RESULTS OF TREATMENT OF 523 PATIENTS FOR TINNITUS WHICH MAY HAVE ORIGINATED IN NEUROVASCULAR COMPRESSION
Junichi Matsushima and Aiko Matsushima
Sapporo, Japan

Abstract

A total of 6472 tinnitus patients examined from July 2008 to January 2015 were treated once a week by autogenic training, life style intervention, and drip infusion of VB12. Among these patients 523 were subject to imitative sounds which may be ascribed to Neurovascular Compression (NVC). An evaluation of the outcomes for the tinnitus therapy was performed at less than 3 months of treatment.

The objective of the study is to establish whether a treatment battery described above is effective for the tinnitus caused by NVC.

Among the 523 patients, 191 patients (37%) experienced complete relief, 262 patients (50%) partial relief, and 70 patients (13%) no relief. The rate of relief for high tone tinnitus was poorer than for low and middle tones (p=0.003, p=0.045). There was more improvement in hearing loss in patients with lower tone tinnitus (p=0.0002). Among the factors affecting the outcomes, the tinnitus intensity where complete relief was achieved was lower than that for patients achieving partial or no relief (p=0.002, p=0.002) and the tinnitus intensity in patients achieving improvements in hearing was lower than in patients who did not improve (p=0.007). The improvement in hearing was associated with relief in tinnitus (p<0.0001).

This study suggests that an autogenic training approach would be advantageous for tinnitus caused by Neurovascular Compression.

Key words: tinnitus, autogenic training, Neurovascular Compression

Introduction

Neurovascular compression syndrome (NVCS) is caused by compression of arteries on nerves and a cause of hemifacial spasms (HFS) and trigeminal neuralgia (TN). In addition, arterial sclerosis is a risk factor because the patients with NVCS are commonly older [1, 2].Reports on tinnitus and hearing loss (HL), symptoms involving the 8th nerve, are fewer than reports on HFS and TN. This is partly because the relationships between NVCS and HFS and TN are more clearly established than those between NVCS and tinnitus and HL [3]. The tone of tinnitus reported in connection with the NVCS includes high pitched [3], pulsatile [4-5], or imitative sounds [1, 3, 6]. Among these tones, tinnitus with imitative sounds may originate from NVC (Neurovascular Compression) of the 8th Nerve [1]. For hearing loss, and as patients with NVCS are generally older, the cause of the hearing loss varies and it may be assumed that different types of HL may be found among patients with NVCS.

A battery of treatments including intravenous drip infusion(IV drip) of VB12 and psychological therapies such as autogenic training, life style intervention, and counseling have been used to treat tinnitus and the outcomes of the treatments have been presented at the 40th NES (Neuro-Equlibriometric Society) congress [7]held in Prague in 2014. Overall 89.2% of 148 patients subject to imitative sounds experienced tinnitus relief using the battery of therapies in our treatment. A total of 6472 tinnitus patients have been treated from July 2008 to January 2015 using our battery of treatments.

One objective of the present study is to determine whether the battery of psychological therapies together with IV drip of VB12 is effective with imitative tinnitus and hearing loss (HL). A further objective is to identify further details of factors affecting the outcomes of tinnitus and hearing loss treatment. Finally, this paper also investigates the relationships between the NVC related type of HL and improvements in tinnitus and hearing.

Methods

A total of 6472 patients with tinnitus visited the clinic of the first author from July 2008 to January 2015 and were treated with a battery of therapies. Among the total 6472 patients, 523 patients reporting imitative sounds were included in the study here. The average age of the included patients were: 60.8±15.4 years and comprising 439 females and 84 males.

The treatment included the VB12 IV drip and the psychological therapies. The B12 IV drip is administered intravenously to patients with hearing losses diagnosed to be of cochlear origin. The psychological component of the treatment includes autogenic training, life style intervention, and counseling by the author. At the first visit patients were instructed to follow methods of autogenic training and imagine that their bodies were warm. They were advised to visit the clinic for treatment once a week. In the first month of the visits, the treatment involved autogenic training, life style intervention, and counseling by the first author. The direct cost of the treatment to the patient was about 5 US dollars (600 yen) at each visit. When the patients were able to perform the autogenic training on their own they were instructed to continue on their own, and were considered not to be in need of further consultations except at the regular monthly checking for HL and tinnitus. When the tinnitus was not relieved, the method of the autogenic training, life style intervention, and counseling were discussed further. Data included in this study are further detailed next, and was generally collected after less than 3 months of treatment. Here patients diagnosed with the pastulous Eustachian tube and patients with the pulsatile tinnitus were excluded. The statistical analysis was performed using JMP 10.0 software.

