Interface pressure, perceptual, and mean arterial pressure responses to different blood flow restriction systems.

This study examined the cuff to limb interface pressure during blood flow restriction (BFR), and the perceptual and mean arterial pressure responses, in different BFR systems. Eighteen participants attended three experimental sessions in a randomised, crossover, counterbalanced design. Participants underwent inflations at 40% and 80% limb occlusive pressure (LOP) at rest and completed 4 sets of unilateral leg press exercise at 30% of one repetition maximum with BFR at 80% LOP. Different BFR systems were used each session: an automatic rapid-inflation (RI), automatic personalized tourniquet (PT) and manual handheld pump and sphygmomanometer (HS) system. Interface pressure was measured using a universal interface device with pressure sensors. Perceived exertion and pain were measured after each set, mean arterial pressure (MAP) was measured pre-, 1-minute post- and 5-minutes post-exercise. Interface pressure was lower than the set pressure in all BFR systems at rest (P < .05). Interface pressure was, on average, 10 ± 8 and 48 ± 36 mm Hg higher than the set pressure in the RI and HS system (P < .01), with no differences observed in the PT system (P > .05), during exercise. Pain and exertion were greater in sets 3 and 4 in the RI and HS system compared to the PT system (P < .05). MAP was higher in the RI and HS system compared to the PT system at 1-minute and 5-minutes post-exercise (P < .05). BFR systems applying higher pressures amplify mean arterial pressure and perceptual responses. Automatic BFR systems appear to regulate pressure effectively within an acceptable range during BFR exercise.

Congenital inflammatory myopathy.

We present 3 patients with congenital inflammatory myopathy and summarize the literature. CNS involvement (microcephaly/intellectual delay) may or may not be present. Serum creatine kinase activity is elevated, the EMG is myopathic, and the muscle biopsy reveals inflammatory infiltrates, muscle fiber damage, and class I major histocompatibility complex products in muscle sarcolemma. Possible etiologies include intrauterine viral infection or an autoimmune process. Treatment with steroids may result in some motor improvement but has no effect on the CNS involvement. Despite a common time of presentation, these patients have a heterogeneous clinical profile, often suggesting a congenital muscular dystrophy syndrome.

Congenital bilateral perisylvian polymicrogyria presenting as congenital hemiplegia.

We report three children with pure congenital hemiplegia found to have congenital bilateral perisylvian polymicrogyria (CBPP). None of our patients had the seizures, oromotor dysfunction, or cognitive impairment usually associated with CBPP. CBPP may be more common and heterogeneous than previously thought, is easily recognized by MRI, and should be included in the differential diagnosis of the young child presenting with congenital hemiplegia.

Hypothalamic hamartomas and gelastic epilepsy: a spectroscopic study.

BACKGROUND: Patients with hypothalamic hamartomas present with epileptic attacks of laughter and later experience multiple seizure types and cognitive decline, suggestive of secondary generalized epilepsy. It has been suggested in the past that gelastic seizures originate in the temporal lobes rather than in the hamartoma, but temporal resections have been ineffective. Recent electrophysiologic evidence suggests that the epileptogenic discharges may originate in the hamartoma itself. METHODS: We used proton magnetic resonance spectroscopic imaging to quantify the amount of neuronal damage in the temporal lobes and hamartomas of patients with hypothalamic hamartomas and gelastic seizures. Five patients were studied and the relative intensity of N-acetylaspartate to creatine (NAA/Cr) was determined for both temporal lobes as well as for the hamartoma. These values were compared with signals from the temporal lobes and hypothalami of normal control subjects. RESULTS: NAA/Cr was not significantly different from normal control subjects for either temporal lobe, nor was there a significant asymmetry between the two temporal lobes for any of the patients. NAA resonance signals were present in the hamartomas, and the ratio of NAA to Cr was decreased in the hamartomas compared with the hypothalami of normal control subjects (t = 4.5, p = 0.005). CONCLUSIONS: We found no detectable neuronal damage in the temporal lobes of patients with hypothalamic hamartomas and gelastic epilepsy. This is further evidence that gelastic seizures do not originate in the temporal lobes of these patients.

Resection of the lesion in patients with hypothalamic hamartomas and catastrophic epilepsy.

