Acute binocular diplopia: peripheral or central?

OBJECTIVES: Acute diplopia is a diagnostic challenge for clinicians, in particular in the emergency department. The most common cause of acute diplopia are ocular motor nerve palsies (OMP). In this prospective study, we focused on identifying the most crucial signs and symptoms for differentiating between peripheral and central OMP. METHODS: We prospectively evaluated 56 non-consecutive patients who presented at our emergency department with acute binocular diplopia (≤ 10 days). The patient history was taken using a standardized questionnaire and patients underwent a neurological, neuro-ophthalmological and neuro-otological examination, including measurement of the subjective visual vertical (SVV), Harms tangent screen test, and cranial MRI. RESULTS: Forty-six out of 56 patients were diagnosed with an ocular motor cranial nerve palsy (OMP), 21 of peripheral and 23 of central origin; in two patients, the etiology remained unknown. The following features were different in peripheral and central OMP: (1) the presence of vertigo/dizziness was more frequent in central (43.5%) than in peripheral (9.5%) OMP. (2) Central ocular motor signs, such as saccadic smooth pursuit, additional internuclear ophthalmoplegia, skew deviation, and saccade palsies, were also found more frequently in the central than in the peripheral group (86.7% vs. 33.3%). (3) Further, a pathological SVV deviation by monocular testing of the non-affected eye was also more common in central (77.3%) than in peripheral OMP (38.9%). The presence of all three factors has a positive predictive value of 100% (CI 50-100%) for the presence of a central lesion. CONCLUSIONS: In acute diplopia due to central OMP, the most important accompanying symptom is vertigo/dizziness, and the most important clinical signs are central ocular motor disorders (which require examination of the non-paretic eye) and an SVV deviation in the non-paretic eye.

What Is Behind Cerebellar Vertigo and Dizziness?

The differential diagnosis of vertigo or dizziness as a result of cerebellar disorders can be difficult as many patients with a cerebellar pathology do not present with the full spectrum of cerebellar signs. The main goal of this study was to describe the typical clinical features of these patients with vertigo or dizziness of a cerebellar origin. We reviewed the medical records of 5400 patients with vertigo and dizziness from our tertiary outpatient clinic for vertigo and balance disorders. In 459 the diagnosis of "cerebellar vertigo or dizziness" was made; 90 patients were excluded from further analysis due to evident structural changes in MRI. Of the remaining 369 patients (67.0 ± 15.1, 54% female, symptom duration until diagnosis 5.5 ± 6.9 years), 81% suffered from persistent vertigo or dizziness, 31% from attacks of vertigo and dizziness and 21% from both. Neuro-ophthalmologically, 95% had saccadic smooth pursuit, 80% gaze-holding deficits, 64% a pathological fixation suppression of the VOR, 24% central fixation nystagmus (in 64% of these cases downbeat nystagmus (DBN)), 23% rebound nystagmus, and an ocular misalignment in 84% in near view and 50% in distance view. Eleven percent had isolated mild to moderate cerebellar ocular motor disturbances without any other typical cerebellar signs. The most common diagnoses were sporadic adult-onset degenerative ataxia in 26%; idiopathic DBN syndrome in 20%; cerebellar ataxia, neuropathy, and vestibular areflexia syndrome in 10%; episodic ataxia type 2 in 7%; and multiple system atrophy cerebellar type in 6%. In posturography, a typical cerebellar 3-Hz sway was found in 16%. The diagnostic key to patients with cerebellar vertigo or dizziness is a careful examination of eye movements since practically all of them have cerebellar ocular disturbances.

Oculomotor and Vestibular Findings in Gaucher Disease Type 3 and Their Correlation with Neurological Findings.

