Ahmed Toma | University College London (original) (raw)

Papers by Ahmed Toma

Research paper thumbnail of Learning to control ICP

Fluids and Barriers of the CNS

Research paper thumbnail of Elective ICP monitoring: how long is long enough?

Fluids and Barriers of the CNS, 2015

Research paper thumbnail of NPH: are we giving up on patients with temporary improvement post shunt?

Fluids and Barriers of the CNS, 2015

Research paper thumbnail of eGFR in CSF-flow disorders - a representation of comorbid state or an element of the underlying pathophysiology?

Fluids and Barriers of the CNS, 2015

Research paper thumbnail of Persistent CSF leak post spinal surgery and cerebrospinal fluid dynamic disturbances: cause or consequence?

Fluids and Barriers of the CNS, 2015

Research paper thumbnail of Shunt assistant device deception due to pseudovertical posturing

Fluids and Barriers of the CNS, 2015

Research paper thumbnail of Differential compartment overdrainage syndrome

Fluids and Barriers of the CNS, 2015

Research paper thumbnail of Venous sinus stenting immediately reduces intracranial pressure in Idiopathic Intracranial Hypertension patients with venous sinus stenosis

Fluids and Barriers of the CNS, 2015

Research paper thumbnail of Intracranial pressure and venous sinus pressure gradients: what happens 3 months after stenting?

Fluids and Barriers of the CNS, 2015

Research paper thumbnail of DESH negative normal pressure hydrocephalus: can patients still benefit from shunt insertion?

Fluids and Barriers of the CNS, 2015

Research paper thumbnail of Intracranial pressure guided management of patients with Chiari malformations presenting with headache: a paradigm shift?

Fluids and Barriers of the CNS, 2015

Research paper thumbnail of Three-hundred cases of Spiegelberg ICP monitoring for hydrocephalus and CSF disorders: the Queen Square experience

Fluids and Barriers of the CNS, 2015

Research paper thumbnail of Elective ICP monitoring: how long is long enough?

Fluids and Barriers of the CNS, 2015

Research paper thumbnail of Comorbidites in NPH - local introspective - ‘Shunt them all’!

Fluids and Barriers of the CNS, 2015

Research paper thumbnail of Cerebrospinal fluid biomarkers in patients with varicella-zoster virus CNS infections

Journal of Neurology, 2013

Varicella-zoster virus (VZV) is one of our most common viruses causing central nervous system (CN... more Varicella-zoster virus (VZV) is one of our most common viruses causing central nervous system (CNS) infection with sometimes severe neurological complications. Glial fibrillary acidic protein (GFAp), light subunit of neurofilament protein (NFL) and S-100β protein are cerebrospinal fluid (CSF) biomarkers that have been used to estimate the severity of brain damage and outcome in various CNS diseases. So far, these biomarkers have not been utilised to investigate glial pathology and neuronal damage in patients with VZV CNS infections. In this prospective study, we measured CSF GFAp, NFL and S-100β as markers of brain damage in 24 patients with acute neurological manifestations and VZV DNA detected in CSF by PCR and compared with a control group (n = 14). Concentrations of CSF NFL and GFAp were increased in patients with VZV CNS infection compared with controls (p = 0.002 and p = 0.03) while levels of S-100β were reduced. In patients with VZV encephalitis the elevations of CSF NFL and GFAp were more pronounced compared with patients with other VZV CNS syndromes. No correlations between the levels of biomarkers and viral load, neurological sequels or clinical outcome were found in this limited number of patients. These results indicate that VZV induces neuronal damage and astrogliosis with more severe brain damage in patients with VZV encephalitis than in patients with other neurological complications caused by this virus.

Research paper thumbnail of Is there a difference in outcomes of patients with idiopathic intracranial hypertension with the choice of cerebrospinal fluid diversion site: A single centre experience

Clinical Neurology and Neurosurgery, Mar 1, 2011

The visual and headache outcomes in patients with idiopathic intracranial hypertension (IIH) unde... more The visual and headache outcomes in patients with idiopathic intracranial hypertension (IIH) undergoing cerebrospinal fluid diversion with a lumboperitoneal (LPS) or ventriculoperitoneal shunting (VPS) have not been well reported. The aims of this study were to: (a) to assess outcomes of CSF diversion in IIH, (b) to understand influence of the type of shunt in outcomes, and (c) to understand factors predisposing in shunt failure. Methods: The medical records of 34 patients who underwent cerebrospinal fluid diversion (CSFD) between 1996 and 2007 were retrieved and epidemiological and clinical data was collected. Results: The mean age was 35 (±7.9) years. Thirty-four patients underwent 63 shunt placements in total. 85% follow-up was achieved. The mean follow-up for the entire group was 28.9 (±31.8) months. Headaches improved more than visual disturbances. There was no significant difference between the groups that received a VPS and those receiving an LPS in both headache and visual outcomes. The rate of complications was 20.5% and the need for revision was 35% for the whole group. Patients with LPS suffered more complications and first time revisions than patients with VPS. No factor recorded could predict the need for revision or final outcomes. The shunts of patients receiving a VPS tend to survive longer than those receiving primarily an LPS, however the difference is not statistically significant. Conclusions: Predicting which patients will improve is not possible at present. The influence of site diversion is not critical but patients with VPS have less complications and revisions than those receiving a LPS.

