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Biomedical subjects

D C McCullough

Publications and source records attributed to D C McCullough.

At least 37 records · Page 2Linked to original sources
PubMed1981

Real-time ultrasonography of neonatal intraventricular hemorrhage and comparison with computed tomography.

Thirty-three low-birth-weight neonates were diagnosed prospectively as having an intraventricular hemorrhage, using a real-time sonographic sector scanner. Ultrasound findings were corroborated in 27 patients by computed tomography (CT) or autopsy. Intraventricular blood is hyperechoic and, in a fresh hemorrhage, a continuous cast-like pattern of increased echogenicity replaces the usually minute, echo-free lateral ventricles. After one to three days, the lateral ventricles begin to enlarge around the echogenic clot if hydrocephalus complicates the hemorrhage. The sonographic findings indicating intraventricular hemorrhage and its progression to hydrocephalus are presented. The accuracy of sonographic real-time sector scanning in the evaluation of neonatal intraventricular hemorrhage is discussed and compared to CT.

Cerebral Hemorrhage↗
PubMed1981

Real-time sonography of the neonatal and infant head.

Fifty neonatal and infant heads were examined using a 5 MHz real-time sector scanner. Anatomic detail superior to that previously described was achieved by this method. Normal structures routinely imaged included the entire ventricular system and many parts of the subarachnoid spaces. The gray scale detail of parenchymal structures was usefully demonstrated. Routinely visualized vascular structures included the anterior cerebral artery system, the middle cerebral arteries, the choroid plexus, and the posterior cerebral arteries. Hydrocephalus, as well as intraventricular hemorrhage and its sequelae, were investigated. Computed tomography (CT) is considered diagnostic in hydrocephalus and intraventricular hemorrhage, but evaluation by sonography compares favorably. Among other advantages of sonography are the feasibility of bedside scans without removing the patient from the intensive care nursery and the elimination of ionizing radiation.

Cerebral Angiography↗
PubMed1980

New phenotypic variant of adrenoleukodystrophy. Pathologic, ultrastructural, and biochemical study in two brothers.

Adrenoleukodystrophy is not usually considered in the differential diagnosis of the infantile onset of failure to thrive with motor and intellectual retardation. Rather, symptoms have started in childhood and have progressed over some years; not all patients have had overt adrenocortical insufficiency. The two brothers reported here developed symptoms in the neonatal period. In each the nature of the primary cerebral disorder was not recognized, because other etiologic factors clouded the diagnostic studies. In the younger brother, Case 1, a high titer (1:256) for cytomegalovirus (CMV) led to the suspicion that CMV infection accounted for the neurologic and ophthalmologic findings. Progressive neurologic deterioration at the age of 6 years prompted brain biopsy to confirm the diagnosis of progressive CMV encephalitis. In the older brother, Case 2, hemogenic hydrocephalus due to traumatic birth injury was held responsible for the psychomotor retardation and cerebral palsy. At necropsy, the adrenal glands in both cases were severly atrophic. In Case 1, a markedly inflammatory leukodystrophic process affected chiefly the frontal centra semiovalia and internal capsules, with relative sparing of parieto-occipital white matter and subcortical U-fibers. Heavy lymphocyte and monocyte cuffs surrounded many blood vessels in the white matter, and oil-red-O and PAS-positive macrophages were scattered in the zones of myelin disintegration and loss. Focally, the leukodystrophic process was so intense that cavitation necrosis was present, especially in the internal capsules. Further, PAS-positive, striated macrophages were aggregated in large clusters in liver, spleen, and lymph nodes. At the ultrastructural level, linear and gently arced, parallel, coapted or widely separated leaflets measuring 3-4 nm in width were identified in macrophages of the brain biopsy and in autopsy liver and lymph node. Biochemical analysis of fresh, frozen autopsy brain demonstrated cholesterol esters with long-chain fatty acids by thin-layer and gas-liquid chromatography. In Case 2, the leukodystrophic process could be readily identified in the brainstem and cerebellum but was masked in the cerebral hemispheres by the extensive hydrocephalus. The adrenal glands were atrophic and at light microscopy revealed adenomatoid nodules, many ballooned coritcal cells and very rare cells with striated cytoplasm. Masses of PAS-positive macrophages were encountered in liver and lymph nodes. In both cases, only old Wallerian degeneration of the corticospinal tracts was found in the spinal cord.

Adrenal Cortex↗
PubMed1980

Computed tomography in the hydrocephalic patient after shunting.

