Machine-learning algorithm in acute stroke: real-world experience.

AIM: To assess the clinical performance of a commercially available machine learning (ML) algorithm in acute stroke. MATERIALS AND METHODS: CT and CT angiography (CTA) studies of 104 consecutive patients (43 females, age range 19-93, median age 62) performed for suspected acute stroke at a single tertiary institution with real-time ML software analysis (RAPID™ ASPECTS and CTA) were included. Studies were retrospectively reviewed independently by two neuroradiologists in a blinded manner. RESULTS: The cohort included 24 acute infarcts and 16 large vessel occlusions (LVO). RAPID™ ASPECTS interpretation demonstrated high sensitivity (87.5%) and NPV (87.5%) but very poor specificity (30.9%) and PPV (30.9%) for detection of acute ischaemic parenchymal changes. There was a high percentage of false positives (51.1%). In cases of proven LVO, RAPID™ ASPECTS showed good correlation with neuroradiologists' blinded independent interpretation, Pearson correlation coefficient = 0.96 (both readers), 0.63 (RAPID™ vs reader 1), 0.69 (RAPID™ vs reader 2). RAPID™ CTA interpretation demonstrated high sensitivity (92.3%), specificity (85.3%), and negative predictive (NPV) (98.5%) with moderate positive predictive value (PPV) (52.2%) for detection of LVO (N=13). False positives accounted for 12.5% of cases, of which 27.3% were attributed to arterial stenosis. CONCLUSION: RAPID™ CTA was robust and reliable in detection of LVO. Although demonstrating high sensitivity and NPV, RAPID™ ASPECTS interpretation was associated with a high number of false positives, which decreased clinicians' confidence in the algorithm. However, in cases of proven LVO, RAPID™ ASPECTS performed well and had good correlation with neuroradiologists' blinded interpretation.

Hyperacute corticosteroid treatment of optic neuritis at the onset of pain may prevent visual loss: a case series.

Aim. To show that high-dose corticosteroids may prevent visual loss in patients with optic neuritis (ON) treated at the prodromal, hyperacute, phase of retrobulbar pain. Method. Prospective case series: patients were recruited with a history of ON associated with pain. The patients were advised to report immediately to the investigators should the pain recur in either eye. Where possible, orbital magnetic resonance imaging (MRI) was performed to confirm a recurrence of ON and treatment with high-dose corticosteroids was commenced. Visual function and the patient's subjective account were monitored. Results. Eight patients (including cases of MS, CRION and NMO) presented in the hyperacute phase. MRI confirmed optic nerve inflammation in 5/5. Treatment was commenced immediately, and, in all cases, no visual loss ensued. Conclusion. MRI can be used to confirm acute optic neuritis prior to visual loss in the hyperacute phase. We suggest that treatment with high-dose corticosteroids may abort the attack and prevent loss of vision in patients with ON who are treated at the onset of pain. This has potential implications for the management of acute ON and also for our understanding of the pathogenesis and potential therapeutic targets in the neuroinflammatory conditions associated with ON.

Syphilis causing hearing loss.

An HIV-positive man with hepatitis B co-infection, naïve to highly active antiretroviral therapy, with a CD4 of 594 copies/mL and HIV-1 viral load of 140,070 copies, presented with right-sided facial weakness and hearing loss. He had been treated for secondary syphilis three months earlier when his rapid plasma reagin (RPR) result was 1:16, this had fallen to neat. At presentation, his RPR had risen to 1:16 again. A magnetic resonance imaging scan showed enhancement of the internal auditory canal and right cochlea. His cerebrospinal fluid examination was normal. He was treated with acyclovir and prednisolone before the syphilis serology was known. He was then treated for syphilis with doxycycline. He made an excellent recovery.

Tuberculous orbital apex syndromes.

AIMS: To describe the clinical and radiological features of orbital apex syndromes caused by presumed tuberculosis (TB). METHODS: A review of the discharge summaries of all patients seen in the Medical Eye Unit (MEU), St Thomas' Hospital between 1975 and 2006 identified seven patients with a diagnosis of orbital apex syndrome or optic neuropathy attributable to TB. Case notes and radiology were reviewed retrospectively for each patient. RESULTS: All of the patients were born outside the UK and were HIV-negative. Four presented during 2005-6. Six of the seven patients presented with a visual acuity (VA) of less than counting fingers (CF), but all achieved a VA of 6/9 or better after a median 3 weeks of treatment with antituberculous treatment and systemic corticosteroids. All patients had constitutional symptoms. Chest x ray and CSF were normal in each case, but MRI was abnormal in six. CONCLUSIONS: We report a recent cluster of tuberculous orbital apex syndromes, in the context of an increasing incidence of TB in the UK. The condition is difficult to diagnose, but the combination of high-dose corticosteroids and anti-TB medication was rapidly effective and achieved a good outcome in all cases.

Cerebral manifestations in liver disease and transplantation.