To identify details of the characteristics of the tinnitus a pitch-matching and loudness balance test was performed. The tone of the tinnitus sounds of 125-250 Hz was defined as low; 500-1000 Hz as middle; and tones at and above 1500 Hz, as high. This definition of tones was shifted to lower frequencies when compared with the continuous tone tinnitus. For effects of the therapy on HL following treatment, the HL configurations observed more often in older patients were excluded, as age-related hearing loss may be induced by various other factors. Here, the excluded configurations which may be age-related hearing loss reported by Dubno were applied [8].The excluded configurations included gradually, sharply, or precipitously sloping HL at higher frequencies, and slight impairment but close to normal hearing. The HL where there was a re-test was also excluded from the statistical analysis.

Table 1. Initially recorded tinnitus tones vs. tinnitus following treatment
Tinnitus Outcomes of tinnitus
tone complete relief partial relief no relief overall
n % n % n % n % p
Low 103 41.9 114 46.3 29 11.8 246 100 0.003
Middle 40 38.8 51 49.5 12 11.7 103 100 0.045
High 48 27.6 97 55.8 29 16.7 174 100 control
P values show low vs. high and middle vs. high

The NVC related types of HL such as up-slowing, low frequency HL, and middle frequency HL [9-11]may fluctuate due to occasional blood flow variations in the cochlea [5, 9].Therefore, low frequency HL, middle frequency HL below 70 dB may offer a potential for hearing improvement following treatment. Hearing improvement of low tone HL was defined to have taken place when there was a 10 dB improvement in 2 consecutive frequencies among 125, 250, and 500 Hz (probably 1 kHz); for the middle frequency HL, and if there is HL at two or more frequencies, a 10 dB improvement in 2 consecutive frequencies; for moderate or moderately severe HL, a 10 dB improvement in 2 consecutive frequencies; for notch HL, when HL is sharply poorer at one frequency in the range of middle frequencies, a 10 dB improvement at the least audible frequency.

Results

Overall 86.6% of the 523 patients covered in this study experienced improvement in tinnitus after the treatment, and among these 191 (37%) experienced complete relief, 262 (50%) experienced some relief, and 70 (13%) experienced no relief. The relationships between tinnitus tones vs. the tinnitus following treatment are shown in Table 1. The number of patients with low tone tinnitus (n=246) is larger than the number with high (n=174), and middle tone (n=103) tinnitus. For a statistical comparison of the relief, the outcomes of the tinnitus treatment were assigned values as follows, for patients reporting no relief, 1 point; partial relief, 2 points; and total relief, 3 points. When compared with the outcomes among the tinnitus tones, the scores for low tone tinnitus are 2.30±0.67; 2.27±0.66 for middle tones; and 2.11±0.66 for high tones. The score for high tones was significantly lower than the scores for low and middle tones (p=0.003, p=0.045), suggesting that high tone tinnitus was more difficult to relieve than the tinnitus at the other tones. No statistically significant differences in the scores were found between the low and middle tones.

For patients with improvements in hearing, Table 2 shows that the ratio of low tone HL in patients with hearing improvement is larger than that at higher tones. To compare improvements in hearing among tinnitus tones, tinnitus tones were assigned values as follows: for patients reporting low tone tinnitus, 1 point; middle tone, 2 points; and high tone, 3 points. When compared with improvements in hearing among tinnitus tones, the tone score for unchanged HL is 2.09±0.86 (n=140), for improvements in hearing, 1.69±0.85 (n=137). This suggests that the likelihood of improvements in hearing following treatment for lower tinnitus tones was better than that with higher tone tinnitus, p=0.0002. When comparing hearing improvement among tinnitus tones, the tone score for NVC related HL is 1.72±0.86 (n=204), and for non NVC related HL it is 1.96±0.89 (n=319). This means that the tinnitus tone in the NVC related type of HL was lower than that in the non-NVC related HL, p=0.0002.

