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Biomedical subjects

D E Sakas

Publications and source records attributed to D E Sakas.

At least 19 recordsLinked to original sources
PubMed2006

Symptomatic syringomyelia secondary to clinically obscure infratentorial tumour.

The formation of a cervical spinal cord syrinx as a result of an infratentorial mass, even though uncommon, has been reported in international literature. In such cases, syringomyelia is usually asymptomatic, while the tumour-related symptoms and signs predominate. We report a patient with a posterior fossa tumour and secondary syringomyelia. In this patient, syringomyelia symptoms and signs were present, and a cervical spine Magnetic Resonance Imaging (MRI) showed a large cervical syrinx. A more careful clinical examination though, revealed a sub-clinical posterior fossa syndrome and brain MRI revealed a large infratentorial meningioma. A posterior fossa craniotomy was performed, followed by complete tumour resection and almost complete remission of the syrinx and its related symptoms. The authors discuss the role of posterior fossa tumour induced tonsillar herniation in the development of secondary syringomyelia, the mechanisms leading to syrinx formation and the conditions that must be fulfilled for that to happen.

Female↗
PubMed2006

Serum S-100B protein as a biochemical marker of brain injury: a review of current concepts.

S-100 protein, described initially by Moore, constitutes a large family of at least 20 proteins with calcium binding ability. It is found as homo- or hetero-dimers of two different subunits (A and B). Types S-100AB and S-100BB are described as S-100B protein and are shown to be highly specific for nervous tissue. It is present in the cytosol of glial and Schwann cells, and also in adipocytes and chondrocytes, although in very low concentrations in the latter two. The role of protein S-100B is not yet fully understood. It is suggested that it has intracellular and extracellular neurotropic as well as neurotoxic function. At nanomolar levels, S-100B stimulates neurite outgrowth and enhances survival of neurons. However, at micromolar levels it stimulates the expression of inflammatory cytokines and induces apoptosis. Recently, serum S-100B protein has been proved to be an attractive surrogate marker of primary severe brain injury and secondary insults. It can be measured in the arterial and venous serum; it is not affected by haemolysis and remains stable for several hours without the need for immediate analysis. Its short half-life makes measurements crucial in the emergency and intensive care settings. This review summarises published findings on S-100B regarding its role as a serum biochemical marker of brain injury, i.e., after severe, moderate or mild neuro-trauma, subarachnoid haemorrhage, thrombo-embolic stroke, cerebral ischaemia and brain tumours, as well as extracranial trauma, neurodegenerative and psychiatric disorders.

Brain Injuries↗
PubMed2005

Chiari malformation: CSF flow dynamics in the craniocervical junction and syrinx.

BACKGROUND: A CSF flow study in patients with Chiari malformation (ChM) who undergo craniocervical junction decompression (CCJD). METHODS: Using spatial modulation of magnetization (SPAMM), cerebrospinal fluid (CSF) flow velocities were measured at the prepontine (PP), anterior cervical (AC), and posterior cervical (PC) subarachnoid spaces (SAS) in healthy subjects (n = 11) and patients with Chiari malformation (ChM) before and/or after CCJD (n = 15). In the syringes, the intrasyrigeal pulsatile CSF motion was estimated qualitatively as present or absent. FINDINGS: In normal subjects, the mean CSF velocities were 2.4 +/- 0.2 cm/s (PP), 2.8 +/- 0.3 cm/s (AC), and 2.4 +/- 0.2 cm/s (PC). Velocities were significantly lower than normal in patients with ChM prior to CCJD, reduced by 38%, 25%, and 79% in the 3 regions, respectively (P<0.001). Post-CCJD, velocities were 20% (PP), 100% (AC), and 40% (PC) greater than preoperatively (P<0.001). CONCLUSIONS: In ChM, the posterior cervical CSF flow velocity was low, increased minimally after CCJD and, by itself, had limited predictive value. Post-CCJD, an increase of the sum of anterior and posterior cervical CSF flow velocities by more than 20% consistently preceded or coincided with marked headache improvement. After CCJD, the finding that the intrasyringeal CSF pulsatile motion had become absent was an earlier and more sensitive predictor of motor or sensory improvement than a reduction in syrinx's size. SPAMM can be used to assess whether CCJD has restored CSF flow, predict outcome and provide pathophysiological insights in ChM and syringomyelia.

Adolescent↗
PubMed2005

Selection of cranial site for shunting debilitated patients.

BACKGROUND/OBJECTIVE: The optimum cranial site for ventricular catheter insertion in CSF shunts is still under debate and there has been no general consensus as far as surgical technicalities are concerned. Furthermore, there have been no reports dealing with appropriate cranial site selection in debilitated patients. The aim of this report is to stress the need to utilize a frontal approach when dealing with patients who are likely to remain bed-bound for long periods and to emphasize the well-known prerequisites such as meticulous surgical technique and peri-operative general and local care. METHOD: A retrospective analysis of all shunt operations and revisions performed in our department during the last 6 years. FINDINGS: This analysis revealed 8 long-term recumbent patients with late valve extrusion (N1 = 5) or primary wound breakdown (N2 = 3), all through the occipital area. Extended periods of bed rest due to neurological disease combined with poor nursing and dietary intake had led to either chronic valve extrusion or wound breakdown. Shunt revision was performed successfully by a frontal approach in 5 whereas 2 tolerated shunt removal and one died of meningitis. CONCLUSION: In debilitated patients or those who are likely to remain bed-bound for long periods, a frontal approach for proximal catheter insertion may help prevent immediate postoperative wound breakdown or late valve extrusion.