Patients with liver disease frequently develop cerebral complications. The brain may be affected directly by the pathological process or agent responsible for the liver disease, as a consequence of the metabolic and haemodynamic derangement caused by hepatic dysfunction, or as a complication of the treatment of liver disease. Computed tomography (CT) and magnetic resonance imaging (MRI) can be helpful in the diagnosis and management of these complications, and advanced techniques such as diffusion weighted imaging (DWI) and magnetic resonance spectroscopy (MRS) are providing new insights into the underlying pathophysiological processes. We present a radiological overview of the cerebral manifestations of liver disease, categorized as acute presentations, chronic presentations, and conditions occurring in the context of liver transplantation.

The clinical value of proton magnetic resonance spectroscopy in adult brain tumours.

Proton magnetic resonance spectroscopy (1H MRS) non-invasively provides information on the biochemical profile (typically including up to nine metabolites and mobile lipids) of brain tissue, which varies according to the underlying disease process. A number of studies have assessed its accuracy in the diagnosis of adult brain tumours. This article describes the basic principles of 1H MRS, the metabolic profiles of different brain tumours, and practical points to aid interpretation of spectra. The literature is reviewed regarding the role of 1H MRS in the diagnosis of brain tumours and more specifically where it has proven to be of additional benefit over conventional magnetic resonance imaging.

Imaging features of central nervous system haemangiopericytomas.

Intracranial and spinal haemangiopericytomas are uncommon, durally based tumours. They macroscopically resemble meningiomas but are distinct histologically, have a more aggressive natural history and require different management. We present a pictorial review illustrating the radiological manifestations of these tumours that will aid in their preoperative identification.

Treatment of a recurrent internal carotid artery pseudoaneurysm with the wallgraft endoprosthesis.

SUMMARY: The use of covered stents to treat traumatic carotid artery pseudoaneurysms is increasingly being documented. Adjunctive antiplatelet therapy is mandatory. We present a case of bilateral traumatic carotid artery pseudoaneuryms in which antiplatelet therapy was contraindicated at presentation, thereby dictating alternative treatment with coil embolization alone. Subsequent aneurysmal recurrence was successfully treated with the Wallgraft prosthesis. The literature on the use of the Wallgraft prosthesis for the treatment of carotid artery pseudoaneurysms is also reviewed.

A randomized open-label study of immediate versus delayed polylactic acid injections for the cosmetic management of facial lipoatrophy in persons with HIV infection.

BACKGROUND: Polylactic acid (PLA, New-Fill; Medifill, London, UK and Dermic Labs, a division of Eventis, Strasbourg, France) injections into the deep dermis increase fibroblast numbers and collagen production. The substance is widely used in medical applications including cosmetic procedures. METHODS: HIV-positive individuals with facial lipoatrophy (based on physician assessment) were randomized to immediate (weeks 0, 2 and 4) or delayed (weeks 12, 14 and 16) PLA given as three bilateral injections 2 weeks apart into the deep dermis overlying the buccal fat pad. Assessments included facial ultrasound, visual analogue scales, the Hospital Anxiety and Depression Scale (HADS) and assessment using photographs at weeks 0, 12 and 24. RESULTS: All 30 patients completed 24 weeks of treatment. The median age of the patients was 41 years, with a mean of 80 months of nucleoside reverse transcriptase inhibitor (NRTI) therapy and a mean of 44 months of prior protease inhibitor (PI) therapy. The median CD4 count was 428-460 cells/microL, with 47% of patients in the immediate-treatment group and 93% of patients in the delayed-treatment groups with <50 HIV-1 RNA copies/mL at baseline. No differences in immunological, virological, biochemical, haematological or metabolic parameters emerged during the study. Injections were well tolerated with only two adverse events (cellulitis and bruising) recorded, one of which delayed treatment by 1 week. There were no discontinuations. Patient visual analogue assessments, photographic assessments, and anxiety and depression scores improved with treatment. At week 12, immediate-treatment patients had significantly better visual analogue scores (7 vs. 1, P<0.001) and lower anxiety scores (6 vs. 9, P=0.056) than delayed-treatment patients. Benefits on visual analogue and HADS scores persisted until week 24. CONCLUSIONS: PLA injections led to improvements in patient self-perception, anxiety and depression scores in individuals with facial lipoatrophy. Adverse events were uncommon. The benefits of PLA persisted for at least 18 weeks beyond the last injection.

HRCT in small and large airways diseases.

High-resolution computed tomography (HRCT) is being increasingly used in the diagnostic work-up of paediatric patients with large and small airways disease due to its ability to provide valuable information far beyond that of other non-invasive investigations. This article highlights the key HRCT appearances of a range of conditions involving the airways in children, and where relevant, the role of HRCT in assessment of disease severity and monitoring of disease progression.

Ubiquitination as a probe for neurodegeneration in the brain in schizophrenia: the prefrontal cortex.

Abnormalities in brain structure and brain function have been described in schizophrenia. It is not yet known whether these are caused by an abnormality of brain development, some form of birth injury, or a neurodegenerative process. Using immunocytochemical methods and a marker for neurodegeneration (ubiquitin), we examined an area of prefrontal cortex from elderly schizophrenic and control subjects for the presence of ubiquitin-positive degeneration products. There was no statistical difference in the degree of ubiquitination between the control and the patient samples. The findings provide no evidence to support a neurodegenerative process.