BACKGROUND: Patients with hypothalamic hamartomas (HH) often have severe refractory epilepsy, incapacitating behavioral abnormalities, and cognitive decline. Attempts to control the seizure disorder by resection of apparently epileptogenic mesial temporal or other cortical structures have failed consistently. OBJECTIVE: To report a series of 13 patients in whom the hamartoma itself was resected. METHODS: All patients underwent preoperative evaluation between ages 2 and 33 years and had subtotal or complete resection of the hamartoma. Follow-up ranged from 1 to 5.5 years (mean: 2.8 y). RESULTS: Preoperatively, all patients had variable combinations of gelastic, complex partial, and generalized seizures. Eight had drop attacks. In addition, all had marked behavior abnormalities and cognitive impairment. Postoperatively, two patients are completely seizure-free and 11 are either seizure-free or have achieved a greater than 90% reduction of drop attacks and generalized tonic-clonic seizures. However, minor gelastic, complex partial, and atypical absence seizures have persisted in 11 patients, although at significantly reduced rates. In addition, there has been a dramatic improvement in behavior and cognition. Three patients had an anterior thalamic and one a capsular infarct, which left only minimal long-term deficits. Exact location of the lesion in relation to the interpeduncular fossa and the walls of the third ventricle correlated with extent of excision, seizure control, and complication rate. CONCLUSION: Resection can alleviate both the seizures and the behavioral and cognitive abnormalities of hypothalamic hamartomas, but complications are frequent.

A distinctive facial appearance in neurofibromatosis von Recklinghausen.

Three children with neurofibromatosis from two unrelated families have unusual facial appearance due to telecanthus, antimongoloid slant of the palpebral fissures, broad nose, and tapering chin. The two boys have large hands and feet, and one is very tall. There were some facial and dermatoglyphic similarities to individuals with the Noonan syndrome, but the manifestations in the children reported here are sufficiently different to suggest the presence of a different type of neurocristopathy in these individuals.

Ring chromosome 20 and possible assignment of the structural gene encoding human carboxypeptidase-L to the distal segment of the long arm of chromosome 20.

We report on a 14-year-old boy with ring chromosome 20. Clinical manifestations included postnatal growth retardation, epilepsy, microcephaly, behaviour disorder, minor facial anomalies, small sella turcica, possible partial growth hormone deficiency, and mental retardation. A decreased activity of enzyme carboxypeptidase-L/protective protein (CP/PP) in cultured fibroblasts was demonstrated in our patient and a patient with a karyotype 46,XY,-14, + der(14)t(14;20)(14pter----14q32.3::20q13.1----20qter)m at. This suggests possible assignment of the CP/PP gene to the distal segment of 20q.

Intractable epilepsy after a functional hemispherectomy: important lessons from an unusual case. Case report.

Residual seizures after functional hemispherectomy occur in approximately 20% of patients with catastrophic epilepsy. These episodes are traditionally attributed to incomplete disconnection, persistent epileptogenic activity in the ipsilateral insular cortex, or bilateral independent epileptogenic activity. The authors report on the case of an 8-year-old boy with an intractable seizure disorder who had classic frontal adversive seizures related to extensive unilateral left hemispheric cortical dysplasia. The initial intervention consisted of extensive removal of the epileptic frontal and precentral dysplastic tissue and multiple subpial transections of the dysplastic motor strip, guided by intraoperative electrocorticography, Subsequently, functional hemispherectomy including insular cortex resection was performed for persistent attacks. After a seizure-free period of 6 months, a new pattern ensued, consisting of an aura of fear, dystonic posturing of the right arm, and unusual postictal hyperphagia coupled with an interictal diencephalic-like syndrome. Electroencephalography and ictal/interictal single-photon emission computerized tomography were used to localize the residual epileptic discharges to deep ipsilateral structures. Results of magnetic resonance imaging indicated a complete disconnection except for a strip of residual frontobasal tissue. Therefore, a volumetric resection of the epileptogenic frontal basal tissue up to the anterior commissure was completed. The child has remained free of seizures during 21 months of follow-up review. Standard hemispherectomy methods provide extensive disconnection, despite the presence of residual frontal basal cortex. However, rarely, and especially if it is dysplastic, this tissue can represent a focus for refractory seizures. This is an important consideration in determining the source of ongoing seizures posthemispherectomy in patients with extensive cortical dysplasia. It remains important to assess them fully before considering their disease refractory to surgical treatment.

Functional interhemispheric asymmetries at birth as demonstrated by somatosensory evoked potentials.