Table 2. Initially recorded tinnitus tones vs. improvements in hearing following treatment
HL Tone  
  low middle high overall  
Outcomes n % n % n % n % p
Improved 77 62.6 25 41.0 35 37.6 137 49.5 0.0002
Unchanged 46 37.4 36 59.0 58 62.4 140 50.5
HL type n % n % n % n % p
NVC related 113 45.9 36 35.0 55 31.6 204 39.0 0.0002
Non NVC related 133 54.1 67 65.0 119 68.4 319 61.0

For factors affecting outcomes of the tinnitus therapy, there was no statistically significant correlation with age. The intensity of the tinnitus with complete relief (41.3±18.1 dB, n=191) was the lowest, compared with partial relief from tinnitus (46.8±19.7 dB, n=262) or no relief (49.6±22.3 dB, n=70) (p=0.002, p=0.002). For the intensity of tinnitus there was no significant relation between patients achieving partial and no relief. The tinnitus duration of patients who experienced no tinnitus relief (2.8±2.8 years) was longer than that in patients with complete relief (1.7±5.4) or partial relief (1.7±4.2), p=0.004, p=0.007. Treatments were stopped after a few visits in 171 of the 523 patients (32.7%) here because of the positive effects on tinnitus reported at the interviews. Among the 171 patients, 138 patients had been treated once, 27 patients twice, and 6 patients three times. The duration of tinnitus in patients with less than 3 treatments was significantly shorter than that in patients with more treatments, 0.61 years (SD: 1.4) vs. 2.4 (SD: 2.44 (SD: 5.7), p<0.0001.

For the effects of therapy on HL, the outcomes of tinnitus following treatment and the tinnitus intensity at the first visit are shown in Table 3. The definition of improvements in hearing and NVC related type HL are described above in METHODS. The HL configurations observed more often in older patients were excluded from the statistical analysis. The excluded HL configurations are also detailed in the METHODS section. Based on the definition for the excluded HL configurations, 246 of the 523 patients were excluded from the statistical analysis. Among the 277 patients where the HL was defined as offering the potential for improvements in hearing, there were 137 (49.5%) patients experiencing improvements in hearing (Table 3). The improvement in hearing was more frequent in patients with overall relief (complete and partial relief) than in patients without any relief (p<0.0001). There were no significant differences in the ratio of patients with improvements in hearing with complete or with partial tinnitus relief. The ratio of patients with improvements in hearing was larger among patients defined as subject to the NVC related type of HL than among the non NVC related type of HL (p<0.0001). The ratio of patients with both tinnitus relief and improvements in hearing was higher than both of patients without tinnitus relief and without improvements in hearing (p<0.0001). The tinnitus intensity in patients with improvements in hearing was lower than that in patients without improvements in hearing (p=0.007).

Discussion

The characteristics of tinnitus accompanying NVCS suggested in different reports vary. Among the various tone characteristics reported, one of the most commonly mentioned related characteristics for tinnitus originating from NVCS may be tinnitus with imitative sounds [1, 6]. The continuous tone type of tinnitus may originate from other causes in addition to NVC. Therefore, patients with imitative sound tinnitus were chosen [1] here and the number of patients treated was 523, which is, to our knowledge, the largest number reported so far in a single study.

A tinnitus suppressor for implantation has been developed by us at Hokkaido University and results with this implant were presented at the 5th International Tinnitus Seminar [12].The device was implanted in 8 patients and the results using the Tinnitus Stress Test have been reported elsewhere [13]. One patient fell asleep during the stimulation of the promontory through the ear drum selected for the implantation. After implantation of the device, electrical stimulation on the round window induced sleep just like stimulation of the promontory through the ear drum in the same patient. The patient did not perceive tinnitus even after switching off the device [12, 14]. We were able to report positive correlations between tinnitus relief and sleep after using the suppressor. A study of laser Doppler flowmetry showed that promontory stimulation of tinnitus patients with tinnitus relief increased the blood flow in the forefinger [15], suggesting that tinnitus relief may be related to increased blood flow in the body. Therefore, it was assumed that relaxation could be one treatment for tinnitus.

