Does severity of cerebral MRI lesions in congenital CMV infection correlates with the outcome of cochlear implantation?

The objective is to investigate whether there is a correlation between the severity of typical brain lesions in congenital cytomegalovirus (cCMV) infection and cochlear implant (CI) outcome. The design of the study is a retrospective single-institutional chart review (2005-2015), performed in a tertiary academic referral center. 23 children with typical signs of cCMV infection on cerebral magnetic resonance imaging (MRI) and bilateral severe-to-profound sensorineural hearing loss were retrospectively evaluated. They were graded in three groups according to the severity of brain involvement. The average implantation age of the first CI is 1.8 years (range 0.6-5.8). Five patients were implanted unilaterally, 18 bilaterally. The average follow-up time after implantation was 3.3 years (range 0.6-6.9). Hearing performance was assessed using the Categories of Auditory Performance (CAP), and speech development was assessed using Speech Intelligibility Rating (SIR). The outcome in each group showed great variation. The majority of children achieved moderate-to-good auditory and speech rehabilitation. The children with severe MRI changes had comparatively better auditory than speech scores. There were children with good auditory performance (CAP ≥6) both in grades II and III, while poor performers (CAP ≤3) were encountered in each group. The severity of brain lesions on its own does not directly correlate with the outcome of cochlear implantation. Despite good retrospective diagnostic evidence of cCMV infection through MRI patterns, this has no predictive role for future hearing and speech rehabilitation.

Neurological Sequelae in Adults After E coli O104: H4 Infection-Induced Hemolytic-Uremic Syndrome.

In an outbreak of shiga toxin-producing Escherichia coli infections and associated hemolytic-uremic syndrome (STEC O104:H4) in Germany in the year 2011 neurological complications in adult patients occurred unexpectedly frequent, ranging between 48% and 100% in different patient groups. Few is known about the long-term effects of such complications and so we performed follow-up exams on 44 of the patients treated for STEC-HUS at Hannover Medical Scool in this observational study. Standardized follow-up exams including neurological and neuropsychological assessments, laboratory testing, magnetic resonance imaging (MRI), and EEG were carried out. Subgroups were examined 2 (n = 34), 7 (n = 22), and 19 (n = 23) months after disease onset. Additionally, at the 19-month follow-up, quality of life, sleep quality, and possible fatigue were assessed.Nineteen months after disease onset 31 patients were reassessed, 22 of whom still suffered from symptoms such as fatigue, headache, and attention deficits. In the neuropsychological assessments only 39% of the patients performed normal, whereas 61% scored borderline pathological or lower. Upon reviewal, the follow-up data most prominently showed a secondary decline of cognitive function in about one-quarter of the patients. Outcome was not related to treatment or laboratory data in the acute phase of the disease nor length of hospitalization. Prognosis of STEC-HUS associated brain dysfunction in adults with regard to severity of symptoms is mostly good; some patients however still have not made a full recovery. Patients' caretakers have to be aware of possible secondary decline of brain function as was observed in this study.

Inner ear anatomy in Waardenburg syndrome: radiological assessment and comparison with normative data.

OBJECTIVE: As patients with Waardenburg syndrome (WS) represent potential candidates for cochlear implantation, their inner ear anatomy is of high significance. There is an ongoing debate whether WS is related to any inner ear dysplasias. Our objective was to evaluate radiologically the inner ear anatomy in patients with WS and identify any temporal bone malformations. METHODS: A retrospective case review was carried out in a tertiary, referral center. The high resolution computed tomography (HRCT) scans of the temporal bone from 20 patients (40 ears) with WS who were managed for deafness in a tertiary referral center from 1995 to 2012 were retrospectively examined. Measurements of 15 different inner ear dimensions, involving the cochlea, the vestibule, the semicircular canals and the internal auditory meatus, as well as measurements of the vestibular aqueduct, were performed independently by two neuroradiologists. Finally, we compared the results from the WS group with a control group consisting of 50 normal hearing subjects (100 ears) and with previously reported normative values. RESULTS: Inner ear malformations were not found in any of the patients with WS. All measured inner ear dimensions were within the normative values compiled by our study group as well as by others. CONCLUSIONS: Inner ear malformations are not characteristic for all types of WS; however, certain rare subtypes might be related to inner ear deformities. Normative cochleovestibular dimensions that can help in assessing the temporal bone anatomy are provided.

Improved imaging of cochlear nerve hypoplasia using a 3-Tesla variable flip-angle turbo spin-echo sequence and a 7-cm surface coil.

