INTRODUCTION Studies of neuroplasticity have shown that the brain’s neural networks change in the absence of sensory input such as hearing or vision. However, little is known about what happens when both sensory modalities are lost (deaf-blindness). Hence, this study of cortical reorganization in visually-impaired child cochlear implant (CI) candidates.

OBJECTIVE Assess cross-modal plasticity, specifically cortical reorganization for tactile representation in visually-impaired child CI candidates, through study of topography of somatosensory evoked potentials (SEP).

METHODS From April through September 2005, SEP from median and tibial nerve electrical stimulation were studied in 12 visually-impaired child CI candidates aged 3–15 years and 23 healthy controls. Following placement of 19 recording electrodes using the International 10-20 System , SEP were recorded and then processed. Topographic maps were obtained for SEP N20 (median nerve) and SEP P40 (tibial nerve), permitting assessment of cortical reorganization by comparing visually-impaired, deaf children’s maps with those of healthy children by means of visual inspection and statistical comparison using a permutation test.

RESULTS SEP N20 topography was significantly more extensive in visually-impaired child CI candidates than in healthy children. An asymmetrical pattern occurred from the expansion of hand tactile activation into the temporal and occipital regions in the left hemisphere on right median nerve stimulation. This did not occur for SEP P40 on tibial nerve stimulation (right and left). Magnitude of expanded SEP N20 response was related to severity of visual impairment and longer duration of dual sensory loss.

CONCLUSIONS Changes in SEP N20 topography are evidence of cross-modal plasticity in visually-impaired child CI candidates, appearing to result from a complex interaction between severity of visual impairment and duration of multisensory deprivation.

KEYWORDS Somatosensory evoked potentials, deaf-blind, hearing and vision loss, sensorineural hearing loss, cochlear implants, neuroplasticity, neuroimaging, neurophysiology, fMRI, functional magnetic resonance imaging, positron-emission tomography, PET scan, Cuba

The following erratum has been corrected in all versions of this article.
Page 26, in the legend for Figure 2 (both a and b), the second group label should read: “Hearing & vision loss.”

Introduction Obesity is a social disease constituting a global pandemic. It is present in 90% of diabetic and 65% of hypertensive patients. It is associated with cardiometabolic syndrome and with damaging physiopathological mechanisms, particularly for the vascular system and the kidneys. On Cuba’s Isle of Youth, a community-based epidemiological study of chronic kidney disease (CKD), hypertension (HTN), diabetes mellitus (DM) and cardio-cerebral vascular disease was carried out in total population, including an examination of common risk factors.

Objective Based on the Isle of Youth Study (ISYS) data, determine prevalence of obesity and overweight, and their association with CKD, HTN, DM, and shared risk factors for all these conditions in total population of the Isle of Youth, Cuba.

Methods Phase 1: Population diagnosis (November 2004-April 2006): 96.6% of the Isle of Youth’s total population (80,117) was studied, including all ages and both sexes. Information was offered to the public, and written informed consent obtained. Screening was conducted by participant questionnaire including risk factors, physical measurements (weight, height, blood pressure and body mass index), and a single first-morning urine sample to determine the presence of vascular-renal damage markers – proteinuria and hematuria (Combur 10 Test, Roche), and microalbuminuria (Micral Test, Roche). When results were positive, serum creatinine was determined and glomerular filtration rate (GFR) estimated with Modification of Diet in Renal Disease (MDRD) formula for adults and Schwartz formula for children <15 years. Data obtained were analyzed to determine association of participants’ nutritional status with prevalence of chronic kidney disease, hypertension and diabetes mellitus, as well as a set of common risk factors.

Results Population <20 years: Obesity prevalence 3.2%; positive urine markers in 56.9% of obese and 8.9% of non-obese participants; positive albuminuria in 38% of obese and 3% of non-obese. Obese participants were found to be hyperfiltrating. DM prevalence was 9.5% in obese and 1.1% in non-obese participants. Population ≥20 years: Overweight, 31.3%; obese, 13.4%. Positive markers in normal-weight, overweight and obese individuals were 18.3%, 21.2% and 32.7%, respectively; microalbuminuria values increased with weight. Obese individuals were found to be hyperfiltrating. HTN prevalence in normal-weight, overweight and obese individuals was 18.3%, 31.5%, and 51.0% respectively; DM rates were 2.8%, 5.2% y 11.3%, respectively.

Conclusion In Cuba, obesity poses significant risk for vascular and renal damage and should be the focus of increased prevention efforts.

Keywords Vascular diseases, chronic kidney disease, CKD, chronic kidney insufficiency, hypertension, diabetes mellitus, risk factors, obesity, overweight, body mass index, glomerular filtration rate