Prognostic value of electroneurography using the midline method for predicting the development of synkinesis after peripheral facial palsy.

OBJECTIVE: The prognostic value of electroneurography (ENoG) for predicting the incidence of synkinesis is reportedly about 40 % using the formal standard method (ENoG-SM). However, the prognostic value of ENoG using the newly developed midline method (ENoG-MM) has not been determined. The aim of this study was to demonstrate the optimal prognostic value and advantages of ENoG-MM for predicting the incidence of synkinesis. METHODS: Participants were 573 patients treated for peripheral facial palsy including Bell's palsy or Ramsay Hunt syndrome. We investigated the clinical presence of any oral-ocular or ocular-oral synkinesis from the medical records. ENoG-MM and ENoG-SM were performed 10-14 days after symptom onset. In ENoG-MM, compound muscle action potentials were recorded by placing the anode on the mental protuberance and the cathode on the philtrum. In ENoG-SM, electrodes were placed on the nasolabial fold. Synkinesis was clinically assessed at the end of follow-up or at >1 year after onset. The sensitivity and specificity of ENoG values for predicting the incidence of synkinesis were compared between ENoG-MM and ENoG-SM at every 5 % around 40 % (range, 30-50 %). RESULTS: At every 5 % of ENoG values around 40 %, ENoG-MM provided higher sensitivity and lower specificity for predicting the incidence of synkinesis compared with ENoG-SM. In particular, when the cut-off value was set at 45 %, sensitivity was 100 % and 95.3 % with ENoG-MM and ENoG-SM, respectively. CONCLUSION: In peripheral facial palsy, ENoG-MM offered higher sensitivity than ENoG-SM for predicting synkinesis. ENoG-MM is useful for screening patients at risk of developing synkinesis. In clinical practice, an ENoG-MM cut-off value of 45 % must be the optimal prognostic value because of the 100 % sensitivity.

Evaluation of Vestibular Functions in a Case of Vestibular Migraine With Successful Treatment With Erenumab.

This is the first report of vestibular examinations before and after the successful treatment of vestibular migraine (VM), a common cause of recurrent vertigo, with calcitonin gene-related peptide (CGRP) receptor inhibitor. We evaluated a 42-year-old female with VM and concomitant probable Meniere's disease, whose headache and dizziness have improved promptly with the administration of erenumab, a CGRP receptor inhibitor. The sensorineural hearing loss in pure-tone audiometry, dysfunctions shown in vestibular examinations (cervical and ocular vestibular evoked myogenic potentials), and mild endolymphatic hydrops shown in gadolinium-enhanced inner ear magnetic resonance imaging, all in the right ear, revealed no change compared with those observed before treatment. This case suggests that VM may be treated by blocking CGRP in the trigeminal ganglion, which suppresses the effects on the vestibular nucleus; herein, no effects were observed in the inner ear despite the clear amelioration of dizziness.

Saccular functions differ for Meniere's disease with and without coexisting headaches.

Objectives: To elucidate the differences between the cases of Meniere's disease (MD) with and without coexisting headaches, especially migraine. The clinical characteristics and vestibular functions are compared. Subjects: Fifteen patients with definite unilateral MD without headaches (MD/H-; 10 males and 5 females; mean age of 55.8 years), and 20 patients with definite unilateral MD with headaches (MD/H+; 3 males and 17 females; mean age of 54.4 years; 15 cases of migraine without aura and 5 cases of suspected migraine or tension-type headache) were enrolled. Methods: The medical records, caloric test results, and cervical vestibular evoked myogenic potential (cVEMP) of the patients were reviewed. A monothermal caloric test by injection of cold water was performed, and canal paresis was assessed. cVEMP was recorded using 500 Hz short tone bursts, and the asymmetry ratio using the corrected amplitude of p13-n23 was determined. Results: The patients in the MD/H- group were predominantly male, whereas more female patients were seen in MD/H+ group (p = 0.004). In the MD/H+ group, the frequency of vertigo and the dizziness handicap inventory (DHI) values were significantly higher than those in the MD/H- group (p = 0.045, <0.001, respectively). There was no statistical difference in the ages, duration of illness, or the hearing levels between both groups. The caloric testing results were abnormal for 10 of the 13 MD/H- cases, and 14 of the 16 MD/H+ cases, which revealed no significant difference between both groups. The cVEMP results revealed positive saccular dysfunction based on the asymmetry ratio of 4 of the 15 MD/H- cases, and 14 of the 20 MD/H+ cases; it was significantly more prevalent in the MD/H+ group than in the MD/H- group (p = 0.018). Multivariate analysis of sex, frequency of vertigo, DHI, and cVEMP results showed significant differences only in the cVEMP results (p = 0.049). Conclusion: The present study revealed differences in patients with MD depending on the presence or absence of headaches. MD without headaches showed a significant male preponderance. MD with coexisting headaches was more associated with severe saccular dysfunctions than MD without headaches. Concomitant headache may affect the manifestations of the vestibular function, especially in the sacculus, in MD cases.

