Use of John Cunningham virus polymerase chain reaction in the diagnosis of progressive multifocal leucoencephalopathy - a rare presenting manifestation in an HIV-positive patient.

John Cunningham virus infection is an important cause of progressive multifocal leucoencephalopathy (PML) in the context of advanced human immunodeficiency virus infection. Limited data are available regarding the true incidence of PML as a presenting manifestation of HIV. We report one such case and also highlight the effective use of polymerase chain reaction in confirming its diagnosis.

Cardiopulmonary resuscitation artifact during electroencephalography.

Artifacts are signals recorded on the electroencephalogram (EEG) that are not cerebral in origin and can be divided into physiological and non-physiological artifacts. We present here an interesting non-physiological EEG artifact generated by cardiopulmonary resuscitation efforts.

Physiological responses to divergent selection for phytate phosphorus bioavailability in a randombred chicken population.

An investigation was conducted to study insulin-like growth factor (IGF)-I, IGF-II, insulin, glucagon, leptin, triiodothyronine (T(3)), and thyroxine (T(4)) levels in a chicken population divergently selected for P bioavailability (PBA). There were differences in growth and feed efficiency between the 2 lines. Concentrations of IGF-I, IGF-II, and T(3) were significantly greater in the high PBA line compared with the low PBA line, whereas the reverse was true for glucagon. There were no correlations between IGF-I and II and PBA in either line, suggesting that the line differences may be the result of factors other than PBA. Glucagon and IGF-I have different relationships with feed conversion ratio in the high PBA line compared with the low PBA line. There was a significant correlation between PBA and T(3) in the low line and between PBA and T(4) in the high PBA line. Thyroid hormone levels may be an indirect indicator of PBA in growing chickens. The genes in the thyroid hormone pathway may be key in the identification of genes associated with PBA.

Ipsilateral hemispheric ischaemic hypoxic changes during central line placement: a video-electroencephalogram correlate.

When venous access is needed for intravenous fluids or antibiotics and a peripheral site is unavailable or not suitable, a central line is placed either in the neck or the groin. Complications have been reported during central line placement including (but not limited to) pneumothorax, haemothorax, arrhythmias, air embolism and introduction of infection. The case history is reported of a patient who developed ipsilateral hemispheric ischaemic hypoxic changes during central line placement. This was represented on the surface electroencephalogram by ipsilateral hemispheric voltage attenuation.

EMG artifact in brain death electroencephalogram, is it a cry of "medullary death"?

The Uniform Determination of Death Act (UDDA) defines death as irreversible cessation of the functions of the entire brain including the brainstem. Many individuals meeting the clinical criteria of brain death can be documented to have some residual sub-cortical and brainstem function on careful testing. Determination of brain death still remains a persistently unresolved issue in health law and bioethics. The determination of brain death is clinical and involves testing for the integrity of brainstem functions. Documentation of irreversible cessation of brainstem functions when the cause of coma is established is usually sufficient to make a diagnosis of brain death. Confirmatory tests like four-vessel angiogram and electroencephalogram (EEG) are required in cases where the clinical testing is inconclusive or unreliable. EEG criteria for electrocerebral silence (ECS) is absence of any detectable cortical activity above 2 microV in a study performed as per the guidelines developed by the American Electroencephalographic Society. EEG studies carried out for ECS are at times contaminated by electromyographic (EMG) artifacts reflecting scalp motor unit activity. A secure EEG diagnosis of ECS cannot be made in such cases. What exactly is the relevance of scalp EMG activity in these clinically brain dead patients? What is the mechanism of generation of this spontaneous scalp EMG activity and how can the diagnosis of brain death be secured in these patients? These issues are explored in this article by highlighting a case.

Cadmium exposure: health hazards of silver cottage industry in developing countries.

In countries such as India, the silver jewelry industry is an important cottage industry. Silver is mixed with cadmium and then used to make silver jewelry. During this process there is a formation of cadmium fumes, and the workers inhale the fumes. Cadmium is a neurotoxic and nephrotoxic heavy metal, and there are no national policies to prevent exposure to such chemicals. We will present a case of cadmium induced peripheral neuropathy, nephropathy, and decreased bone density.

Zolpidem at supratherapeutic doses can cause drug abuse, dependence and withdrawal seizure.

Zolpidem is a non-benzodiazepine hypnotic drug, acts selectively through omega 1 receptors of GABAA. It is thought to be safer than benzodiazepines but we report a case of zolpidem drug abuse, dependence and withdrawal seizure.

Megalencephalic leukoencephalopathy with subcortical cysts.

Megalencephalic leukocncephalopathy is rare disorder seen in India in patient belonging to Agarwal community. Many of the patients may have a mild clinical course with gradual worsening of neurological disability. A case is being reported who was followed for 17 years and paradoxically showed radiological and clinical improvement.

Brainstem death: implications in India.

Brainstem death and brain death although practically same with regards to the concept of organ donation, remain technically different. Brain death mandates irreversible cessation of all the functions of the entire brain and brainstem while brainstem death signifies irreversible damage to the brainstem. As per the Indian law, brainstem death is the legal requirement and not brain death.