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Biomedical subjects

J R Grigg

Publications and source records attributed to J R Grigg.

17 recordsLinked to original sources
PubMed2003

Endocrine status in patients with optic nerve hypoplasia: relationship to midline central nervous system abnormalities and appearance of the hypothalamic-pituitary axis on magnetic resonance imaging.

We here: 1) describe the phenotypic spectrum, including magnetic resonance imaging (MRI) appearances of the pituitary stalk and anterior and posterior pituitary [H-P (hypothalamic-pituitary) axis], in children with optic nerve hypoplasia (ONH) with or without an abnormal septum pellucidum (SP); and 2) define endocrine dysfunction according to the MRI findings. Medical records of 55 children with ONH who had been assessed by ophthalmology and endocrine services were reviewed. All had MRI of the brain and H-P axis. Forty-nine percent of the ONH patients had an abnormal SP on MRI, and 64% had a H-P axis abnormality. Twenty-seven patients (49%) had endocrine dysfunction, and 23 of these had H-P axis abnormality. The frequency of endocrinopathy was higher in patients with an abnormal SP (56%) than a normal SP (39%). Patients were divided into four groups based on SP and H-P axis appearance: 1) both normal; 2) abnormal SP and normal H-P axis; 3) normal SP and abnormal H-P axis; and 4) both abnormal. The frequency of multiple pituitary hormone deficiency was highest (56%) in group 4, lower (35%) in group 3, and even lower (22%) in group 2. Precocious puberty was most common in group 2. None of the patients in group 1 had endocrine dysfunction. Thus, SP and H-P axis appearances on MRI can be used to predict the likely spectrum of endocrinopathy.

Adolescent↗
PubMed2001

Spinocerebellar ataxia type 7: a distinctive form of autosomal dominant cerebellar ataxia with retinopathy and marked genetic anticipation.

When a child presents with progressive ataxia, there is a broad differential diagnosis and a very long list of potential investigations. Spinocerebellar ataxia type 7 presenting in infancy is a rare condition where a presumptive diagnosis can be made based on the clinical features alone. These include rapidly progressive ataxia, retinopathy and autosomal dominant inheritance with marked genetic anticipation of paternal origin. The father of the infant may manifest minimal symptoms at a time when the infant is severely affected. Diagnosis is confirmed by the demonstration of an expansion of a CAG repeat in the coding region of the gene on chromosome 3p. We present a case to illustrate the diagnostic difficulties. Antenatal diagnosis was performed in two subsequent pregnancies.

Fatal Outcome↗
PubMed2000

Objective VEP perimetry in glaucoma: asymmetry analysis to identify early deficits.

PURPOSE: The multifocal visual evoked potential (VEP) shows markedly symmetrical responses between the two eyes of control subjects. Patients with glaucoma and patients considered at high risk for glaucoma were examined to determine if VEP asymmetry could be identified and used for diagnosis and detection of early damage. METHODS: Multifocal pattern VEP recordings were performed using a single channel bipolar occipital electrode position and the Visual Evoked Response Imaging System (VERIS). There were 125 subjects: 24 control subjects, 70 patients with glaucoma, and 31 patients considered at high risk for glaucoma. A between-eye relative asymmetry coefficient (RAC) was determined for each of the 60 test points in the VEP field. The RAC for patients with glaucoma and patients considered at risk for glaucoma were compared with values from control subjects. Correlation between Humphrey thresholds and RAC scores was performed. RESULTS: Patients with glaucoma and patients considered at risk for glaucoma both showed significantly larger mean quadrant RAC values. When point by point analysis was performed, 69 out of 70 scotomas were identified with a cluster of at least 3 points of P < 0.05. For those considered at high risk for glaucoma, 10 out of 31 patients had abnormal areas in the VEP field. There was a strong correlation (r = 0.82) between quadrantic RAC mean values and Humphrey quadrant threshold scores in an asymmetric glaucoma subgroup. Abnormal VEP responses were identified in parts of the visual field that were still normal on perimetry. CONCLUSIONS: Asymmetry analysis correctly identifies patients with glaucomatous field loss and shows abnormalities in many patients considered at high risk for glaucoma who still have normal fields. Asymmetry analysis is able to identify objectively the extent of glaucomatous damage and may be able to detect changes before subjective field loss occurs.

Adolescent↗
PubMed1999

Objective perimetry in glaucoma: recent advances with multifocal stimuli.

The introduction of multifocal stimulus recording has enhanced our ability to examine the human visual field with electrophysiologic techniques. We have adapted the multifocal pattern visual evoked potential (PVEP) to detect visual field loss. In glaucoma patients we sought to determine the extent to which the PVEP amplitudes correlate with perimetric thresholds. Multifocal pseudorandomly alternated pattern stimuli, which were cortically scaled in size, were presented with use of the VERIS-Scientific system. Bipolar occipital straddle electrode positions were used. The visual field up to 25 degrees of eccentricity was investigated. Forty-three glaucoma patients with reproducible visual field defects were tested. The bipolar PVEP corresponded well with Humphrey visual field defects, showing loss of signal in the scotoma area. For Humphrey quadrant threshold totals and PVEP quadrant amplitudes, the correlation coefficient was strong (r = 0.49, P < 0.0001). The multifocal PVEP demonstrates good correspondence with the topography of the visual field. This technique represents the first practical application of the multifocal PVEP to objective detection of visual field defects in glaucoma.