Research paper thumbnail of Surgically managed idiopathic intracranial hypertension in adults: a single centre experience

Acta Neurochirurgica, 2015

Idiopathic intracranial hypertension (IIH) is a rare condition that is often managed conservative... more Idiopathic intracranial hypertension (IIH) is a rare condition that is often managed conservatively. In patients with aggressive progression of the disease surgical options are considered. There are few data on the outcomes of these patients when surgically managed. We describe our experience of surgically managed IIH and the outcomes of these patients, in particular the surgical revision rate and interventions required for resolution of symptoms. A retrospective review of all patient files coded with benign intracranial hypertension, idiopathic intracranial hypertension or pseudotumour cerebri was undertaken. Files were searched with the date of diagnosis and the date these patients were referred for surgical intervention. The surgical interventions and complications were then documented and note was made of the number of inpatient admissions and days spent in hospital. From 2000-2013, 79 patients were identified as patients with IIH that had required surgical intervention; 52 % required further surgical intervention. The average number of surgical interventions was 5.6. For patients requiring further intervention the average number of surgical interventions was 8.6. On average patients with IIH also spent 42 inpatient days in neurosurgical beds, whilst those patients who required further intervention spent 63 days on average in neurosurgical beds. The length of the average individual admission was longer for patients requiring repeated surgical interventions. Based on our experience, patients that require surgical management of IIH frequently require further surgical interventions to control symptoms and manage complications of CSF diversion surgery. Those that require such further intervention on average will have six further operations and spend significantly longer in hospital. Lumboperitoneal (LP) shunting is an effective first line surgical intervention for 52 % of our patient cohort. This sub-group of patients therefore requires specialist neurosurgical input for this long-term and challenging pathological process.

Research paper thumbnail of NPH: are we giving up on patients with temporary improvement post shunt?

Fluids and Barriers of the CNS, 2015

Research paper thumbnail of eGFR in CSF-flow disorders - a representation of comorbid state or an element of the underlying pathophysiology?

Fluids and Barriers of the CNS, 2015

Research paper thumbnail of Persistent CSF leak post spinal surgery and cerebrospinal fluid dynamic disturbances: cause or consequence?

Fluids and Barriers of the CNS, 2015

Research paper thumbnail of Learning to control ICP

Fluids and Barriers of the CNS

Research paper thumbnail of Elective ICP monitoring: how long is long enough?

Fluids and Barriers of the CNS, 2015

Research paper thumbnail of NPH: are we giving up on patients with temporary improvement post shunt?

Fluids and Barriers of the CNS, 2015

Research paper thumbnail of eGFR in CSF-flow disorders - a representation of comorbid state or an element of the underlying pathophysiology?

Fluids and Barriers of the CNS, 2015

Research paper thumbnail of Persistent CSF leak post spinal surgery and cerebrospinal fluid dynamic disturbances: cause or consequence?

Fluids and Barriers of the CNS, 2015

Research paper thumbnail of Shunt assistant device deception due to pseudovertical posturing

Fluids and Barriers of the CNS, 2015

Research paper thumbnail of Differential compartment overdrainage syndrome

Fluids and Barriers of the CNS, 2015

Research paper thumbnail of Venous sinus stenting immediately reduces intracranial pressure in Idiopathic Intracranial Hypertension patients with venous sinus stenosis

Fluids and Barriers of the CNS, 2015

Research paper thumbnail of Intracranial pressure and venous sinus pressure gradients: what happens 3 months after stenting?

Fluids and Barriers of the CNS, 2015

Research paper thumbnail of DESH negative normal pressure hydrocephalus: can patients still benefit from shunt insertion?

Fluids and Barriers of the CNS, 2015

Research paper thumbnail of Intracranial pressure guided management of patients with Chiari malformations presenting with headache: a paradigm shift?

Fluids and Barriers of the CNS, 2015

Research paper thumbnail of Three-hundred cases of Spiegelberg ICP monitoring for hydrocephalus and CSF disorders: the Queen Square experience

Fluids and Barriers of the CNS, 2015

Research paper thumbnail of Elective ICP monitoring: how long is long enough?

Fluids and Barriers of the CNS, 2015

Research paper thumbnail of Comorbidites in NPH - local introspective - ‘Shunt them all’!

