Biomedical subjects

R W Baloh

Publications and source records attributed to R W Baloh.

At least 91 records · Page 5Linked to original sources

PubMed1996

Neurotology.

As in most areas of clinical medicine, the history often is the key to determining the diagnosis in patients presenting with neurotologic symptoms. The most common cause of vertigo--benign positional vertigo--can be diagnosed at the bedside based on the characteristic history and the finding of fatigable positional nystagmus on the Dix-Hallpike positional test. Furthermore, it can be cured with a simple positioning maneuver. Quantitative auditory and vestibular function tests are important for documenting the site and severity of deficit in patients with chronic neurotologic symptoms. Only a few presentations (listed in section on acute vertigo) require immediate neuroimaging.

Audiometry↗

PubMed1996

Migraine as a cause of sudden hearing loss.

Sudden hearing loss is common, but unexplained in many cases. Although usually attributed to a viral infection of the inner ear in most patients, the abrupt onset of the hearing loss in many patients argues against a viral etiology. We present 13 cases of unexplained sudden hearing loss who meet the diagnostic criteria for migraine. All had the sudden onset of hearing loss and other neurologic phenomena that could be attributed to vasospasm, including vertigo, amaurosis fugax, hemiplegia, facial pain, chest pain, and visual aura. We suggest that vasospasm of the cochlear vasculature was the cause of the sudden hearing loss in these patients. A personal and family history of migraine should be sought in patients with sudden hearing loss and when found, a trial of antispasmodic agents should be considered.

Acute Disease↗

PubMed1996

Histopathology of idiopathic chronic recurrent vertigo.

Vestibular neuritis is a degenerative neuropathy of the peripheral vestibular system. The etiology of this condition is uncertain, although it is generally believed to be viral. A small percentage of patients with vestibular neuritis have chronic recurrent episodes of vertigo. Detailed cytologic descriptions of acute or chronic vestibular neuritis are lacking, and no previous studies have reported evidence of chronic inflammation in human temporal bone specimens. The authors of this study examined temporal bone specimens from three patients with a history of chronic recurrent vertigo of unknown cause. Varying degrees of inflammation and destruction were seen in the vestibular system, and mild involvement of the cochlear system was noted. These findings are consistent with postinfectious inflammatory changes of the cochlear-vestibular system analogous to a postinfectious syndrome involving the central nervous system.

Cochlear Nerve↗

PubMed1996

Vestibular and auditory disorders.

Benign positional vertigo, the most common cause of vertigo, can now be cured with a simple bedside maneuver. A series of recent publications have clarified the pathophysiology of benign positional vertigo and documented the efficacy of particle repositioning maneuvers for treating the condition. The number of genetic loci and abnormal genes associated with inherited auditory and vestibular disorders is rapidly expanding. Within the past years, genes have been identified for Usher syndrome, Alport syndrome, deafness with fixation of the stapes and familial periodic ataxia. These discoveries should lead to improved diagnosis and, eventually, specific treatments for these disorders.

Auditory Diseases, Central↗

PubMed1996

Familial migraine with vertigo and essential tremor.

We report a family with dominantly inherited migraine headaches, episodic vertigo, and essential tremor. All symptoms improved with the use of acetazolamide. Linkage analysis ruled out linkage to markers on chromosome 19p, known to be linked to the genetic defect in families with the clinically similar syndromes of hemiplegic migraine and periodic ataxia. This genetic heterogeneity of migraine syndromes could result from defects in a family of genes coding proteins with similar properties.

Adult↗

PubMed1996

Quantitative evaluation of dizziness characteristics and impact on quality of life.

Patients attending an outpatient clinic with the complaint of dizziness were given a set of five items to rank the magnitude of the frequency and severity of their dizziness and the impact of dizziness on their quality of life. They were given instruments to evaluate their degree of anxiety and depression. The impact of frequency and severity on the patients' daily activities, on the quality of life, and on the fear of becoming dizzy was self-rated by the patient. The score on quality of life was compared with that provided by the physician in a blind questionnaire. The items that were developed addressed the physical, functional, and emotional impact of dizziness and can be considered promising for the evaluation of the patients' degree of overall impairment.