OBJECTIVE/HYPOTHESIS: Magnetic resonance imaging of the temporal bone has an important role in decision making with regard to cochlea implantation, especially in children with cochlear nerve deficiency. The purpose of this study was to evaluate the usefulness of the combination of an advanced high-resolution T2-weighted sequence with a surface coil in a 3-Tesla magnetic resonance imaging scanner in cases of suspected cochlear nerve aplasia. STUDY DESIGN: Prospective study. METHODS: Seven patients with cochlear nerve hypoplasia or aplasia were prospectively examined using a high-resolution three-dimensional variable flip-angle turbo spin-echo sequence using a surface coil, and the images were compared with the same sequence in standard resolution using a standard head coil. Three neuroradiologists evaluated the magnetic resonance images independently, rating the visibility of the nerves in diagnosing hypoplasia or aplasia. RESULTS: Eight ears in seven patients with hypoplasia or aplasia of the cochlear nerve were examined. The average age was 2.7 years (range, 9 months-5 years). Seven ears had accompanying malformations. The inter-rater reliability in diagnosing hypoplasia or aplasia was greater using the high-resolution three-dimensional variable flip-angle turbo spin-echo sequence (fixed-marginal kappa: 0.64) than with the same sequence in lower resolution (fixed-marginal kappa: 0.06). CONCLUSIONS: Examining cases of suspected cochlear nerve aplasia using the high-resolution three-dimensional variable flip-angle turbo spin-echo sequence in combination with a surface coil shows significant improvement over standard methods.

Aplasia of the cochlea: radiologic assessment and options for hearing rehabilitation.

OBJECTIVE: Hearing rehabilitation of patients with severe inner ear malformations remains controversial. Our objective was to describe the radiologic findings of aplasia of the cochlea (AC) and evaluate the existing therapeutic options in such patients. STUDY DESIGN: Retrospective cohort study. SETTING: Tertiary referral center. PATIENTS: Pediatric and adult patients with AC evaluated at our institution from 1995 to 2010. INTERVENTIONS: The precise radiologic findings were identified using high-resolution computed tomography (HRCT) and magnetic resonance imaging (MRI) scans of the inner ear. In cases of auditory implantation on the AC side, the achieved outcome was recorded using categories of auditory performance (CAP). Related surgical aspects were analyzed. RESULTS: Twenty-three patients (28 ears) with AC were found. In 5 patients AC was bilateral. The remaining unilateral cases had contralateral normal ears (2 patients), cochlea hypoplasia (5 patients), common cavity (6 patients), incomplete partition Type I (4 patients), and atresia of the internal auditory canal (1 patient). Four patients (3 bilateral, 1 unilateral ACs) were treated with cochlear implants in ears with AC, and 1 patient underwent auditory brainstem implantation. All implanted patients achieved speech perception with limited vocabulary (CAP scores between 4 and 5). CONCLUSION: AC is defined as the total absence of the cochlea, with a present, although malformed, vestibule. Although a distinct auditory nerve was not seen in these cases of AC, results following cochlear implantation suggest functional cochlear nerve fibers in the remaining dysplastic inner ear structures. In selected cases, cochlear implantation may be a reasonable option for the habilitation of deafness associated with AC.

Quantitative MRI shows cerebral microstructural damage in hemolytic-uremic syndrome patients with severe neurological symptoms but no changes in conventional MRI.

INTRODUCTION: Severe neurological symptoms in Shiga toxin-producing Escherichia coli infection associated hemolytic-uremic syndrome (STEC-HUS) are often accompanied by none or only mild alterations of cerebral magnetic resonance imaging (MRI). This study aims to analyze if quantitative MRI is able to reveal cerebral pathological alterations invisible for conventional MRI. METHODS: In nine patients with STEC-HUS associated severe neurological symptoms but inconspicuous cerebral MRI findings maps of the parameters T2 relaxation time, relative proton density (PD), apparent diffusion coefficient (ADC), and fractional anisotropy (FA) were generated. Quantitative values of these parameters were measured at the basal ganglia, thalamus, and white matter of the frontal and parietal lobe and compared to those of nine age- and sex-matched controls. RESULTS: Significant T2 prolongation (p < 0.01) was found in the basal ganglia of all patients compared to controls. PD and ADC were not significantly altered. A significant reduction of FA in patients was seen at caput nuclei caudati (p < 0.01). CONCLUSION: Prolonged T2 relaxation time indicates cerebral microstructural damages in these patients despite their inconspicuous MRI findings. T2 relaxometry could be used as a complementary tool for the assessment of metabolic-toxic brain syndromes.

Neurologic manifestations of E coli infection-induced hemolytic-uremic syndrome in adults.