Adult↗
PubMed2005

Primitive supratentorial neuroectodermal tumor in an adult.

We report the case of a 32-year-old female with a diagnosis of supratentorial tumour. Total removal of the tumour was achieved in a two-stage procedure. Histopathology revealed a primitive neuroectodermal tumour (PNET), an unusual and highly malignant, mainly infratentorial tumour of childhood that is uncommonly described in the supratentorial compartment of adults. We review the literature and describe the existing knowledge of these tumours.

Adult↗
PubMed2005

Spontaneous subarachnoid haemorrhage in the era of transition from surgery to embolization. A study of the overall outcome.

The aim of the investigation was to evaluate the outcome of spontaneous subarachnoid haemorrhage, in the era of new techniques, patient centralization and subspecialization, by taking into account the local conditions in Greece. A prospective observational study was conducted during a 4-year period. All patients with a first-ever spontaneous subarachnoid haemorrhage were enrolled. Clinical, management and outcome data were recorded. Two-hundred-and-eighteen consecutive patients with an 81% good, medium clinical grade (Hunt & Hess I-III) were identified. Rebleed and rebleed leading to death rates were 22 and 11%, respectively. Permanent deficit or death from vasospasm was 15%. Twenty-eight per cent of the study population died early, were unsuitable for further management (poor clinical status, advanced age) or declined angiography or treatment, and another 22% had a negative angiogram. The remaining 50% underwent intervention (neurosurgical/endovascular), for obliteration of an aneurysm. The overall favourable 6-month outcome was 59%, whereas the favourable outcome of the intervention group was 70%. Our results confirm the findings of previous series. The relatively worse results are due to delayed referral, and lack of availability of surgical or endovascular management in the early post-haemorrhage period (28% of the patients), particularly in potentially salvageable cases. On the basis of these observations, we recommend early intervention (surgery or embolization) and centralization/subspecialization, in order to improve the outcome.

Adolescent↗
PubMed2004

Infected CNS infusion pumps. Is there a chance for treatment without removal?

BACKGROUND: Intrathecal baclofen administration by means of an implantable pump is nowadays a safe and effective method in the treatment of spasticity. One of the rare but devastating complications of this technique is pump infection, with a variety of Gram (-) and Gram (+) organisms being involved. Treatment of these infections, according to international literature, requires removal of the device and appropriate antibiotic therapy. METHOD: This article reports the authors experience in treating 3 patients with severe, medically intractable spasticity, suffering from infection of the intrathecally-delivering pump. A decision was made not to replace the device, but to treat this complication with pump disinfection and with a new treatment modality that has never been used before, the intra-pocket administration of antibiotics. FINDINGS: In all cases the infection was eradicated and the integrity of the pump maintained. None of the patients required a procedure under general anesthesia. CONCLUSIONS: Removal should no longer be considered the first treatment option in infections of intrathecally delivering pumps, especially those due to non-adherent bacteria, with mild clinical symptomatology. An initial attempt should always be made for conservative treatment. Intra-pocket administration of antibiotics helps in achieving high drugs levels locally, and may prove an important element in our armamentarium against such infections.

Adult↗
PubMed2004

Peritumoural haematoma and meningioma: a common tumour with an uncommon presentation.

Spontaneous peritumoural haemorrhage in meningiomas is a rare but serious complication with a grave prognosis. It occurs at the interface between the tumour and the parenchyma, either from the tumour surface or the cortical vessels in association with it. Although several pathophysiologic mechanisms for this complication have been proposed, they all remain speculative. We report a 72-year-old female who presented with sudden onset of headache and a left homonymous hemianopia. Neuroimaging revealed a parasagittal meningioma at the posterior third of the superior sagittal sinus with peritumoural intracerebral haematoma, 1 cm away from the tumour. An uncomplicated gross total excision of the meningioma and aspiration of the haematoma was achieved through a craniotomy. The postoperative course was uneventful with an excellent clinical outcome. Possible mechanisms for this unusual complication are discussed. We emphasise the importance of prompt diagnosis and simultaneous excision of the tumour and aspiration of the haematoma as prerequisites for a favourable outcome.

Aged↗
PubMed2004

Occult traumatic dissection of vertebral artery with an excellent outcome.

We present the case of a young male with severe head injury, cervico-thoracic fractures, and an initially unrecognized brainstem infarct due to unilateral dissection of vertebral artery, who made an unusually excellent recovery. This report stresses the importance of prompt clinico-imaging diagnosis and prophylactic anticoagulant treatment in such cases.

Accidents, Traffic↗
PubMed2004

Complex neurobehavioural syndrome due to bilateral thalamic glioma.

