Brainstem and cranial nerve involvement in multiple sclerosis

Taste dysfunction in multiple sclerosis

Empirical studies of taste function in multiple sclerosis (MS) are rare. Moreover, a detailed assessment of whether quantitative measures of taste function correlate with the punctate and patchy myelin-related lesions found throughout the CNS of MS patients has not been made. We administered a 96-trial test of sweet (sucrose), sour (citric acid), bitter (caffeine) and salty (NaCl) taste perception to the left and right anterior (CN VII) and posterior (CN IX) tongue regions of 73 MS patients and 73 matched controls. The number and volume of lesions were assessed using quantitative MRI in 52 brain regions of 63 of the MS patients. Taste identification scores were significantly lower in the MS patients for sucrose (p = 0.0002), citric acid (p = 0.0001), caffeine (p = 0.0372) and NaCl (p = 0.0004) and were present in both anterior and posterior tongue regions. The percent of MS patients with identification scores falling below the 5th percentile of controls was 15.07 % for caffeine, 21.9 % for citric acid, 24.66 % for sucrose, and 31.50 % for NaCl. Such scores were inversely correlated with lesion volumes in the temporal, medial frontal, and superior frontal lobes, and with the number of lesions in the left and right superior frontal lobes, right anterior cingulate gyrus, and left parietal operculum. Regardless of the subject group, women outperformed men on the taste measures. These findings indicate that a sizable number of MS patients exhibit taste deficits that are associated with MS-related lesions throughout the brain.

Predictors of Conversion to Multiple Sclerosis in Patients with Clinical Isolated Syndrome Using the 2010 Revised McDonald Criteria

Background. Clinically isolated syndrome (CIS) is the first neurologic episode of multiple sclerosis (MS). Magnetic resonance imaging (MRI) and clinical features are used to predict risk of conversion to MS. Objectives. The aim of this prospective study is to evaluate predictors of conversion of CIS to McDonald MS. Method. 97 patients with CIS have been followed for 2 years. Age of onset, gender, initial clinical presentation, and MRI brain and spine were assessed. The 2010 revised McDonald criteria were applied. Results. Fifty-nine patients (60.8%) with CIS converted to McDonald MS after 10.1 + 4.2 months. Thirty-seven (38.1%) of the convertors satisfied the diagnostic criteria based on the radiological parameters, while 21.7% sustained their second clinical events. A multivariate regression analysis revealed that high number of lesions in MRI (P = 0.001) and earlier age of onset (P = 0.043) predicted the conversion of CIS to McDonald MS. Gender (P = 0.5) and initial clinical presentation (optic pathway (P = 0.4), supratentorial (P = 0.91), brain stem/ cerebellum (P = 0.97), and spinal (P = 0.76)) were not statistically significant. Conclusion. Age of onset and MRI parameters can be used as predictors of CIS conversion to McDonald MS. Application of the 2010 revised McDonald criteria allows an earlier MS diagnosis.

Superficial siderosis of the central nervous system: phenotype and implications for audiology and otology

OBJECTIVE

Superficial siderosis of the central nervous system (SSCN) results after chronic subarachnoid hemorrhage. Consequent demyelination, particularly of the cochleovestibular nerve and cerebellum, causes auditory-vestibular dysfunction. Predominant symptoms include progressive sensorineural hearing loss, imbalance, and ataxia. Despite characteristic auditory-vestibular involvement, SSCN is not well known among the hearing health community.

STUDY DESIGN

Clinical records of 49 patients diagnosed with SSCN were reviewed. Analysis included review of demographic, audiometric, and vestibular data of the largest sample to date and comparison to 31 audiovestibular case reports in the literature.

RESULTS

Hearing loss and disordered balance were reported by 92% and 67% of patients, respectively. Results suggest variable but substantial auditory-vestibular involvement related to SSCN. Hearing loss is typically progressive, sloping, and asymmetric and exceeds hearing loss expected based on age or sex. Decreased word recognition is possible and traditional amplification may fail to provide benefit.