Functional cerebral hemispheric asymmetries detectable at birth have been suggested by a number of neuroanatomic, neuroradiologic, and clinical neurophysiologic modalities. The aim of this study was to determine whether functional interhemispheric asymmetries can be identified using electrophysiologic measures. As part of a prospective study, somatosensory evoked potentials following median nerve stimulation were recorded in nine healthy full-term newborns on day 2 or 3 of life, and somatosensory evoked potentials were repeated at 2 and 6 months of age. These children were subsequently examined at 1 and 3 years of age by a pediatric neurologist and all had normal examinations. Handedness was determined at 3 years by questioning the parent and by clinical observation. Three of nine were left-handers. All three left-handers had clearly identifiable neonatal N19 parietal potentials over the right hemisphere. Following right median nerve stimulation, contralateral parietal potentials were absent on two of the three and questionable in the third. Asymmetries were not clearly present in right-handers although only one showed an increased maturation of the right hemisphere relative to the left. At 2 months of age, interhemispheric differences were no longer clearly evident. This data suggests that preferential hemispheric asymmetries are masked by 2 months of age. This differential rate of development demonstrated by neonatal somatosensory evoked potentials may be an early indicator of ultimate handedness.

Prediction of outcome at school age in neonatal intensive care unit graduates using neonatal neurologic tools.

Prediction of outcome for neonatal intensive care unit graduates is clinically useful to counsel families effectively and target those who may benefit from early interventions. Evoked potentials have proven prognostic value of neurologic outcomes in early childhood; however, their long-term predictive validity remains to be determined. The objective of this prospective study was to determine the long-term predictive value of three neonatal neurologic assessments: brainstem auditory evoked potentials, somatosensory evoked potentials, and the Einstein Neonatal Neurobehavioral Assessment Scale. Seventy-eight high-risk newborns and 28 healthy controls were recruited and were assessed in the newborn period using these tests. At 8 to 9 years of age, 42 subjects and 13 controls were re-evaluated for developmental progress using a range of psychologic, sensorimotor, and neurologic measures. Findings indicated that the somatosensory evoked potential was most accurate at predicting outcome at school age, with high specificity (83-100%) across all domains tested and good sensitivity (80-100%) for intellectual performance and sensorimotor abilities. The brainstem auditory evoked potential was limited by false-negatives, whereas the neonatal neurobehavioral assessment yielded many false-positives. This study provides new evidence that associations between neonatal somatosensory evoked potentials and developmental sequelae continue to be significant at school age.

The effect of gestational age at birth on somatosensory-evoked potentials performed at term.

Multimodality-evoked potentials are widely used in newborns to assess the maturation and integrity of the sensory pathways. Reliable normative data are needed to maximize the utility of this technique as a diagnostic and research tool. Several electrophysiologic studies on the maturational changes of the auditory brain-stem response have demonstrated that latency measurements decrease as a function of increasing conceptional age. However, maturational studies of the somatosensory-evoked potential, particularly in low-risk premature infants, are limited. The existing evoked potential literature in healthy newborns proposes that maturation of the central nervous system occurs at a predictable rate, irrespective of a given gestational age at birth. Behavioral studies of premature infants suggest that neurologic development may be altered by early extrauterine exposure. The purpose of this study was to determine whether brain-stem auditory- or somatosensory-evoked potential conduction times were comparable in premature and full-term infants matched for conceptional age. The results of this study suggest that myelination is determined by conceptional age, independent of premature birth.

The determination of sensory deficits in children with hemiplegic cerebral palsy.

Therapeutic intervention for children with cerebral palsy begins with accurate appraisal of abilities and disabilities. Currently, treatment focuses on the identified motor deficits, with any underlying sensory deficits often being overlooked. Sensory input is an essential component of motor function and motor control. Therefore, the objective of this study was to determine the presence and extent of sensory deficits in school-aged hemiplegic children using a formal clinical sensory battery, as well as somatosensory evoked potentials. A cross-sectional comparative study was performed comparing sensory function in hemiplegic children and healthy controls. Nine hemiplegic children and 41 healthy controls between 4 and 19 years of age were assessed. Hemiplegic children were included if they had a minimum level of receptive language function of 30 to 33 months and expressive language ability of 24 to 27 months, and no severe limitation of joint range of the hand. Significant bilateral sensory deficits (88.8%) were ascertained in hemiplegic children (P < .05), when compared to the performance of the healthy controls. Stereognosis and proprioception were the chief modalities affected bilaterally. The extent of sensory loss did not mirror the severity of motor deficit. Conversely, findings on somatosensory evoked potentials were closely related to motor function. Thus, a clinical sensory evaluation should be an integral part of the assessment of children with cerebral palsy. The likelihood of sensory impairment in one or more modalities on the hemiplegic or nonhemiplegic side is underappreciated and needs to be identified by rehabilitation specialists to maximize the functional potential of these children.

