Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0028738 (nystagmus)
 7,431 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Vestibular dysfunction is a significant differential diagnosis in patients who have unexpected falls without: loss of consciousness, paresis, sensory loss, or cerebellar deficit. Either peripheral or central vestibular disorders cause postural instability with preferred directions of falling, some of which can be attributed to either the particular plane of the affected semicircular canal or a central pathway mediating the 3-dimensional vestibulo-ocular reflex in yaw, pitch, and roll. Ipsiversive falls occur in vestibular neuritis or in Wallenberg's syndrome--where they are known as lateropulsion. Contraversive falls are typical for the otolith Tullio phenomenon, vestibular epilepsy, and thalamic astasia. Predominant fore-aft instability is observed in bilateral vestibulopathy, benign paroxysmal positioning vertigo, as well as in downbeat or upbeat nystagmus syndrome. Falls can be diagonally forward (or backward) and toward or away from the side of the lesion, depending on the site of the lesion (the ocular tilt reaction is ipsiversive in medullary lesions, but contraversive in mesencephalic lesions) and on whether vestibular structures are excited or inhibited.
 ...
PMID:Vestibular falls. 827 42

We present a clinical classification of central vestibular syndromes according to the three major planes of action of the vestibulo-ocular reflex: yaw, roll, and pitch. The plane-specific syndromes are determined by ocular motor, postural, and perceptual signs. Yaw plane signs are horizontal nystagmus, past pointing, rotational and lateral body falls, deviation of perceived straight-ahead to the left or right. Roll plane signs are torsional nystagmus, skew deviation, ocular torsion, tilts of head, body, and perceived vertical in a clockwise or counterclockwise direction. Pitch plane signs are upbeat/downbeat nystagmus, forward/backward tilts and falls, deviations of the perceived horizon. The thus defined vestibular syndromes allow a precise topographic analysis of brainstem lesions according to their level and side. Special emphasis is placed on the vestibular roll plane syndromes of ocular tilt reaction, lateropulsion in Wallenberg's syndrome, thalamic and cortical astasia and their association with roll plane tilt of perceived vertical. Recovery is based on a functionally significant central compensation of a vestibular tone imbalance, the mechanism of which is largely unknown. Physical therapy may facilitate this central compensation, but this has not yet been proven in prospective studies.
 ...
PMID:Perceived vertical and lateropulsion: clinical syndromes, localization, and prognosis. 1122 44

"Unertan syndrome" consists of two main symptoms: quadrupedal gait and primitive cognitive abilities including language and conscious experience. To assess the central mechanisms involved in this syndrome, the authors performed MRI and PET scans on affected and unaffected individuals from both families. All affected individuals were also subjected to neurological examination. To assess the integrity of the peripheral and central vestibular system, Barany's caloric test was applied to the affected individuals. Brain MRI and PET scans were performed on normal subjects (n = 7) and patients (n = 7). Right- and left-cerebral and cerebellar areas, including the vermial and callosal areas, were measured on the MRI scans using a computer cursor. Quadrupedal gait, mental retardation, dysartric speech, nystagmus, severe truncal ataxia, hyperreflexia, astasia, and abasia were observed in the affected individuals from both families. Cerebellum and vermis were atrophic in the MRI and PET scans of the first family. In contrast, the brain MRI seemed to be normal in the MRI and PET scans of affected individuals from the second family. The caloric test revealed central vestibular damage in patients from the first family and peripheral vestibular damage in patients from the second family. The results suggest that "Unertan syndrome," discovered in two unrelated families, may be caused by peripheral or central vestibular damage resulting from different genetic defects. Cerebellar hypoplasia may not be a prerequisite for the emergence of this syndrome. Primitive mental abilities may be explained by damage within the vestibulo-cerebellar system, whereas the quadrupedal gait may be due to a genetic defect within the higher brain centers that suppress the atavistic brain networks controlling quadrupedal gait and helped in the emergence of the habitual bipedal gait during human evolution. This retarded development of human locomotion - devolution - may illuminate the brain mechanisms responsible for the transition from quadrupedality to bipedality in human evolution.
 ...
PMID:"Unertan syndrome" in two Turkish families in relation to devolution and emergence of Homo erectus: neurological examination, MRI, and PET scans. 1830 5

Isolated vertigo is generally attributed to labyrinthine disease, but may also signal otherwise asymptomatic cerebellar infarction. Of 309 subjects admitted between April 2004 and March 2009 for the single symptom of acute vertigo initially thought to be labyrinthine, four were found to have cerebellar infarction of the posterior inferior cerebellar artery area (PICA). All were over 60 years old and had risk factors including hypertension, diabetes mellitus, arrhythmia, and/or hyperlipidemia. Two had trunk ataxia, with magnetic resonance imaging (MRI) showing infarction within a few days. The other two could walk without apparent trunk ataxia, however, it took 4 to 7 days to find the infarction, mainly through neurological, neurootological, and MRI findings. Neurologically, astasia, dysbasia or trunk ataxia were important signs. Neurootologically, nystagmus and electronystagmographic testing involving eye tracking, saccade, and optokinetic patttens were useful.
 ...
PMID:[Study of cerebellar infarction with isolated vertigo]. 2071 5