Autogenic training would make patients feel comfortable and lessen both affective elements and the sensory memories in the limbic system, overall resulting in tinnitus relief [16-18].

Table 3. Effects of therapy on hearing loss and tinnitus at the first visit
HL Tinnitus NVC related HL Inten-sity
Outcomes complete partial overall relief no relief yes no dB
  n n % n % n % n % n % n % mean ± SD
Improved 137 66 58.9 64 52.0 130 55.3 7 16.7 93 64.6 44 33.1 47.2 ± 18.7
Unchanged 140 46 41.1 59 48.0 105 44.7 35 83.3 51 35.4 89 66.9 57.3 ± 21.2
Overall 277 112 100 123 100 235 100 42 100 144 100 133 100 50.4 ±20.2
p   ns p<0.0001 p<0.0001 P=0.007
SD: standard deviation; ns: p>0.05

The stress is ascribed to the augmented modulator of both affective elements and the sensory memories [16-17]. Life style intervention was needed to improve the sleep condition and also counseling was needed to give patients psychological relief. These psychological therapies would suggest that tinnitus is related to the unconscious level via the limbic system. In addition to anatomical causes of NVCS, there would be enlargement of the arteries due to blood flow congestion in the brain with the occurrence of NVCS [4].Tinnitus relief caused by NVCS could be achieved by improving the blood flow although other conservative therapies have not been effective to relieve compression of the blood artery on the nerve. This suggests the value of the battery of treatments described in this study as suitable for tinnitus patients with NVCS to reduce blood flow congestion in the brain. In addition, our treatment modulates the excitability of the amygdala by the somatosensory nerves and the brain cortex inhibition on the amygdala induced by the counseling and autogenic training [13].

Details of hearing loss configurations accompanied by NVC are more confusing than tinnitus because aging would modify the HL originated in NVC [19]. Configurations of the low tone type and middle frequency HL other than at 4 kHz may be related to HL originating in NVC [9-11]. Deteriorating types of HL such as moderate to moderately severe HL at the middle frequencies may also be related to NVC. For HL originating in NVC the HL was reported to be fluctuating, possibly induced by variations in the blood flow to the cochlea by vascular cross-compression [5, 9], however no fluctuating HL was observed in patients with HFS [10].

Among the 523 patients studied here only 3 were diagnosed to suffer from HFS and they were treated by neurosurgery. None of these 3 patients experienced fluctuations in HL from July 2008 to January 2015 following the surgery. This study showed that HL is possibly related to NVC such as of the low tone type, middle frequency HL including moderate to moderately severe HL could improve when tinnitus improved by the treatment reported here.

In conclusion, this study is not a placebo-controlled, randomized study, however the overall 87% relief rate makes it sufficiently successful to be able to recommend the therapy detailed here for tinnitus caused by NVCS. This study covers patients treated for 6 and a half years and also showed that the ratio of patients with tinnitus due to NVC, nearly 10%, was larger than would commonly be assumed. It is suggested that the better tinnitus relief was achieved by a therapy which considers the limbic system in reducing the affective element in tinnitus. The therapy included intravenous injection of VB12, and psychological therapies such as autogenic training, counseling, and life style intervention. Reducing compression of the arteries on the 8th nerve was a factor in improving hearing. Therefore, it is also suggested that some cases of patients with Meniere’s disease or with low tone hearing loss may suffer from blood flow impairment including NVC. Hearing loss accompanied by NVCS is less easy to relieve than tinnitus, and further details of this kind of HL are not reported due to the word limit here. Here tinnitus caused by NVCS was diagnosed based on tinnitus with imitative sounds.

Abbreviations

NVC, neurovascular compression; NVCS, neurovascular compression syndrome; HFS, hemifacial spasms; TN, trigeminal neuralgia; HL, hearing loss.

Acknowledgement

We wish to thank the nursing and hospital staff for assistance in collecting the data.

Conflicts of interest

The authors declare that no conflict of interest is involved here.

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RESULTS OF TREATMENT OF 523 PATIENTS FOR TINNITUS WHICH MAY HAVE ORIGINATED IN NEUROVASCULAR COMPRESSION