frequently when larger perforations were closed in contrast to repair of small ones. We found that other pre-operative factors (“dry” or “wet” ear, site of the perforation) or grafting technique (“underlay” or “overlay”) did not affect the graft take-rate. Adhesive eardrums were found in 23 ears (5.5%). These were more common when ears were infected pre-operatively, when middle ear mucosa was removed during the primary operation, or when squamous epithelium was present on the tympanic mucosa. Lateralization of the grafted eardrum was found in two cases (0.5%), both of which had been operated on using the sandwich technique.

Perilymph fistula : a diagnostic dilemma

A retrospective series is presented of 51 cases operated on for suspected perilymph fistula. In 26 ears a fistula was identified at surgery. A positive fistula test was found to strongly indicate a perilymph fistula but was more often negative than positive in surgically demonstrated fistula ears. Other vestibular tests were found to be of little value in the pre-operative diagnosis. Ears with a surgically demonstrated fistula and sensorineural hearing loss had either flat or downward-sloping audiograms. Difficulties in diagnosing a perilymph fistula at tympanotomy are discussed. At follow-up, vestibular symptoms were found to be eliminated or improved in 96 per cent of cases with surgically demonstrated fistulae and in 68 per cent of cases in which no fistula was detected at tympanotomy but hearing improved significantly in only one ear (4 per cent) of the former group and in five ears (20 per cent) of the latter group.