CONCLUSION

SSCN is a destructive disorder affecting the auditory-vestibular system. Although not a common diagnosis, SSCN may be more prevalent than clinicians realize. Site of lesion may be anywhere within the auditory-vestibular system from the inner ear to the cortex, although the cochleovestibular nerve and cerebellum are particularly vulnerable. The progressive retrocochlear nature of the disorder makes differential diagnosis difficult and development of effective treatment options challenging. It is essential that audiologists and otologists recognize this uncommon cause of sensorineural hearing loss and balance disorder and the implications for evaluation, treatment, and counseling.

Less known non-infectious and neuromusculoskeletal system-originated anterolateral neck and craniofacial pain disorders

Pain syndromes of neuromusculoskeletal origin are not well-known by most of the clinicians working on head and neck area. As a result, most of the patients with these syndromes are either overlooked without having any treatment or they inappropriately have antibiotic treatments or surgical interventions such as dental extractions and tonsillectomies. Better recognition of the pain syndromes of the neck and face region or entities related to neuromusculoskeletal system may result in more appropriate and effective management of such conditions while avoiding unnecessary medical and surgical treatments. In this review, causes, clinical characteristics, diagnostic and treatment modalities of relatively less known craniofacial and neck pain entities including Eagle syndrome, carotidynia, glossopharyngeal neuralgia, superior laryngeal neuralgia, hyoid bone syndrome, acute calcific retropharyngeal tendinitis, temporal tendinitis, thyroid and cricoid cartilage syndromes, and mastoid process syndrome are summarized.

The dizzy patient

The dizzy patient often presents a challenge to the physician. The history is the most important component of the evaluation of the dizzy patient and often allows the cause of the dizziness to be categorized as peripheral or central. Peripheral causes include benign paroxysmal positional vertigo, Meniere's disease, and vestibular neuritis. Central causes include migraine-associated dizziness, postconcussion syndromes, cerebrovascular disease, and multiple sclerosis. Treatment depends on the cause of the dizziness and may include dietary modifications, diuretics, vestibular suppressants, vestibular rehabilitation, or surgical intervention.

Cranial Polyneuropathies in Multiple Sclerosis: Case Report and Literature Review

Although cranial neuropathies are common disorders in multiple sclerosis patients, multiple cranial nerve involvement is an unusual occurrence. Correlation of clinical symptoms with magnetic resonance imaging evidence of demyelinating central nervous system lesions can confirm the diagnosis. The authors report on the case of a 43-year-old woman who initially was thought to have suffered a brainstem infarct but, in fact, had developed multiple cranial nerve functional deficits. Treatment of multiple sclerosis remains primarily supportive in nature, with corticosteroids used for acute exacerbations and chronic progression.

Multiple sclerosis: a cause of sudden hearing loss

Sudden hearing loss is a clinical entity which has numerous aetiologies. In cases where the aetiology is not determined, evaluation and treatment of sudden hearing loss are very difficult. A case of probable multiple sclerosis with sudden hearing loss as the initial symptom is reported. The pure-tone audiometry showed a quasi-total sensorineural hearing loss in the left ear; the left side displayed only wave I in the auditory brainstem response (ABR). Electronystagmographic examination revealed hypometric dysmetria and saccadic pursuit abnormalities. Magnetic resonance imaging (MRI) showed high-intensity lesions with multiple foci. After steroid therapy, the patient's hearing loss, vertigo and visual problems improved, but the ABR findings remained unchanged. We have decided to present this case because of the interesting ABR finding revealing the presence of wave I and the absence of all other waves after the normalization of the hearing.