Recurrent facial palsy: Characteristics of ipsilateral and alternative palsies of 104 cases.

OBJECTIVE: Recurrent facial palsy is relatively rare and its clinical details of recurrent facial palsy are not well known. We analyzed recurrent facial palsy cases and clarified its characteristics, especially the difference between ipsilateral and alternative palsies. The analysis aimed to obtain information about recurrent facial palsy that would be useful for delivering explanations to patients and help improve recurrent facial palsy treatments based on the etiology. METHODS: We picked up data from the chart and analyzed the clinical characteristics of patients with recurrent facial palsy from 1243 facial palsy patients (Bell's palsy, VZV-related palsy (Ramsay Hunt syndrome and zoster sine herpete [ZSH])) between 2006 and 2020. RESULTS: Recurrent facial palsy was observed in 104 of 1243 patients (8.4%). There were 35 cases (34%) of ipsilateral palsy and 69 cases (66%) of alternative palsy. The mean age at the onset of the first palsy was 38.9 years old in the ipsilateral group and 48.4 years old in the alternative group, and a significant difference was observed between them. The number of recurrences ranged from 1 to 4. Among the ipsilateral group, 6 patients experienced more than second recurrence. In two cases, the condition failed to resolve after the second recurrence. A serological examination confirmed that 4 cases had recurrent VZV-related palsy (both the first and second palsies were VZV-related) and all of them initially had ZSH: no cases had Hunt syndrome as the first palsy. CONCLUSIONS: The VZV-specific immunity obtained with ZSH might be insufficient to suppress VZV reactivation, and VZV vaccination should be recommended for ZSH patients to prevent further recurrence of VZV-related facial palsy. More than 2 ipsilateral recurrent episodes may be a risk factor for incomplete recovery.

Different results of vestibular examinations and blood flow in cases with transient vascular vertigo/dizziness with or without central nervous system symptoms.

BACKGROUND: The condition of vestibular dysfunction and blood flow in the vertebral artery (VA) in transient vascular vertigo/dizziness (TVV) is not well established. OBJECTIVES: To clarify the pathophysiology of TVV, especially the difference between the isolation of vestibular symptoms. MATERIALS AND METHODS: Ten TVV patients with central nervous system symptoms (TVVw) and 12 TVV patients without central nervous system symptoms (TVVo) underwent duplex color-coded ultrasonographic evaluation of VAs, caloric test, and cervical vestibular-evoked myogenic potential (cVEMP). RESULTS: The mean flow velocity (MV) ratio (peak MV of contralateral VA divided by target VA) was significantly higher in TVVw than in TVVo. There was no difference in the occurrence of canal paresis between TVVw and TVVo. Abnormal asymmetry ratios (ARs) of cVEMP were observed only in TVVo cases (6 of 12 cases), revealing a statistically significant difference in the number of cases between TVVw and TVVo. CONCLUSIONS AND SIGNIFICANCE: Measuring VAs using duplex color-coded ultrasonography and cVEMP may help evaluate TVV. Different results of MV ratio and cVEMP between TVV cases with or without central nervous system symptoms may indicate differences in the pathophysiology between TVVw and TVVo.

Facial Nerve Palsy in a Young Patient With Acute Lymphoblastic Leukemia Possibly Induced by Herpes Virus Reactivation in the Facial Nerve.

Facial palsy in acute lymphoblastic leukemia (ALL) patients is diagnosed as tumor cell invasion of the central nervous system (CNS) following the ALL guidelines. Facial palsy in a 6-year-old ALL patient was diagnosed as leukemia cell invasion into the CNS by hemato-oncologists. Pretreatment magnetic resonance image (MRI) revealed gadolinium enhancement of the first genu and meatal portion of the facial nerve. After chemotherapy, although the ALL tumor cells disappeared from both the blood and the cerebrospinal fluid, and the facial palsy resolved, a posttreatment MRI showed no change in terms of enhancement of the facial nerve. These findings indicated the possibility of herpetic viral reactivation in the geniculate ganglion of the facial nerve. We must be aware and discuss with hemato-oncologists the possibility that not only tumor cell invasion into the CNS, in accordance with the guidelines, but also that herpetic virus reactivation arising in the facial nerve may be causes of facial palsy.