Multimodality evoked potential findings in infants with congenital heart defects.

Evoked potentials are sensitive prognostic tools in young infants at risk for developmental disability. The objective of this prospective study was to determine whether infants with congenital heart defects demonstrate evoked potential abnormalities prior to or following open heart surgery, and to examine the association between these abnormalities and developmental status 1 year following surgery. A consecutive series of newborns (less than 1 month old) and infants (1 month to 2 years old) were recruited. Somatosensory and brain stem auditory evoked potentials were carried out before or after cardiac surgery, or both. One year later, neurologic examination and standardized measures of motor performance and functional independence were carried out. Twenty-seven newborns and 31 infants underwent perioperative somatosensory evoked potential recordings. Results indicate that perioperative somatosensory evoked potential abnormalities were common in newborns (41%) but not in infants (13%) with congenital heart defects. Brainstem conduction times were within normal limits in all subjects; however, 32% presented with mild elevations in hearing thresholds. All newborns with abnormal somatosensory evoked potentials had abnormal neurologic examinations both perioperatively and again 1 year after open heart surgery. Moreover, standardized developmental assessments 1 year following surgery indicate that all newborns with somatosensory evoked potential abnormalities had developmental deficits in one or more domains. Somatosensory evoked potential abnormalities in the perioperative period are common in newborns with congenital heart defects, and are strongly predictive of persistent developmental delay later.

Association between electroencephalographic findings and neurologic status in infants with congenital heart defects.

Neurologic status is of concern in infants with congenital heart defects undergoing open heart surgery. The association between perioperative electroencephalography (EEG) with acute neurologic status and subsequent outcome was examined in a cohort of 60 infants. Preoperative EEG and neurologic examinations were performed within 1 to 2 days prior to surgery (n = 27) and postoperatively (n = 47). Prior to surgery, 15 of 27 infants had normal EEG, whereas 5 had epileptiform activity and 9 had disturbances in background activity that were primarily moderate (8/9) and diffuse (7/9). Postoperatively, only 17 of 47 infants had normal recordings. Newborns (<1 month) were more likely (P< .001) to demonstrate EEG abnormalities than infants. Epileptiform activity was documented in 15, whereas 28 had background abnormalities that were moderate-severe (22/28) and diffuse (20/28) in most. Epileptiform activity prior to surgery was always associated with an abnormal neurologic examination, and this association persisted postoperatively (86%). Moderate to severe background abnormalities in the postoperative EEG was also strongly associated with acute neurologic abnormalities (93%). Severe background abnormalities (n = 5) were 100% predictive of death or severe disability. Long-term follow-up revealed that all children with normal postoperative EEGs had positive neurologic outcomes (P = .04); however, there were many false positives. Perioperative EEG abnormalities increased the likelihood for acute neurologic findings, whereas normal recordings following surgery were reassuring with regard to a favorable outcome.

Monitoring the central nervous system in children with congenital heart defects: clinical neurophysiological techniques.

The neurological sequelae following surgery for complex cardiac malformations is being increasingly recognized. The electroencephalogram (EEG) and evoked potentials may be used as monitors of neurological integrity. Criteria for a successful intensive care unit monitoring system have been proposed. EEG findings in the preoperative, perioperative, and postoperative periods are reviewed and may aid in the prediction of neurological sequelae. Recent advances in the development of a computerized neurophysiological monitor at the Montreal Children's Hospital are reviewed. Evoked potentials, auditory, somatosensory, and visual can be used to monitor children with complex cardiac lesions and evaluate them for potential neurological sequelae.

Computerized EEG monitoring.

Monitoring of central nervous system function in the intensive care unit is becoming more widely accepted as an integral part of critical care. The history of developments in electroencephalogram (EEG) technology is reviewed to better appreciate the rate of technological developments and their application to clinical practice. Basic concepts of digital EEG are reviewed. Principals of intensive care unit monitoring as they apply to clinical neurophysiological techniques are examined to better understand the goals for an "ideal central nervous system monitor." Some current advances and directions for future development in computerized EEG monitoring are discussed.