Adolescent↗

PubMed1995

White matter lesions and disequilibrium in older people. I. Case-control comparison.

OBJECTIVE: To investigate the relationship between subcortical white matter lesions identified on magnetic resonance imaging and gait and balance problems in older people. DESIGN: Magnetic resonance imaging scans of the brain in 27 community-dwelling older patients (> 75 years of age) who had subjective and objective abnormalities of gait and balance of unknown cause were compared with those of 27 age- and sex-matched control subjects. The T2-weighted intense lesions of the subcortical white matter were graded on a scale of 0 to 2. SETTING: Outpatient clinic. RESULTS: The patient had significantly (P < .01, chi 2) more severe subcortical white matter hyperintensities on magnetic resonance imaging than did the control group. Patients fell more frequently than did the control subjects and had slower motor responses and prolonged reaction times compared with the control subjects. CONCLUSIONS: Subcortical white matter lesions identified on magnetic resonance imaging are associated with gait and balance dysfunction in ambulatory older people. These lesions probably interfere with central processing of sensorimotor signals leading to impaired postural responses.

Aged↗

PubMed1995

White matter lesions and disequilibrium in older people. II. Clinicopathologic correlation.

OBJECTIVE: To identify the cause of subcortical white matter lesions seen on magnetic resonance imaging in older patients with progressive deterioration of gait and balance. DESIGN: Postmortem examination of three patients with objective impairment of gait and balance thought to be due to subcortical white matter lesions identified on magnetic resonance imaging. Brain sections were stained with routine methods and for glial fibrillary acid protein using an immunoperoxidase technique. PATIENTS: Part of a prospective study of gait and balance problems in older people. None had a history of hypertension or discrete strokelike episodes. RESULTS: Other than a few small infarcts in the basal ganglia and internal capsule in the patient with the mildest gait disorder, there were no gross or microscopic features on routine examination post mortem to explain the white matter hyperintensities on magnetic resonance imaging or the progressive gait deterioration. By contrast, immunohistochemical staining with anti-glial fibrillary acid protein showed prominent astrocytosis T2-weighted high-intensity signal areas on magnetic resonance imaging. CONCLUSIONS: The astrocytes presumably swell as they take up extravasated protein at the site of a breakdown in the blood-brain barrier, and the increased water content per unit volume increases the magnetic resonance imaging proton signal. We hypothesized that the astrocytes may have been initially activated by small infarcts or subclinical ischemia, but the process then became self-perpetuating, ultimately involving most of the white matter and producing the severe gait disorder.

Aged↗

PubMed1995

Approach to the evaluation of the dizzy patient.

Dizziness is a nonspecific symptom caused by many different pathophysiologic mechanisms. Vertigo, an illusion of movement, indicates a lesion within the vestibular system. The duration of attacks and associated symptoms helps to determine the site of lesion and likely diagnosis. Examination of the dizzy patient should include a careful assessment of gait and balance and a search for spontaneous and positional nystagmus. The vestibulo-ocular reflex can be evaluated qualitatively at the bedside with the doll's eye, dynamic visual acuity, and ice water caloric tests. Each test provides different information about vestibular function.

Dizziness↗

PubMed1995

Vertebrobasilar insufficiency and stroke.

Vertigo is the most common symptom of transient ischemia within the vertebrobasilar system. Episodes typically come on abruptly and last minutes. Although there are usually associated symptoms, isolated attacks of vertigo can occur. Vertigo is also a common symptom with brain stem and cerebellar strokes. Isolated cerebellar infarction can mimic peripheral vestibular disorders because vertigo and imbalance are the main symptoms with both disorders. Modern neuroimaging techniques have markedly improved diagnostic capabilities.