Asymmetry and tuning shift of the cervical vestibular evoked myogenic potential indicate saccular dysfunction in idiopathic normal pressure hydrocephalus.

OBJECTIVE: The purpose of this study was to investigate the effects of excessive cerebrospinal fluid (CSF) retention on the peripheral vestibular function and the inner ear fluid in patients with idiopathic normal pressure hydrocephalus (iNPH). METHODS: In 25 patients with iNPH (14 females, age 65-88 years), cervical vestibular evoked myogenic potential (cVEMP) was measured before the spinal tap test. The asymmetry ratios (ARs) and tuning properties in 500 Hz and 1,000 Hz short-tone burst stimuli of cVEMP were evaluated. Furthermore, cVEMP was measured in an age-matched control group of 12 non-iNPH patients. RESULTS: Seven (28%) iNPH patients exhibited a cVEMP asymmetry (AR > 33%). cVEMP tuning was significantly shifted to a higher frequency in the iNPH group than in the age-matched control group. CONCLUSIONS: One-fourth of patients with iNPH had obvious saccular dysfunction. A high rate of a shift in cVEMP tuning in the iNPH group indicated that excessive CSF accumulation propagated to the endolymph and perilymph. SIGNIFICANCE: Saccular dysfunction might be one of the possible causes of imbalance in iNPH, and the shift in cVEMP tuning may be a determining factor in the diagnosis and treatment strategy.

Effects of Endoscopic Sinus Surgery for Eosinophilic Chronic Rhinosinusitis on Respiratory Functions and FeNO Production in the Lower Respiratory Tract.

OBJECTIVE: To confirm the relevance of upper and lower airway inflammation in eosinophilic chronic rhinosinusitis (ECRS), the effects of endoscopic sinus surgery (ESS) on lower airway functions and inflammation need to be examined in ECRS patients. METHODS: Chronic rhinosinusitis patients with nasal polyps (25 non-ECRS, 28 ECRS) were enrolled. The 12 patients in the ECRS group had comorbid asthma, in contrast to none in the non-ECRS group. We divided ECRS patients into 2 groups of ECRS with and without asthma. Clinical markers, including fraction of exhaled nitric oxide (FeNO), respiratory functions, and the Asthma Control Test (ACT) questionnaire, were investigated before and after ESS. RESULTS: The FeNO levels in the ECRS with asthma group decreased after ESS. The mean FeNO levels in this group were 56.3 ppb before ESS and 24.9, 25.1, 25.0, and 15.5 ppb 1, 2, 3, and 4 months, respectively, after ESS. The mean forced expiratory rates in 1 second before and after ESS were 67.6% and 73.0%, respectively. The mean maximal expiratory flow rates at 50% of the vital capacity before and after ESS were 45.8% and 58.0%, respectively. Significant differences were observed in respiratory functions before and after ESS. The mean ACT scores in the ECRS with asthma group before and after ESS were 17.5 and 23.5, respectively. The ACT scores were significantly higher after than before ESS. CONCLUSIONS: The present results indicate that ECRS and bronchial asthma are common eosinophilic airway inflammatory diseases, and ESS for eosinophilic sinusitis may improve lower airway function.

Mild blast wave exposure produces intensity-dependent changes in MMP2 expression patches in rat brains - Findings from different blast severities.

Matrix metalloproteinase 2 (MMP2) is a gelatinase with multiple functions at the neurovascular interface, including local modification of the glia limitans to facilitate access of immune cells into the brain and amyloid-beta degradation during responses to injury or disease. This study examines regional changes in immunoreactive MMP2 in the rat brain after a single mild (2.7-7.9 psi peak) or moderate (13-17.5 psi peak) blast overpressure (BOP) exposure. Immunopositive MMP2 expression was examined quantitatively in histological sections of decalcified rat heads as a marker at 2, 24, and 72 h after BOP. The MMP2 immunoreactivity was isolated to patchy deposits in brain parenchyma surrounding blood vessels. Separate analyses were conducted for the cerebellum, brain stem caudal to the thalamo-mesencephalic junction, and the cerebrum (including diencephalon). The deposits varied in number, size, staining homogeneity (standard deviation of immunopositive region), and a cumulative measure, the product of size, average intensity and number, as a function of blast intensity and time. The sequences of changes in MMP2 spots from sham control animals suggested that the mild BOP exposure differences normalized within 72 h. However, the responses to moderate exposure revealed a delayed response at 72 h in the subtentorial brain stem and the cerebrum, but not the cerebellum. Hence, local MMP2 responses may be a contextual biomarker for locally regulated responses to widely distributed brain injury foci.