Auditory brainstem response abnormalities in autistic children.

In an attempt to clarify issues of brainstem dysfunction and hearing thresholds in autistic children, we studied the Auditory Brainstem Responses (ABRs) in 32 children who clearly fit within the criteria of autism established by the National Society for Autistic Children (1977). ABRs were recorded between Cz and ipsilateral ear in response to click stimuli. Interwave latencies and auditory threshold in each ear were determined. Of the 32 children, 11 had moderate hearing loss (8 bilaterally) and 3 had severe to profound hearing loss, all bilaterally. 8 of the 14 with hearing loss also had associated features (e.g., perinatal encephalopathy). The I-III and I-V interwave latencies were significantly longer in the autistic children compared to normal control children; the increased conduction times were found mainly in the early portion of the auditory brainstem pathway. These data confirm some earlier reports of ABR abnormalities in autistic children and are concordant with some theories of the etiological basis of autism. The high incidence of hearing loss in these children is significant and routine ABR testing is recommended.

Inflammatory myopathy and Walker-Warburg syndrome: etiologic implications.

Walker-Warburg syndrome is a well delineated clinical entity with characteristic brain and eye anomalies. Recent diagnostic surveys have revealed that muscular dystrophy is an obligatory feature of this syndrome. We report a patient with an inflammatory myopathy that preceded dystrophic changes. While reports of parental consanguinity and multiple affected sibships strongly suggest an autosomal recessive genetic basis for this syndrome, previous pathological analyses of the CNS have suggested an inflammatory process. Our case supports both the notion of an aberrant inflammatory process that is likely under genetic control or etiologic heterogeneity (phenocopies) underlying this syndrome.

Reliability of parental recall of developmental milestones.

The developmental history is a key element of the pediatric evaluation. Precise determination of a child's milestones depends on the parent's recollection of developmental events. As part of a prospective study examining neonatal predictors of outcome, healthy and high-risk newborns were assessed by a neurologist at 1, 3, and 5 years of age. The consistency of a parent's recall of two milestones (i.e., first steps and first meaningful word) was examined at 3 and 5 years. The answers provided by the parent(s) at the first visit (mean/S.D.: 12.67/1.19 months) provided the comparison standard. Twenty-five healthy and 50 high-risk infants had acquired 1 or both developmental skills by the first visit. Of 75, 63 were reexamined at 3 and/or 5 years by the same neurologist. For first steps, excellent correlations were obtained at 3 years (r = 0.74) and modest correlations were determined at 5 years (r = 0.41). The mean difference in age reported between 1 and 3 years was 0.36 +/- 1.81 months, and 0.33 +/- 2.46 months between 1 and 5 years. For first word, correlations were poor at 3 and 5 years (r = 0.27 and r = -0.11, respectively), with mean discrepancies in recall of 2.43 +/- 4.37 months (3-year visit) and 2.74 +/- 5.56 months (5-year visit). Twenty percent (n = 13) of parents reported discrepancies of 6 or more months (mean: 9.4; range: 6-25 months). Furthermore, this error in reporting of first word was later than the correct age in all patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Evoked potentials as predictors of outcome in neonatal intensive care unit survivors: review of the literature.

Neonatal intensive care unit survivors are at substantial risk for a range of neurodevelopmental sequelae, and therefore a variety of clinical diagnostic techniques have been evaluated as predictors of outcome. We summarize the prognostic value of evoked potentials in newborns at risk. A review of the literature reveals that brainstem conduction abnormalities in auditory brainstem evoked potentials are associated with neuromotor impairment; however, there are many false negative studies. Visual evoked potentials are highly accurate in predicting neurologic deficits in early childhood in asphyxiated term neonates. Sensitivity and specificity are consistently high for somatosensory evoked potentials in term newborns; however, correlations with outcome in premature infants is controversial. Several studies have compared neonatal findings on neuroimaging studies and evoked potentials, and concordant results between these two tests are highly predictive. However, neurologic sequelae often can most accurately be predicted by visual or somatosensory evoked potentials. Evoked potentials may therefore be a useful adjunct to the clinical investigation and prognostication of outcome in the high risk newborn.