The interpretation of postshunt computed tomographic (CT) scans of hydrocephalic patients presents numerous difficulties unless the interpreter has a thorough knowledge of the clinical symptoms, type and cause of hydrocephalus, preshunt morphology of ventricles and subarachnoid spaces, possible complications of shunt placement, and signs of shunt failure. A review of 368 scans from 108 hydrocephalic patients included subgroup statistical analysis of the development of ventricular asymmetry and of subarachnoid space changes after shunting. The situation and appearance of ventricular catheters were quite variable. Subarachnoid space enlargement after shunting usually was related to long-standing high-grade ventriculomegaly, and was observed most commonly in congenital or acquired nonneoplastic hydrocephalus with little relationship to the site of blockage. Ventricular asymmetry developed in one third of the cases and was related to the site of the shunt catheter tip. Preshunt asymmetry persisted in spite of shunt placement in the larger ventricle. Accurate diagnosis of shunt failure usually required baseline CT studies, correlation with clinical findings, and, in some cases, serial scans.

Adolescent↗
PubMed1980

A critical evaluation of continuous intracranial pressure monitoring in pediatric hydrocephalus.

An evaluation of continuous intracranial pressure (ICP) monitoring in 42 hydrocephalic infants and children helps to establish the role of this method in comparison with other clinical techniques for estimating the occurrence of progressive hydrocephalus. Transducer monitoring via ventricular catheters in term and premature infants revealed average ICP in the 5--12 mm Hg range. The higher values were recorded from patients with noncommunicating hydrocephalus but did not correlate with the extent of ventriculomagaly. The method has very litte predictive value in estimating the progressive nature of infantile hydrocephalus. In older children ICP monitoring provides a useful adjunct in decisions for shunting after intracranial surgery and in suspected 'normal pressure' hydrocephalus. Monitoring from shunt reservoirs in cases of suspected shunt obstruction, although accurate in most situations, is probably inferior to clinical examination and serial computed tomography considering the expense and the risk of introducing shunt sepsis.

Adolescent↗
PubMed1980

Antibiotic prophylaxis in ventricular shunt surgery. II. Antibiotic concentrations in cerebrospinal fluid.

Investigation of cerebrospinal fluid (CSF) antibiotic levels from patients operated upon under short-term prophylactic protocols for shunt insertions or revisions revealed low-level CSF penetration by nafcillin and virtually no methicillin activity. Nafcillin levels were not influenced by route of injection or CSF sampling time, but were inversely proportional to ventricular size. The authors recommend nafcillin over methicillin as the preferred prophylactic agent in shunt surgery. Although the 25 mg/kg preoperative dose may be adequate for reducing infection risk, higher dosages should be considered when the ventricles are markedly dilated.

Cerebrospinal Fluid Shunts↗
PubMed1980

Large arachnoid cysts at the cranial base.

Two infants who presented with macrocephaly had very large noncommunicating cysts at the cranial base that were displacing the brain. Only one of the patients was hydrocephalic; he eventually underwent ventriculoperitoneal shunting after craniotomy and attempted internal drainage of the cyst. The other infant had a cystoperitoneal shunt. Both have done well after 4 and 6 years of follow-up, respectively. These large arachnoid cysts are bilateral lesions with the potential for severe surgical complications and a questionable possibility of cure. The authors recommend systematic radiological investigation to decide the appropriate therapy, including an analysis of the patency of the subarachnoid pathways with radionuclide cisternography and cystography. Simple cystoperitoneal shunting may be the appropriate therapy for most of these large lesions. (Neurosurgery, 6: 76--81, 1980).

Arachnoid↗
PubMed1980

Antibiotic prophylaxis in ventricular shunt surgery. I. Reduction of operative infection rates with methicillin.

Administration of prophylactic antibiotics is not a proven or universal practice in cerebrospinal fluid (CSF) shunt surgery although case and operative infection rates in hydrocephalic patients average 20 and 8%, respectively. In sequential series from 1969 through 1978 the authors achieved a reduction in case infection rates from 10.9 to 8.9% and in operative infections from 8 to 2.6% with the use of short-term prophylactic methicillin. Comparison of these results to those of other reported series supports the case for short-term prophylactic antibiotics in shunt surgery. Further reduction in shunt sepsis may be possible with the appropriate selection of other semisynthetic penicillins which achieve higher levels in CSF.

Bacterial Infections↗
PubMed1979

Unilateral megalencephaly, cerebral cortical dysplasia, neuronal hypertrophy, and heterotopia: cytomorphometric, fluorometric cytochemical, and biochemical analyses.

