Rudolf Häusler

A Controlled Study of Early Neurologic Abnormalities in Men with Asymptomatic Human Immunodeficiency Virus Infection

BACKGROUND Although neurologic complications are frequent in the acquired immunodeficiency syndrome, their incidence and progression in early human immunodeficiency virus (HIV) infection remain controversial. The goal of this study was to assess neurologic manifestations in asymptomatic carriers of HIV. METHODS We studied 29 HIV-seropositive homosexual men and 33 seronegative homosexual controls by means of neurologic and neuropsychological examinations, magnetic resonance imaging (MRI), and electrophysiologic tests (electroencephalography, multimodal evoked-potential tests, and otoneurologic tests). After six to nine months, the tests were repeated in 27 seropositive men and 30 controls. The investigators were blind to the serologic status of the subjects. RESULTS The seropositive subjects had a mean CD4+ lymphocyte count of 635 X 10(6) per liter. Neurologic and neuropsychological examination, MRI, and measurements of pattern visual evoked potentials did not show significant differences between the two groups. The latencies of the median-nerve somatosensory evoked potentials were slightly prolonged in the seropositive men. The initial electroencephalogram was judged abnormal in 8 of 27 of the seropositive subjects (30 percent) as compared with none of the controls, with a slowing of fundamental activity, anterior spread [corrected] of alpha rhythm, subnormal reactivity, and unusual anterior theta activities. These findings were confirmed by computerized spectral analysis. The second electroencephalogram was abnormal in 10 of 25 of the seropositive men (40 percent). The otoneurologic evaluation identified abnormalities in the central auditory or vestibulo-ocular pathways in 34 percent of the seropositive men (10 of 29), as compared with 6 percent of the controls (2 of 33), on the first examination and in 44 percent (12 of 27) and 7 percent (2 of 30), respectively, on the second examination. Altogether, electrophysiologic abnormalities were found in 67 percent of the seropositive men (18 of 27) and 10 percent of the controls (3 of 30) (P less than 0.00005). CONCLUSIONS In persons with asymptomatic HIV infection, electrophysiologic tests may be the most sensitive indicators of subclinical neurologic impairment. Electrophysiologic abnormalities are far more common in asymptomatic carriers of HIV than in controls and tend to progress over time.

Carcinoma of the parotid gland

BACKGROUND: The low incidence and heterogeneity of histiotypes of primary parotid carcinomas makes these tumors histologically and epidemiologically difficult to evaluate. The present study reviews a single institutions experience in the treatment of primary parotid carcinomas during the last 10 years. METHODS: The charts of 98 consecutive patients who had a primary parotid carcinoma and who received primary curative treatment were analyzed retrospectively. The tumors were grouped into high-grade and low-grade malignancies. The effect of treatment modalities on locoregional control, the incidence of locoregional recurrences and distant metastases, and survival rates are evaluated and compared between high- and low-grade malignancies. RESULTS: High- and low-grade malignant tumors were observed in 50 and 48 cases, respectively. Lymph node metastases were detected in 25 of 98 (25%) patients, of whom 8 of 22 (22%) clinically NO staged patients underwent elective neck dissection. In 24 of 26 resected facial nerves, a histologic tumor infiltration was confirmed, in 14 high-grade and 10 low-grade tumors. Local recurrence developed in 13 patients and was associated in 7 with high-grade and in 6 with low-grade tumors. All but 1 of the low-grade malignancies with local recurrence did not receive postoperative irradiation. Regional recurrence developed in 11 patients and distant metastases developed in 10, 3 in combination with a neck recurrence and 1 with a local recurrence. The survival rate at 5 years for low- and high-grade carcinomas was 87% and 56% and the disease-free survival rate 72% and 48%, respectively. CONCLUSIONS: The incidence of occult metastases in clinically N0-elective neck dissection was 22%. A routine elective neck dissection in all N0 parotid carcinomas is suggested. There is no statistically significant difference between low- and high-grade tumors as for the rate of local recurrence and, as all except one of the low-grade malignancies with local recurrence did not receive postoperative irradiation, postoperative irradiation is not only suggested for high-grade carcinomas but also for T2 to T4 low-grade carcinomas.

Benign paroxysmal positional vertigo in older women may be related to osteoporosis and osteopenia.