We present a 65-year-old female with bilateral thalamic astrocytoma. The unusual long survival of this patient allowed the manifestation of a complex neurobehavioural syndrome due to gradual involvement of several thalamic nuclei. An attempt is made to approach the complexity of symptoms according to the anatomical areas, nuclei and thalamic connections infiltrated.

Aged↗
PubMed2003

Protein S-100b serum levels in trauma-induced brain death.

OBJECTIVE: To analyze the time course of serum protein S-100b in patients with traumatic brain injury deteriorating to brain death and to investigate the predictive value of initial S-100b levels in relation to clinical and radiologic measures of injury severity with regard to brain death. METHODS: Forty-seven patients who sustained severe head injury were studied. Blood samples for measurement of S-100b were drawn on admission in the intensive care unit and every 24 hours thereafter for a maximum of 6 consecutive days or until brain death occurred. Variables related to outcome were recorded, including age, sex, Glasgow Coma Scale (GCS), and brain CT findings on admission. Outcome was defined as deterioration to brain death or not. RESULTS: Of the 47 patients studied, 17 deteriorated to brain death and 30 did not. On admission, patients who became brain dead had higher median serum S-100b levels compared with those who did not (2.32 microg/L vs 1.04 micro g/L, p = 0.0028). Logistic regression analysis showed that initial S-100b was an independent predictor of brain death (p = 0.041), in the presence of advanced age (p = 0.043) and low GCS score (p = 0.013). The odds ratio of 2.09 (95% CI, 1.03 to 4.25) indicates a more than doubling of the probability of deteriorating to brain death per 1- micro g/L increase in S-100b on admission. At clinical brain death, median S-100b was higher in patients with brain death compared with the peak S-100b value obtained over a 6-day period in those who did not become brain dead (6.58 microg/L vs 1.49 microg/L, p < 0.0001). CONCLUSIONS: Prediction of brain death after severe head injury can be improved by combining clinical and S-100b data; thus, serum S-100b determination deserves to be included in the neuromonitoring of patients with severe traumatic brain injury.

Adolescent↗
PubMed2003

CT-guided stereotactic biopsies of brain stem lesions: personal experience and literature review.

Appropriate therapy of brain stem lesions should be guided by an accurate diagnosis. Clinical evaluation combined with modern neuroimaging techniques may nowadays approach the diagnosis but not always with accuracy, thus leading to erroneous treatment. We report a series of 11 patients who underwent stereotactic biopsy for brain stem lesions. In 8 patients, the lesion was approached transfrontally. In the remaining 3 patients, the lesion was approached via the suboccipital transcerebellar route. There was no surgical mortality. Precise histological diagnosis was achieved in all patients. Three patients (27.2%) suffered complications attributed to the procedure and were successfully treated conservatively. Histological results were in accordance with preoperative diagnosis in 9 patients (81.8%). Despite the limited number of patients, our data suggest that stereotactic biopsy of brain stem lesions is a safe technique that can obtain adequate tissue for histological diagnosis, thus providing each patient with the best available treatment.

Adult↗
PubMed2003

Atypical presentation of an extradural hematoma on the grounds of a temporal arachnoid cyst.

We report a 56-year-old man, with atypical presentation of an extradural hematoma caused by head injury after a fall. The presence of a temporal arachnoid cyst on the grounds of temporal lobe agenesis altered the clinical image of this man, causing only mild symptoms where an otherwise acute neurologic deterioration would be expected in the case of an epidural hematoma of such extent. The hematoma was evacuated through a left pterional craniotomy and a tear in the middle meningeal vein was recognized as the source of bleeding. Postoperative course was uneventful and the patient was discharged within 5 days. An extensive review of literature available to us revealed only 5 other such cases reported that all were younger patients.

Arachnoid Cysts↗
PubMed2003

Stereotactic biopsy in the era of advanced neuroimaging. Does the minimal therapeutic gain justify its current wide use?

OBJECTIVE: This study reviewed the contribution of stereotactic brain biopsy in the management and final outcome of a series of patients with presumed inoperable lesions. PATIENTS AND METHODS: Sixty-nine consecutive patients underwent a CT-guided lesion biopsy (n = 67) or abscess/cyst aspiration (n = 2) using the Cosman-Roberts-Wells (CRW) frame. RESULTS: A definitive specific diagnosis was made in 53 of 67 patients (79 %). The remaining procedures did not provide a diagnosis because of failure to obtain appropriate specimen (11 patients), findings consistent with non-specific inflammation (2 patients) or uneventful surgical complication requiring termination of the procedure (1 patient). A total of 55 patients (80 %) died due to the malignant nature of the lesion, most within six months after the biopsy. The preoperative imaging diagnosis was consistent with the histological diagnosis in 60 patients (87 % accuracy). The perioperative morbidity and mortality were nil and most of the patients were discharged within twenty-four hours. CONCLUSIONS: The stereotactic biopsy did not alter either the therapeutic management or the mortality due to the natural course of the lesion. These findings indicate that the current principle of mandatory histological diagnosis in virtually all non-resectable brain lesions should be re-evaluated taking into account parameters such as: age, medical/neurological status, neuroimaging characteristics, patients' best interest and health care financial shortages.

Adolescent↗