OBJECTIVE: To describe the neurologic and neuroradiologic complications of Shiga toxin producing Escherichia coli infection (STEC)-associated hemolytic-uremic syndrome (HUS) in adults. METHODS: All 52 adult patients with STEC O104:H4 infection cared for at Hannover Medical School during the outbreak in Germany through May-July 2011 are considered in this observational study. Forty-three of the 52 patients underwent a standard neurologic diagnostic procedure including clinical examination, Mini-Mental State Examination, and Glasgow Coma Scale Score. Thirty-six patients underwent EEG, and 26 had cerebral MRI, 9 of them repeatedly. Case records of 9 patients who had not been seen by a neurologist were analyzed retrospectively. RESULTS: Forty-eight of the 52 patients had HUS. All but 1 of these showed neurologic symptoms. Focal neurologic signs like double vision, difficulties in finding words, or hyperreflexia were present in 23, additional deficits in orientation, attention, memory, or constructive abilities in 9, and marked impairment of consciousness in 15. MRI showed brainstem, midbrain, thalamus, corpus callosum, and white matter lesions in half of the patients, predominantly in diffusion-weighted images. The extent of MRI lesions did not correlate with clinical symptoms. General slowing but no focal alteration was found in half of the patients examined by EEG. CONCLUSION: Our findings suggest a toxic-metabolic pathology behind the neurologic impairment instead of multiple infarction due to microthrombosis. Future studies should aim to clarify if early antibiotic therapy or bowel cleansing might help to decrease the rate of neurologic complications in STEC-HUS.

Treating hearing loss in patients with infantile Bartter syndrome.

OBJECTIVES/HYPOTHESIS: Most existing studies about infantile Bartter syndrome (BS) have focused on renal function, and deafness has not been closely studied. Our objective was to evaluate the treatment of hearing impairment in children with infantile BS and analyze relevant, unexplored issues. STUDY DESIGN: Retrospective chart review. METHODS: The present study was conducted in a tertiary referral center over a 20-year period involving children with infantile BS. Demographic factors, general health status, genetic information, features of hearing loss, and the outcome of cochlear implantation as determined mainly by the categories of auditory performance (CAP), as well as imaging of the temporal bones, were evaluated. RESULTS: Six children with infantile BS were identified, four girls and two boys. One child had terminal renal insufficiency and one had undergone kidney transplantation; all children had several hospital admissions due to renal dysfunction. Sensorineural hearing loss was congenital, bilateral, and profound in all children. Five patients were treated with cochlear implants resulting in improved speech perception and development without any exceptional performance (CAP scores, 4-6), mainly because of the delayed treatment and the comorbidities. Anatomic ear anomalies were not observed in any case. CONCLUSIONS: Hearing loss in children with infantile BS is congenital and profound but not related to inner ear malformations. Although cochlear implantation results in certain benefits, general health status and delayed referral to cochlear implant centers have a negative impact on speech perception and development.

Controlling the position and the dislocation of the middle ear transducer with high-resolution computed tomography and digital volume tomography: implications for the transducers' design.

A minimal tip dislocation of the middle ear transducer (MET(®), Otologics Ltd) may result in poor hearing performance. Our objective was to examine if a defined MET dislocation can be diagnosed by high-resolution computed tomography (HRCT) or digital volume tomography (DVT). A human cadaver head was sequentially implanted with different MET tips (incus application) including a ceramic tip (T 1c), a titanium tip (T 1t), a new, thinner titanium tip (T 2), and a spherical titanium tip (Ts). HRCT and DVT studies were performed. Afterward, the tips were pulled back 0.5 mm, so that they were not attached to the incus. HRCT and DVT scans were repeated to identify the dislocation. Using the best plain in HRCT images, the dislocation of the transducer could be measured reliably and reproducibly in half of the cases. In particular, the precise positioning and the dislocation could be identified when T 1t and Ts were implanted, with the Ts showing the best visibility. DVT failed in recognizing the dislocation in all cases. The identification of MET tip's dislocation with HRCT depends on the shape, size, and material of the tip. This knowledge is useful for the design of the implants, as determination of the right position of the middle ear transducer may be proven important for the hearing outcome. In some cases, however, surgical exploration may still be required. Although DVT represents a promising imaging method for the otologists, it can barely help when MET dislocation is suspected.

Radiological diagnosis of incomplete partition type I versus type II: significance for cochlear implantation.

