Abnormal eye movements in unconscious patients serve as crucial diagnostic instruments, offering insights into the function of the central nervous system. Understanding these movements can aid in diagnosing the cause of unconsciousness, localizing brain lesions, and predicting outcomes. We report a patient who presented with spontaneous horizontal nystagmus unaffected by light in delayed post-hypoxic encephalopathy. Video-oculography showed exponentially increasing slow phases, with an amplitude ranging from 3° to 9° and a frequency of 0.5 Hz. Based on the results of oculography and neuroimaging, persistent horizontal nystagmus in our patient may be ascribed to an unstable neural integrator, possibly caused by disrupted cerebellar feedback mechanisms for horizontal gaze holding.
This study describes an unusual case of fluctuating unilateral high-frequency hearing loss with vertigo resembling Menière’s disease. The current diagnostic criteria for definite Menière’s disease include audiometrically documented low- to medium-frequency sensorineural hearing loss on at least one occasion before, during, or after an episode of vertigo. This case presented a diagnostic dilemma. Brain MRI was nonspecific, and a bithermal caloric test showed unilateral weakness of 44% on the affected side. The results of electrocochleography and cervical vestibular evoked myogenic potential tests were within the normal ranges. Persistent geotropic or ageotropic positional nystagmus was observed during each vertigo attack; the mechanism underlying this characteristic nystagmus needs further investigation.
This study describes an unusual case of fluctuating unilateral high-frequency hearing loss with vertigo resembling Menière’s disease. The current diagnostic criteria for definite Menière’s disease include audiometrically documented low- to medium-frequency sensorineural hearing loss on at least one occasion before, during, or after an episode of vertigo. This case presented a diagnostic dilemma. Brain MRI was nonspecific, and a bithermal caloric test showed unilateral weakness of 44% on the affected side. The results of electrocochleography and cervical vestibular evoked myogenic potential tests were within the normal ranges. Persistent geotropic or ageotropic positional nystagmus was observed during each vertigo attack; the mechanism underlying this characteristic nystagmus needs further investigation.
This study describes an unusual case of fluctuating unilateral high-frequency hearing loss with vertigo resembling Menière’s disease. The current diagnostic criteria for definite Menière’s disease include audiometrically documented low- to medium-frequency sensorineural hearing loss on at least one occasion before, during, or after an episode of vertigo. This case presented a diagnostic dilemma. Brain MRI was nonspecific, and a bithermal caloric test showed unilateral weakness of 44% on the affected side. The results of electrocochleography and cervical vestibular evoked myogenic potential tests were within the normal ranges. Persistent geotropic or ageotropic positional nystagmus was observed during each vertigo attack; the mechanism underlying this characteristic nystagmus needs further investigation.
This study describes an unusual case of fluctuating unilateral high-frequency hearing loss with vertigo resembling Menière’s disease. The current diagnostic criteria for definite Menière’s disease include audiometrically documented low- to medium-frequency sensorineural hearing loss on at least one occasion before, during, or after an episode of vertigo. This case presented a diagnostic dilemma. Brain MRI was nonspecific, and a bithermal caloric test showed unilateral weakness of 44% on the affected side. The results of electrocochleography and cervical vestibular evoked myogenic potential tests were within the normal ranges. Persistent geotropic or ageotropic positional nystagmus was observed during each vertigo attack; the mechanism underlying this characteristic nystagmus needs further investigation.
Introduction: Cholinesterase inhibitors (ChEIs) are widely used to treat mild to moderate Alzheimer disease and vascular dementia. Even though dizziness due to medication of ChEIs has been ascribed to adverse effects on the cardiovascular or central nervous system, the mechanisms remain unclear and objective indicators are not available.
Methods We recorded the eye movements using video-oculography in three patients who developed dizziness and unsteadiness after initiation or increment of ChEI, donepezil (Aricept).
Results The patients showed frequent saccadic oscillations that improved after discontinuation of ChEI.
Conclusions Frequent saccadic oscillations may be an indicator of dizziness in patients taking ChEIs.
Arnold Chiari malformation is a disease which is characterized by herniation of a portion of the cerebellum through the foramen magnum. Symptoms vary depending on the extent of the affected area, including posterior neck pain, upper limb pain, paralysis, paresthesia, weakness, dizziness, and ataxia. Among the patients presenting with dizziness, nystagmus is frequently observed, which is primarily characterized by down-beating nystagmus. We experienced a 42- years-old female patient presented with vertigo and gait disturbance, who were diagnosed with type 1 Arnold-Chiari malformation and treated by surgical decompression.
Seesaw nystagmus (SSN) is characterized by conjugate torsional nystagmus with opposite vertical components in the two eyes. The waveform may be pendular or jerk (hemi-seesaw nystagmus, HSSN), in which the slow phase corresponds to one half-cycle and the quick phase to the other. Pendular SSN and HSSN have distinct clinical presentations and underlying causes. The pathophysiology of pendular SSN may be instability of visuovestibular interactions, while the underlying mechanism for HSSN may be related to the ocular tilt reaction or an imbalance in vestibular pathways. We report a patient with HSSN due to unilateral mesodiencephalic infarction that becomes apparent during visual fixation only.
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Midbrain lesion-induced disconjugate gaze: a unifying circuit mechanism of ocular alignment? Maximilian U. Friedrich, Laurin Schappe, Sashank Prasad, Helen Friedrich, Michael D. Fox, Andreas Zwergal, David S. Zee, Klaus Faßbender, Klaus-Ulrich Dillmann Journal of Neurology.2024;[Epub] CrossRef
Ocular flutter is a rare, horizontal eye movement disorder characterized by intermittent bursts of conjugate horizontal saccades without intersaccadic intervals. It can occur in various clinical conditions such as metabolic dysfunction, infection and paraneoplastic syndrome. Herein, a 50-year-old male showed ocular flutter in parainfectious meningoencephalitis and immunoglobulin therapy led to an improvement of symptoms. This case can improve the understanding of the pathological mechanisms of ocular flutter.
Sarcoidosis is a rare, multisystem granulomatous disease. Neurological complications occur in about 5% of patients and vestibulocochlear involvement is even rarer. A 27-year-old woman presented with acute spontaneous vertigo for 5 days. She was diagnosed with pulmonary sarcoidosis 4 months ago, but specific treatments have not yet started. She had preceding otologic symptoms including bilateral tinnitus and ear fullness in the right for 3 months without hearing loss. Initial bedside examinations revealed spontaneous right-beating nystagmus and abnormal catch-up saccades in the left during head impulse tests (HIT). After 2 weeks, video-oculography documented the direction of spontaneous nystagmus was changed into left-beating. Caloric test showed canal paresis in the left, and video HIT showed subtle covert saccades. After starting oral prednisolone, her symptoms improved rapidly. In our case, acute vestibular syndrome and otologic symptoms might be associated with sarcoidosis when considering clinical course and treatment response. Sarcoidosis may be considered as a cause in cases with audiovestibulopathy of unknown etiology.
The upward deviation could be explained by loss of inhibitory inputs from the cerebellum onto the brainstem anterior semicircular canal projections for upward vestibulo-ocular reflex, which would lead to an upward bias in static eye position. Therefore, upward gaze deviation has been reported in comatose patients after resuscitation and diffuse cerebrocerebellar damage sparing the brainstem. Herein, we report a patient with ingestion of glufosinate ammonium presented with cerebellar ataxia and ocular motor findings suggestive of cerebellum involvement such as upward gaze tendency, spontaneous downbeat, gaze-evoked nystagmus, perverted head impulse test, and impaired smooth pursuit.