Cerebellum↗

PubMed1995

Paraneoplastic cerebellar disorders.

Paraneoplastic cerebellar degeneration typically begins with rapidly progressive ataxia of the trunk and extremities. Antineuronal antibodies are found in about half the patients. The most specific autoantibody is an anti-Purkinje cell antibody found in women with gynecologic tumors. Even after the tumor is removed, the cerebellar deficit persists in most patients.

Autoantibodies↗

PubMed1995

Posturography and balance problems in older people.

OBJECTIVE: To determine which measurements and test conditions on posturography are most useful for identifying balance problems in older people. SUBJECTS: Two samples of 70 community-dwelling older subjects (> 75 years). One group (controls) considered their balance normal for their age, and the other (patients) complained of imbalance. MEASUREMENTS: Velocity of sway on static (with and without foam) and dynamic posturography, Tinetti gait and balance score, self-reported fear of falling, and number and circumstances of falls. RESULTS: Mean sway velocity was significantly increased in patients compared with controls. The greatest difference between patients and controls occurred with measures of anterior-posterior sway velocity during angular tilt of the platform. Sway velocity was not significantly increased in patients or controls who reported falls compared with those who did not report falls. Even when comparing those who fell as a result of loss of balance with those who fell because of trips or slips, there was no significant difference in sway velocity. By contrast, those who reported fear of falling (patients and controls) had significantly increased sway velocity compared with those who did not report fear of falling. CONCLUSION: On average, velocity of sway (particularly in the anterior-posterior direction) is higher in older subjects who complain of imbalance compared with age-matched controls, and the difference is greater with dynamic posturography than with static posturography. However, the posturography data provided little information about the cause of the imbalance and did not correlate with the frequency of reported falls.

Accidental Falls↗

PubMed1995

Persistent direction-changing positional nystagmus: another variant of benign positional nystagmus?

Positional nystagmus that does not fatigue, persists as long as the position is held, and changes direction in different head positions has typically been attributed to central vestibular lesions. We recently studied three patients who presented with positional nystagmus having these features but almost certainly of benign peripheral origin. All three had an initial history typical of benign positional vertigo and, in two, the persistent direction-changing positional nystagmus occurred after the patient underwent a maneuver to remove debris from the posterior semicircular canal. The positional nystagmus profile and clinical course are consistent with the debris leaving the posterior semicircular canal and becoming attached to the cupula of the horizontal semicircular canal.

Aged↗

PubMed1994

Comparison of oculomotor findings in the progressive ataxia syndromes.

In this study we compare the results of quantitative oculomotor function testing in patients with Friedreich's ataxia (FA), olivopontocerebellar atrophy (OPCA) and cerebello-olivary atrophy (CA). Common features in all three syndromes included gaze-evoked nystagmus, saccade dysmetria and prolonged saccade reaction times. Patients with FA showed a characteristic combination of frequent saccadic intrusions, especially ocular flutter, relatively preserved optokinetic nystagmus (OKN) and smooth pursuit, and impaired vestibulo-ocular reflex (VOR) responses. In patients with CA saccadic intrusions were infrequent, OKN and smooth pursuit were severely impaired and VOR gain was normal or increased. Results in OPCA were more variable. When present, slowing of saccades or the combined loss of pursuit and vestibular function were characteristic for OPCA. The ability to suppress the VOR with a head fixed target was relatively preserved in FA, normal to moderately impaired in OPCA and always severely impaired in CA. We conclude that oculomotor testing is useful in the differential diagnosis of the progressive ataxia syndromes.

Adult↗

PubMed1994

Age-related changes in visual tracking.