OBJECTIVES: To evaluate the function of the oculomotor and vestibular systems and to correlate these findings with the clinical status of patients with Gaucher disease type 3 (GD3). The goal of this cross-sectional and longitudinal study was to find oculomotor biomarkers for future clinical trials. METHODS: Twenty-six patients with GD3 were assessed for eligibility and 21 were able to perform at least one task. Horizontal and vertical reflexive saccades, smooth pursuit, gaze-holding, optokinetic nystagmus, and horizontal vestibulo-ocular reflex (VOR) were examined by video-oculography/video-head impulse test and compared concurrently with 33 healthy controls. The Scale for the Assessment and Rating of Ataxia (SARA), the modified Severity Scoring Tool (mSST), and Grooved Pegboard Test (GPT) were administered to assess overall neurological function. Eleven patients were also re-assessed after 1 year. RESULTS: Nine out of 17 patients exhibited gaze-holding deficits. One patient had upbeat nystagmus. Three patients presented with bilateral abducens palsy in combination with central oculomotor disorders, suggesting a bilateral involvement of the abducens nucleus. Horizontal angular VOR gain was reduced in all patients (0.66 ± 0.37) compared with controls (1.1 ± 0.11, p < 0.001). Most strongly correlated with clinical rating scales were peak velocity of downward saccades (SARA: ρ = -0.752, p < 0.0005; mSST: ρ = -0.611, p = 0.003; GPT: ρ = -0.649, p = 0.005) and duration of vertical saccades (SARA: ρ = 0.806, p < 0.001; mSST: ρ = 0.700, p < 0.0005; GPT: ρ = 0.558, p = 0.02) together with the VOR gain (SARA: ρ = -0.63, p = 0.016; mSST: ρ = -0.725, p = 0.003; GPT: ρ = -0.666, p = 0.004). Vertical smooth pursuit gain decreased significantly at follow-up. INTERPRETATION: This study shows neuronal degeneration of the brainstem and cerebellum with combined involvement of both supranuclear and nuclear oculomotor structures and the vestibular system in GD3. We also identified oculomotor parameters that correlate with the neurological status and can be used as biomarkers in future clinical trials.

Comparison of the Bedside Head-Impulse Test with the Video Head-Impulse Test in a Clinical Practice Setting: A Prospective Study of 500 Outpatients.

OBJECTIVES: The primary aim was to determine the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the bedside head-impulse test (bHIT) using the video HIT (vHIT) as the gold standard for quantifying the function of the vestibulo-ocular reflex (VOR). Secondary aims were to determine the bHIT inter-rater reliability and sensitivity in detecting unilateral and bilateral vestibulopathy. METHODS: In this prospective study, 500 consecutive outpatients presenting to a tertiary neuro-otology clinic with vertigo or dizziness of various vestibular etiologies who did not have any of the pre-defined exclusion criteria were recruited. Bedside HITs were done by three experienced neuro-otology clinicians masked to the diagnosis, and the results were compared with the vHIT. The patients were likewise blinded to the bHIT and vHIT findings. Patients with VOR deficits were identified on the vHIT by referencing to the pre-selected "pathological" gain of <0.7. The data were then analyzed using standard statistical methods. RESULTS: For the primary outcome (vHIT "pathological" VOR gain <0.7), the three-rater mean bHIT sensitivity = 66.0%, PPV = 44.3%, specificity = 86.2%, and NPV = 93.9%. Shifting the "pathological" threshold from 0.6 to 0.9 caused the bHIT sensitivity to decrease while the PPV increased. Specificity and NPV tended to remain stable. Inter-rater agreement was moderate (Krippendorff's alpha = 0.54). For unilateral vestibulopathy, overall bHIT sensitivity = 69.6%, reaching 86.67% for severely reduced unilateral gain. For VOR asymmetry <40% and >40%, the bHIT sensitivity = 51.7 and 83%, respectively. For bilateral vestibulopathy, overall bHIT sensitivity = 66.3%, reaching 86.84% for severely reduced bidirectional gains. CONCLUSION: For the primary outcome, the bHIT had moderate sensitivity and low PPV. While the study did not elucidate the best choice for vHIT reference, it demonstrated how the bHIT test properties varied with vHIT thresholds: selecting a lower threshold improved the sensitivity but diminished the PPV, while a higher threshold had the opposite effect. The VOR was most likely normal if the bHIT was negative due to its high NPV. The bHIT was moderately sensitive for detecting unilateral and bilateral vestibulopathy overall, but better for certain subgroups.

Esophoria or esotropia in adulthood: a sign of cerebellar dysfunction?

