Biomedical subjects

William Harkness

Publications and source records attributed to William Harkness.

6 recordsLinked to original sources

PubMed2003

Intraventricular migration of a Rickham reservoir: endoscopic retrieval.

CASE REPORT: An unusual case of the intraventricular migration of a Rickham reservoir in a child and its subsequent removal by endoscopy is described. A newborn boy presenting with hydrocephalus secondary to intraventricular haemorrhage, had a Rickham reservoir inserted through a frontal burr hole, made adjacent to the anterior fontanel. Later, serial CT scans of the brain over a 3-year period revealed progressive migration of the Rickham reservoir into the lateral ventricle and then into the third ventricle. As the ventricles were also enlarged, they were explored endoscopically and the Rickham reservoir was removed. DISCUSSION: Intracranial migration of a Rickham reservoir is rare. It is suggested that the placement of a small burr hole, away from the fontanels and growing sutures and the use of anchoring sutures to hold the reservoir to the periosteum are important steps in avoiding this unusual complication.

Cerebral Hemorrhage↗

PubMed2003

Current status of surgery in the management of epilepsy.

PURPOSE: To review systematically the available evidence with regard to the current status of epilepsy surgery in the management of patients with epilepsy. METHODS: A careful search of published literature, including Medline, published reviews, chapters, and cross-references thereof. RESULTS: With medical treatment of epilepsy being unsuccessful in many cases, the importance of surgical approaches cannot be underscored. Early surgery is the treatment of choice for patients with clear-cut mesial temporal sclerosis and results in significant clinical improvement in up to 80% of cases, provided the EEG, neuropsychological, and neuropsychiatric results are in concordance with this approach. In patients with poorly defined, widespread, or dual pathology, however, invasive recordings may be necessary, and while this is performed in major centres, the outcome is rather more variable in this group. Improved surgical techniques, and the use of stereotactic approaches and image guidance procedures, have resulted in surgical resections becoming more selective. With isolated structural lesions such as dysembryoplastic tumours, low-grade astrocytomas, or focal vascular abnormalities, total macroscopic and radiological evidence of lesional excision is associated with excellent seizure-free outcome. The first randomised controlled trial of epilepsy surgery has demonstrated clearly the efficacy of these techniques, and the risk of complications. DISCUSSION: Increasing sophistication of noninvasive presurgical evaluation enables surgical candidates to be identified at an earlier stage and presents a realistic alternative to medical treatment in many cases. The introduction of minimally invasive techniques has had a significant impact on surgical practice and its associated morbidity. The future of epilepsy surgery lies with continued basic science research and its application to clinical medicine.

Epilepsy↗

PubMed2002

Diffusion tensor imaging in refractory epilepsy.

Diffusion tensor imaging is an imaging method that is sensitive to the molecular movement of water, which indicates cellular integrity and pathology. A patient with refractory epilepsy and normal conventional MRI was examined with diffusion tensor imaging. An area of abnormal diffusion in the right frontal lobe was identified and surgically resected. The patient had a good clinical outcome. Histopathological examination of the resected tissue showed gliosis. Our findings may affect the investigation of similar patients, and provide histopathological confirmation of diffusion abnormalities.

Adult↗

PubMed2002

Cytoarchitectural abnormalities in hippocampal sclerosis.

Hippocampal sclerosis (HS) is the most common pathological substrate for temporal lobe epilepsy with a characteristic pattern of loss of principle neurons primarily in CA1 and hilar subfields. Other cytoarchitectural abnormalities have been identified in human HS specimens, including dispersion of dentate granule cells and cytoskeletal abnormalities in residual hilar cells. The incidence of these features, their relationship to the severity of HS and potential indication of underlying hippocampal maldevelopment is unverified. In a series of 183 hippocampectomies we identified classical HS (grades 3 and 4) in 90% of specimens, granule cell disorganization or severe dispersion in 40% of cases with a bilaminar pattern in 10%, and cytoskeletal abnormalities in hilar cells in 55% of cases. The severity of granule cell disorganization correlated closely with the degree of hippocampal neuronal loss but not with the age at first seizure or a history of a precipitating event for epilepsy such as prolonged febrile seizures. These findings suggest that granule cell disorganization is closely linked with the progression of HS rather than a hallmark of impaired hippocampal maturation. Furthermore, stereological quantitation of granule cells showed evidence of cell loss but greater numbers in regions of maximal dispersion, which may indicate enhanced neurogenesis of these cells. Quantitation of reelin-and calretinin-positive Cajal-Retzius cells in the dentate gyrus molecular layer in 26 cases showed no correlation between the number of these cells and the severity of granule cell dispersion, but increased numbers of these cells were present in HS with respect to control groups. Although a role for Cajal-Retzius cells is therefore not implicated in the mechanism of granule cell disorganization, their excess number may be indicative of underlying hippocampal maldevelopment in HS.

Adolescent↗

PubMed2002

Intractable epilepsy and olfactory bulb hamartoma. A case report.

The objective of this case report is to demonstrate that a benign tumour arising solely from the olfactory bulb can act as a primary epileptic focus and to illustrate the difficulty in making a preoperative diagnosis of pathological lesions in this area. The case of a 29-year-old male with intractable epilepsy is presented. Radiological imaging demonstrated a conspicuous, calcified lesion in the mesial inferior frontal lobe. Electroclinical findings confirmed this to be the epileptogenic zone. Surgery and subsequent histology surprisingly revealed this focal lesion to be a benign hamartoma arising solely from the olfactory bulb. Resection resulted in seizure resolution. Tumours of the olfactory apparatus are extremely rare, but can present with epilepsy.

Adult↗

PubMed2002

Surgical procedures for posterior fossa tumors in children: does craniotomy lead to fewer complications than craniectomy?

OBJECT: Traditionally, access to the posterior fossa involved a suboccipital craniectomy. More recently, posterior fossa craniotomies have been described, although the long-term benefits of this procedure are not clear. The authors compared the postoperative complications of craniectomies and craniotomies in children with posterior fossa tumors. METHODS: From a total of 110 children undergoing surgery for posterior fossa tumors, 56 underwent craniectomy and 54 had a craniotomy. The mean duration of the hospital stay was longer in the craniectomy group (17.5 compared with 14 days). At operation, similar numbers of patients in both groups had total macroscopic clearance of the tumor, complete dural closure, and duraplasty. Postoperatively, more patients in the craniectomy group were noted to have cerebrospinal fluid (CSF) leakage (27 compared with 4%; p < 0.01) and pseudomeningoceles (23 compared with 9%; p < 0.05). There was no significant difference between the two groups in the numbers of patients with CSF infections, wound infections, or hydrocephalus requiring permanent CSF drainage. Patients with CSF leaks had a longer duration of hospital stay (20.7 compared with 14.9 days; p < 0.01), and were more likely to have CSF infections (35 compared with 12%; p < 0.01) and wound infections (24 compared with 1%; p < 0.01) than patients without CSF leaks. Postoperatively, wound exploration and reclosures for CSF leakage were more likely in the craniectomy group (11 compared with 0%; p < 0.01). Multivariate analysis revealed that the only predictor of CSF leakage postoperatively was the type of surgery (that is, craniotomy compared with craniectomy; odds ratio 10.8; p = 0.03). CONCLUSIONS: Craniectomy was associated with postoperative CSF leaks, pseudomeningocele, increased wound reclosures, and thus prolonged hospital stays. In turn, CSF leakage was associated with infections of the CSF and wound. The authors propose mechanisms that may explain why CSF leakage is less likely if the bone flap is replaced.

Cerebrospinal Fluid↗