Biomedical subjects

A Graham Fieggen

Publications and source records attributed to A Graham Fieggen.

4 recordsLinked to original sources

PubMed2026

Chiari I malformation.

Chiari I malformation (CM1), the most common structural hindbrain disorder in humans, is traditionally characterized by the downward displacement of the cerebellar tonsils through the foramen magnum. However, this definition does not reflect the variability in clinical presentation, natural history and treatment response of this disorder. Some individuals with minimal tonsillar descent have severe neurological symptoms and syringomyelia, whereas others with extensive descent remain asymptomatic. Emerging evidence from neuroimaging, developmental biology and human genetics indicates that CM1 is not a single anatomical entity but a spectrum of disorders resulting from disruptions in coordinated growth and homeostasis across the cerebellum, posterior fossa, craniocervical junction, cerebrospinal fluid and neurovascular systems. CM1 may be best understood as a disorder of disrupted developmental scaling, in which the tightly regulated relationships between cerebellar growth and cranial accommodation are altered within a dynamic neurovascular and cerebrospinal fluid environment. In this context, tonsillar herniation is a geometric consequence rather than the primary disease process. This Primer synthesizes current knowledge on the epidemiology, mechanisms, diagnosis and management of CM1 across the lifespan. We highlight advances in neuroimaging, genomics and phenomics that support a shift from anatomy-based definitions towards an integrated genomic-phenomic classification.

Humans↗

PubMed2005

Value of early follow-up CT in paediatric tuberculous meningitis.

BACKGROUND: The value of CT in the diagnosis of tuberculous meningitis (TBM) in children is well reported. Follow-up CT scanning for these patients is, however, not well described and, in particular, the value of early follow-up CT has not been addressed for children with TBM. OBJECTIVE: To assess the value of early follow-up CT in children with TBM in identifying diagnostic, prognostic and therapeutically relevant features of TBM. MATERIALS AND METHODS: A retrospective 4-year review of CT scans performed within 1 week and 1 month of initial CT in children with proven (CSF culture-positive) and probable TBM (CSF profile-positive but culture-negative) and comparison with initial CT for the diagnostic, prognostic and therapeutic CT features of TBM. RESULTS: The CT scans of 50 children were included (19 "definite" TBM; 31 "probable" TBM). Of these, 30 had CT scans performed within 1 week of the initial CT. On initial CT, 44 patients had basal enhancement. Only 24 patients had contrast medium-enhanced follow-up scans. Important findings include: 8 of 29 patients (who were not shunted) developed new hydrocephalus. New infarcts developed in 24 patients; 45% of those who did not have infarction initially developed new infarcts. Three of the six patients who did not show basal enhancement on initial scans developed this on the follow-up scans, while in seven patients with pre-existing basal enhancement this became more pronounced. Two patients developed hyperdensity in the cisterns on non-contrast medium scans. Eight patients developed a diagnostic triad of features. Three patients developed CT features of TBM where there was none on the initial scans. CONCLUSIONS: Early follow-up CT is useful in making a diagnosis of TBM by demonstrating features that were not present initially and by demonstrating more sensitive, obvious or additional features of TBM. In addition, follow-up CT is valuable as a prognostic indicator as it demonstrates additional infarcts which may have developed or become more visible since the initial study. Lastly, follow-up CT has therapeutic value in demonstrating hydrocephalus, which may develop over time and may require drainage. We advise routine follow-up CT in patients with suspected TBM within the first week of initial CT and optionally at 1 month.

Adolescent↗

PubMed2004

Ischiopagus and pygopagus conjoined twins: neurosurgical considerations.

BACKGROUND: Neurosurgeons are familiar with the challenges presented by craniopagus twins, but other types of conjoined twins may also have neurosurgical implications. We report our experience in the management of ischiopagus and pygopagus conjoined twins. METHODS: This is a retrospective review of the management of conjoined twins at Red Cross Children's Hospital in Cape Town, South Africa. RESULTS: Twenty-three pairs of symmetrical conjoined twins were managed over a 40-year period (1964-2003), of which 16 (70%) were separated. Of these cases, 6 are the focus of this study, namely 4 pairs of ischiopagus twins and 2 pairs of pygopagus twins seen between 1993 and 2003. In 2 cases, there was direct involvement of the nervous system at the site of union, with 1 pair of ischiopagi manifesting end-to-end union of their spinal cords, while a pair of pygopagi had back-to-back fusion of the conus. Another pair of ischiopagi had a fused dural sac without joined neural elements, but one of these children developed syringomyelia 2 years after separation. Neuroimaging was invaluable in detecting these abnormalities. The one pair of ischiopagi who died before separation were HIV positive and had severe brain atrophy and cystic encephalmalacia at autopsy. Nine of the 12 children (75%) had bony abnormalities of the spine remote from the area of conjunction. The most common finding was the presence of hemivertebrae, usually in the thoracic spine. Six children manifested scoliosis, which has already progressed in the oldest two. Technical aspects such as timing and sequence of separation, the division of neural tissues and reconstruction are discussed, as are the long-term complications of their spinal abnormalities. CONCLUSIONS: Ischiopagus and pygopagus conjoined twins manifest an interesting array of spinal abnormalities, which present challenges, not only at the time of separation, but also in their long-term management.

Buttocks↗

PubMed2003

Craniocerebral gunshot injuries in children.

INTRODUCTION: Despite the worldwide increase in the incidence of gunshot injuries, there are few large published series on craniocerebral gunshot injuries in children. MATERIALS AND METHODS: The records of 30 consecutive children who were treated for craniocerebral gunshot injuries at the Red Cross War Memorial Children's Hospital from 1989 to 2002 were reviewed retrospectively. The circumstances of the injury, clinical status, CT findings, complications, and outcome were assessed. RESULTS: The median age was 7 years. Seventy-seven percent of the victims were boys. The majority of the children were injured in the crossfire of civilian violence. The initial management consisted of debridement under local anesthesia in 16 children and neurosurgical procedures under general anesthesia were performed in 14. Sixteen children sustained transhemispheric injuries, 5 bihemispheric injuries, 5 tangential injuries, and 4 transventricular injuries. All 3 children with a GCS <4 died within 72 h of admission. Three of the 7 children with GCS 4-7 died but there were no deaths in those children whose GCS was >7 post-resuscitation. Motor deficits, cranial nerve palsies, and visual field defects were very common. Early post-traumatic seizures were the commonest complication (18%). CONCLUSION: Children with higher post-resuscitation GCSs fared better than adults in terms of mortality but not necessarily morbidity. As in the case with adults, the GCS after resuscitation is a very good prognostic indicator of mortality.

Adolescent↗