ABSTRACT
OBJECTIVE: We aimed to describe vestibular/oculomotor function of 7-12-year-old children with CP, Gross Motor Function Classification System (GMFCS) levels (I-III), in comparison to an age-matched control group to understand the effect of the vestibular system on activities and participation of children with CP. METHODS: Vestibular, oculomotor and balance function were tested in children with CP. Central and peripheral vestibular function was examined using an enclosed rotary chair and infrared video goggles (100â¯Hz) that measured eye movements. Oculomotor tests included smooth pursuit and optokinetic nystagmus (OKN). Vestibulo-Ocular Reflex (VOR) tests, done in complete darkness, included step rotation (STEP), sinusoidal harmonic acceleration (SHA) test, VOR cancellation and enhancement, and subjective visual vertical and horizontal (SVV/SVH). The integrity of the saccule was tested with the Cervical Vestibular Evoked Myogenic Potential. If able, the participants' balance abilities were examined using the Sensory Organization Test (SOT) to determine ability to maintain standing balance during six conditions that challenged the visual, somatosensory and vestibular systems. Independent t-tests and Mann-Whitney U tests were used to compare results between groups. RESULTS: Forty-one children with CP (mean ageâ¯=â¯9.44 years, SDâ¯=â¯1.66; 23F/18M; Gross Motor Function Classification System levels: I (nâ¯=â¯19), II (nâ¯=â¯7), III (nâ¯=â¯15) and thirty-three typically developing (TD) children (mean ageâ¯=â¯10.16 years, SDâ¯=â¯1.6; 13F/20M) were recruited from the Birmingham, AL community. There was no significant difference between children with CP and TD children in saccular function (i.e. C-VEMP test), and peripheral vestibular end organ (i.e. SHA test and STEP test), VOR enhancement, or OKN gain. Velocity gain for horizontal smooth pursuit was significantly worse in children with CP (pâ¯=â¯0.009), compared to TD children. Poor mediation of central vestibular function were that evident with significantly higher VOR cancellation gain in children with CP (pâ¯<â¯0.0001), compared to TD children and significantly higher SVV variance (pâ¯=â¯0.002), SVH mean (pâ¯=â¯0.001), and SVH variance (pâ¯<â¯0.0001) in children with CP compared to TD children. Compromised balance abilities in children with CP was evident with significantly lower composite scores (pâ¯<â¯0.0001), vestibular ratio (pâ¯<â¯0.0001), and visual ratio (pâ¯=â¯0.021). The somatosensory ratio (pâ¯=â¯0.798) of children with CP was similar to children with TD. CONCLUSIONS: Although peripheral vestibular function was intact, children with CP had difficulty coupling eye and head movement (VOR cancellation), using the vestibular system for postural control (SOT), demonstrated poor perception of upright (SVV/SVH), and had difficulty following a slow moving target (smooth pursuit eye movement). These results implicate a central vestibular and oculomotor function impairment the severity of which corresponded with severity of the level of CP.
Subject(s)
Cerebral Palsy/physiopathology , Evoked Potentials, Somatosensory , Nystagmus, Optokinetic , Postural Balance , Pursuit, Smooth , Case-Control Studies , Child , Female , Head Movements , Humans , Male , Reflex, Vestibulo-Ocular , Saccule and Utricle/physiopathologyABSTRACT
An oligonucleotide DNA probe (VVAP) was constructed from a portion of the Vibrio vulnificus cytolysin gene (hylA) sequence and labeled with alkaline phosphatase covalently linked to the DNA. Control and environmental isolates probed with VVAP showed an exact correlation with results obtained with a plasmid DNA probe (derived from pCVD702) previously described as having 100% specificity and sensitivity for this organism. Identification of V. vulnificus strains was confirmed independently by analysis of the cellular fatty acid composition and by API 20E. Naturally occurring V. vulnificus bacteria were detected without enrichment or selective media by VVAP in unseeded oyster homogenates and seawater collected from a single site in Chesapeake Bay during June at concentrations of 6 x 10(2) and 2 x 10(1) bacteria per ml, respectively. V. vulnificus bacteria were also enumerated by VVAP in oysters seeded with known concentrations of bacteria and plated on nonselective medium. The VVAP method provides a rapid, accurate means of identifying and enumerating V. vulnificus in seawater and oysters without the use of selective media or additional biochemical tests.