A 13-month-old boy with intractable seizures, left hemiparesis, and psychomotor retardation due to right unilateral megalencephaly, died in hypovolemic shock 1 day after hemispherectomy. The gyral pattern of the hypermegalic hemisphere was simplified and coarse. The cortical cytoarchitecture was disarrayed by a population of giant neurons. Hippocampus and calcarine cortex were cytoarchitectonically normal, as was the entire left cerebral hemisphere. Neuronal heterotopias were present in the right centrum semiovale and both cerebellar hemispheres. Cytomorphometric study of parietal cortex of each cerebral hemisphere revealed a 4-fold increase in neuronal nuclear, and 11-fold increase in neuronal nucleolar, volume in the hypermegalic hemisphere, whereas glial nuclear volume was only one-third as great, in part because of edema of the left hemisphere. Microfluorometric cytochemical analysis demonstrated a 16% increase in neuronal DNA, 40% increase in total neuronal RNA, 12% increase in glial DNA, and 15% increase in glial RNA on the right. Biochemical analysis of tissue extracts disclosed increases in the right hemisphere of 40%, 56%, and 66%, respectively, for DNA, RNA, and protein. The data suggest heteroploidy of chromosomal DNA and enhanced transcription and translation in the hypermegalic hemisphere. Thus, a defect in regulation of cell metabolism may account for the morphologic and clinical abnormalities.

Brain↗
PubMed1979

Herpes simplex type 2 encephalitis concurrent with known cerebral metastases.

A 62-year-old woman developed neurologic deficits 7 months after pulmonary lobectomy for alveolar cell carcinoma of the lung. CT scan of the head demonstrated two metastases with marked peritumoral edema. Administration of Decadron, chemotherapy and 3,000 rad cranial radiation resulted in dramatic improvement of dysphasia and right hand paresis. Almost 2 months later, rhythmic, involuntary movements of the left hand developed. There was progression to multifocal seizures, grand mal seizures, postictal depression, status epilepticus, and coma, with death 9 days after onset of the movement disorder. Bronchoalveolar carcinoma was widely disseminated in lungs and bones, and as three metastases in brain. Bland "ischemic" necrosis in a pseudolaminar pattern was present in the neocortex. Innumerable Cowdry type A intranuclear inclusion bodies were seen in neurons, astrocytes, and oligodenodroglia. Immunofluorescence demonstrated Herpes simplex virus type 2 antigen and electron microscopy revealed virions with the morphology of the Herpes group. The case is significant for (1) the concurrence of intracranial metastases and Herpes simplex encephalitis, and (2) the causal agent, Herpes simplex virus type 2. The implication for the clinical neurocientist is the potential in a patient with systemic cancer, for the causation of neurologic complications by more than one factor or mechanism.

Adenocarcinoma, Bronchiolo-Alveolar↗
PubMed1979

Correlation between volumetric CT imaging and autopsy measurements of glioblastoma size.

A three-dimensional reconstruction and display technique (THREAD SYSTEM) for serial computed tomography (CT) was employed in monitoring tumor volumes in two children under chemotherapy for glioblastoma multiforme of the cerebral hemispheres. Progressive diminution of tumor bulk was documented in the first patient and an increase in volume in the second. The first patient expired of the complications of his therapy and the second of transtentorial herniation. Independent measurements of the tumors as determined by a CT scan near the times of death and tumor dimensions measured at autopsy revealed good correlations between the radiographic and the anatomical data. The final CT measurement of tumor volume of 20 cm3 compared with an autopsy calculation of 13.3 cm3 in the first case. In the second case, CT volume was 417 cm3 and the actual volume of the primary tumor mass at autopsy was 437 cm3. The results suggest that the THREAD system is a practical method for monitoring the results of radiotherapy and chemotherapy in certain types of cerebral neoplasms.

Adolescent↗
PubMed1978

Sacral rootlet rhizotomy at the conus medullaris for hypertonic neurogenic bladder.

Three patients with spastic neurogenic bladder underwent sacral root stimulation and appropriate section of motor rootlets to the detrusor at the levels of the conus medullaris. Compared to the results obtained with rhizotomies at the sacral levels in a previous series of patients, urinary frequency and infection were inhibited for longer periods of time, but some uninhibited bladder activity recurred in all three patients. Analysis of anatomical and electrophysiological data serves to emphasize the complexity and asymmetry of efferent supply to detrusor muscle. The authors conclude that the role of selective rhizotomy for inhibition of the spastic bladder is inconclusive, and perhaps a combination of surgery and medications that inhibit smooth-muscle contraction may be required for long-term protection of urinary collection systems.

Adult↗
PubMed1977

Computed cranial tomography and radionuclide cisternography in hydrocephalus.

Computerized Cranial Tomographic scanning has replaced radionuclide cisternography in screening both adult and pediatric patients for hydrocephalus. Nevertheless, cisternography provides indispensable information about the CSF clearance capacity and remains a valuable adjunct to the excellent anatomic detail provided by CCT scans. In patients without emergency symptoms, cisternography provides the best indication as to whether or not diversionary shunting is likely to relieve the patient's symptoms.