Steroids Inhibit Eosinophil Accumulation and Downregulate Hematopoietic Chemotaxic Prostaglandin D2 Receptor in Aspirin-Exacerbated Respiratory Disease.

BACKGROUND: Aspirin-exacerbated respiratory disease (AERD) is characterized by eosinophilic rhinosinusitis, nasal polyposis, aspirin sensitivity, and asthma. Aims/Objectives: This study aims to identify a mechanism to target for the future treatment of AERD via the elucidation of the effect of systemic steroids on the expression of hematopoietic prostaglandin D2 synthase (HPGDS) and chemotaxic prostaglandin D2 (DP2) receptor relative to eosinophil activation in the nasal polyps of patients with AERD. MATERIALS AND METHODS: Among 37 patients undergoing endoscopic sinus surgery, 28 received systemic steroids preoperatively. Nasal polyps were harvested from all 37 patients. After routine processing of paraffin sections, immunohistochemistry was performed using specific antibodies for HPGDS, eosinophil peroxidase (EPX), and DP2. RESULTS: Expression of HPGDS, DP2, and EPX by eosinophils was higher and more frequent in patients with non-preoperative steroid therapy. Likewise, HPGDS and DP2 were highly expressed in activated eosinophils in the nasal polyps, but not in normal eosinophils. CONCLUSION AND SIGNIFICANCE: This study provides clear evidence that systemic steroid therapy inhibits eosinophil activation and decreases HPGDS and DP2 expression in patients with AERD, indicating a reduction in prostaglandin D2 production and hence control hyperplasia of nasal polyps.

Optimal current intensity for supramaximal stimulation during electroneurography for facial palsy.

OBJECTIVE: To determine the optimal current intensity for supramaximal stimulation during electroneurography (ENoG) for facial palsy. METHODS: Forty patients with unilateral facial palsy (32 Bell's palsy, 7 Ramsay Hunt syndrome, and 1 temporal bone fracture) were enrolled. All patients were initially treated with intravenous steroid injections and examined using ENoG. Compound muscle action potentials (CMAPs) of the orbicularis oris muscle were measured on the paralyzed and healthy sides. Stimulation current intensity was varied every 5 mA from 20 mA to 50 mA using two recording methods (the midline and standard methods). The CMAPs of both sides were monitored to see whether they would saturate under the high current intensity stimulation or not. RESULTS: No obvious saturation of CMAPs was observed in either side with the midline or standard methods. Statistically, a current of 35 mA and above in the healthy side, and 30 mA and above in the paralytic side, resulted in no difference to each side when using the midline recording method. On the other hand, a current of 35 mA and above in the healthy side, and 25 mA and above in the paralytic side, resulted in no difference to each side when using the standard recording method. CONCLUSIONS: These results indicate that a current intensity of at least 35 mA is required to achieve supramaximal stimulation on the healthy side in a patient with unilateral facial nerve palsy. Clinically, for simplicity or standardization purposes, if the same current intensity is introduced bilaterally for ENoG measurements, adopting 40 mA (35 mA plus 10-20%) stimulation would be appropriate for supramaximal stimulation, while being cognizant of the potential effects of artifacts from other muscles.

Facial nerve course in the temporal bone: Anatomical relationship between the tympanic and mastoid portions for safe ear surgery.