Benign paroxysmal positional vertigo (BPPV), so-called canalolithiasis and cupulolithiasis, usually occurs after head trauma or viral vestibular neuritis. In many cases, the cause remains obscure, and it often affects women more than 50 years old. The goal of this work was to study a possible relationship between BPPV and osteopenia or osteoporosis. Thirty-two women, whose ages ranged from 50 to 85 years (median age, 69 years), who had BPPV and were free of any other otoneurologic history, were selected. The diagnosis of osteopenia or osteoporosis was confirmed by a bone mineral density measurement made with dual x-ray absorptiometry of spine and hip (T-score). The BPPV was unilateral in 26 patients and bilateral in 6 patients. Our results showed osteopenia or osteoporosis in 24 of the 32 patients (75%) with BPPV. The T-scores were compared in 3 age groups to those of 83 healthy women. The patients with BPPV had a significantly lower (p < .026) T-score in all groups. Possible pathophysiological mechanisms are discussed to explain the apparent correlation between BPPV and osteopenia or osteoporosis.

Auditory Dysfunction in Stroke

The auditory and vestibular systems share the same end organ and cranial nerve, yet vestibular signs and symptoms are common with stroke, whereas hearing disturbances are much less frequent. Several reasons would appear to account for this striking dissimilarity. One is that the auditory pathway is less ubiquitous than the vestibular pathways. The likelihood that a stroke involves the auditory pathway is, therefore, less on this basis alone. A second difference, to our knowledge not previously reported, is that the auditory pathway is often spared by the most common strokes. This is because major parts of the auditory pathway, such as the cochlear nucleus, inferior colliculus and medial geniculate body, have multiple sources of blood supply. A third well-recognized factor is the redundancy of the central auditory system and its strong bilateral representation above the level of the cochlear nuclei. Consequently, rostral to the cochlear nuclei gross deficits in hearing, such as those measured by standard pure-tone audiometry and speech discrimination, only occur if lesions are bilateral. Furthermore, widespread bilateral lesions of the auditory system typically render the patient unable to respond or are incompatible with life. In contrast, language disorders are more frequent because language is usually unilaterally represented in the cortex. Certainly, cerebral stroke often includes the auditory system, resulting in various types of auditory disorders, but most hemispherical lesions produce subtle hearing dysfunctions that can only be detected with sophisticated psychoacoustic and electrophysiological testing. The purpose of this review is to provide an overview of the auditory system and its blood supply and to review how auditory processing can be affected by stroke. Psychoacoustic and electrophysiological test procedures for identifying lesions in the central auditory system are described. The literature of hearing disorders due to stroke is reviewed and illustrative cases are presented.The auditory and vestibular systems share the same end organ and cranial nerve, yet vestibular signs and symptoms are common with stroke, whereas hearing disturbances are much less frequent. Several reasons would appear to account for this striking dissimilarity. One is that the auditory pathway is less ubiquitous than the vestibular pathways. The likelihood that a stroke involves the auditory pathway is, therefore, less on this basis alone. A second difference, to our knowledge not previously reported, is that the auditory pathway is often spared by the most common strokes. This is because major parts of the auditory pathway, such as the cochlear nucleus, inferior colliculus and medial geniculate body, have multiple sources of blood supply. A third well-recognized factor is the redundancy of the central auditory system and its strong bilateral representation above the level of the cochlear nuclei. Consequently, rostral to the cochlear nuclei gross deficits in hearing, such as those measured by standard pure-tone audiometry and speech discrimination, only occur if lesions are bilateral. Furthermore, widespread bilateral lesions of the auditory system typically render the patient unable to respond or are incompatible with life. In contrast, language disorders are more frequent because language is usually unilaterally represented in the cortex. Certainly, cerebral stroke often includes the auditory system, resulting in various types of auditory disorders, but most hemispherical lesions produce subtle hearing dysfunctions that can only be detected with sophisticated psychoacoustic and electrophysiological testing. The purpose of this review is to provide an overview of the auditory system and its blood supply and to review how auditory processing can be affected by stroke. Psychoacoustic and electrophysiological test procedures for identifying lesions in the central auditory system are described. The literature of hearing disorders due to stroke is reviewed and illustrative cases are presented.

Prevention of Vertigo in Ménière’s Syndrome by Means of Transtympanic Ventilation Tubes

The insertion of a transtympanic ventilation tube prevented the occurrence of vertiginous attacks in 82% of a series of 28 patients suffering typical Ménières syndrome with incapacitating vertigo resistant to medical treatment. The follow-up time exceeds 2 years for all cases. It ranges from 2 to 4 years with an average of 2.5 years. This treatment had no effect on drop attacks. Also, hearing loss does not seem to be influenced. The presence of a transtympanic ventilation tube has not caused any major complications in these patients. Obstruction or loss of the tube was in some cases followed by the reappearance of vertigo. It is therefore important to check the patency of the tube before concluding that treatment has failed. The apparent benefit of ventilation tubes in reducing the occurrence of vertiginous attacks suggests that patients with endolymphatic hydrops are particularly sensitive to middle ear pressure.