Evoked otoacoustic emissions and electrocochleography in a patient with multiple sclerosis

A 24-year-old woman with multiple sclerosis had right-sided hearing impairment with tinnitus. She underwent electrocochleography (ECochG) and examination of evoked otoacoustic emissions (EOAEs) to assess cochlear function. An acoustic probe to measure EOAEs was inserted into the external ear canal. The ECochG action potential and cochlear microphonics were recorded by a transtympanic needle electrode technique. Both fast and slow components of EOAEs appeared in either the period of deteriorated hearing acuity or when it was improved. They showed normal detection thresholds and input-output curves during both periods. Cochlear microphonics with almost normal detection thresholds and input-output functions were obtained during the period of deteriorated hearing acuity. Action potential (N1) input-output curves during relapse with hearing loss were notably lower in amplitude and longer in latency than those obtained at the time hearing impairment showed improvement. The EOAE and ECochG findings suggested that this patient had almost normal cochlear function, and we assumed from the magnetic resonance imaging and auditory brain stem response findings as well as the ECochG that the hearing impairment was caused by dysfunction of auditory pathways in the brain stem, including structures that contribute to generation of the N1 potential of the ECochG.

Glossopharyngeal neuralgia with cardiac syncope

Glossopharyngeal Neuralgia is an uncommon craniofacial pain syndrome that is occasionally associated with cardiac syncope. Involvement of the glossopharyngeal nerve may be painless or may be marked by true episodic neuralgia, and this justifies the term neuralgia reported here. We present 5 cases of this uncommon syndrome, of a total of 15 observed cases of glossopharyngeal neuralgia, successfully treated by section of the rootlets of Cranial Nerves IX and X or by microvascular decompression in the posterior cranial fossa. We also analyze the relevant literature and discuss the pathogenesis and treatment of the syndrome.

Dizziness in childhood

There is a scant literature regarding vestibular evaluation of children with complaints of dizziness or vertigo. Considerable time and effort are expended on the problem and prevention of hearing loss in children, yet we often ignore concurrent or subsequent vestibular disorders. This neglect could be due to several factors, perhaps the most common being the fact that vertiginous crises in childhood are often attributed to problems of behavior or incoordination. In this article, we offer an approach to the dizzy child based on presenting symptoms. We discuss features of the history, examination, and laboratory evaluation key to determining the cause of dizziness. Finally, we discuss management, which varies according to the diagnosis.

Glossopharyngeal neuralgia associated with cardiac syncope: long term treatment with permanent pacing and carbamazepine

Glossopharyngeal neuralgia associated with cardiac syncope developed in a 53 year old man. Symptoms were controlled with temporary and permanent transvenous pacing and carbamazepine.

Central trochlear palsy

Historically, the trochlear (IV) nerve has been "neglected" by neurologists and ophthalmologists. However, the reported incidence of trochlear palsy in two large series has more than doubled in the past two decades, indicating increasing awareness of this nerve. Trauma is the most common cause of trochlear palsy, as the trochlear nerve is anatomically more vulnerable to trauma than the other ocular motor nerves. Trochlear palsy can also be caused by vascular and inflammatory diseases, congenital factors, toxic substances and tumors. Diplopia secondary to vertical and horizontal deviation is the most common presentation. The trochlear nerve has a relatively high recovery rate after the underlying cause of injury has been corrected. In this article, the anatomy and physiology of the trochlear nerve are described, and the various etiologies, methods of diagnosis and differential diagnosis of trochlear palsy are reviewed.

The acute deafness of definite multiple sclerosis: BAEP patterns

Of 705 patients with or suspected of multiple sclerosis who underwent evoked potential recording during a 5 year period, 12 patients with definite multiple sclerosis experienced an acute hearing loss during a relapse of the demyelinating disease. Hearing loss was unilateral in all of the 12 cases but one; tinnitus was associated with hearing loss in 9 of the 12 patients. Deafness is an unfrequent symptom in the course of multiple sclerosis, being estimated to be no more than 3% in large series of multiple sclerosis. Brain-stem auditory evoked potentials were recorded in all 12 patients, during the relapse with acute hearing loss in 4 of them, after the relapse with hearing loss in the 8 others. During the relapse with hearing loss, BAEP abnormalities were present ipsilateral to the hearing loss in all 4 patients, wave I being absent in 2 of them. BAEPs were drastically improved when recorded after the relapse with hearing loss in 2 of the 3 patients in whom repeated records were made. BAEPs were abnormal on the side of the previous hearing loss in 5 out of the 8 patients recorded after the relapse with hearing loss. Clinical and BAEP data suggest that, in accordance with the anatomical organization of the auditory pathways, the lesion causing unilateral hearing loss in multiple sclerosis could be situated in the cochlear nerve or close to its entry zone in the brain-stem. However, dissociation between unilateral hearing loss and a normal peak I and I-III interval may occur.