Chronic Disease↗
PubMed1998

Electrode position and the multi-focal visual-evoked potential: role in objective visual field assessment.

PURPOSE/METHODS: To improve the performance of visual-evoked potentials (VEP) in the assessment of the human visual field, the multi-focal cortically scaled pattern VEP was recorded up to 250 of eccentricity in normal subjects. Monopolar and varying bipolar electrode positions were used. RESULTS: The monopolar response was strongly biased towards the lower hemifield. Bipolar leads straddling the inion (2 cm above and below) achieved approximately equal signals from the upper and lower visual field. Division into sectors of similar wave-form augments the analysis compared with summed full-field responses. CONCLUSION: With this technique, the multi-focal VEP can be used to objectively assess the visual field.

Cerebral Cortex↗
PubMed1998

Multifocal topographic visual evoked potential: improving objective detection of local visual field defects.

PURPOSE: To investigate the relationships between the pattern stimulation of different parts of the visual field (up to 25 degrees of eccentricity), the electrode position, and the cortical response to improve objective detection of local visual field defects. METHODS: The human visual evoked potential (VEP) was assessed using multifocal pseudorandomly alternated pattern stimuli that were cortically scaled in size. Monopolar and bipolar electrode positions were used. The visual field was investigated up to 26 degrees of eccentricity. Twelve normal subjects and seven subjects with visual field defects of different nature were studied. RESULTS: Although the monopolar response is heavily biased toward the lower hemifield, bipolar leads overlying the active occipital cortex (straddling the inion) demonstrate good signals from all areas of the visual field tested. The amplitude is almost equal for the averaged upper and lower hemifields, but the polarity is opposite, causing partial cancellation of the full-field VEP. The degree of cancellation depends mainly on latency differences between the vertical hemifields. The bipolar VEP corresponded well with Humphrey visual field defects, and it showed a loss of signal in the scotoma area. CONCLUSIONS: The multifocal VEP demonstrates good correspondence with the topography of the visual field. Recording with occipital bipolar electrode placement is superior to standard monopolar recording. To avoid a full-field cancellation effect, a separate evaluation of upper and lower hemifields should be used for the best assessment of retinocortical pathways. This technique represents a significant step toward the possible application of the multifocal VEP to objective detection of local defects in the visual field.

Adult↗
PubMed1995

Congenital ptosis: results of surgical management.

PURPOSE: To determine the visual and cosmetic outcome following the surgical correction of isolated congenital ptosis. METHODS: A retrospective review of the outcome of isolated congenital ptosis corrected under the supervision of one surgeon at The Children's Hospital, Camperdown, between January 1983 and January 1993 was examined. Some 65 patients with 80 involved eyes were identified; 30 eyes underwent a levator resection procedure, 40 eyes underwent a brow suspension using donor stored fascia lata, and in 10 eyes a brow suspension was performed using mersilene mesh. RESULTS: In 78 eyes of 63 patients, a good cosmetic result was achieved. In two patients (two eyes) a poor cosmetic result was achieved. These two patients refused further surgery following an undercorrection of their initial ptosis. The recurrence rates for the primary procedures were 16.7% for levator resection procedures, 35% for brow suspension procedures using donor fascia lata, and 30% for brow suspension surgery using mersilene mesh. Some 35.3% of eyes following mersilene slings required further surgery for granulomas and exposed mersilene mesh compared with 6% having similar complications with stored fascia lata. Nine patients (11.25%) had reduced visual acuity (one line or more on the Snellen chart or its equivalent with the other tests used) on the operated side. Only one patient was found to have significant astigmatism. CONCLUSIONS: An acceptable cosmetic result was achieved with one operation in 75.3% of cases. In 20.8% of cases a second operation was required and in 3.9% of cases three or more operations were required. This series supports the view that where possible, levator resection is the preferred form of surgery to correct congenital ptosis. When the levator function is inadequate, brow suspension is performed. The use of donor fascia lata resulted in a good cosmetic appearance with a low occurrence of surgical side effects. Amblyopia, when strictly defined, occurred in 11.25% of eyes despite early surgery for severe cases and intensive amblyopia therapy. Management requires repeated follow up for early detection and introduction of occlusion therapy or surgical ptosis correction.

Adolescent↗
PubMed1990

Suicide prevention at a United States Navy training command.

In a 2-year retrospective study, suicide prevention efforts produced a significant reduction in suicide attempts at a U.S. Navy training command. Evidence was presented that suicide prevention may be a more pressing issue at training commands than operational commands. The approach described here focused on instructors rather than on the students who were the usual patients presenting with suicidal ideation or attempts. Instructors were taught how to identify and help individuals at risk and how to get help for them.

Adolescent↗
PubMedDate not supplied

Prednisone mood disorder with associated catatonia.

Since steroid-induced psychoses often appear as mood disorders and since catatonia may be associated with psychotic mood disorders, the possibility exists for a steroid-induced psychotic mood disorder to present with associated catatonia. In a computer review of the medical literature, however, I found no such cases in adult patients. This report is presented as a possible case of steroid-induced catatonia in a 62-year-old woman following treatment with melphalan, prednisone, and cimetidine for multiple myeloma of the IgA class with associated mild hypercalcemia.

Akathisia, Drug-Induced↗