A Novel Implantable Hearing System with Direct Acoustic Cochlear Stimulation

A new implantable hearing system, the direct acoustic cochlear stimulator (DACS) is presented. This system is based on the principle of a power-driven stapes prosthesis and intended for the treatment of severe mixed hearing loss due to advanced otosclerosis. It consists of an implantable electromagnetic transducer, which transfers acoustic energy directly to the inner ear, and an audio processor worn externally behind the implanted ear. The device is implanted using a specially developed retromeatal microsurgical approach. After removal of the stapes, a conventional stapes prosthesis is attached to the transducer and placed in the oval window to allow direct acoustical coupling to the perilymph of the inner ear. In order to restore the natural sound transmission of the ossicular chain, a second stapes prosthesis is placed in parallel to the first one into the oval window and attached to the patient’s own incus, as in a conventional stapedectomy. Four patients were implanted with an investigational DACS device. The hearing threshold of the implanted ears before implantation ranged from 78 to 101 dB (air conduction, pure tone average, 0.5–4 kHz) with air-bone gaps of 33–44 dB in the same frequency range. Postoperatively, substantial improvements in sound field thresholds, speech intelligibility as well as in the subjective assessment of everyday situations were found in all patients. Two years after the implantations, monosyllabic word recognition scores in quiet at 75 dB improved by 45–100 percent points when using the DACS. Furthermore, hearing thresholds were already improved by the second stapes prosthesis alone by 14–28 dB (pure tone average 0.5–4 kHz, DACS switched off). No device-related serious medical complications occurred and all patients have continued to use their device on a daily basis for over 2 years.

Vestibular Function in Patients With Cochlear Implantation

The aim of this work was to determine the influence of cochlear implantation (CI) on vestibular canal and otolithic function. Between 1995 and 1999, 15 patients (6 females, 9 males; 9-77 years old) underwent a vestibular examination before and after CI. Electronystagmography was performed between 5 and 8 days after CI in 9 patients, and with a time delay of 2-24 months in 10 patients. Pre- and postoperative evaluation included electronystagmography with caloric (44 degrees C, 30 degrees C, ice-water) and pendular rotatory testing. Otolithic function was measured postoperatively using off-vertical axis rotation (OVAR) in six patients. Preoperative data (n = 14) showed areflexia on caloric and rotatory pendular testing in deafness cases due to meningitis (n = 2) and in 2/5 patients with sudden idiopathic bilateral deafness. Two patients suffering from an idiopathic deafness had a unilateral hyporeflexia. Vestibular function was normal in the other eight patients. Immediately following CI, among patients with normal preoperative canal function, three developed vertiginous symptoms with spontaneous nystagmus, which disappeared within days to weeks. Later, postoperative canal evaluation was normal in 5/8 patients (62%) with initially preserved vestibular function: areflexia was measured ipsilaterally to the implanted ear in 1 patient and contralaterally in 2 patients. Hyporeflexia was measured ipsilateral to the implanted ear in two patients. OVAR examination, performed 2-19 months after surgery, showed a preserved otolithic function in all 6 tested patients. Transient vertigo on electrical CI stimulation was described in only one patient during the first postoperative weeks. The following conclusions can be drawn. Patients with deafness due to meningitis had an eradicated vestibular function. In other etiologies, vestibular function was most often preserved. CI did not usually abolish vestibular function, but the canal function was disturbed temporarily in 20% of cases. Otolithic function was preserved in all six CI patients tested in this series.The aim of this work was to determine the influence of cochlear implantation (CI) on vestibular canal and otolithic function. Between 1995 and 1999, 15 patients (6 females, 9 males; 9-77 years old) underwent a vestibular examination before and after CI. Electronystagmography was performed between 5 and 8 days after CI in 9 patients, and with a time delay of 2-24 months in 10 patients. Pre- and postoperative evaluation included electronystagmography with caloric (44°C, 30°C, ice-water) and pendular rotatory testing. Otolithic function was measured postoperatively using off-vertical axis rotation (OVAR) in six patients. Preoperative data ( n = 14) showed areflexia on caloric and rotatory pendular testing in deafness cases due to meningitis ( n = 2) and in 2/5 patients with sudden idiopathic bilateral deafness. Two patients suffering from an idiopathic deafness had a unilateral hyporeflexia. Vestibular function was normal in the other eight patients. Immediately following CI, among patients with normal preoperative canal function, three developed vertiginous symptoms with spontaneous nystagmus, which disappeared within days to weeks. Later, postoperative canal evaluation was normal in 5/8 patients (62%) with initially preserved vestibular function: areflexia was measured ipsilaterally to the implanted ear in 1 patient and contralaterally in 2 patients. Hyporeflexia was measured ipsilateral to the implanted ear in two patients. OVAR examination, performed 2-19 months after surgery, showed a preserved otolithic function in all 6 tested patients. Transient vertigo on electrical CI stimulation was described in only one patient during the first postoperative weeks. The following conclusions can be drawn. Patients with deafness due to meningitis had an eradicated vestibular function. In other etiologies, vestibular function was most often preserved. CI did not usually abolish vestibular function, but the canal function was disturbed temporarily in 20% of cases. Otolithic function was preserved in all six CI patients tested in this series.