Convergent strabismus is a common diagnosis in early childhood, when it is mostly considered benign. If it develops later in life, strabismus can, however, be a sign of neurological disease. In these cases the underlying pathophysiological mechanisms are largely unknown. In this retrospective case-control study we analyzed the neuro-ophthalmological examination reports of 400 adult patients who presented at the German Center for Vertigo and Balance Disorders to determine an association between ocular misalignment and cerebellar dysfunction. Patients with cerebellar signs (i.e., cerebellar ataxia and/or cerebellar ocular motor signs) had a 4.49 (95 % CI [1.60; 13.78]) times higher frequency of ocular misalignment and specifically a 13.3 (95 % CI [3.80; 55.73]) times increased frequency of esophoria/esotropia (ESO) during distant gaze than patients without cerebellar dysfunction. ESO when looking into the distance was associated with saccadic smooth pursuit, dysmetria of saccades, and downbeat nystagmus (DBN) (χ (2) test, p < 0.0001 for all associations). Patients with cerebellar dysfunction also showed mildly impaired eye abduction (χ (2) test, left eye and right eye: p < 0.0001), associated with horizontal gaze-evoked nystagmus (χ (2) test, p < 0.0001). The association of ESO and DBN implicates a pathophysiological involvement of the cerebellar flocculus, while the association with dysmetric saccades suggests involvement of the oculomotor vermis. This is compatible with animal studies showing that the pathways of the flocculus/posterior interposed nucleus and vermis/nucleus fastigii are both involved in vergence movements and static binocular alignment. From a clinical point of view, a newly diagnosed esophoria/esotropia only during distant gaze may be a sign of a cerebellar disease.

Long-term prophylactic treatment of attacks of vertigo in Menière's disease--comparison of a high with a low dosage of betahistine in an open trial.

CONCLUSION: Despite the considerable limitations of an open, non-masked trial, particularly in Menière's disease (MD), a higher dosage of betahistine-dihydrochloride and a long-term treatment seems to be more effective than a low dosage and short-term treatment. OBJECTIVE: To evaluate the prophylactic effects of a low versus high dosage long-term treatment with betahistine-dihydrochloride on the number of attacks in MD. PATIENTS AND METHODS: We performed an open, non-masked trial, in which patients with MD received either a low dosage of betahistine-dihydrochloride (16 or 24 mg tid) or a higher dosage of 48 mg tid for at least 12 months. The outcome measure was the number of attacks per month during a 3-month period. Non-parametric tests and a random effects model were used for statistical analysis. RESULTS: A total of 112 patients were included in the analysis: 50 received betahistine-dihydrochloride in a low dosage (16 mg tid, n=21, 24 mg, n=29) and 62 received 48 mg tid. Follow-up examination every 3 months showed that the number of attacks per month decreased in both groups over time. For instance, after 12 months the mean (median) number of attacks dropped from 7.6 (4.5) to 4.4 (2.0) (p<0.0001) in the low-dosage group, and from 8.8 (5.5) to 1.0 (0.0) (p<0.0001) in the high dosage group. The number of attacks after 12 months was significantly lower in the high dosage group than in the low dosage group (p(12M)=0.0002). The treatment was well tolerated in both groups.

Causative factors and epidemiology of bilateral vestibulopathy in 255 patients.

OBJECTIVE: To determine the causative factors and epidemiology of bilateral vestibulopathy (BV). METHODS: This is a retrospective review of 255 patients (mean age, 62 +/- 16 years) with BV diagnosed in our dizziness unit between 1988 and 2005. All patients had undergone a standardized neurophthalmological and neurootological examination, electronystagmography with caloric irrigation, cranial magnetic resonance imaging or computed tomography (n = 214), and laboratory tests. RESULTS: Sixty-two percent of the study population were male subjects. Previous vertigo attacks had occurred in 36%, indicating a sequential manifestation. The definite cause of BV was determined in 24% and the probable cause in 25%: The most common causes were ototoxic aminoglycosides (13%), Menière's disease (7%), and meningitis (5%). Strikingly, 25% exhibited cerebellar signs. Cerebellar dysfunction was associated with peripheral polyneuropathy in 32% compared with 18% in BV patients without cerebellar signs. Hypoacusis occurred bilaterally in 25% and unilaterally in 6% of all patients. It appeared most often in patients with BV caused by Cogan's syndrome, meningitis, or Menière's disease. INTERPRETATION: The cause of BV remains unclear in about half of all patients despite intensive examinations. A large subgroup of these patients have associated cerebellar dysfunction and peripheral polyneuropathy. This suggests a new syndrome that may be caused by neurodegenerative or autoimmune processes.