BACKGROUND: To reassess conflicting findings in earlier studies on the effect of aging on smooth pursuit and saccadic eye movements, we compared visual tracking in a large number of elderly normal subjects aged 75 to 93 years and a group of young adults aged 18 to 43 years. METHODS: Saccades and smooth pursuit were induced by a laser target projected onto a screen. Eye movements were recorded with electrooculography and analyzed with a digital computer. RESULTS: Smooth pursuit gain was significantly decreased at all target velocities in the older subjects, and the difference between young and old increased with increasing target velocity and acceleration. Peak saccade velocity was significantly slower for amplitudes exceeding 20 degrees, and saccadic reaction times were prolonged in older subjects compared with younger subjects. Mean saccade accuracy was not significantly different between age groups. Within tests, variability increased with aging for smooth pursuit, saccadic reaction time, and saccadic accuracy measurements. CONCLUSION: The increased intratest variability in older subjects probably resulted from nonspecific changes in alertness and attention commonly occurring with aging, whereas the decreased gain of smooth pursuit and saccades with increasing stimulus magnitude most likely resulted from age-related neural degeneration in specific visuomotor pathways.

Adolescent↗

PubMed1994

Comparison of static and dynamic posturography in young and older normal people.

OBJECTIVE: To measure sway velocity during static and dynamic posturography in "normal" older people and to determine which tests best distinguish young from older subjects. SUBJECTS: A sample of 30 young (18-39 years) and 82 community-dwelling older (> 75 years) subjects who reported normal balance underwent a battery of balance tests. MEASUREMENTS: Velocity and frequency of sway, Tinetti gait and balance score, self-reported fear of falling and number of falls. RESULTS: Mean sway velocity and the ratio of high to low frequency sway velocity were significantly increased in older subjects compared with younger subjects for static and dynamic tests with eyes open and with eyes closed. Measures of anterior-posterior sway velocity during angular tilt of the platform with eyes closed best distinguished young from older subjects (almost three-fourths of older subjects had values greater than 2 standard deviations from the young normal mean). Older subjects who reported falls in the past year did not have a significantly higher sway velocity on static or dynamic tests compared with those who did not report falls. However, subjects who reported a fear of falling had significantly higher sway velocity on dynamic tests with eyes closed compared to those who did not report a fear of falling. CONCLUSIONS: On average, velocity of sway is higher in older subjects compared with younger subjects, and the difference between young and old is greater with dynamic posturography than with static posturography.

Accidental Falls↗

PubMed1994

Familial vestibulopathy: a new dominantly inherited syndrome.

Three patients who presented with episodic vertigo followed by gait imbalance and oscillopsia had profound bilateral vestibular loss despite normal hearing. All had a parent with similar findings. The patients, their affected parent, and multiple other family members had a history of migraine headaches, although several of the latter had normal vestibular function. Acetazolamide stopped or markedly decreased the frequency of vertigo attacks in the three patients treated but had little effect on the chronic vestibular loss. This is the first report of a dominantly inherited bilateral vestibulopathy associated with normal hearing.

Acetazolamide↗

PubMed1994

Approach to the dizzy patient.

As dizziness can be caused by so many different pathophysiological mechanisms, it is crucial to determine the type of dizziness before proceeding with the diagnostic evaluation. Vertigo, defined as an illusion of movement, is an important subtype of dizziness that indicates a lesion somewhere within the vestibular system. Probably the most useful feature for differentiating between peripheral and central causes of vertigo is the associated symptoms. Vertigo of peripheral origin is typically associated with auditory symptoms such as hearing loss and tinnitus, while vertigo of central origin is nearly always associated with neurological symptoms such as diplopia, weakness, numbness and ataxia. Each of the common causes of vertigo has a characteristic clinical profile that should suggest a likely diagnosis after the history and examination are complete. Probably the most important treatment breakthrough is the positional manoeuvre that reliably cures benign positional vertigo (see Chapter 6). The treatment strategy for an acute peripheral vestibular lesion has evolved over the past few years. Patients are encouraged to return to normal physical activity as rapidly as possible. Repeated head, eye and body movements (vestibular rehabilitation) help the brain to recalibrate the relationship between visual, proprioceptive and vestibular signals (Chapter 9).

Anxiety Disorders↗