OBJECTIVE: Avoidance of iatrogenic injury to the facial nerve is crucial during ear surgery. The anatomical relationship between the tympanic portion of the facial canal (FC) and the mastoid portion of the facial nerve was analyzed using multi-slice computed tomography (CT) scans to avoid iatrogenic facial nerve injury. METHODS: In total, 364 ears of 351 patients who underwent CT scans were enrolled. The 364 ears were divided into two groups: 281 ears with middle ear inflammation (MEI) and 83 ears without middle ear inflammation (non-MEI). The anatomical relationship between the tympanic portion of the FC and mastoid portion of the facial nerve was analyzed on multi-slice CT images. The ears were categorized into three subgroups based on the course of the mastoid portion of the facial nerve to the tympanic portion of the FC: ("lateral running course", LRC), "on the tympanic line course" (OL), and "medial running course" (MRC). The proportions of ears in each subgroup were compared between the MEI and non-MEI groups. RESULTS: Overall, 15% of ears were categorized as LRC, 30% were OL, and 55% were MRC. In the MEI group, the proportions of LRC, OL, and MRC ears were 17%, 32%, and 51%, respectively, whereas they were 7%, 24%, and 69% in the non-MEI group. The proportion of LRC ears in the MEI group was significantly higher than that in the non-MEI group. CONCLUSIONS: Especially in patients with MEI, a more LRC for the facial nerve increases the risk of facial nerve injury during posterior tympanotomy or canal wall down mastoidectomy. The course of the facial nerve in the temporal bone should be evaluated before surgery on multi-slice CT images.

Latency shift in compound muscle action potentials during electroneurography in facial palsy.

OBJECTIVE: Electroneurography (ENoG) reliably predicts the prognosis of facial palsy. However, the results of ENoG are dependent on the location, where the wave is detected, as a compound muscle action potential (CMAP) arising from the facial muscles. To minimize errors in prognostic prediction, we analysed the latencies of facial CMAPs. MATERIALS AND METHODS: Fifty-seven patients with unilateral peripheral facial palsy and 24 healthy volunteers were enrolled. Amplitudes, negative peak latencies (NPL), and rise latencies (RL) of CMAPs were measured on the paralysed and healthy sides in patients and in healthy volunteers. The relationships of these latencies with ENoG values and the lowest House-Brackmann (H-B) scores were also analysed. RESULTS: The amplitude of CMAP on the paralysed side was smaller, and NPL and RL were longer, than those on the healthy side in patients and healthy volunteers (p < 0.01). In patients, there was no difference in NPL between the ENoG < 40% group and the ENoG ≥ 40% group. Conversely, there was a significant difference in RL between the ENoG < 40% group and ENoG ≥ 40% group (p = 0.03). No relationships were observed between NPL or RL and the lowest H-B score. CONCLUSIONS: NPL and RL of CMAP on the paralysed side were equivalent or longer than those on the healthy side. During ENoG for facial palsy, CMAP should be measured on the healthy side first, and then detected (and the amplitude measured) on the paralysed side with reference to CMAP latency on the healthy side, to reduce errors in detecting facial CMAPs.

Recurrent benign pleomorphic adenoma of the parotid gland: Facial nerve identification and risk factors for facial nerve paralysis at re-operation.

OBJECTIVE: Surgery for recurrent pleomorphic adenoma of the parotid gland is challenging since there is a considerable risk of facial nerve injury and a high re-recurrence rate. We investigated surgery for recurrent pleomorphic adenoma, focusing on management of the facial nerve. METHODS: We reviewed 29 patients who underwent surgery for recurrent benign pleomorphic adenoma of the parotid gland at our department between 1999 and 2018. We examined clinicopathologic features and risk factors for facial nerve injury during reoperation. RESULTS: Factors associated with difficulty in identifying the main trunk of the facial nerve during surgery were bilobar tumors, multiple tumors, and use of an S-shaped skin incision at the previous operation. When the facial nerve was identified intraoperatively, it could be preserved in 2/3 of patients, while the nerve was only preserved in 1/3 of patients when it was not identified. Factors related to permanent postoperative paralysis included recurrence in the deep lobe or both lobes and multiple tumors. CONCLUSION: The probability of successfully preserving the facial nerve is relatively high if the nerve can be identified during surgery for recurrent pleomorphic adenoma, although intentional resection is necessary in some patients. Factors associated with difficulty in identifying the facial nerve are similar to those related to permanent postoperative paralysis, including bilobar tumors and multiple tumors. In patients with recurrent pleomorphic adenoma, preservation of the facial nerve is difficult, when they may have undergone previous extensive resection or have multiple tumors requiring subtotal or more extensive resection.

Regulatory T and B cells in peripheral blood of subcutaneous immunotherapy-treated Japanese cedar pollinosis patients.