Quality-specific taste changes in multiple sclerosis

Taste sensitivity in 79 patients with multiple sclerosis (MS) and 65 age- and sex-matched control subjects was measured with a sip-and-spit, suprathreshold scaling, magnitude estimation procedure using six concentrations each of sodium chloride, sucrose, citric acid, and quinine hydrochloride. Results were analyzed with a taste scoring system and by plotting psychophysical functions (log concentration versus log magnitude estimate) normalized to 1.0 M sucrose. Gender did not affect taste scores, but age was inversely related, so the results were analyzed by an analysis of covariance with age as the covariant. There was a significant alteration in taste sensitivity in the subjects with MS for sodium chloride and quinine hydrochloride stimuli but not for sucrose and citric acid; these results were confirmed by a separate analysis of the psychophysical functions. Some of the MS taste scores correlated with MS functional and physical disability scores. Taste sensitivity was not correlated with clinical history or presence of facial symptoms.

Optic neuritis in relation to multiple sclerosis

Available estimates of the frequency with which a patient with optic neuritis develops multiple sclerosis range from as low as 13% to as high as 87%. In an effort to obtain a better estimate, a nation-wide study of optic neuritis was carried out in Israel. Patients who fulfilled strict diagnostic criteria of optic neuritis were identified and examined periodically. Between 1955 and 1964, 105 patients were found and on the basis of these, the average annual age-adjusted incidence of optic neuritis in Israel was 0.56 per 10(5) population compared to 1.2 per 10(5) cases of multiple sclerosis per year, i.e. optic neuritis was about half as frequent as multiple sclerosis each year. As with multiple sclerosis, optic neuritis was more common in European immigrants to Israel than Afro-Asian immigrants. During a follow-up interval which ranged from 3.3 to 15.6 years (mean 9.5 years), at least 27 of the 105 patients developed multiple sclerosis (28%). A life-table analysis showed that after 10 years 32.3 +/- 5.6% of patients with optic neuritis would develop multiple sclerosis and, after 14 years, about half would develop multiple sclerosis. Risk of dissemination was highest in those who were youngest when optic neuritis developed. Neither sex nor ethnic background influenced risk significantly. Results of the present study support earlier work using life-table methods carried out in Hawaii which also showed that between 29 and 39% of patients with optic neuritis will develop multiple sclerosis within 10 years of onset. The life-table method is a better predictor of prognosis than newer laboratory techniques such as spinal fluid studies of IgG, kappa-lambda light chain ratios and serum/CSF IgG ratios.

Visual pattern evoked responses and blink reflexes in assessment of MS diagnosis. A clinical study of 135 multiple sclerosis/pathol

VEPs were measured after pattern reversal in 135 MS patients and 30 control subjects. Neurological findings were documented in a standard manner. An extensive ophthalmological examination of all subjects was part of the study. The latency of P2 was abnormally delayed in 82% of the "definite", in 60% of the "probable" and in 65% of the "possible" MS groups respectively. The VEP was more often delayed in relation to ophthalmological disturbances. Changes in the MS classification had to be made in more than 10% of the patients, due to delay of VEP latency. These were patients with a "spinal" form of MS, which is known to create diagnostic problems. Optically and electrically evoked blink reflexes were recorded in 107 MS patients. All patients with mesencephalic lesions had delayed responses of the optically evoked reflex. 74% of the patients with caudal brainstem lesions had delayed latencies of the components of the electrically evoked blink reflex. The blink reflex was delayed in 18 additional patients without brainstem signs. The possibility of delineating clinically silent brainstem lesions by investigating blink reflexes is discussed.