Ultrastructural Changes in Otoconia of Osteoporotic Rats

The etiology of benign paroxysmal positional vertigo (BPPV) remains obscure in many cases and women are affected more often than men. A recent prospective study, performed in women >50 years of age suffering from recurrent BPPV, showed associated osteopenia or osteoporosis in a large percentage of these patients. These results suggested the possible relationship between recurrent BPPV and a decreased fixation of calcium in bone in women >50 years. To test this hypothesis, an experimental study was performed in adult female rats. Utricular otoconia of female rats in which osteopenia/osteoporosis was induced by bilateral ovariectomy (OVX) were compared to those of sham-operated adult females rats (SHAM), as control group. First Study: The morphology of theutricles of OVX and SHAM rats was analyzed with scanning electron microscopy. In osteopenic/osteoporotic rats, the density of otoconia (i.e. the number of otoconia per unit area) was decreased (p = 0.036)and their size was increased (p = 0.036) compared to the control group. Second Study: To test the role of calcium turnover in such morphological changes, utricular otoconia of 2 other groups of OVX and SHAM rats, previously injected with calcein subcutaneously, were examined by conventional and epifluorescence microscopy. In epifluorescence microscopy, labeling with calcein showed no significant fluorescence in either group. This finding was interpreted as a lack of external calcium turnover into otoconia of adult female rats. The ultrastructural modifications of otoconia in osteopenic/osteoporotic female adult rats as well as the role of estrogenic receptors in the inner ear are discussed. The possible pathophysiological mechanisms which support the relationship between recurrent BPPV in women and the disturbance of the calcium metabolism of osteopenia/osteoporosis are debated.

Frameless Computer-Aided Surgery System for Revision Endoscopic Sinus Surgery

To increase the intraoperative safety factor and to acquire anatomic assistance during revision endoscopic sinus surgery (RESS), we used an optical computer-aided surgery (CAS) system that we developed collaboratively in Bern, Switzerland. During 1 year, 25 RESSs were performed with CAS: recurrent polyposis (n = 20), recurrent frontal recess stenosis (n = 3), and recurrent frontal recess stenosis with mucocele (n = 2). These patients were compared with a control group of 10 patients undergoing RESS without CAS. The same surgeon (M.C.) performed all operations, and there were no minor or major complications in either group. The clinical inaccuracy of our system is between 0.5 and 2 mm with paired-point and surface matching. The navigation system is an important aid to surgeons in identifying anatomic landmarks that are typically difficult to visualize in this type of surgery, thus reducing the stress placed on the surgeon.

Bilateral idiopathic loss of peripheral vestibular function with normal hearing.

From 1982 to 1993, 52 electronystagmograms (FNG) revealed an absent nystagmic reaction on both caloric (44 30 and 10 degrees C water irrigation) and rotatory pendular testing (0.05 Hz/peak velocity 60 degrees/s), which represents 0.6% of all FNG performed during this period. Among these examinations, 14 patients (27%) presented a bilateral idiopathic loss of vestibular function (BILVF) with normal hearing and without associated neurological symptoms. Two different groups emerged: one group with simultaneous onset of BILVF ( 10 patients), with sudden imbalance and disequilibrium, worse in darkness, with an absence of bilateral caloric and pendular response. The other group (4 patients) was characterized by sequential onset of BILVF. These patients experienced several episodes of acute vertigo with persistent imbalances caloric and pendular responses showed unilateral, then contralateral loss with or without recovery of function. Eleven were controlled with a follow-up from 1 to 7 years. Patients of both groups remained permanently or episodically symptomatic, but only 4 patients complained of persistent oscillopsia. Viral infections, systemic diseases (hypertension, hypothyroidism, asthma), immune reactions (vaccination) and toxic factors (herbicide exposure) may play a role in the etiology of this rare bilateral peripheral vestibulopathy.