AIM: The aim of this study was to clarify whether there are more regulatory T (Treg) and regulatory B (Breg) cells, and higher levels of IL-10-related transcription factors in subcutaneous immunotherapy (SCIT)-treated pollinosis patients than in non-SCIT-treated patients. METHODS: Japanese cedar pollinosis patients undergoing SCIT had received treatment for at least 2.8 years. Peripheral blood mononuclear cells were used for flow cytometer analyses and mRNA measurement. RESULTS: The numbers of type 1 regulatory T (Tr1)-like cells and Breg cells, and expression of E4BP4 mRNA by peripheral blood mononuclear cells in SCIT-treated patients were higher than those in non-SCIT-treated patients. CONCLUSION: Tr1-like cells, Breg cells and E4BP4 may be involved in the effectiveness of SCIT.

Novel differential diagnostic method for superficial/deep tumor of the parotid gland using ultrasonography.

BACKGROUND: The purpose of this study was to prepare the ultrasonographic diagnostic criteria on parotid tumors for preoperative differentiation of superficial and deep tumors. METHODS: We evaluated 154 patients with a benign parotid tumor who underwent surgery. The minimum thickness of normal parotid gland tissue between the parotideomasseteric fascia and tumor (minimum fascia-tumor distance [MFTD]) was measured on preoperative ultrasonography and compared among tumors at different locations, and the optimum cutoff value to differentiate a deep tumor was identified. RESULTS: The MFTD showed significant differences between superficial and deep tumors and between inferior pole and deep tumors. The sensitivity, specificity, and accuracy of an MFTD ≥3 mm for the differentiation of deep tumors were 85%, 91%, and 89%. CONCLUSION: A tumor with an MFTD ≥3 mm on preoperative ultrasonography is very likely to be a deep tumor based on a new differentiation method for deep parotid tumors considering those present at other locations.

Ca(2+) regulation of endocochlear potential in marginal cells.

We examined the effect of the cytosolic Ca(2+) concentration ([Ca(2+)](c)) in marginal cells on the asphyxia- or furosemide-induced decrease in the endocochlear potential (EP) by perfusing the endolymph with or without a Ca(2+) chelator or inhibitors of Ca(2+)-permeable channels or Ca(2+)-pump during transient asphyxia or intravenous administration of furosemide. We obtained the following results. (1) Endolymphatic administration of SKF96365 (an inhibitor of TRPC and L-type Ca(2+) channels) or EGTA-acetoxymethyl ester (EGTA-AM) significantly inhibited both the transient asphyxia-induced decrease in EP (TAID) and the furosemide-induced decrease in EP (FUID). (2) Endolymphatic perfusion with nifedipine significantly inhibited the TAID but not the FUID. (3) The recovery from the FUID was significantly suppressed by perfusing the endolymph with EGTA-AM, nifedipine, or SKF96365. (4) Endolymphatic administration of thapsigargin inhibited both the FUID and TAID. (5) The recovery rate from the FUID was much slower than that from the TAID, indicating that furosemide may inhibit the Ca(2+)-pump. (6) A strong reaction in immunohistochemical staining for TRPC channels was observed in the luminal and basolateral membranes of marginal cells. (7) A positive staining reaction for the gamma subunit of epithelial Na(+) channels was observed in the luminal and basolateral membranes of marginal cells. (8) Positive EP was diminished toward 0 mV by the endolymphatic perfusion with 10 muM amiloride or 10 muM phenamil. Taken together, these findings suggest that [Ca(2+)](c) regulated by endoplasmic Ca(2+)-pump and Ca(2+)-permeable channels in marginal cells may regulate the positive EP, which is partly produced by the diffusion potential of Na(+) across the basolateral membrane in marginal cells.

Planned fractionated boron neutron capture therapy using epithermal neutrons for a patient with recurrent squamous cell carcinoma in the temporal bone: a case report.

BACKGROUND: We describe the first case of extensive squamous cell carcinoma in the temporal bone recurring after surgery, conventional radiotherapy, and chemotherapy, which was treated using planned fractionated boron neutron capture therapy (BNCT). METHODS: A 42-year-old patient received BNCT twice with a 1-month interval to ensure neutron capture in the deep lesion. We used an epithermal neutron beam as the neutron source and boronophenylalanine as the boron compound. The total radiation doses in the tumor beneath the skin, at the deepest point of the tumor, and in the skin around the right auricle were estimated as 41.8, 36.9, and 15.8 Gy-Eq, respectively. RESULTS: Radiological studies performed 6 months after the first BNCT showed obvious tumor shrinkage and no evidence of residual tumor. CONCLUSION: We believe that planned fractionated BNCT is an effective treatment option for patients with inoperative extended carcinomas in the temporal bone.