Cerebral autosomal dominant arteriopathy with subcortical infarcts and leucoencephalopathy (CADASIL)

Background. Cerebral autosomal dominant arteriopathy with subcortical infarcts and leuco-encephalopathy (CADASIL) is a hereditary autosomal dominant non-atherosclerotic nonamyloidcerebral arteriopathy. The disease was identified in 1993. We are not aware of reports in the literature of its occurrence in South Africa, and we present the clinical and laboratory features of 5 patients with CADASIL.Methods. Patients with the characteristic radiological white matter disease and typical features (family history, ischaemic events, migraine or dementia) were evaluated for possible CADASIL by means of clinical examination, routine investigations for strokes, magnetic resonance imaging, skin biopsy electron microscopy, evoked potentials and electroencephalography.Results. The clinical and laboratory features of our study largely correlate with reported studies. However, all of the skin biopsies were positive, and the onset of migraine in our patients was considerably earlier. A new finding, to our knowledge, was the normality of visual, somatosensory and auditory evoked potentials.Conclusion. Our study confirms the existence of CADASIL inSouth Africa, and also suggests that skin electron microscopyis useful, despite recent reports of its low sensitivity, and thatevoked potentials in CADASIL are likely to be normal

AIDS-related progressive multifocal leukoencephalopathy (PML): A retrospective study from Pretoria, South Africa

Introduction and objectives. Progressive multifocal leukoencephalopathy (PML), caused by the John Cunningham (JC) virus, results from lytic infection of predominantly oligodendrocytes. Following the HIV pandemic, the incidence of PML has risen sharply, but has rarely been reported in Africa. An increasing number of PML cases were seen recently in a tertiary South African hospital, and this study describes their clinical and radiological features.Methods. Patients with positive cerebrospinal fluid (CSF) JC virus confirmed by real-time polymerase chain reaction (PCR) were retrospectively identified from January 2008 to June 2012. Adults seen at Neurology with PML were identified, and clinical features, laboratory findings and imaging studies were analysed.Results. Of 121 specimens, 19 were positive; records of 17 patients were available (ages 27 - 64; CD4 counts 11 - 328 x106/ìl); clinical manifestations included focal weakness (47%), impaired co-ordination (41%), and speech disturbances (12%), and CSF analysis showedhigh protein in 76%, and pleocytosis in 35%. Fifteen patients had CT brain scans, showing white matter involvement in 12; MRI studies in 13 patients showed typical PML lesions.Conclusion. This report is the first case series of patients with PML from a South African neurology unit, emphasising the fact that PML occurs commonly in South African patients with HIV infection

Spontaneous Raman scattering for simultaneous measurements of in-cylinder species

A technique for multi-species mole fraction measurement in internal combustion engines is described. The technique is based on the spontaneous Raman scattering. It can simultaneously provide the mole fractions of several species of N-2, O-2, H2O, CO2 and fuel. Using the system, simultaneous measurement of air/fuel ratio and burnt residual gas are carried out during the mixture process in a Controlled Auto Ignition (CAI) combustion engine. The accuracy and consistency of the measured results were confirmed by the measured air fuel ratio using an exhaust gas analyzer and independently calculated mole fraction values. Measurement of species mole fractions during combustion process has also been demonstrated. It shows that the SRS can provide valuable data on this process in a CAI combustion engine

Comparison of HTLV-associated myelopathy (HAM) in HIV-positive and HIV-negative patients at a tertiary South African hospital