Adult↗
PubMed1977

Computerized axial tomography in clinical pediatrics.

Computerized axial tomography (CAT), a noninvasive radiologie method, provides a new dimension in screening and diagnosis of intracranial pathology. Evaluation of 725 scans in infants and children demonstrates that CAT may be performed with negligible risk, although sedation and restraint are essential to the successful performance of studies in children under 6 years of age. CAT is the preferred initial diagnostic method in suspected hydrocephalls and is accurate in the detection and precise localization of brain tumors. The management of hydrocephalus and brain tumors has been significantly altered by the availability of CAT. Few invasive neuroradiologic procedures are required and pneumography is especially curtailed. Serial scanning is the best available method of monitoring ventricular alterations in hydrocephalus, tumor size during radiotherapy or chemotherapy, and postoperative recurrence of benign neoplasms. Complex intracranial anomalies are detectable with computerized tomography, but complete definition of pathology often requires angiography and air studies. Limited clinical experience in detecting neonatal intraventricular hemorrhage suggests that CAT will be a valuable tool for futlre investigations of that problem.

Adolescent↗
PubMed1975

Observations on patients with neural-tube defects in a metropolitan hospital clinic: an epidemiological history.

A survey of the population of the Spina Bifida Service (107 patients) of Georgetown University Hospital, Washington, D.C., and of a control population in the same hospital revealed that, although situated in an ethnically heterogeneous area, Service patients with a history of neural-tube defects in siblings or family significantly more often had ancestors on both sides from the British Isles than did either isolated cases or the controls. In addition, of 107 families reviewed, nine had more than one affected child, nine had a positive family history for neural-tube defects, and nine of the patients and seven of an estimated total of 220 siblings had an unrelated major birth-defect. These incidences are among the highest published so far. Contrary to other surveys, there was no deficiency of twinning among the sibships, nor of males among the Spina Bifida Service patients. These observations indicate the desirability of studying each population of patients with neural-tube defects in order to provide more realistic counseling and so that clues may be gathered as to the genetic mechanisms and environmental factors which led to the production of such defects.

Consanguinity↗
PubMed1975

Selective sacral rootlet rhizotomy for hypertonic neurogenic bladder.

The authors describe a highly selective transsacral microsurgical procedure for sacral nerve rootlet interruption in five patients with hypertonic neurogenic bladder. Magnification and systematic stimulation of sacral roots provided accurate identification of motor fibers supplying bladder detrusor muscle and differentiation of efferent components to the legs and anal sphincter. Although the technique prevented incontinence and adverse effects of nerve section on rectal and lower extremity function improvement in voiding patterns and diminution of urinary sepsis was of brief duration in three of the five patients. Physiological data from these procedures reaffirms the importance of S-3 and S-4 motor roots in detrusor innervation, but clinical responses bring into question the possibility of sustained improvement from such a highly selective procedure at the sacral level. The authors suggest that alternative pathways, not apparent on initial stimulation, may develop after section of sacral root components, and that dissection and stimulation of fibers at the level of the conus medullaris should be investigated as an alternative procedure.

Adult↗
PubMed1973

Effect of cerebrospinal fluid shunts on intracranial pressure and on cerebrospinal fluid dynamics. 2. A new technique of pressure measurements: results and concepts. 3. A concept of hydrocephalus.

Part 2 describes measurements of intracranial cerebrospinal fluid (CSF) pressure in 18 adult patients with CSF shunts, all pressure measurements being referred to a horizontal plane close to the foramina of Monro. All 18 patients had normal CSF pressure by lumbar puncture; however, in one patient an intracranial pressure of +280 mm was subsequently measured after pneumoencephalography. Twelve patients had pre-shunt CSF pressures measured intracranially: 11 ranged from +20 to +180 mm H(2)O and one was +280 mm H(2)O in the supine position. In the upright posture nine patients had values of -10 to -140 mm H(2)O, while three others were +60, +70, and +280 mm H(2)O. After CSF shunting in these 18 patients the pressures were -30 to +30 mm H(2)O in the supine position and -210 to -370 mm in the upright position. The effect of posture on the siphoning action of these longer shunts in the erect, adult patient is a major uncontrollable variable in maintenance of intracranial pressure after shunting. Other significant variables are reviewed. In Part 3 a concept of the hydrocephalus phenomenon is described. Emphasis is placed on the pressure differential (P(d)) and force differential (F(d)) causing pre-shunt ventricular enlargement and post-shunt ventricular size reduction. The site of P(d), which must be very small and not to be confused with measured ventricular pressure, P, must be at the ventricular wall.

Adult↗