OBJECTIVES: To investigate an extended cohort of patients with incomplete partition (IP) and examine the adequacy of the existing classifications based on radiological criteria and on their implications for cochlear implantation. METHODS: Patients with IP admitted to a tertiary referral centre during the period 2000-2010 were retrospectively examined. The subjects were initially classified into IP-I, IP-II and atypical cases. For cochlear implant recipients relevant aspects were analysed. RESULTS: Eighty-three ears (49 patients) with IP were found, 19 with IP-I, 54 with IP-II and 10 atypical. Thirty-three patients received a cochlear implant (11 with IP-I, 19 with IP-II and three atypical) achieving heterogeneous though mostly promising results. Cerebrospinal fluid gushing was the commonest surgical complication, particularly in cases of IP-I. In general, patients with IP-II performed better than those with IP-I. CONCLUSIONS: Cochlear implantation promises adequate hearing rehabilitation for most patients with IP. As we move from IP-I to IP-II better results and lower risk for gushing shall be expected. Based on radiological findings we suggest a modified classification into IP-I, atypical IP-I (with large vestibular aqueduct (LVA) and better partition), IP-II (Mondini deformity) and atypical IP-IIa (without LVA) and b (without LVA but with semicircular canal dysplasia). KEY POINTS: • Radiological (CT and MR) features are of crucial importance for cochlear implantation • Imaging can identify two types of incomplete cochlear partition and atypical cases • Detailed pre-operative radiological assessment can help predict complications and outcome • A more comprehensive radiological classification of these anomalies is proposed.

Bilateral trochlear nerve palsy subsequent to ventriculoperitoneal shunting of normal pressure hydrocephalus.

Misplacement of the ventricular catheters of shunt systems may result in shunt dysfunction or a variety of neurological symptoms. Bilateral fourth nerve palsy has not been reported thus far after shunting. Here, we describe the occurrence of this unusual neurological deficit in a patient who underwent shunting for normal pressure hydrocephalus, and demonstrate its pathoanatomical correlate.

The vestibulocochlear nerve: aplasia and hypoplasia in combination with inner ear malformations.

OBJECTIVE: To determine features of hypoplasia and aplasia of the vestibulocochlear nerve (VCN) in combination with inner ear malformations (IEMs). METHODS: Index cases were retrospectively selected from all IEMs collected since 1995. CT and MRI data were reviewed by two neuroradiologists. The number and thickness of visible nerves in the cerebellopontine angle cistern and inside the internal auditory canal (IAC) were analysed. RESULTS: MR images for 176 patients with IEMs were analysed. Labyrinthine aplasia and otocyst deformity showed 100% correlation, and IAC malformations exhibited 92% correlation with VCN aplasia. Cochlear aplasia, complete aplasia of the semicircular canals, severe cochlear hypoplasia, common cavity, incomplete partition type 1 and mild cochlear hypoplasia showed decreasing degrees of correlation with hypoplasia of the VCN. The remaining types of IEM did not demonstrate VCN hypoplasia. CONCLUSIONS: Certain forms of IEM show 100% correlation with hypoplasia or aplasia of the VCN, while others correlate less strongly and some do not usually exhibit VCN hypoplasia. MRI should always be carried out for those forms often correlated with VCN hypoplasia. KEY POINTS: Vestibulocochlear nerve deficiency can be strongly suspected in certain inner ear malformations • Bony cochlear aplasia and cochlear nerve aplasia are strongly correlated • In semicircular canal aplasia, hypoplasia of the vestibular nerve can be found • Before cochlear implantation, the type of any IEM should be fully understood.

Persistent petrosquamosal sinus: high incidence in cases of complete aplasia of the semicircular canals.

PURPOSE: To determine the frequency and to describe the morphologic characteristics and associated skull base anomalies of the petrosquamosal sinus (PSS) in cochlear implant candidates with complete aplasia of the semicircular canals (SCCs). MATERIALS AND METHODS: Ethics committee approval was obtained. Index cases were retrospectively selected from an electronic database in which all inner ear malformations observed in patients presenting to a tertiary referral center between 1995 and 2010 were collected. Computed tomography (CT) data were reviewed by neuroradiologists. Clinical consequences of the neuroradiologic findings were analyzed. The Pearson χ(2) test and the Mann-Whitney U test were used to determine significant differences between the number of PSSs observed in cases of complete aplasia of the SCCs and the number observed in cases of other types of inner ear malformations. RESULTS: Inner ear malformations were analyzed in 241 patients. Thirty-one patients (13%) with bilateral SCC aplasia were identified. Among 31 patients, a uni- or bilateral PSS was observed in 25 (81%). In the ears with SCC aplasia, a PSS was observed in 40 (65%) of 62. The three cases in which these PSS occupy the largest area correlate with bilateral absence of the jugular foramen. In seven of eight ears with a PSS, the PSS inhibited surgical exposure or resulted in accidental opening of the PSS during surgery. In all other patients with inner ear malformations, a PSS was observed in 39 (9%) of 412 ears only. CONCLUSION: The PSS presents a risk for cochlear implant surgery that can be detected by the neuroradiologist in advance. Venous CT angiography is advisable in certain cases. The previous assumption that a persistent PSS is encountered more frequently in cases of skull base deformity can be affirmed in the special situation of complete aplasia of the SCCs.