Background. HTLV-1 associated myelopathy (HAM), or tropical spastic paraparesis, is caused by a retrovirus, the human T-cell lymphotropic virus (HTLV). Although patients with HAM and HIV infection have been described, to our knowledge no direct comparison has been made between patients who are HIV positive and suffering from HAM (HHAM) v. those who are HIV negative and suffering from HAM.Aim. We aimed to compare clinical and radiological findings in HIV-positive and -negative patients with HAM.Methods. Adult patients who presented to the Neurology Unit at the Steve Biko Academic Hospital from May 2005 to June 2012 with a progressive myelopathy and HTLV seropositivity were retrospectively identified and their clinical and radiological data were collected and reviewed.Results. 21 patients with HAM were identified, of whom 9 were HIV-positive and 11 HIV-negative. One patient, whose HIV status had not been established, was not included in the study. Although the trend did not reach statistical significance, co-infected patients tended to present at an earlier age (HHAM 6/9 (66%) <40 years old; HAM 2/11 (18%) <40 years old) and presented to hospital earlier (HHAM 6/9 (66%) < 3 years symptomatic; HAM 7/11 (63%) > 3 years symptomatic). Cord atrophy occurred in 7/8 dually infected patients and 8/10 HIV-negative patients.Conclusion. Although the study is limited by the small number of patients, co-infected patients tended to have a younger age of onset and to present to hospital sooner, and thoracic cord atrophy was very common

TOR1A mutation-related isolated childhood-onset generalised dystonia in South Africa

Background. Childhood-onset generalised dystonia is commonly caused by TOR1A mutations and is known to respond well to pallidal deep-brain stimulation (DBS) surgery. The incidence and prevalence of monogenic dystonia in individuals from Africa and specifically of African ancestry are unknown, and no local cases of TOR1A mutation dystonia are found in the literature.Objectives. To describe our experience with the outcome of TOR1A mutation-positive patients with isolated generalised dystonia (IGD) of childhood onset who were treated with pallidal DBS.Methods. All patients with TOR1A mutations from Steve Biko Academic Hospital and the Pretoria Neurology Institute in Pretoria, South Africa (SA), who underwent DBS for IGD of childhood onset were identified. We conducted a retrospective analysis of their demographics, clinical presentation and time to generalisation, genetic status and family history, and response to DBS treatment of the internal segment of the globus pallidus (GPi), utilising pre- and post-surgical scores of the United Dystonia Rating Scale (UDRS).Results. Three patients, all of black African ancestry, were identified. The median age at onset was 12 years and the median time to surgery from dystonia generalisation was 3 years. Two children presented with cervical-onset dystonia. Two patients were related, representing the only two with a positive family history. All three patients had a positive outcome after surgery, with improvement of 67 - 90% on the UDRS recorded at last follow-up.Conclusions. TOR1A mutations are found in SA patients of black African ancestry, with age of onset and generalisation comparable to those described in international studies. However, onset with cervical dystonia was more common than previously reported. Response to GPi DBS was excellent in all patients.

Autoimmune encephalitis: Epidemiology, pathophysiology and clinical spectrum (part 2)

Autoimmune encephalitis (AE) represents a growing number of severe autoimmune-inflammatory diseases affecting both the white and grey matter of the brain. In part 1 of this series we focused on the epidemiology, pathophysiology and clinical presentation of this condition, with two illustrative cases. In this part, we will introduce the clinical criteria for AE, particularly for the diagnosis of anti-N-methyl-D-aspartate (NMDA) receptor encephalitis, which were developed to facilitate immune treatment in suspected cases before antibody results are available. We subsequently discuss the work up, differential diagnosis and treatment options for patients with this disease.

Blackbody-radiation-assisted molecular laser cooling

The translational motion of molecular ions can be effectively cooled sympathetically to temperatures below 100 mK in ion traps through Coulomb interactions with laser-cooled atomic ions. The distribution of internal rovibrational states, however, gets in thermal equilibrium with the typically much higher temperature of the environment within tens of seconds. We consider a concept for rotational cooling of such internally hot, but translationally cold heteronuclear diatomic molecular ions. The scheme relies on a combination of optical pumping from a few specific rotational levels into a ``dark state'' with redistribution of rotational populations mediated by blackbody radiation.Comment: 4 pages, 5 figure