Fluids and Barriers of the CNS, 2015

Research paper thumbnail of Cerebrospinal fluid biomarkers in patients with varicella-zoster virus CNS infections

Journal of Neurology, 2013

Varicella-zoster virus (VZV) is one of our most common viruses causing central nervous system (CN... more Varicella-zoster virus (VZV) is one of our most common viruses causing central nervous system (CNS) infection with sometimes severe neurological complications. Glial fibrillary acidic protein (GFAp), light subunit of neurofilament protein (NFL) and S-100β protein are cerebrospinal fluid (CSF) biomarkers that have been used to estimate the severity of brain damage and outcome in various CNS diseases. So far, these biomarkers have not been utilised to investigate glial pathology and neuronal damage in patients with VZV CNS infections. In this prospective study, we measured CSF GFAp, NFL and S-100β as markers of brain damage in 24 patients with acute neurological manifestations and VZV DNA detected in CSF by PCR and compared with a control group (n = 14). Concentrations of CSF NFL and GFAp were increased in patients with VZV CNS infection compared with controls (p = 0.002 and p = 0.03) while levels of S-100β were reduced. In patients with VZV encephalitis the elevations of CSF NFL and GFAp were more pronounced compared with patients with other VZV CNS syndromes. No correlations between the levels of biomarkers and viral load, neurological sequels or clinical outcome were found in this limited number of patients. These results indicate that VZV induces neuronal damage and astrogliosis with more severe brain damage in patients with VZV encephalitis than in patients with other neurological complications caused by this virus.

Research paper thumbnail of Is there a difference in outcomes of patients with idiopathic intracranial hypertension with the choice of cerebrospinal fluid diversion site: A single centre experience

Clinical Neurology and Neurosurgery, Mar 1, 2011

The visual and headache outcomes in patients with idiopathic intracranial hypertension (IIH) unde... more The visual and headache outcomes in patients with idiopathic intracranial hypertension (IIH) undergoing cerebrospinal fluid diversion with a lumboperitoneal (LPS) or ventriculoperitoneal shunting (VPS) have not been well reported. The aims of this study were to: (a) to assess outcomes of CSF diversion in IIH, (b) to understand influence of the type of shunt in outcomes, and (c) to understand factors predisposing in shunt failure. Methods: The medical records of 34 patients who underwent cerebrospinal fluid diversion (CSFD) between 1996 and 2007 were retrieved and epidemiological and clinical data was collected. Results: The mean age was 35 (±7.9) years. Thirty-four patients underwent 63 shunt placements in total. 85% follow-up was achieved. The mean follow-up for the entire group was 28.9 (±31.8) months. Headaches improved more than visual disturbances. There was no significant difference between the groups that received a VPS and those receiving an LPS in both headache and visual outcomes. The rate of complications was 20.5% and the need for revision was 35% for the whole group. Patients with LPS suffered more complications and first time revisions than patients with VPS. No factor recorded could predict the need for revision or final outcomes. The shunts of patients receiving a VPS tend to survive longer than those receiving primarily an LPS, however the difference is not statistically significant. Conclusions: Predicting which patients will improve is not possible at present. The influence of site diversion is not critical but patients with VPS have less complications and revisions than those receiving a LPS.

Research paper thumbnail of Surgically managed idiopathic intracranial hypertension in adults: a single centre experience

Acta Neurochirurgica, 2015

Idiopathic intracranial hypertension (IIH) is a rare condition that is often managed conservative... more Idiopathic intracranial hypertension (IIH) is a rare condition that is often managed conservatively. In patients with aggressive progression of the disease surgical options are considered. There are few data on the outcomes of these patients when surgically managed. We describe our experience of surgically managed IIH and the outcomes of these patients, in particular the surgical revision rate and interventions required for resolution of symptoms. A retrospective review of all patient files coded with benign intracranial hypertension, idiopathic intracranial hypertension or pseudotumour cerebri was undertaken. Files were searched with the date of diagnosis and the date these patients were referred for surgical intervention. The surgical interventions and complications were then documented and note was made of the number of inpatient admissions and days spent in hospital. From 2000-2013, 79 patients were identified as patients with IIH that had required surgical intervention; 52 % required further surgical intervention. The average number of surgical interventions was 5.6. For patients requiring further intervention the average number of surgical interventions was 8.6. On average patients with IIH also spent 42 inpatient days in neurosurgical beds, whilst those patients who required further intervention spent 63 days on average in neurosurgical beds. The length of the average individual admission was longer for patients requiring repeated surgical interventions. Based on our experience, patients that require surgical management of IIH frequently require further surgical interventions to control symptoms and manage complications of CSF diversion surgery. Those that require such further intervention on average will have six further operations and spend significantly longer in hospital. Lumboperitoneal (LP) shunting is an effective first line surgical intervention for 52 % of our patient cohort. This sub-group of patients therefore requires specialist neurosurgical input for this long-term and challenging pathological process.

Research paper thumbnail of NPH: are we giving up on patients with temporary improvement post shunt?

Fluids and Barriers of the CNS, 2015

Research paper thumbnail of eGFR in CSF-flow disorders - a representation of comorbid state or an element of the underlying pathophysiology?

Fluids and Barriers of the CNS, 2015

Research paper thumbnail of Persistent CSF leak post spinal surgery and cerebrospinal fluid dynamic disturbances: cause or consequence?

Fluids and Barriers of the CNS, 2015